tag:blogger.com,1999:blog-33315632627011172712024-03-14T10:05:41.544-07:00Engineering the Interfaceiyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.comBlogger150125tag:blogger.com,1999:blog-3331563262701117271.post-3542185605401714932018-06-15T21:57:00.003-07:002018-06-15T22:11:43.308-07:00Guatemala, Day 26Its over! We did our final hospital visit today and the students did really well. The program's first month has come to a close. In a couple hours, I'll be heading to the bus station to catch my 4 hour ride back to Guatemala City and then to the airport. The students head to their new assignments on Sunday afternoon and they all seem capable and ready to go. Its been a fun month, and even though I missed my family something wicked, I learned a lot, which is really all I could have hoped for.<br />
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So today we visited a dental school and clinic. The facility is associated with a local university and I believe is set up to train dental hygienists and dentists, as well as treat patients. The facility was a big open space which it appeared was owned by the Lions Club. The main hall was the size of a basketball court and filled with maybe 35 dental chairs, some desks, and an x-ray lab in the back.<br />
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We were asked to take a look at some of the dental chairs that were having various issues. A couple of them had problems with the control unit that you use to make the chair go up and down and a couple more had lighting issues. Given the chairs were a good 20 years old, it was no surprise that everything we looked at had been messed around with by some other engineers at some point, and some of that work was, regrettably, a bit sloppy. We got to work.<br />
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The control pedals were pretty interesting. It turns out that the four-way controller (up, down, recline, sit up) is just a knob that forces one of four switches to close. When the switch is closed, the appropriate motor wire is connected to power, and the motor turns causing the chair to move.<br />
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<tr><td class="tr-caption" style="text-align: center;">Inside the chair's control unit - just four switches!</td></tr>
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One of the two units we looked at was just a bit loose and we got it working by tightening up the cover. The other one was a hot mess of short circuits and amateur soldering. I had the students take it all apart and resolder all the connections, testing them one by one as they went, and they did a great job fixing it.<br />
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We also looked at some lighting problems. One light had a loose connection and flickered on and off quite a lot. That turned out to be an easy (but very time consuming) fix. It just needed a few loose wires re-connected and soldered, but the wires were very hard to access and it took a long time just to get them sufficiently free to work with.<br />
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<tr><td class="tr-caption" style="text-align: center;">What should have been an easy fix wound up being very time consuming!</td></tr>
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It didn't help at all that the Portugal-Spain World Cup match was on and people kept running to the TV when things got interesting!<br />
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While the students were working, I decided to teach myself exactly how a dental chair works. I got down on all fours (and then flat on my stomach) to see what mysteries lurked beneath. Turns out it's pretty straightforward. There are two motors, one for the up-down action, and the other for the recline action. Each motor is only connected to power when the user pushes the control switch. There were two especially cool parts. First: the up-down motor was connected to two massive start capacitors. Most AC motors need some sort of a start cap in order to get spinning. In this case, there were two 147uF caps connected - real monsters!</div>
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<tr><td class="tr-caption" style="text-align: center;">As capacitors go, this one is pretty big!</td></tr>
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The second cool thing was the mechanism the chair uses to know when to stop going up and down. I found two little switches under the chair that get depressed when the chair gets too high or too low. Once the switch is depressed, it cuts off power to the motor and the chair stops.</div>
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Overall, it's a pretty simple design but elegantly done.<br />
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That was pretty much it. After work, we went back to our classroom so the students could reorganize their tools and supplies for their Sunday departure. Afterwards, there was a funny ceremony of sorts where I was presented with a plastic trophy cup that says "#1" on it, along with a photo of our group. It was a wonderful gesture and also very goofy and we all laughed pretty hard.<br />
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<tr><td class="tr-caption" style="text-align: center;">Me and our outstanding TA, Paul.</td></tr>
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I was really proud of our group: smart, resourceful, and diligent, all of them. It was really fun to work with them and they made the effort of teaching very much worthwhile. They're all going to make excellent engineers.<br />
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And that was that! Another successful EWH trip is in the books. All that's left to do is get home safely ... and start planning for the next adventure.</div>
iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com1tag:blogger.com,1999:blog-3331563262701117271.post-1471058799781291842018-06-11T21:12:00.000-07:002018-06-11T21:12:32.224-07:00Guatemala, Day 22Well its Day 22 and I'm almost done here. I miss my family very much and I'm counting the hours till I can go home. Today I booked my transportation back to the airport (4:30am bus, anyone?) and if everything goes according to plan, I should sleep in my own bed on Saturday night.<br />
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Our program is wrapping up. The afternoon labs are pretty much finished and now we're just focused on drilling the students on the all-important "soft skills" they'll need. For example, they need to know how to write effective instructions (including diagrams) for equipment usage, as well as detailed summaries on how equipment was repaired. We're also training them to do staff interviews (as a means of needs assessment) and equipment inventories. The equipment inventories are helpful, as they get tracked from year to year so we can see what equipment falls into disrepair at a given hospital. Engineering students often complain about having to learn soft skills, but I can guarantee that its even harder when doing so in a foreign language!<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDP9ryUR8O6ZpbOZbvb6FYXK-ghEHhyphenhyphenDKXqygMdydeg02NslUQq2dCHKX9utPVaPJEjuFwEFDBxrugNuSLmzLaLs13NHWT7JuAlvX9uSfhKM__JnD4w4aHpk_i1TtOxAtX8oouIf_YVx0m/s1600/619Ixchel-3.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="798" data-original-width="604" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDP9ryUR8O6ZpbOZbvb6FYXK-ghEHhyphenhyphenDKXqygMdydeg02NslUQq2dCHKX9utPVaPJEjuFwEFDBxrugNuSLmzLaLs13NHWT7JuAlvX9uSfhKM__JnD4w4aHpk_i1TtOxAtX8oouIf_YVx0m/s320/619Ixchel-3.jpg" width="242" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Typical Guatemalan dress (not my photo: shamelessly <br />stolen off some website)</td></tr>
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The Guatemalan people are really something. There are many women around town who dress in colorful traditional clothes and carry their babies in cloth swaddles on their backs. I've been wanting to take some photos but its pretty hard to do so without looking like a jerk tourist. One nutty thing we've all observed is how unfiltered some of the locals are when they interact with us. Last week at the clinic we visited, some random woman on the street stopped in her tracks to tell our Indian American student that he was the most exotic looking young man she'd seen in forever. Que guapo!!! In my own experience, people have said some daffy stuff to me when I've told them I'm "árabe". At one hospital, the technicians started miming machine guns and and giggling, and last week the clinic director decided I had to be filthy rich with petroleum money! The comments aren't malicious (and I wasn't really offended) but still its nutty to see people say stuff out loud that wouldn't fly in the States.<br />
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Last Friday we visited the local health clinic in town. From what I could tell, it seemed like a place for regular checkups and somewhat-urgent care, especially for mothers and children. It was pretty small but quite packed. There was tons of equipment for us to look at - some infant scales to weigh newborn babies that needed calibrating and cleaning, some blood pressure cuffs with leaks, and a wonky handheld ultrasound device. A good chunk of the day was devoted to cleaning and de-scaling the autoclaves.<br />
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<tr><td class="tr-caption" style="text-align: center;">Super old school autoclave</td></tr>
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The autoclaves at this place were super minimal - basically just industrial sized pressure cookers. Without any fancy electronics, it falls on the user to manually monitor the pressure gauges and use a stopwatch to time the whole process. One model went right on the stove to get heated, whereas the rest were electric. The electric ones have a heating coil like you would see in an electric kettle or coffee maker. The problem with these things is that if you don't use distilled water, then over time the minerals in the water will come out of solution and stick to the heating coils, which in turn become insulated and lose their ability to heat the water. Those minerals are super hard to get off - you can't chip them or scrub the coils with anything abrasive, because you'll ruin the metal coating on the heating element.<br />
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<tr><td class="tr-caption" style="text-align: center;">Severe scaling means subpar heating.</td></tr>
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The best course of action is to soak the coils in an acidic solution and hope that dissolves the minerals. In your home coffee pot, you might use vinegar and let it soak over night. In this case, we didn't have all night and we had a lot of scaling to clean up so we did what any reasonable person would do: we bought a liter of hydrochloric acid for about a dollar and got to work.<br />
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<tr><td class="tr-caption" style="text-align: center;">Muriatic (hydrochloric) acid</td></tr>
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The plan was to dilute the acid down to a 4:1 ratio and let it soak for about three hours. We were about to get started when we decided maybe we should wear some protective equipment. We ran to the hardware store to get some safety glasses, but came up short looking for rubber gloves. Every hardware store we went to told us to try at the pharmacy. Every pharmacy we tried said to check at a hardware store. Even the local supermarket was a bust. Finally, after an hour of searching, we wound up at a high end supermarket and eventually found some garden variety dishwashing gloves. Finally! Time to soak the autoclaves!<br />
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<tr><td class="tr-caption" style="text-align: center;">Enjoying sweet victory after an epic goose chase</td></tr>
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<br />While they were soaking, we realized that we had a new problem: how to dispose of a the dangerous hydrochloric acid. We certainly couldn't dump it in the sewer or down the drain. After some debate and Googling, we decided to try to neutralize it with baking soda. To my surprise, the very first tienda I went to had some in stock, although I was amused to see that it was sold in pre-packaged plastic baggies that made me look like I was carrying around a few grams of blow.<br />
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<tr><td class="tr-caption" style="text-align: center;">Hey man, you know were I can score some baking soda?</td></tr>
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Eventually someone found a more normal sized container of baking soda and we started mixing it into the acid. It took an entire pound of baking soda before the acid finally stopped bubbling and we were able to pour the mess down the drain with a clean conscience. The process definitely worked to some extent, although it had been so long since the autoclaves were cleaned that they definitely need another round, possibly with a less diluted acid soak.<br />
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<tr><td class="tr-caption" style="text-align: center;">Scrubbing autoclaves right on the sidewalk</td></tr>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjqTewmGVtsafd3lHP_ywjne3befr-faA6pXrUdJ8ntVgCHTHIm9kCkza_Myi7lXxRYfpUwW1qmD2d9ch8VS1fQ_a1DgCVXp02xV1rLM7fh373hH-lkbOoutsqLflr43oPRU2EEWeaRn4IV/s1600/IMG_20180608_145322.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjqTewmGVtsafd3lHP_ywjne3befr-faA6pXrUdJ8ntVgCHTHIm9kCkza_Myi7lXxRYfpUwW1qmD2d9ch8VS1fQ_a1DgCVXp02xV1rLM7fh373hH-lkbOoutsqLflr43oPRU2EEWeaRn4IV/s320/IMG_20180608_145322.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Pretty thankless job</td></tr>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi2e4hGY1dpqYviofyk050R6FNIoHHggLe3ELZmTEfuxWelTPXhP22rwYTMcP_vynvkUiRKhyDJACJw6N23uYmS4CkvFibn2hmhxGBefthLn6wLor52SYQxrgQIdNg8UaEMCkW462Ib2GD5/s1600/IMG_20180608_145853.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi2e4hGY1dpqYviofyk050R6FNIoHHggLe3ELZmTEfuxWelTPXhP22rwYTMcP_vynvkUiRKhyDJACJw6N23uYmS4CkvFibn2hmhxGBefthLn6wLor52SYQxrgQIdNg8UaEMCkW462Ib2GD5/s320/IMG_20180608_145853.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Acid plus baking soda equals lots of bubbles</td></tr>
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<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhGX6ko3EA-dnMP0D7kbthLY2Tpl26ncnxxwG8uYQM2QzWyVPlXSyHd2rtQ_qPsShylfQHjVExzIoe1yZ7DAeYsx3ESCZPrHQOneyO5DB9_d2_7xxN9FEPSBNA60kVQvP-N3q-0AhXMuw-b/s1600/IMG_20180608_151539.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhGX6ko3EA-dnMP0D7kbthLY2Tpl26ncnxxwG8uYQM2QzWyVPlXSyHd2rtQ_qPsShylfQHjVExzIoe1yZ7DAeYsx3ESCZPrHQOneyO5DB9_d2_7xxN9FEPSBNA60kVQvP-N3q-0AhXMuw-b/s320/IMG_20180608_151539.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Oops! Too much baking soda too quickly and it overflowed...</td></tr>
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<br />
Oh, one last thing I loved about this clinic. At the entrance, there were these three ladies selling all sorts of snacks. Two of them had babies with them, which they had carried to the clinics in swaddles on their backs while they carried big cardboard boxes with the snacks. Once they arrived, they set up the snacks on a blanket on the ground and then put their babies to sleep in the now-empty cardboard boxes! Seeing "babies in boxes" was definitely a first for me, but I guess as long as the cardboard stays dry, its a pretty good bassinet in a pinch!<br />
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One last hospital visit to go this coming Friday, and then I'll be heading home the next morning. Hopefully there'll be time for one last post before I head home!iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-43875173071123272652018-06-07T20:52:00.000-07:002018-06-07T20:52:48.807-07:00Guatemala, Day 18Well the volcano eruption turned out to be pretty serious, but it seems that the devastation is contained to the villages directly in the line of ash flow. I'm well over 50 miles from the volcano so there's nothing to see here. The locals are all hustling to take relief supplies to the affected areas. People are donating cash and goods, and pickup trucks are being loaded with supplies and driven down. Its a pretty impressive mobilization effort. These are good, good people.<br />
<br />
Lab has continued to be a lot of fun. Earlier this week the students finished building their variable power supplies. The supplies convert wall AC into a DC source that can go from 1-29V and source up to 2 amps. We use a full wave rectifier, some big smoothing capacitors, a linear voltage regulator, and a 2A fuse, just to be safe.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbMeIpK9rJXXL36fum40uYaPTC67m23rSiWuO5Ny4vfG_gUamQvRuKxVXAaDehtLc5cOy5bZzUWJ-evSMFoFlaEkZovF4RHtm0LE6mSO2wvXARLu4R4vr0bjfuU19oH-fqXUWKQJt5zQcA/s1600/IMG_20180604_201501.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbMeIpK9rJXXL36fum40uYaPTC67m23rSiWuO5Ny4vfG_gUamQvRuKxVXAaDehtLc5cOy5bZzUWJ-evSMFoFlaEkZovF4RHtm0LE6mSO2wvXARLu4R4vr0bjfuU19oH-fqXUWKQJt5zQcA/s320/IMG_20180604_201501.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The finished product! A variable DC power supply.</td></tr>
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The lab took forever, because getting all the connections soldered correctly and safely is a time consuming process. It was getting really late and I was getting really hungry, and so it was a blessing when there was a city-wide power outage and we were forced to pack up in the dark and go home.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhWHUtVBWZUGDYaGgGSMhHPWwKj64SmJ2-Nbi20x03p3LXEL-d-twfVyNqv7tisv6HZI3JTC14Z-p6XTKUmtloRtTmCB3ZDRNG2h2apBDWHldZ9J5xp1rIyx6im8-VMEvbxyXoZerte8rOb/s1600/IMG_20180604_202647.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1200" data-original-width="1600" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhWHUtVBWZUGDYaGgGSMhHPWwKj64SmJ2-Nbi20x03p3LXEL-d-twfVyNqv7tisv6HZI3JTC14Z-p6XTKUmtloRtTmCB3ZDRNG2h2apBDWHldZ9J5xp1rIyx6im8-VMEvbxyXoZerte8rOb/s320/IMG_20180604_202647.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Engineering in the dark.</td></tr>
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We used our power supplies to recharge some NiCad batteries yesterday. Students had to work out a series of equations in order to satisfy the following requirements:<br />
<br />
<ol>
<li>Battery has to charge at a reasonable speed</li>
<li>In order to charge the battery at that speed, you need voltage and current. Both those elements have to be in the range that can be delivered by our homemade power supplies</li>
<li>There needs to be a current limiting resistor. You can't dissipate more power in the resistor than its max rating, or else it'll burn up</li>
<li>You can reduce power in the resistor by reducing the current flow, but then your battery will take longer to charge</li>
</ol>
<div>
Eventually each group settled on a series of parameters and we connected up their batteries and waited for them to charge. No one started any electrical fires in the process, which was certainly appreciated.</div>
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<div>
We hold our classes in a community work space, where anyone can rent out space. One of our space-mates is a woman who works with a Michigan-based non-profit that builds and places water purifiers around the world. She showed us an example of one of their water systems. It was super interesting! The group is called <a href="https://cleanwaterfortheworld.org/" target="_blank">Clean Water for the World</a> (follow that link to read about what they do and maybe even donate a few bucks). The system is pretty simple (by design) - a thick paper filter followed by a UV light tank that kills all the biologicals in the water. It can do up to five gallons per minute and can be installed in a school or other community center. The specific one you see in the picture below will be installed at the volcano rescue and relief center this weekend. They have 270 of these suckers in use around the world!</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi_S-Jlj13QdhOPjZMyKjGQnxQZ3x6a5e1piFwXDLW_uxN6oIefwBj8Zpnnc8y7s2U4YekTl4VbCVO0xoD00VpbbmZSp7TsRGNJnr4ofINFSVRzyuKQi18DPwVVQVkAsSiPuAGT53I3Ex4J/s1600/IMG_20180606_154530.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi_S-Jlj13QdhOPjZMyKjGQnxQZ3x6a5e1piFwXDLW_uxN6oIefwBj8Zpnnc8y7s2U4YekTl4VbCVO0xoD00VpbbmZSp7TsRGNJnr4ofINFSVRzyuKQi18DPwVVQVkAsSiPuAGT53I3Ex4J/s320/IMG_20180606_154530.jpg" width="240" /></a></div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhtjG7krmbQRyFBSWpsF0Siq64HerxpP8ci4jNm4fSfoERo-vJ88Gksimy5FqpwcXHmg0bsG083opTBri1lGvl-Lo7Wn2B1Ihbe_9wWb3AVWHdUh-uikL2aKK9DSS4g8j3CqOeBcFuHy1D7/s1600/IMG_20180606_160050.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhtjG7krmbQRyFBSWpsF0Siq64HerxpP8ci4jNm4fSfoERo-vJ88Gksimy5FqpwcXHmg0bsG083opTBri1lGvl-Lo7Wn2B1Ihbe_9wWb3AVWHdUh-uikL2aKK9DSS4g8j3CqOeBcFuHy1D7/s320/IMG_20180606_160050.jpg" width="240" /></a></div>
<div>
The system has a built in counter that lets the locals know when its time to change the UV lightbulb. Units get delivered with enough filters and bulbs to last for two years, after which time the local communities must start buying their own.</div>
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<div>
Another fun experiment we did was testing to see what percentage of the air we breath is oxygen. This is a useful skill because a common piece of medical equipment in the developing world is the oxygen concentrator. These gizmos pump pressurized atmospheric air into special "zeolite" tubes that sequester nitrogen and allow mostly pure oxygen to pass through. How do you know if your concentrator is working? Well you have to test the percent oxygen that gets produced. We didn't have an oxygen concentrator to work with so we just tested atmospheric air. Here's how the test went:</div>
<div>
<ol>
<li>Fill a glass with the gas you intend to test (regular air in our case)</li>
<li>Stick a candle to the bottom of a tub, and then fill the tub with some water. Light the candle</li>
<li>Flip the glass over the lit candle, and submerge the lip of the glass.</li>
<li>As the candle burns the oxygen in the glass, it will suck water up into the upside-down glass.</li>
<li>The more water gets sucked up, the more oxygen there was in the glass that had to be displaced as it burned.</li>
<li>If you measure the percentage of the glass that fills up, that tells you the percentage of the air that is oxygen</li>
</ol>
<div>
Insanely, this nonsense actually worked, and we found that our glass sucked up 20% of its volume with water, which is roughly the percent of oxygen in the air we breath. We tried doing a follow-up test where we filled the glass with only exhaled air (which is a little lower in oxygen than atmospheric air) but alas our system wasn't sensitive enough to notice the difference.</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhj8FIQgtCgDhGQOvzK96wfJJlMZeNYmK-1OZvNUNmqsibruO3cIfmha6QMX6zgDe-Ap3Qs2Kt77Np3I-7LmqtUxCjLz-RJbrK7ZX1iKfg96Mbb_YPRSRFpA6D8W_FcRooWW_KZv0r7aQJy/s1600/IMG_1399.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1067" data-original-width="1600" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhj8FIQgtCgDhGQOvzK96wfJJlMZeNYmK-1OZvNUNmqsibruO3cIfmha6QMX6zgDe-Ap3Qs2Kt77Np3I-7LmqtUxCjLz-RJbrK7ZX1iKfg96Mbb_YPRSRFpA6D8W_FcRooWW_KZv0r7aQJy/s320/IMG_1399.JPG" width="320" /></a></div>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjqY9a2zBD8ZfKsutirejM7-Q_IDDwNmaSoxlAOY-m3XlY_XyFiR5cNaoWaKJLnHasOtOsTB4JwNOvoCe-ee-9w7P8-1idEfIaKe0tBJ71F9aV4iahTKLTgx5fGe1R19AhGUuysTSaF44sg/s1600/IMG_20180605_164953.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjqY9a2zBD8ZfKsutirejM7-Q_IDDwNmaSoxlAOY-m3XlY_XyFiR5cNaoWaKJLnHasOtOsTB4JwNOvoCe-ee-9w7P8-1idEfIaKe0tBJ71F9aV4iahTKLTgx5fGe1R19AhGUuysTSaF44sg/s320/IMG_20180605_164953.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">If you look closely, you can see that there is some water that's been sucked up in to the glass</td></tr>
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<div>
That's pretty much all the fun news to share. Here are a few other tidbits you might enjoy. Today we were testing whether an IV infusion pump was properly working and we needed something to function as an IV bag for the test. My students came up with a pretty cool solution:</div>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEit2lKGF0Mb_P17UKlOP8LNW12Zor-Zn6sLCUrhdUTpFkg-Soam4TfKIUd8kbzVhL1sbmnMh_tAz6BWOmi0LGtKOmGJkHqvot0ukEAZ04fqVrlnQKnYqDRoKdSuWCTwS1i5jzoclxLs-2Ca/s1600/IMG_20180607_181020.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEit2lKGF0Mb_P17UKlOP8LNW12Zor-Zn6sLCUrhdUTpFkg-Soam4TfKIUd8kbzVhL1sbmnMh_tAz6BWOmi0LGtKOmGJkHqvot0ukEAZ04fqVrlnQKnYqDRoKdSuWCTwS1i5jzoclxLs-2Ca/s320/IMG_20180607_181020.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Yes, that's a rubber glove filled with water and tied to the tubing using a hair band.</td></tr>
</tbody></table>
Next tidbit - I took apart a potentiometer to show the students how the magic inside works. Turns out, its just a strip of resistive material...<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhisCjKNFMZ2vchfJ2M5lSEXWGjX_RxFU_pXy6_j_OhZ2WzoWg-4g6Rwi_5DmYQyq3-qTAjqOEXCAUELeNbhLfcffULyUZQoywgTEKPVkcS_Ao1Bd-aHW2KZozTtjY_E0ZfKjhp42UIwTbE/s1600/IMG_20180607_154722.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhisCjKNFMZ2vchfJ2M5lSEXWGjX_RxFU_pXy6_j_OhZ2WzoWg-4g6Rwi_5DmYQyq3-qTAjqOEXCAUELeNbhLfcffULyUZQoywgTEKPVkcS_Ao1Bd-aHW2KZozTtjY_E0ZfKjhp42UIwTbE/s320/IMG_20180607_154722.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">This is the guts of a potentiometer. There is a wiper (which I pulled out) that connects a point on the outer ring to the smaller inner ring that's connected to the middle contact.</td></tr>
</tbody></table>
<br />Tidbit 3: here's the teaching staff. Me, Paul, and Luis. Paul teaches computer science at the University of Kansas and is on his third trip with EWH. Luis is our logistics coordinator, which works out nicely since he's a native Spanish speaker.<br /><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhu5OmC0duiugBZMvD5Zt9FIhlub-Wc1Plum_xOYsjqTFoRRoJHD_ribE3xDDKWanj76uIneTqWmZUS1ZTNu1oTzVm3USEOTIE0DbD5iyBKZeJKRwF3PSChWnRB4ca0xXyNRy9uppfuKcaA/s1600/edit_0950.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1067" data-original-width="1600" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhu5OmC0duiugBZMvD5Zt9FIhlub-Wc1Plum_xOYsjqTFoRRoJHD_ribE3xDDKWanj76uIneTqWmZUS1ZTNu1oTzVm3USEOTIE0DbD5iyBKZeJKRwF3PSChWnRB4ca0xXyNRy9uppfuKcaA/s320/edit_0950.jpg" width="320" /></a></div>
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Finally, here's a shot of most of our group on our first hospital visit two weeks ago.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh3DqVS2E0o9HqGNVdGnDzyXJWPveNx55x_ubio1D_nHmZzLemd3XCuNXIQ3iNRiSLv3RB7sdy6CErXFUO-Zyqf6aRLTftSNIZMsYQ3XIb07CyNuxnvqWKxwTa4Ma0nHRMqekK3rWvAr97g/s1600/Before+first+hospital+visit.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="900" data-original-width="1600" height="180" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh3DqVS2E0o9HqGNVdGnDzyXJWPveNx55x_ubio1D_nHmZzLemd3XCuNXIQ3iNRiSLv3RB7sdy6CErXFUO-Zyqf6aRLTftSNIZMsYQ3XIb07CyNuxnvqWKxwTa4Ma0nHRMqekK3rWvAr97g/s320/Before+first+hospital+visit.jpg" width="320" /></a></div>
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We're going to a community health center tomorrow - should be an interesting site visit. Stay tuned for more pictures and stories.</div>
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iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-70363976166093209152018-06-03T21:15:00.000-07:002018-06-07T20:05:38.831-07:00Guatemala, Day 14<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiFVvYVPP3LDMIuMzpGi_LLlFIn1dhiAJPa-6v4xHL079RXrDOQA9TMyaaQSO87qnEWLrg20ES3yMeW1eDCwdvOLFKlUBMLcLKft7g2so_T0Ff28sdBhxoeDSPWI34wkj1ARxl6qzwrzEpa/s1600/IMG-20180603-WA0000.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1280" data-original-width="720" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiFVvYVPP3LDMIuMzpGi_LLlFIn1dhiAJPa-6v4xHL079RXrDOQA9TMyaaQSO87qnEWLrg20ES3yMeW1eDCwdvOLFKlUBMLcLKft7g2so_T0Ff28sdBhxoeDSPWI34wkj1ARxl6qzwrzEpa/s320/IMG-20180603-WA0000.jpg" width="180" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">A relative of someone I know took this photo<br />
of Volcan de Fuego today.</td></tr>
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Today's big news is that a volcano near Antigua erupted pretty dramatically today. Several people died and hundreds were injured. Luckily its nowhere near where I am but it may impact my family's arrival on Saturday, as well as some of our vacation plans. Pretty nuts.<br />
<br />
Our program is going well. We had lectures about suction pumps, ventilators, anesthesia machines, and medical gasses, and we started working on building our power supplies. We'll be spending lab this week making them into variable DC power supplies suitable for actual use! On Friday I took a group of five students back to the public Occidental hospital to work on more equipment. Apparently I had come away with an unrealistically rosy picture of the hospital last week. My host family assured me that despite some newer equipment, the hospital is poor and underequipped. Families of inpatients are often given prescriptions and told to go buy the meds at a pharmacy because they aren't available in the <br />
hospital. Anyone who can afford it goes to the private hospitals. I haven't been to any but I'm told they're pretty nice. With that said, villagers sometimes travel for hours on end to visit the public hospital and their families even camp out front if they have nowhere else to stay.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh6XhdAFyhzl-pQg2WfDq4-WjTKkhXoJ63Jgq_g6EITyWMwTMwDo0_qtsA0oo5SsAY7f7VHnSu6kQbo1YFPsazR3zu2rSY-dyTV23P0Iy2USsDq2hW0y2XlI9oMQ-35NuAsDTsHU2U5H0gw/s1600/IMG_20180601_091951.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1200" data-original-width="1600" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh6XhdAFyhzl-pQg2WfDq4-WjTKkhXoJ63Jgq_g6EITyWMwTMwDo0_qtsA0oo5SsAY7f7VHnSu6kQbo1YFPsazR3zu2rSY-dyTV23P0Iy2USsDq2hW0y2XlI9oMQ-35NuAsDTsHU2U5H0gw/s400/IMG_20180601_091951.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Laundry air-drying at the hospital.</td></tr>
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We spent a good chunk of the day back in the odontology office. We were trying to fix two things - a small autoclave which was on the fritz and the suction system which wasn't quite working right. They have three dental chairs but the suction mechanism (for sucking up saliva and blood from the mouth) on one of them hadn't worked for four years! We started by looking at the compressors to make sure they were working properly. They have two compressors tied together without the use of any check valves or anything, which seemed a bit fishy to me. I wasn't sure if that was causing any problems so I spent a good hour plus messing around with them. Eventually I determined that the suction problem in the clinic still existed if I only used a single compressor. Furthermore, I decided that I could probably tie them together if I set the tank pressures as close together as possible. If you don't do this, then one compressor tries to fill up the other one and it gets messy. All of this was made massively more complicated by the fact that none of the plastic tubing they had was the right size to fit any of the nozzles, so moving and testing different configurations took a lot of doing just to get things airtight. We resorted to using a lighter to melt the tubing a little so it would wiggle down on the various nozzles. After that we started debugging why there was no suction at the one chair. It didn't help things whatsoever that neither me nor any of my students know how the suction and water on a dental chair are connected.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgo14_-CN0I6Ou6gMs20wugt3yesW2LfhlrLiRDAIo-ojkzEF919QGMhexoAzB1j_XKuMd-XAeS-ohqo6jNizZotx-xvbPkrgDSsr8TfYRDe99b1R65t-12gPNrZbWB10ZLcVO6j5Rt2W6N/s1600/IMG_20180601_135433.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1200" data-original-width="1600" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgo14_-CN0I6Ou6gMs20wugt3yesW2LfhlrLiRDAIo-ojkzEF919QGMhexoAzB1j_XKuMd-XAeS-ohqo6jNizZotx-xvbPkrgDSsr8TfYRDe99b1R65t-12gPNrZbWB10ZLcVO6j5Rt2W6N/s400/IMG_20180601_135433.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Lots of tubing to sort out.</td></tr>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEglxlfS_dfURhR483zYfJ31iPaSNUCJ5jcror8OKIZNnNZtYe74W7HPToSW6NCz-5hVAZSazPF7MbpJep9Mr-ROmmC6299cMGJY86JPwBki4dHDb8s_tSwaiP57vyPfvYeNR8T8RCvyBncc/s1600/IMG_20180601_135422.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEglxlfS_dfURhR483zYfJ31iPaSNUCJ5jcror8OKIZNnNZtYe74W7HPToSW6NCz-5hVAZSazPF7MbpJep9Mr-ROmmC6299cMGJY86JPwBki4dHDb8s_tSwaiP57vyPfvYeNR8T8RCvyBncc/s400/IMG_20180601_135422.jpg" width="300" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The yellow line holds pressurized air (from the compressor) and the green line is the suction. High speed air blows past the suction tube and into the drain (at left). As the air draws across the port to the suction tube, it creates negative pressure.</td></tr>
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But as engineers are wont to do, we worked to isolate the problem - tracing the air lines to see how far the pressurized air was getting. We had to take some of the dental chair apart to do this but in the end we discovered a pretty elegant mechanism. The pressurized air is forced through a very narrow channel. On the side of that channel there is an outlet port that connects to the suction tube. As the pressurized air flows past that port at high speeds, it creates negative pressure, which is the source of suction. All the liquids that are sucked up by the suction get pulled through that port and whooshed into a drain in the floor. Everything seemed to be mostly in order so we tried to clean all the tubing and valves as best we could, suspecting a small clog was to blame. Eventually we got it all back together and lo and behold: suction! The dentist was besides himself and was very grateful. I had a lot of fun because I got to take something apart and learn how it works. And the students had fun watching and learning too. Good times. The only downside was that I got <b>really </b>dirty. There is some unspeakable funk lurking inside tubes and valves that don't get cleaned very often. Needless to say I took an aggressive shower when I got home.<br />
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Earlier today I went to a barbecue fundraiser for an Australian lady who lives in town. She shelters dogs and has a monthly cookout to raise money for their care. I had an incredibly delicious plate of ribs and beans. I also got to taste an unusual drink. I don't remember what its called but its basically a Bloody Mary with beer instead of vodka. I enjoyed it - very refreshing and just perfect to wash down the ribs.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhGLDKMz3QNIkR05PTbzCkq_ZUWLfTE6-bdK1GmDEBoC9W4A1j2ZHzCDb-_XmsYKyQLyJtW6g_F_x9ds46FIbbwtlDo40wldg2DkRUYeFJ2uFdITcE6gqaq2wuxTDdlPtlvZ3zfNCa__ik9/s1600/IMG_20180603_142950.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhGLDKMz3QNIkR05PTbzCkq_ZUWLfTE6-bdK1GmDEBoC9W4A1j2ZHzCDb-_XmsYKyQLyJtW6g_F_x9ds46FIbbwtlDo40wldg2DkRUYeFJ2uFdITcE6gqaq2wuxTDdlPtlvZ3zfNCa__ik9/s320/IMG_20180603_142950.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">This very adorable creature wanted to share my ribs.</td></tr>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiFsiEwRpT-vMm31Iu2TvWNiY9mpY_vsIYc7dSqoG4LMOsAGeHL_hJNzvw6e-YFHxsxMeRHwzwxiMbIRB43V8VLFR08Ir8ScAX5ebrQ7TYSHrw_e9p26Adri-3jbGyKGm3wEoGnf6xjlQB_/s1600/IMG_20180603_133701.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiFsiEwRpT-vMm31Iu2TvWNiY9mpY_vsIYc7dSqoG4LMOsAGeHL_hJNzvw6e-YFHxsxMeRHwzwxiMbIRB43V8VLFR08Ir8ScAX5ebrQ7TYSHrw_e9p26Adri-3jbGyKGm3wEoGnf6xjlQB_/s400/IMG_20180603_133701.jpg" width="300" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">A very satisfying lunch!</td></tr>
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<br />iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-69150620633769265112018-05-30T07:16:00.000-07:002018-05-30T07:16:02.441-07:00Guatemala, Day 10Greetings again from Quetzaltenango. I spent my first weekend down here trying to get some work done as well as exploring the town a bit. I found a laundromat that charged Q20 (about $3USD) to do my laundry (washed and folded!), and I got invited to a family gathering by my host family. We drove out to Tio Tito's house to celebrate his birthday. The family was highly amused by my weak Spanish skills and so we laughed alot and bonded over a tipple or two. Families are fun.<br />
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More relevant to this blog, we've been busy working with our students to strengthen their basic engineering and fix-it skills. On Monday I gave a lecture on the fundamentals of motors - just about everything we'll be tackling in a hospital will have a motor of some sort in it. And yesterday (Tuesday) the lecture was about ventilators and oxygen concentrators. We talked about way of testing whether a ventilator is pushing out the correct volume an pressure. To measure volume, you can use the ventilator to inflate a balloon, and then put the balloon in a bucket of water to see how many inches the water level goes up. From there you can calculate the volume of displaced water, which is more or less the volume of air. To measure air pressure you can connect the ventilator to a clear tube with a u-bend that's filled with water. The more pressure, the more the column of water will be displaced.</div>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhpCwFXMvhsen2AnzahLMXAVJZ4u3ehheGU6Jqn3DEGyeHtLpj1ggC0hxyBWKOVbyVxcTWmGLz7_V0rM4GmnVTxF0sNzyo-hBHHCUaxx5ikSK142pKUV2nc_Qko2etP8tKtz5T5hh9If6x5/s1600/IMG_1114.JPG" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1067" data-original-width="1600" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhpCwFXMvhsen2AnzahLMXAVJZ4u3ehheGU6Jqn3DEGyeHtLpj1ggC0hxyBWKOVbyVxcTWmGLz7_V0rM4GmnVTxF0sNzyo-hBHHCUaxx5ikSK142pKUV2nc_Qko2etP8tKtz5T5hh9If6x5/s320/IMG_1114.JPG" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The transformer and light bulb.</td></tr>
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Our labs have been fun, too. On Monday we had the students solder a cable into a transformer that we're going to be using to build a power supply later this week. The transformers are supposed to convert 115V input to 24V output, but we measured outputs closer to 27V. After some research, we decided that this difference was because we were running the transformers without loads. Loads draw current, which will tend to lower the output voltage a bit. To test this hypothesis, we endeavored to try loading our transformers. The transformers are rated for 2.5A, so we needed a lot of load. We found some ceramic-encased high-power resistors in our toolkits and tried putting two of them in parallel. That drew a measly 200mA and barely affected the output voltage. Then we had the idea to take a light bulb out from the ceiling fixture and try putting that in the circuit as well. The bulb drew an additional 300mA and we succeeded in getting the output down to about 26V. I'm guessing we'd need to draw something closer to the full 2.5A rating to get the actual 24V output. We had fun though - the students got a kick out of seeing the lightbulb used as a tool.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiRfsNmMbBYzAao6lJBNAbv6PDP6FGeOUbIH3KukuQhhoGDNkJKxNfqSzGBUq2T9OuCmZG_4pz3hkSL6lEesq-Af-X0xquFXm05KVMLIzS6rIRkojQ8_TdoUPLEl9tfxmFwVRdpkn7TfuCX/s1600/IMG_20180529_175930.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiRfsNmMbBYzAao6lJBNAbv6PDP6FGeOUbIH3KukuQhhoGDNkJKxNfqSzGBUq2T9OuCmZG_4pz3hkSL6lEesq-Af-X0xquFXm05KVMLIzS6rIRkojQ8_TdoUPLEl9tfxmFwVRdpkn7TfuCX/s320/IMG_20180529_175930.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Battery pack, switch (red), and LED (clear, at left)</td></tr>
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Yesterday we had the students wire up a flashlight using a very simple circuit of batteries, a switch, and an LED. The point of the lab is to get some more experience soldering and trying to think through basic issues such as how should I glue this all together to make it feel like a useful tool. We also had the students determine whether a current limiting resistor was needed. The two AA batteries gave 3V total, and the forward voltage rating for our LED was about 3.6V. Because we're operating below the diode "on" voltage, we knew there was a good chance that we could use the diode resistance to limit current. We tested this by wiring up the circuit with a potentiometer in series and then slowly decreasing the resistance while simultaneously measuring the current. Sure enough, even when the resistor went to zero, the diode wasn't drawing more that its max recommended current of 20mA, and that sucker was *bright*.<br />
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We also spent some time learning about fuses. Every lab group took a 1A fuse and shorted it across a pair of AA batteries. That created more than enough current to get the fuse to blow - we looked at the fuses before and after and you can see the little fuse wire inside gets physically burned away. Blown fuses are a constant source of headache when repairing medical equipment!</div>
iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-54506028747348072552018-05-25T20:33:00.000-07:002018-05-25T20:33:12.272-07:00Guatemala, Day 5We've spent the past few days getting our students up to speed on the basics of medical electronics. So far we've mostly covered electrical safety and power supplies (and batteries). Experience has shown that most of the problems we will tend to encounter are due to either power supply problems or user error. The lectures were supplemented with a series of labs designed to underscore basic electrical skills. We started by having the students make an extension cord - we give them the cable, the plug, and the outlet receptacle, and they have to connect it all together. Its not super complicated but it does require attention to detail. We also practiced soldering: resistors onto perfboard and spliced wires. The soldering irons we got this year seem to work pretty well but they came with massive chisel tips which aren't exactly ideal for fine pitch soldering.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEihiUayV7EdpOaq3JAvtt-qcHrc-NuFFBs7ERBhSg0v1iRHH9qjKJlQFasHiyFsORZMf6AlSSfsPpt58IeVJBNGEOf1_3_vi0nnYzBoAnpK1eIHQqbZAHDAOd9JJrk-gx6CKXYju5K5f9FS/s1600/IMG_20180523_175727.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEihiUayV7EdpOaq3JAvtt-qcHrc-NuFFBs7ERBhSg0v1iRHH9qjKJlQFasHiyFsORZMf6AlSSfsPpt58IeVJBNGEOf1_3_vi0nnYzBoAnpK1eIHQqbZAHDAOd9JJrk-gx6CKXYju5K5f9FS/s320/IMG_20180523_175727.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Wiring together our extension cords</td></tr>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi61EU_pewn0Om4oE7wNz8JlvfeodFzeVDj24IQ2AySDccHZaBrOd8a9CkkQE680O5tNf9hjX9VPh_0aX608CId8GJXbS1cpPlAQAWIGJB2t8N9fjRAOIaIr9qVGxWnix_gC8dThLnW82j3/s1600/IMG_20180524_180059.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi61EU_pewn0Om4oE7wNz8JlvfeodFzeVDj24IQ2AySDccHZaBrOd8a9CkkQE680O5tNf9hjX9VPh_0aX608CId8GJXbS1cpPlAQAWIGJB2t8N9fjRAOIaIr9qVGxWnix_gC8dThLnW82j3/s320/IMG_20180524_180059.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Wrangling the soldering iron</td></tr>
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Today we had our first hospital visit, at the "Hospital Regional de Occidente". My first impression was that the hospital was in decent shape all things considered. The building infrastructure seems solid enough and we saw lots of equipment that looked relatively new and well maintained. Our hosts took us around the hospital to see different services with equipment that might need to be repaired. Our goal with these day trips is mostly to learn what we can, although if we can fix things along the way that's nice too. Sometimes it can be helpful just to take things apart and observe how they're supposed to work.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhTyrNiDWd-4QYrtyWERvy_hKUYwxslhNtvLl55uTzJHwckXeBMW0_MDHGB_6ZdHE88OC82LsFeQOGzyG2QFrcmpkYxQTiFtrZNBlAXQ0J_hzWBsM201AcXPUr8xbYuqj5e-RpTQqMAJQPR/s1600/IMG_20180525_155058.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1200" data-original-width="1600" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhTyrNiDWd-4QYrtyWERvy_hKUYwxslhNtvLl55uTzJHwckXeBMW0_MDHGB_6ZdHE88OC82LsFeQOGzyG2QFrcmpkYxQTiFtrZNBlAXQ0J_hzWBsM201AcXPUr8xbYuqj5e-RpTQqMAJQPR/s320/IMG_20180525_155058.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Hospital main entrance</td></tr>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAsi-7SLx_bwn1j34gtn57hvJQzRDSBD8OXuult-Pu2sDwLPGfxAv5IGgxNmJMM-xBs6eRrD_Wm0JRbqDlneUV2VvVMSTkKl37WpB5Nxx8TK_hEcg6a6zUiGjH6qRx1RM25B-wBJN3sjOz/s1600/IMG_20180525_075505.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1200" data-original-width="1600" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAsi-7SLx_bwn1j34gtn57hvJQzRDSBD8OXuult-Pu2sDwLPGfxAv5IGgxNmJMM-xBs6eRrD_Wm0JRbqDlneUV2VvVMSTkKl37WpB5Nxx8TK_hEcg6a6zUiGjH6qRx1RM25B-wBJN3sjOz/s320/IMG_20180525_075505.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Waiting to be allowed on-site</td></tr>
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Our first stop was the sterilization facility, where all manner of surgical instruments are autoclaved. They had five or six fairly large steam autoclaves. One of them had a burned out heating element and they didn't have a replacement handy, so we just learned to follow the flow of the pipes to gauge how it worked. We also inspected a water purifier that just boils water and then collects the condensate.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiK1L1wlcQ47vE14bB831o2n2kceMFfuTusun8zyBJ4y9X4JFhOGq5NUULqszEENAHzvR6atNXy9zOH4FrJdWEatIxub9ajjacXqAh29Jmo745Lf4wd6roKca7GITTSotUspmlz3IUKXYAk/s1600/IMG_20180525_095551.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiK1L1wlcQ47vE14bB831o2n2kceMFfuTusun8zyBJ4y9X4JFhOGq5NUULqszEENAHzvR6atNXy9zOH4FrJdWEatIxub9ajjacXqAh29Jmo745Lf4wd6roKca7GITTSotUspmlz3IUKXYAk/s320/IMG_20180525_095551.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">One of the bigger autoclaves</td></tr>
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Next we visited the lab, where there was a fume hood which occasionally made a rattling noise. We took of the front cover and it was pretty icky back back where the fan unit runs - lots of dust and debris that "naturally" builds up over time. We cleaned it as much as we could. We tried to get the HEPA filter out to see if there was something loose close by it but couldn't work out how to get it out. We'll research that and try again next week.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjJKGjD6giab_aGBUN3ZYj98kw9t8ASCXABhyphenhyphenfm36XhnhQUmb8ws6gzsgfzS3MvD2CfKPkBxsrQTU4as9nHisnXl2YoUDYIX7PuhUwrOQyxgFw9QKcflM4Nz0H5v3ttpAPiTsMjqHKYDW9/s1600/IMG_20180525_103310.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1200" data-original-width="1600" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjJKGjD6giab_aGBUN3ZYj98kw9t8ASCXABhyphenhyphenfm36XhnhQUmb8ws6gzsgfzS3MvD2CfKPkBxsrQTU4as9nHisnXl2YoUDYIX7PuhUwrOQyxgFw9QKcflM4Nz0H5v3ttpAPiTsMjqHKYDW9/s320/IMG_20180525_103310.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Does anyone know how to change the air filter on a fume hood?</td></tr>
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Then it was off to the oral care clinic. They have a pair of air compressors, which apparently are responsible for all the magic one sees in a dentists chair: the compressed air can be used to make suction, and it apparently pressurizes the water pik. Anyways, they were complaining about no pressure at the chairs, so we spent some time trying to debug what was going on. The compressors seem to be working ok but something might be amiss with one of the flow valves that sends the compressed air out where it's needed. We ran out of time but we'll have another whack next week.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEixZlDqEYc_Uoxe7uMWmaQem43EJPNoQQqLXQCPlZf1tl-LZvVk2-4N_Ee7F7m1z0C8pLdlUd6kkvdVFvg0FHcsm4hvWqQ4OoArZ3AimGRS6I_yZ9rb6IkGMBqS2PNBHLViCuh1hfAq8uIF/s1600/IMG_20180525_121058.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1200" data-original-width="1600" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEixZlDqEYc_Uoxe7uMWmaQem43EJPNoQQqLXQCPlZf1tl-LZvVk2-4N_Ee7F7m1z0C8pLdlUd6kkvdVFvg0FHcsm4hvWqQ4OoArZ3AimGRS6I_yZ9rb6IkGMBqS2PNBHLViCuh1hfAq8uIF/s320/IMG_20180525_121058.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The air compressors that weren't quite doing their job</td></tr>
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After lunch (tacos, duh), we toured the surgery suite. They seem to be having a problem with bulbs burning out prematurely in their surgical lights. We made a note to look into it next week. I'm worried it might be poorly regulated AC service to that part of the hospital which is burning out the bulbs - if so that isn't something we can do much about. It may be time for them to call an electrician.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjabcRMVUSkt28sH12Vla7GRgMzi8Z01yoIWgd8yK-Y1PcwWRwdRUJ0BuilYZq1m1r8zF5XvSw9aceyorWdbu6DgRqL1-G7N9aCr3KmFN5WVn8qGzLl5XHLL3qJh0V7yoUSqAxn0nR-fGQT/s1600/IMG_20180525_145811.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjabcRMVUSkt28sH12Vla7GRgMzi8Z01yoIWgd8yK-Y1PcwWRwdRUJ0BuilYZq1m1r8zF5XvSw9aceyorWdbu6DgRqL1-G7N9aCr3KmFN5WVn8qGzLl5XHLL3qJh0V7yoUSqAxn0nR-fGQT/s320/IMG_20180525_145811.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Surgical lights with burned out bulbs</td></tr>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgEPt-IcNIbxXbhaeVSNo_cGe3kH6wp9qjpbtXX9SOuQ0xi20j7KvGY6Y3J6Mq_4mpReGGNCU1lJBxNwVBCWIQ5o3ede8AFbEAV_Xkn3Jd9JdF8kV0eVojc5MwYLAB0P0GzHuV0V7w44GiI/s1600/IMG_20180525_150551.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgEPt-IcNIbxXbhaeVSNo_cGe3kH6wp9qjpbtXX9SOuQ0xi20j7KvGY6Y3J6Mq_4mpReGGNCU1lJBxNwVBCWIQ5o3ede8AFbEAV_Xkn3Jd9JdF8kV0eVojc5MwYLAB0P0GzHuV0V7w44GiI/s320/IMG_20180525_150551.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">An operating room</td></tr>
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<br />
So that was our trip. I learned a lot because I got to see a few odds and ends I haven't seen before, which makes me happy. The students seem to be pretty sharp and are learning quickly.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiB6iUat_vAt7WFHyOiu3VoVwvPqIbVBrBtzMS8BmYTCpssbtJnxGNDJqgrZy1oBEfDkgLNi5fKUqAlZ1aO3o-YKshRlparjfo5oJRpiIpG4Aow27wnrr0HE7qpyyqs4kRyH7Dn_9Ka6AcJ/s1600/IMG_20180525_132743.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1200" data-original-width="1600" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiB6iUat_vAt7WFHyOiu3VoVwvPqIbVBrBtzMS8BmYTCpssbtJnxGNDJqgrZy1oBEfDkgLNi5fKUqAlZ1aO3o-YKshRlparjfo5oJRpiIpG4Aow27wnrr0HE7qpyyqs4kRyH7Dn_9Ka6AcJ/s320/IMG_20180525_132743.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Taco lunch: $3</td></tr>
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<br />iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-22674342531852758362018-05-22T19:35:00.001-07:002018-05-22T19:35:48.976-07:00Guatemala, Day 2<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgHSkSF3dfP22BP2NAQvEVTkIfZcvOVM74TiPXhdDXhy0NnE8jpBgJWWERFHNEpuQGUUIHJKvwNq6Audvn7_sx0nGJsfqD8TsYCUq_IF2tO5VIex85040FI4Y-AArGQXBpT2Eey3KzS8Ps2/s1600/IMG_20180522_070115.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1200" data-original-width="1600" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgHSkSF3dfP22BP2NAQvEVTkIfZcvOVM74TiPXhdDXhy0NnE8jpBgJWWERFHNEpuQGUUIHJKvwNq6Audvn7_sx0nGJsfqD8TsYCUq_IF2tO5VIex85040FI4Y-AArGQXBpT2Eey3KzS8Ps2/s320/IMG_20180522_070115.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Minerva Temple</td></tr>
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I woke up a bit early this morning and went for an hour's walk before breakfast. I wandered over to what turned out to be a somewhat drabber neighborhood. There were lots of kids running to school and people heading to work. I wound up near a structure called the Minerva Temple, which is one of a number of similar structures built around the country in the early 1900's. They symbolized wisdom, I believe. There was an outdoor market next to the temple with produce and meat but I didn't have time to get a good look. I also learned that right around the corner from there is a Walmart, of all things. I am definitely going back to check out the Walmart sometime. I am curious whether the "people of Walmart" phenomenon exists in Central America or whether its just a US thing.<br />
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At work today I went through the basics of working with hospital equipment in the developing world - why equipment fails to work and what we can and can't expect to do about it during our short time here. We also had an interesting discussion about the complex dynamics surrounding equipment donations and repairs. For example, apparently a lot of countries in the developing world have programs to educate people on repairing and maintaining hospital equipment, but once trained, those people can make a lot more money in other sectors than healthcare. Our TA was telling us that in Tanzania, where he worked last year, they get so many donations that they often don't bother to repair broken equipment. They know that some do-gooder hospital in the west will be sending them new equipment sooner or later. There was also an interesting discussion around the topics of "what metrics distinguish a country as a 'developing' nation" and "why are some countries poor". Just for good measure, I also threw in a mini-lecture covering what is essentially the first two years of a typical electrical engineering undergrad curriculum, condensed down to about 30 slides.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiUXCvbfD9uUHf7l8zr0tumAYFDbuM9P_atwxYUibfj2u1xPnJ8rYXz00T15zsScY74YFOANC7EPhl1bcHgxyfgZjrTrWZo8qMvINrlESEJF_Xu8zutfx-yxdoBREg61Go45LudEWwlYZWF/s1600/IMG_20180522_193706.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1200" data-original-width="1600" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiUXCvbfD9uUHf7l8zr0tumAYFDbuM9P_atwxYUibfj2u1xPnJ8rYXz00T15zsScY74YFOANC7EPhl1bcHgxyfgZjrTrWZo8qMvINrlESEJF_Xu8zutfx-yxdoBREg61Go45LudEWwlYZWF/s320/IMG_20180522_193706.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Nachos for dinner!</td></tr>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhiV3JR8s9l7GaRoODoa-b4DqDvDnezQLpBGZ_qZnnAnDnZHkAjKYEg01RVKV5eZfAwKPaUQ10yw6l_x5iB-sibAfREvsRZv-52pPc66_zYQlYBnNovZ0PB5gIFVpTuBFVujFQSrzKttyTm/s1600/IMG_20180522_195204.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1200" data-original-width="1600" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhiV3JR8s9l7GaRoODoa-b4DqDvDnezQLpBGZ_qZnnAnDnZHkAjKYEg01RVKV5eZfAwKPaUQ10yw6l_x5iB-sibAfREvsRZv-52pPc66_zYQlYBnNovZ0PB5gIFVpTuBFVujFQSrzKttyTm/s320/IMG_20180522_195204.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fried banana goodness</td></tr>
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Food-wise, we had another pretty good day. We had nachos for dinner and for dessert we had these amazing bananas that were floured, fried, and then garnished with milk, cinnamon, and sugar. Our host mom was telling us about all the different kids of bananas they get in Central America. The ones we had for desert were "bananos de manzana" but there are a ton of others, each with their own flavor. I have made a mental note to taste as many as possible.<br />
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Below are a few photos I snapped of the town today. Enjoy!<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSDbat0GqG-HBmqIUkK1abZDnUlUOMoM4r8QhXj4v0kCVlpAYcQcpQDzaQ2np0my811lcVhHoknEhToHEJrD49jJDsPyTz-ZBgA_ZnzMpooXhDvIKbGkmGyz7LUmvyTUJ4EO3ELe2LTvTK/s1600/IMG_20180522_125446.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1200" data-original-width="1600" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSDbat0GqG-HBmqIUkK1abZDnUlUOMoM4r8QhXj4v0kCVlpAYcQcpQDzaQ2np0my811lcVhHoknEhToHEJrD49jJDsPyTz-ZBgA_ZnzMpooXhDvIKbGkmGyz7LUmvyTUJ4EO3ELe2LTvTK/s320/IMG_20180522_125446.jpg" width="320" /></a></div>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjOPE7vReazBzr7bWmAdS5sWCNC86Rhs5lv8o-ySYwtij82Bmm7B94HcCdPQ5iPBncis3C_ZLdPszNjd5PbHnNf0201KI0Vxo2lgA38jsLXvNB4jioWnVyVpltZ1fO532AR0YG5C6AZ6ydC/s1600/IMG_20180522_124441.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjOPE7vReazBzr7bWmAdS5sWCNC86Rhs5lv8o-ySYwtij82Bmm7B94HcCdPQ5iPBncis3C_ZLdPszNjd5PbHnNf0201KI0Vxo2lgA38jsLXvNB4jioWnVyVpltZ1fO532AR0YG5C6AZ6ydC/s320/IMG_20180522_124441.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">I want to guess these are walnuts but I'm not sure.</td></tr>
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<tr><td class="tr-caption" style="text-align: center;">The courtyard at our school</td></tr>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjp2e591CsBX1T0y906U7wDdVBU1wAF3AGfuGnDGapQ31qjKtBhps_mDAPTv_X2fCIc2niCUiVErsV5Bs6x-IaQnkJwwHaazPm9uSS79dBcbtAgO5xk2U4waffOLJkuwWtC-8BWVGRxuZKM/s1600/IMG_20180522_102728.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1200" data-original-width="1600" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjp2e591CsBX1T0y906U7wDdVBU1wAF3AGfuGnDGapQ31qjKtBhps_mDAPTv_X2fCIc2niCUiVErsV5Bs6x-IaQnkJwwHaazPm9uSS79dBcbtAgO5xk2U4waffOLJkuwWtC-8BWVGRxuZKM/s320/IMG_20180522_102728.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The coffee shop where I drink tasty espresso drinks</td></tr>
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<br />iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-77174263111924345592018-05-21T19:19:00.000-07:002018-05-21T19:19:00.566-07:00Guatemala, Day 1Greetings from Quetzaltenango, Guatemala. We arrived here last night after a long day that included two flights and a four hour van ride. Quetzaltenango is a fairly large town but its pretty out of the way. It's also at about 8,000 feet elevation, so I've been finding myself getting winded by just walking around.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhBJItySrul2bFn1sAJwBG_pFA8lNbfr40JlC9dcJbhqaYCV6kxHIH36vwBE3yAfRzohtBcw38fASz1uy-WoaV5HJzKWPc-rd3BbeBptYfkvdJaVmbQk_tE1bK6lZ87NrGodlxzfs6fK5_M/s1600/IMG_20180521_112322.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1200" data-original-width="1600" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhBJItySrul2bFn1sAJwBG_pFA8lNbfr40JlC9dcJbhqaYCV6kxHIH36vwBE3yAfRzohtBcw38fASz1uy-WoaV5HJzKWPc-rd3BbeBptYfkvdJaVmbQk_tE1bK6lZ87NrGodlxzfs6fK5_M/s320/IMG_20180521_112322.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Central Park</td></tr>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhULgaKJ0kq71OrFWkXVYKHgnYXTf-d7V48uYQ3S1xrnJ-9I1yUTCZyMkK84EaFjHHZbgOq7qLTxTGfzz1t6ed_5B5yyPVQKa4dcQ2iRkBT_Ck-5RxDLXhaJoAJBFJMxG35HRLBWuT0b2eY/s1600/IMG_20180521_104339.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhULgaKJ0kq71OrFWkXVYKHgnYXTf-d7V48uYQ3S1xrnJ-9I1yUTCZyMkK84EaFjHHZbgOq7qLTxTGfzz1t6ed_5B5yyPVQKa4dcQ2iRkBT_Ck-5RxDLXhaJoAJBFJMxG35HRLBWuT0b2eY/s320/IMG_20180521_104339.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The view from the door of our school building.</td></tr>
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Six weeks ago, the plan was for this summer program to be held in Nicaragua, where I've already taught on four separate occasions. Unfortunately, the political instability there made it inadvisable for us to go there, so the coordinators decided to move the program to Guatemala instead. Its time for a new adventure!<br />
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I am the instructor for the Engineering World Health (EWH) Summer Institute. We bring a handful of students from the US (mostly) and bring them to the developing world for the summer. The first month is "training" which means learning the local language and customs, and studying the basics of hospital instrumentation. During the second month, the students work full time at various hospitals around the country fixing broken medical equipment. The program is held in a number of countries, including Tanzania, Nicaragua, Guatemala, Uganda, and Rwanda. The program's founders discovered that although a lot of medical equipment gets donated to the developing world, it often falls into disrepair or isn't used properly. Our goal is to help address that deficit. Equipment falls into disrepair for a number of reasons - sometimes there's just on one around who can spend a day taking something apart and cleaning it; sometimes the instruction manual isn't in the local language; sometimes there's no manual at all and no one knows how to use it.<br />
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Every year the program size changes. This year we have ten students, one TA, one coordinator, and me, the instructor. The students tend to be mostly engineering students but really anyone willing to wield a screwdriver and apply themselves has the capacity to succeed.<br />
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I am staying with a host family. They speak Spanish with me and cook me three squares a day. So far the food has been pretty awesome. They get fresh corn tortillas three times a day! The mom has three adult daughters with families of their own and the grandkids are running all over the place this evening. There's also a little Scotty dog named "Bidoo" (as in "Scooby Doo") who likes to get petted. Lots of action. The weather is all over the place. During the earlier part of the day its pretty hot. In the afternoon it rains like crazy and then it gets cold at night.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhi88IRBG_F4GjeMTMONwSpU8jw94k2QcD4Dd_XS9BtqENC28WVDBugcEhDgbK0z2ysSN5A28AxFamXDzqcFAfJDALITF5o3_Jzn7TnSdzWi-KnofGtjlPTBafrMi964fr_24PacM8G6yq4/s1600/IMG_20180521_134326.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhi88IRBG_F4GjeMTMONwSpU8jw94k2QcD4Dd_XS9BtqENC28WVDBugcEhDgbK0z2ysSN5A28AxFamXDzqcFAfJDALITF5o3_Jzn7TnSdzWi-KnofGtjlPTBafrMi964fr_24PacM8G6yq4/s320/IMG_20180521_134326.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Lunch! Soup, shredded beef, boiled veggies.</td></tr>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgCabN5ghfUqL8sMRdFxAtwFMQLOxyeLfDv4nHmvXB_daYpHAuGtuex6dOtfMx9ViFW6J9kCXfVezX2RI9s3rLoTuHoe4apF8qQU-p4-YaErVsB9dyAkT8c495oOBOJ_BAaEP6shUyx-EA5/s1600/IMG_20180521_193110.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgCabN5ghfUqL8sMRdFxAtwFMQLOxyeLfDv4nHmvXB_daYpHAuGtuex6dOtfMx9ViFW6J9kCXfVezX2RI9s3rLoTuHoe4apF8qQU-p4-YaErVsB9dyAkT8c495oOBOJ_BAaEP6shUyx-EA5/s320/IMG_20180521_193110.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Dinner! Shredded beef empanadas. Delicious!</td></tr>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhnLRkSTFvrOzYNNcDzvfnqXVKC0x8Aao4BLgW29NgVXF3_W4hfXJaPTzDYgutczqnlHnli9MuQTQbkJ6JsilFwQ4FCBak2MkjnpQcARlmU2bbUW6FhuI_hSUFrcQgKnku64z3SP9Arm8CR/s1600/IMG_20180521_133055.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1600" data-original-width="1200" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhnLRkSTFvrOzYNNcDzvfnqXVKC0x8Aao4BLgW29NgVXF3_W4hfXJaPTzDYgutczqnlHnli9MuQTQbkJ6JsilFwQ4FCBak2MkjnpQcARlmU2bbUW6FhuI_hSUFrcQgKnku64z3SP9Arm8CR/s320/IMG_20180521_133055.jpg" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">My new buddy, Bidoo.</td></tr>
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Not much happened today. We exchanged some dollars and bought SIM cards for the student phones (which took forever), and then I worked for a bit on actual University stuff. I spent the afternoon trying to sleep off some general malaise which is probably a combination of a few nights of lousy sleep, a change of water, and altitude adjustment. Hopefully I'll be a bit more on my game tomorrow!iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-89193188125376372812016-09-19T12:35:00.002-07:002016-09-19T12:35:29.467-07:003D PrintingI've been having some fun getting to know the 3D printers in Temple's College of Engineering. I've been using a StrataSys Objet 3D printer to create parts for EEG headsets for a <a href="http://www.tubrainhack.com/" target="_blank">hackathon</a> we're running this weekend (more details on that soon). We've been using <a href="https://github.com/OpenBCI/Ultracortex/tree/master/Mark_III_Nova_REVISED" target="_blank">headset designs from OpenBCI</a>. We bought the electronics from them and we're printing our own headsets. The first part of the print took some 60 hours but man are the parts nice.
The parts come off the printer embedded in a flimsy scaffolding:
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDHjHk_EU83Cd2epmAuEwpOrX8yzURyn3iE7NleFsPXAROD1coGJrUdTQm9p2BuCcrVo64jpViv8mjDByGkFgyrz0RVfVE7NAnbOt2EBzMXza661pm4vq70h-UTuf6oXs1IfNNUf5PgK7i/s1600/2016-09-19+10.57.44.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="180" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDHjHk_EU83Cd2epmAuEwpOrX8yzURyn3iE7NleFsPXAROD1coGJrUdTQm9p2BuCcrVo64jpViv8mjDByGkFgyrz0RVfVE7NAnbOt2EBzMXza661pm4vq70h-UTuf6oXs1IfNNUf5PgK7i/s320/2016-09-19+10.57.44.jpg" width="320" /></a></div>
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The scaffolding is manually removed using a pressure washer to strip it all away:</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhatT805cmjHzrB3bSeM2Q__G8h2KTigJ_lsnpI_3R3ZFJd84uYPOQ5FW_orchArjSgPtUryMJ0SKN3VZLtZzJiSErXyto5t7rdJRnk0L2xuDs5cD8C3VfFeSa3mQQFWq5u9l5VdP385q_u/s1600/2016-09-19+11.04.30.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhatT805cmjHzrB3bSeM2Q__G8h2KTigJ_lsnpI_3R3ZFJd84uYPOQ5FW_orchArjSgPtUryMJ0SKN3VZLtZzJiSErXyto5t7rdJRnk0L2xuDs5cD8C3VfFeSa3mQQFWq5u9l5VdP385q_u/s320/2016-09-19+11.04.30.jpg" width="180" /></a></div>
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The finished products are firm and very cleanly articulated:</div>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhUIu9qox2tb2KMh45MqRpqESQAHNlReTKoAdttBwQvUTOvVbDMDbVeOh7UKJpyUMugnDSAVy_PDioTE453hvgVGkTY4W2_u-r-rBts-odEWsUhCxy-0N-b-TaEc-hwWj3i90RjyPKPIAwU/s1600/2016-09-19+11.09.40.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhUIu9qox2tb2KMh45MqRpqESQAHNlReTKoAdttBwQvUTOvVbDMDbVeOh7UKJpyUMugnDSAVy_PDioTE453hvgVGkTY4W2_u-r-rBts-odEWsUhCxy-0N-b-TaEc-hwWj3i90RjyPKPIAwU/s320/2016-09-19+11.09.40.jpg" width="180" /></a> </div>
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I'll post some pictures of the headsets once they're completely put together. Overall though, its a really neat process!</div>
iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-30508936922691360662016-03-10T07:46:00.000-08:002016-03-10T07:46:09.929-08:00Brain EfficiencyI've been thinking a lot recently about how efficient the brain is. I like to spend time thinking about how neural interfaces will change the nature of humanity. Presumably, at some point, it will be possible to create computers that have intelligence that is on par with that of humans. Does that mean the end of humanity? Maybe, but maybe not.<br />
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Computers were designed to crunch numbers, and they are ruthlessly efficient at it. Unfortunately for them, most of the tasks we associate with "intelligence" are not associated with number crunching operations. Human intelligence is essentially a feat in pattern recognition - when we recognize patterns, we learn to predict the future based on previous experience. We can teach computers to perform pattern recognition tasks, but first we have to convert those tasks into number crunching operations. This is a pretty inefficient way of solving those problems, but we make up for that inefficiency by using super fast computers. Think of it as trying to drive a square peg into a round hole: its a bad idea from the start, but you might be able to make some progress if you just agree to use a humongous hammer.<br />
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So, number crunching machines are inherently inefficient at recognizing patterns. Is there another type of computing system that would be more efficient? Yes! Millions of years of evolution have placed a very efficient pattern recognition system right between your ears: your brain. Brains are insanely efficient at pattern recognition tasks. Lets see how efficient:<br />
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<ul>
<li>The average adult consumes about 2,000 calories per day</li>
<li>Of those, about 1,300 are the "resting metabolic rate" which is basically how much energy you'd burn if you just lay in bed all day and didn't move - its what you burn to keep your organs running to stay alive</li>
<li>Of those, about 20%, or 260 calories, are consumed by your brain</li>
<li>260 calories in 24 hours converts to about 1.1 million joules per 86400 seconds, which reduces to 12.7 joules per second which is basically 13 watts.</li>
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That's right. 13 watts to keep the universe's most sophisticated intelligence machine operational. Astounding. By comparison, the fancypants laptop I'm using to type this blog post with consumes about 45W. The Watson computer that succeeded in playing Jeopardy reportedly uses something like 200,000W, a factor of over 15,000x more. Perhaps a more impressive feat than Watson beating Ken Jennings would have been Watson beating 15,000 Ken Jennings! And lets remember, Watson didn't 'have fun' playing Jeopardy, or parlay its experience into planning for its future: Ken did. Even super computers like Watson, with all their power, are inferior to the wonder of the human brain.</div>
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So, will a computer ever become as smart as a person? While it's hard to say, I believe that it will be damn near impossible for a computer to become as smart as a person using only 13 watts of power. I suspect that the only material that can be made to operate as efficiently as a human brain is ... a human brain. You'll never get down to 13 watts with transistors, memristors, or whatever the next great innovation is. Nothing beats neurons with respect to efficiency.</div>
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A separate question worth asking is whether a computer that can think as fast as a person (regardless of the wattage) can compete with humanity in terms of collective intelligence. I'll save that question for another day.</div>
iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com1tag:blogger.com,1999:blog-3331563262701117271.post-25663438468629271472016-02-03T18:35:00.000-08:002016-02-04T11:16:28.766-08:00DARPA NESD Program<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj8klqhNEqWpORyxcDTxYFNzbdgtU9bSXYckeWPpwVTOevIUqssMMmzJ65W9AFVdrYi_m0uDkx17AUZF3t6zPAsn9VMpE3XcB41QG8RWSsW6q8G7sU7vSC827WtPdG5A9iP4qtBuViZ-jO_/s1600/brain.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="180" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj8klqhNEqWpORyxcDTxYFNzbdgtU9bSXYckeWPpwVTOevIUqssMMmzJ65W9AFVdrYi_m0uDkx17AUZF3t6zPAsn9VMpE3XcB41QG8RWSsW6q8G7sU7vSC827WtPdG5A9iP4qtBuViZ-jO_/s320/brain.jpg" width="320" /></a></div>
I spent the past two days at the Proposer's Day meeting for the DARPA Neural Engineering System Design (NESD) program. It was ... interesting. The program manager wants teams to create technology that can record from 1 million neurons, stimulate 100,000 neurons, and do full duplex (read and write simultaneously) from 1,000 neurons. And he wants it done in four years. And he wants this done in the context of addressing a real neuroprosthetics application such as prosthetic vision or audition. And he wants it done wirelessly. And don't forget to do your FDA IDE application, or to come up with a non-nonsensical financial model for bringing this to market. Oh, it can't be larger than 1cm^3, either. Never mind that the science of cortical stimulation for prosthetic sensory input is basically in its infancy. Or that no one can seem to work out to to keep neural electrodes viable in the brain for more than a couple of years reliably.<br />
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Phew.<br />
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On the plus side, DARPA is willing to throw up to $60M on the problem. So there's that.<br />
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My sense was that very few of the people in the room actually thought it was technically viable to do all these things in the allotted time (even though it'd still be a major accomplishment if only a subset of the desired outcomes are achieved). This sets up an interesting Catch 22: in order to be a successful proposer, you have to propose a project which you claim will meet the program's goals, even if you don't actually believe that your own goals are realistic. That only seems like a logical conundrum until you remind yourself that $60M is an insane amount of money.<br />
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To be fair, its _up to_ $60M, and that's divided out among all winning teams. And each winning team will likely have a large number of teammates in order to have a prayer of addressing all the program's requirements. So the money will have to divide down a lot. But, hey, you can divide $60M a lot of times and still have real money left.<br />
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DARPA is an interesting part of the funding ecosystem. Its pretty great that someone is willing to throw big money at over-the-horizon technology. Not all technology develop should necessarily be practical if we (the US? the world?) are to make real progress. And that's actually what bugged me most about this program. The emphasis on 'addressing a real problem', jumping through the various FDA hoops, and/or trying to figure out how any of this could be turned into an end product pretty much misses the point. This research is worth doing just because its worth doing. If there was a business case to be made for any of this stuff, some company would already be on it.<br />
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Final thought: there was a lecture on ethics this morning. The speaker brought up some interesting points: most notably about the need to deal head-on with the tin-foil-hat crowd. But the bigger point seemed lost: the time to have an ethical debate is before you start a sustained, decades-long, multi-agency research portfolio on brain interfaces. The best we can do now is to make sure we design systems that are therapeutic, safe, and secure. Discussing the bigger questions of "should we engage in this research" is largely moot at this point.<br />
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Anyways, the full DARAPA call for proposals (or Broad Agency Announcement - BAA in the DARPA parlance) can be found <a href="https://www.fbo.gov/index?s=opportunity&mode=form&id=d6357be260091fd05c950d159e3e9473&tab=core&_cview=0" target="_blank">here</a>.iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-63503337906629774212016-01-25T20:00:00.001-08:002016-01-25T20:08:41.913-08:00Remembering Marvin Minsky<div class="separator" style="clear: both; text-align: center;">
<a href="https://upload.wikimedia.org/wikipedia/commons/thumb/2/28/Marvin_Minsky_at_OLPCb.jpg/800px-Marvin_Minsky_at_OLPCb.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="200" src="https://upload.wikimedia.org/wikipedia/commons/thumb/2/28/Marvin_Minsky_at_OLPCb.jpg/800px-Marvin_Minsky_at_OLPCb.jpg" width="199" /></a></div>
MIT Professor Marvin Minsky has died. This is very sad news - Prof. Minsky was perhaps the single most seminal pioneer of Artificial Intelligence research. I was fortunate enough to take his graduate course "Society of Mind" in the spring of 1998. It was pretty mind blowing. I'm not sure how much I understood, but it was fairly self-evident that we were in the presence of genius. If I remember correctly, much of what we discussed in the class was a series of logic exercises designed to help us reverse-engineer the brain. I loved the idea of studying the brain by conceptualizing it as a complex interconnection of simple components - using engineering to forward neuroscience?! Like I said: mind blowing. A unique, quirky, and brilliant individual.<br />
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The Washington Post obit:<br />
<a href="https://www.washingtonpost.com/news/speaking-of-science/wp/2016/01/25/marvin-minsky-1927-2016/">https://www.washingtonpost.com/news/speaking-of-science/wp/2016/01/25/marvin-minsky-1927-2016/</a><br />
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The New York Times obit:<br />
<a href="http://www.nytimes.com/2016/01/26/business/marvin-minsky-pioneer-in-artificial-intelligence-dies-at-88.html">http://www.nytimes.com/2016/01/26/business/marvin-minsky-pioneer-in-artificial-intelligence-dies-at-88.html</a><br />
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His textbook was pretty excellent, too. I recommend it highly!<br />
<a href="http://www.amazon.com/Society-Mind-Marvin-Minsky/dp/0671657135/ref=sr_1_1?ie=UTF8&qid=1453780785&sr=8-1&keywords=society+of+mind">http://www.amazon.com/Society-Mind-Marvin-Minsky/dp/0671657135/ref=sr_1_1?ie=UTF8&qid=1453780785&sr=8-1&keywords=society+of+mind</a>iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-11736928639118495292016-01-25T10:26:00.000-08:002016-01-25T10:26:09.775-08:00Compressive SensingSo I've kinda hand my mind blown over the past couple days by the discovery of a signal processing technique called <i>compressive sensing</i>. Compressive sensing allows you to skirt the Nyquist sampling theorem in certain cases, which means effectively sampling a signal at rates lower than twice the maximum signal frequency. Wh<i>aaaaaa</i>t?<br />
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The idea seems to be based on a couple important assumptions and certainly isn't applicable to most signal sampling cases. The most important assumption is that the signal being sampled must be sufficiently sparse, meaning that most of the samples are zero.<br />
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I may update this post in the coming days with more details, but right now, the best resource I've found so far to explain things is here: <a href="http://www.codeproject.com/Articles/852910/Compressed-Sensing-Intro-Tutorial-w-Matlab">http://www.codeproject.com/Articles/852910/Compressed-Sensing-Intro-Tutorial-w-Matlab</a>. Other decent resources appear to be <a href="https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwicr-neysXKAhXFFz4KHebqDkcQFggfMAA&url=http%3A%2F%2Fdsp.rice.edu%2Ffiles%2Fcs%2FCSintro.pdf&usg=AFQjCNE-MigteZ9z3y-GWgVIyh4i2DSM6Q" target="_blank">here</a>, <a href="https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwj_z8PrysXKAhUIcD4KHWB4D0YQFggfMAA&url=http%3A%2F%2Fstatweb.stanford.edu%2F~candes%2Fpapers%2FCompressiveSampling.pdf&usg=AFQjCNGfAR6K6ZodeLb7a2Bso5Ek2NnIKg" target="_blank">here</a>, and <a href="https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwif6tr-ysXKAhVE2D4KHWXPC0AQFggdMAA&url=http%3A%2F%2Fdsp.rice.edu%2Ffiles%2Fcs%2FbaraniukCSlecture07.pdf&usg=AFQjCNG7kbUr_h1JsvOiJQCY3sDhT-AXjA" target="_blank">here</a>.iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-84004612700683909432016-01-19T14:09:00.000-08:002016-01-19T14:09:04.590-08:00More NFL Concussion Drama<div class="separator" style="clear: both; text-align: center;">
<a href="https://upload.wikimedia.org/wikipedia/commons/b/b8/Antwaan_Randle_El_2006.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="211" src="https://upload.wikimedia.org/wikipedia/commons/b/b8/Antwaan_Randle_El_2006.jpg" width="320" /></a></div>
Here comes Antawaan Randal El saying he regrets ever having played football. Ouch.<br />
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<a href="https://www.washingtonpost.com/news/dc-sports-bog/wp/2016/01/19/former-nfl-receiver-antwaan-randle-el-regrets-ever-playing-football/?tid=pm_pop_b">https://www.washingtonpost.com/news/dc-sports-bog/wp/2016/01/19/former-nfl-receiver-antwaan-randle-el-regrets-ever-playing-football/?tid=pm_pop_b</a></div>
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iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-56150825275602620482015-12-02T09:30:00.001-08:002017-06-29T12:49:59.029-07:00High Performance Computing Cluster<div class="separator" style="clear: both; text-align: center;">
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This past summer and fall, my research partners built our own personal high performance computing cluster. Temple has its own cluster (<a href="https://computerservices.temple.edu/high-performance-computing-hpc" target="_blank">Owls Nest</a>) but it's always in heavy use by others around the university and so we're always scrapping for resources. So we built our own cluster. First we built a testbed cluster by lashing together a handful of surplus PCs and then we used that to spec out a formal HPC cluster that we paid about $27k for out of a grant.<br />
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The cluster is pretty awesome. Our student, Devin Trejo, put together a very comprehensive blog post on how the cluster was designed and built. You can read all about it here:<br />
<a href="http://www.tdevin.com/2015-11-30-hpc-batch-processing/" target="_blank">http://www.tdevin.com/2015-11-30-hpc-batch-processing/</a>iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com1tag:blogger.com,1999:blog-3331563262701117271.post-40911011715779611692015-10-30T06:44:00.001-07:002015-10-30T06:44:45.089-07:00New Publications!Its been a pretty great week for the Neural Instrumentation Lab in terms of publications. My former graduate student, Alessandro Napoli, and I have recently published two papers together about multielectrode array dynamics with rat and human neurons. We're pretty proud of these, if we do say so ourselves...<br />
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<strong><u>Article 1</u></strong><br />
Investigating brain functional evolution and plasticity using micro electrode array technology<br />
Brain Research Bulletin<br />
<a href="http://www.sciencedirect.com/science/article/pii/S0361923015300423">http://www.sciencedirect.com/science/article/pii/S0361923015300423</a><br />
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<strong><u>Article 2</u></strong><br />
Comparative Analysis of Human and Rodent Brain Primary Neuronal Culture Spontaneous Activity Using Micro-Electrode Array Technology<br />
Journal of Cellular Biochemistry<br />
<a href="http://onlinelibrary.wiley.com/doi/10.1002/jcb.25312/abstract">http://onlinelibrary.wiley.com/doi/10.1002/jcb.25312/abstract</a>iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-22139640975509974572015-10-29T07:36:00.001-07:002015-10-29T07:36:23.974-07:00Football Stadium<div class="separator" style="clear: both; text-align: center;">
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Depending where you live, you might be aware that Temple's football team is having a pretty good year, and the powers that be are capitalizing on the momentum to put together a deal to build a stadium on campus. Currently, Temple's football games are played at Lincoln Financial Field, which is where the Eagles play, on the other side of Philadelphia.<br />
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I don't really see the wisdom in building a stadium on campus. For starters, there's no great place to put it. More pressingly, there's zero (literally) space for parking. And finally, there's no great way for 35,000 fans to get to Temple's campus all at once. It's a logistical mystery.<br />
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More importantly are the financial question marks. The administrators claim that tuition dollars won't be used to fund any of the operation, but its hard to see how any future losses would otherwise be absorbed.<br />
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Happily, someone did the research into how these things usually turn out. This article is fantastic. I think everyone at Temple should read it:<br />
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http://www.philly.com/philly/sports/colleges/temple/20151029_Questioning_Temple_s_proposed_football_stadium.htmliyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-11470036317162831342015-09-15T09:37:00.001-07:002015-09-15T09:37:49.077-07:00Announcement: New DoD Grant!<div class="separator" style="clear: both; text-align: center;">
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I'm thrilled to announce a new DoD grant in collaboration with my partner Dr. Carole Tucker. Our grant is titled "Automated Assessment of Postural Stability" and its goal is to study computer automated methods for measuring balance deficits in military personnel as a proxy for concussion. The award is for three years.<br />
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<br />iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-83085743069557664162015-08-31T12:07:00.001-07:002015-08-31T12:07:12.655-07:00Concussion ... The Movie<div style="text-align: center;">
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I'm excited to see the trailer for the upcoming movie "Concussion" starring Will Smith about CTE in the NFL...iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-66789648042152085142015-07-10T20:14:00.001-07:002015-07-10T20:14:10.436-07:00NSF I-Corps<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
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<tr><td class="tr-caption" style="text-align: center;">Team "AutoEEG" - Me, Mentor Lou Bucelli, and <br />Grad Student / Entrepreneurial Lead Meysam Golmohammadi</td></tr>
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This week I attended the NSF Innovation Corps (or I-Corps, for short) program. It was held in Chicago and attended by about 80 people. I-Corps is a program intended to teach researchers how to develop research creations for commercialization. NSF wants more of the science and engineering it funds to enter the marketplace, and so it is teaching academics how to be entrepreneurs. It follows the <a href="http://steveblank.com/" target="_blank">Steve Blank</a> method, which as far as I can tell is similar or related to the <a href="http://theleanstartup.com/" target="_blank">Lean Startup</a> approach.<br />
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The program instructors are all entrepreneurs. Each team includes three people: the Principal Investigator (the academic whose research lab birthed the technology), the Entrepreneurial Lead (typically a grad student or postdoc who will do the lions share of the business development), and a Mentor (an experienced entrepreneur who will guide the team). The program is seven weeks long. The kick-off week is held in person, followed by five weekly all-afternoon Webex meetings and lectures. Then we'll head back to Chicago on Week 7 for wrap-up meeting in person.<br />
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The main point of the program is to use the scientific method (data driven hypothesis testing) to discover who you customers are, what quantifiable value your product brings to them, and whether there is a viable pathway to deliver your technology to them. The trap academics fall into (we are told) is to have assumptions about what the customer wants. This leads many people to spend time solving a problem that customers might not care that much about, or that customers might not be able to use or integrate into their workflow, or pay for, etc. The only way to do this is to go out and talk to as many people as humanly possible to find out what their needs are, how they work, who makes financial decisions, etc etc. We are expected to interview at least 100 people at all levels of the customer pipeline over the next seven weeks. We've been given a pretty healthy budget to support us traveling around and meeting with people, but its still going to be hard (that's over 15 interviews per week!). The hypothesis-driven method makes a lot of sense. You make a hypothesis like "Neurologists at community hospitals are unhappy with how much time they spend reading EEGs". You can then test this hypothesis by speaking to neurologists, and depending on the outcome, set up another testable hypothesis. In this manner, you drill down until you understand which customer is feeling the worst pain that you can address (and that they can pay for).<br />
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The boot-camp was pretty brutal. For three days, all I had time to think about was how to advance our business concept. The set-up was similar to Shark Tank on TV. Our team would get up to discuss our technology and sometimes we'd get yelled at during our very first sentence. The honest was brutal, but also refreshing. The mantra was that we shouldn't be afraid to discover that our 'baby' is ugly :)<br />
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So I'm looking forward to the next seven weeks. We'll be busy, but hopefully we'll learn how to get a sustainable business launched...iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com1tag:blogger.com,1999:blog-3331563262701117271.post-5936847584054725552015-06-22T18:36:00.001-07:002015-06-22T18:36:44.966-07:00Plane of the EclipticThis post has nothing to do with engineering, interfaces, brains, or Nicaragua, but I thought it was cool nonetheless. I took these photos tonight (6/22/2015, Philadelphia) and Friday evening (6/19/2015, Managua). You can see that the angle of the plane of the ecliptic is very different in the two pictures. I tried to measure the angle in both pictures (very rough estimate) and they seem to be about (62.5-28.3) = 34.2 degrees apart. This number should be roughly the same as their differences in latitude, which google tells me is (40d [Philly] - 12d [Managua]) = 28 degrees. That's pretty close considering my non-scientific measurement approach. Pretty neat!!!<br />
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<br />iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-21218164705301973512015-06-13T06:18:00.001-07:002015-06-13T06:20:21.290-07:00Nicaragua - Day 27We finally reached the end of the program. Well, at least the first month, which is where my contribution ends. The last week was filled with a handful of interesting labs. One of them involved us picking through a big box of old medical equipment that someone had left in the school supply closet for us to look at. We took apart a blood pressure cuff, a nebulizer, and a few other odds and ends. The nebulizer was fun because it seem to follow the same basic pattern that all other suction and pressure devices follow. We tried to strip it down to its barest minimum, but were foiled by a lousy screw that stripped itself into smithereens and would not budge. In another lab, the students programmed a PIC to interface with a thermal probe to measure temperature and to set an alarm in case the ambient temperature was too low or too high. The students had to attempt to calibrate the system by mapping the arbitrary units from the analog to digital converter into degrees Celsius. The thermal sensor wasn't exactly the most accurate gizmo ever, so it was a challenging lab, but still enlightening. One highlight was the various methods students took to raise the temperature of their probe in order to calibrate it. One team put their probe in a ziplock bag and dipped it in the coffee pot only to discover that their ziplock bag was not exactly waterproof!<br />
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<tr><td class="tr-caption" style="text-align: center;">A thermal probe unit in a very leaky ziplock bag.</td></tr>
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Yesterday, Friday, I took three students back to Nandaime hospital where we attempted wh tie up some loose ends. First thing on the agenda was the fetal doppler unit which I screwed up a couple weeks ago. Thanks to some friends of ours who flew in Thursday night from the United States, I had brand new mini USB Type B connectors in hand, and we were able to desolder the old connector and put in the new one without too much fanfare. unfortunately, I think we must have damaged some of the traces on the board during our first attempt to fix it and we were unable to get it working. I tried to guess where the broken traces might be so that I could short them but no luck. Well, at least we gave it everything we had. We also started working on an electric heater. We added a power cord (which somebody had cut off) but that didn't seem to be the only problem. We didn't have time to get to the bottom of it, but I'm pretty sure the heating coil needed a massive scrub because it was completely rusted through. For comic relief, we were handed a floor lamp that looked pretty new but we were told it didn't work. In trying to diagnose the problem, I happened to pull on one wire and the whole lamp snapped into life. I guess we got lucky! As the director of the hospital wryly noted, well at least you fix the lamp today. A bit of a hollow victory, but a victory none the less.</div>
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<tr><td class="tr-caption" style="text-align: center;">My biggest "engineering" victory of the week was replacing a light switch at my old homestay. You take your victories where you can!</td></tr>
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The students are officially sufficiently trained to spend a month working in hospitals. They are a great bunch, and I expect they will all learn something and find some way of being of service to their various hospitals. I'm looking forward to keeping up with their exploits once I'm back home. And naturally, I take credit for all their successes and none of their failures :)</div>
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I'm off to the beach for a few days before heading back to Philadelphia. See you all soon.</div>
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iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-42498295484433045432015-06-09T07:13:00.006-07:002015-06-09T11:16:03.165-07:00Nicaragua - Day 23Our third week in Nicaragua went really well. For the most part, students seem to be progressing well and making the most of their weekly hospital visits. In lab, we've been combining technical with non-technical experiences. One of our technical labs involved using our variable power supply to recharge a battery. Although successful, it was a little frustrating since the battery voltage does not vary much between discharged and charged. one of the non technical as we did was disgusting the nature of poverty and what it means to be a developing nation. We challenged are students and to define poverty and to discuss whether the existing metrics for being a developed nation or biased and if so how. We had some really nice conversations about whether poverty is an absolute or a relative benchmark, and the extent to which personal liberty and freedom are indicators of wealth. If you have money but you aren't free to spend it how you wish, then what's the point?<br />
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On Thursday we went back to the hospital in Nandaime. the first thing we tried to do was fix the microscope from the previous week which we thought only needed a new fuse. We install the new fuse and plugged it in and there was smoke and sparks! So we took the microscope apart again and took out the circuit board and discovered that it had been burned completely through. Charred to a crisp!<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg-QtjYgsunrfNFgHh3b79JzxoUN9gG1JVXx4TBoE9QWXq1290eQB54oo0SyTMUr7vbqIP-ymzga41XqU77DiXx5BlS7b-CMpV8N7doQibg-KjbmduRATUrOTJoW0EYYF_y8ABLu3Q3mwVi/s1600/IMG_20150604_120848433.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg-QtjYgsunrfNFgHh3b79JzxoUN9gG1JVXx4TBoE9QWXq1290eQB54oo0SyTMUr7vbqIP-ymzga41XqU77DiXx5BlS7b-CMpV8N7doQibg-KjbmduRATUrOTJoW0EYYF_y8ABLu3Q3mwVi/s400/IMG_20150604_120848433.jpg" width="225" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">One seriously cooked microscope circuit board</td></tr>
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In retrospect, I don't think that burning event was from our fuse attempt. I think that burning was a more significant event that happened when the gecko met its fiery end (see last week's post if you have no idea what I'm talking about). so that was a bummer, not much we can do there. on the plus side, we were able to fix several centrifuges and to put both autoclaves that we started working on back in service.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiVA9_y2b3s6lBOKi1PxMjcNxi8MejEFw027Z-eik1Qku5ut5OSef3EKKubyJGpZihqlKUdp_ATN9-cY39bkTQJDl-mOS8E6D1mLpNZDqVND8-YdhSNqm7gt9ZLgyuLfzZZevtOztlr_BBz/s1600/IMG_20150604_114547287.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="225" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiVA9_y2b3s6lBOKi1PxMjcNxi8MejEFw027Z-eik1Qku5ut5OSef3EKKubyJGpZihqlKUdp_ATN9-cY39bkTQJDl-mOS8E6D1mLpNZDqVND8-YdhSNqm7gt9ZLgyuLfzZZevtOztlr_BBz/s400/IMG_20150604_114547287.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fixing centrifuges is challenging because they typically contain three very stiff springs that must be wrangled back into place</td></tr>
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We also cleaned and calibrated some more scales and even tried to fix a blender.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh0g8LrxDHeswkV1uoLiOOgbwuuuEpfJKvBeP1CEgqAT6XjhNa6e5TAYaY4R4HDUGpKdyidEyeuWPGecU5aNOdGS9u0ubAqAZi2pKnCGqrN79GOSa-g4XYuphgFpRis8LhoAw-Z6Pfgc2H0/s1600/IMG_20150604_153741252.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="225" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh0g8LrxDHeswkV1uoLiOOgbwuuuEpfJKvBeP1CEgqAT6XjhNa6e5TAYaY4R4HDUGpKdyidEyeuWPGecU5aNOdGS9u0ubAqAZi2pKnCGqrN79GOSa-g4XYuphgFpRis8LhoAw-Z6Pfgc2H0/s400/IMG_20150604_153741252.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">When you need parts, you must visit the local ferreteria, or hardware store.</td></tr>
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On Friday we visited a central repair facility in Managua. There are a handful of engineers there who attempt to repair all the broken medical equipment from across hospitals in Nicaragua. some equipment is brought to their facility and some is fixed on site at the hospital. They are massively under staffed but they do some amazing work. The engineers are not formally trained, but rather learn in an apprentice style manner. But this system seems to work incredibly well, and everyone we interacted with could run circles around me with their eyes closed. They had a very well stocked machine shop, where they can engineer just about any widget of any size they need. they are also very creative in terms of rewiring and redesigning electronics is necessary.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj6gCUW1YT1SiqvwGyRw3ildOnu1WOPUueg33TZmkftwSDFM1Vwj_u7Ag9y5BwYbwg-7Up_yoHX1S6DnejhHyfxTIhSkbuSOmFXgQUs_9goF9MZ4e77fEBLMRhJpaI60kpB5bZ0RGxSL5nT/s1600/IMG_20150605_135239559.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="225" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj6gCUW1YT1SiqvwGyRw3ildOnu1WOPUueg33TZmkftwSDFM1Vwj_u7Ag9y5BwYbwg-7Up_yoHX1S6DnejhHyfxTIhSkbuSOmFXgQUs_9goF9MZ4e77fEBLMRhJpaI60kpB5bZ0RGxSL5nT/s400/IMG_20150605_135239559.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">An old school mercury thermostat that we spotted in a heater at the facility in Managua.</td></tr>
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We showed them the picture of the fried microscope circuit board and they laughed and said that even if they had to redesign it from scratch with a reduced set of features, they would still get that microscope to turn on somehow. Super impressive. I'm not sure how much actual good we were able to do, although they gave us some work to keep us occupied. but we definitely learned a ton, and that's all that really matters.<br />
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So we have three lectures and three labs remaining, and then one more hospital visit on Friday. and that's it! The students will have officially finished their training and will move to hospitals across Nicaragua next week. I for one will be moving to a beach for 5 days where I intend to do very little engineering, and maybe try surfing again!iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-3057170594948558252015-06-03T08:56:00.001-07:002015-06-03T08:56:25.301-07:00Nicaragua - Day 17We are now officially past the halfway mark in our program, and the students are coming along really well. We are going through the trickiest of the labs, and the students are struggling and learning pretty effectively I think. Last Friday, I asked the students to take some time over the weekend to reflect on the first two weeks, and to think about what they still want or need to learn in the second half of the course before we unleash them into the wild. Judging from their weekend activities, I'm not sure how many of them took that message to heart, but at least I tried!<br />
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Our most recent labs included creating a variable DC power supply, and then using it to charge a rechargeable battery. The variable DC supply turned out to be fairly troublesome for many of the groups, since it involved a lot of soldering and a lot of components. The DC supply consisted of a full wave rectifier, a handful of capacitors, a voltage regulator, and a potentiometer. A lot of students tried to compact their components tightly, but that often made for wiring headaches, especially since we were using untinned perfboard. To help out one of the teams, I rewired their board, being careful to arrange the components exactly as they were on the wiring diagram. This significantly simplified soldering job, as most of the nodes that needed to be soldered together we're all laying in a neat row. It occurred to me that simplifying the layout of the circuit elements is roughly equivalent to practicing good coding style in that you are massively reducing the likelihood of a mistake and making the overall design much easier for other people to follow. We had a nice classroom discussion about importance of good engineering practices in order to stack the odds in one's own favor for success.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhQk1fLAMGB1aZgGHQVkl7RfQDU_L8sqswxt-HRbzX0JO75B2riHDJKeFfpFqym_9QlCg_Mfy7oRb7aDrv6m-A1H6lEVMMhuE5j_XlEaaZ9eyDzvqrewdVo-U4dm35wwrvtmFv1Da0vUc6z/s1600/IMG_20150602_150557763.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="225" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhQk1fLAMGB1aZgGHQVkl7RfQDU_L8sqswxt-HRbzX0JO75B2riHDJKeFfpFqym_9QlCg_Mfy7oRb7aDrv6m-A1H6lEVMMhuE5j_XlEaaZ9eyDzvqrewdVo-U4dm35wwrvtmFv1Da0vUc6z/s400/IMG_20150602_150557763.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Our variable power supply with circuit elements all laid out in a row, just like in the circuit diagram.</td></tr>
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKtENkxI8wG_O9NvhubI5JQnXeHh4AJe2rx3w79lHSm5skBG7PpJS_dWArS-gj62NKy9ji-oLXYontHSQ85dAp4dX6JzaQmoqZs0LVp4-cOzhNKSohB9PfYSiJw5IT72C-mh5sC-ZAuj9k/s1600/IMG_20150602_150527997.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="225" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKtENkxI8wG_O9NvhubI5JQnXeHh4AJe2rx3w79lHSm5skBG7PpJS_dWArS-gj62NKy9ji-oLXYontHSQ85dAp4dX6JzaQmoqZs0LVp4-cOzhNKSohB9PfYSiJw5IT72C-mh5sC-ZAuj9k/s400/IMG_20150602_150527997.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The resulting solder work is fairly easy to follow. You can see the ground bus going from left to right across the bottom.</td></tr>
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For yesterday's lab, we used the variable supply to charge a battery. This was an interesting challenge, as students had to select both the power supply voltage and the current limiting resistor value. They had to make sure that they pick a power supply voltage that we could actually generate, a resistor value that we actually had, keep the power below what the resistor could safely dissipate, and keep the total charging time between 10 and 100 hours. That last constraint is because we were attempting to create a trickle charge. Overall the lab went well, but it was a little anti climactic, since battery voltages don't vary all that much between being charged and discharged, so there wasn't a whole lot to observe over the hour or so that we let our batteries charge up.<br />
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I'm looking forward to tomorrow and Friday, as it's back to the hospitals! Tomorrow we will return to Nandaime, and Friday we will be visiting a new facility in Managua which is run by the National Ministry of Health. Its not a hospital per se but rather a large central facility where they collect equipment from around the country to be repaired. Stay tuned for updates.iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com0tag:blogger.com,1999:blog-3331563262701117271.post-85679278014456240532015-05-29T08:14:00.000-07:002015-05-29T08:14:08.722-07:00Nicaragua - Day 12Hello again from Nicaragua! The weather has been getting steadily hotter and so our daily trips to the pool feel less like an indulgence and more like a necessity. On days that I teach, I typically spend my morning at home with my family. We spend the time playing Uno, reading, and going to the playground. In the afternoons while I go to class, they usually go to the pool or have some other type of adventure. On hospital days, my schedule is pretty different as I'm typically out of the house by 7 a.m. It's hard to believe that we are already halfway through the program. Two weeks down and two to go.<br />
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This week in class, we did lectures on a variety of equipment such as ventilators, oxygen concentrators, electrocardiograms, and defibrillators. We also did some pretty nice labs which get the students accustomed to dealing with hands-on electrical circuits. We did one lab where students had to construct a flashlight from a battery, a switch, and an LED.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEilxZhp-ROJZorU9kDk-gb4arz1ryaPAKC2NIjJE_hak1x70iw75ojE5DgkL-66mEt1-pI0HPoeKcPW_QXbAwzEYpxQ9sCcXsMN9w_xgBJYW174sXXV4tmFJs0BnqoNqNChmSPfa5BHI_4K/s1600/IMG_20150526_161711661_HDR.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="180" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEilxZhp-ROJZorU9kDk-gb4arz1ryaPAKC2NIjJE_hak1x70iw75ojE5DgkL-66mEt1-pI0HPoeKcPW_QXbAwzEYpxQ9sCcXsMN9w_xgBJYW174sXXV4tmFJs0BnqoNqNChmSPfa5BHI_4K/s320/IMG_20150526_161711661_HDR.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">a basic flashlight!</td></tr>
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Not all of our students are electrical engineering majors, so this can actually be very helpful. We constructed a power supply using a transformer, a full wave rectifier, and a capacitor. We also got to blow a fuse with a battery, just to see what what happened. The students are asking lots of really good questions, and as always I'm probably learning more than they are in the process.<br />
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Yesterday I took 12 students back to the hospital in Nandaime. This is a small hospital in a village which doesn't have an engineering staff. This means that when things get broken or fall out of calibration, there is really no one to help them. Therefore, they had a huge inventory of things for us to look at. These ranged from the somewhat mundane, like a floor lamp, to tediously complicated, like an autoclave.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjn0nF71GmFTCv-sgNX10ejYLW7JRE5gT6Epj34lEexvBwalYJ2RFMTt8tKa3c0LeNOuCWw2D2Bu7jnXP4vVgjPPFS677oN9sBB2xIiFSclezg5mVswg5t6vf_aXmPHq0ZnUe3FC3yx_aso/s1600/IMG_20150528_133605821.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjn0nF71GmFTCv-sgNX10ejYLW7JRE5gT6Epj34lEexvBwalYJ2RFMTt8tKa3c0LeNOuCWw2D2Bu7jnXP4vVgjPPFS677oN9sBB2xIiFSclezg5mVswg5t6vf_aXmPHq0ZnUe3FC3yx_aso/s320/IMG_20150528_133605821.jpg" width="180" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">the control panel on the autoclave is simply a metal rod with some screws in it that open and close a series of switches when it is turned.</td></tr>
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We successfully recalibrated about eight standard scales, and also repainted them because they were pretty grungy. We fixed 3 or 4 blood pressure cuffs which weren't working for various reasons. A couple just had some minor tubing problems that weren't too hard to fix. We were given a nebulizer which basically worked OK, except it was chock full of dust, which was taxing the motor. We clean it thoroughly, and returned it to the floor. We re-tackled the two autoclaves that we started working on last week. We took them all apart and washed out all of the copper tubing with vinegar, hoping to dissolve any mineral deposits inside. Even though these things are frighteningly complicated, we succeeded in putting them back together properly, which was a victory in and of itself! One of them appears to have been completely fixed! We still need to do a little testing, but it successfully pumped water into the chamber, heated it up, and then pumped it out afterwards. The biggest problem seems to have been that someone mis-wired the power supply switch. The other autoclave still doesn't work quite right, but it gets much further in its cycle than it used to, so I guess that its own little victory for now. Hopefully we will get another crack at both of those next week.<br />
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In one of the more bizarre things that I have ever seen, one of our students was taking apart a microscope that wouldn't turn on. She discovered that a lizard had crawled into the microscope and shorted out the power supply. The fuse had successfully blown to protect the electronics, but the lizard didn't fare so well and was found petrified on the circuit board!<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjNYtYRhd3FijeH0Mf87Ov2ChTdPxUbwcCfvwQRJdOgAmNaLBRAjDE0F7KhSkvB-k5ImISKzeb-y3-7NeLWqUQJmCDAmluSTnHh2To0llk1PvubpdxjnFD09sg7aKQE5Fwm5N15RbIQonwC/s1600/IMG_20150528_163049537.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjNYtYRhd3FijeH0Mf87Ov2ChTdPxUbwcCfvwQRJdOgAmNaLBRAjDE0F7KhSkvB-k5ImISKzeb-y3-7NeLWqUQJmCDAmluSTnHh2To0llk1PvubpdxjnFD09sg7aKQE5Fwm5N15RbIQonwC/s320/IMG_20150528_163049537.jpg" width="180" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">a petrified lizard!</td></tr>
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As if that wasn't enough, we found a clutch of lizard eggs in the microscope, and then we accidentally discovered that one of those eggs still contained a live baby.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjz8_2YGoL01qDOmX87JoFvuZWmB25QjJZeDCSnt0cfaZNtJFDWImJcFs2huiy8ecpkzWrrTn2nZGbzNMN2D6yJXn1IzUWu-dJCMcECiCOvcgdx_TrVFSIU3RIirFdRq2aUnNHL2cv_xbGJ/s1600/IMG_20150528_164713930.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="180" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjz8_2YGoL01qDOmX87JoFvuZWmB25QjJZeDCSnt0cfaZNtJFDWImJcFs2huiy8ecpkzWrrTn2nZGbzNMN2D6yJXn1IzUWu-dJCMcECiCOvcgdx_TrVFSIU3RIirFdRq2aUnNHL2cv_xbGJ/s320/IMG_20150528_164713930.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">a clutch of lizard eggs found deep inside the microscope</td></tr>
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Unfortunately, we accidentally cracked that egg open, so the baby was born right in front of us, albeit somewhat prematurely. If you aren't squeamish, be sure to check out the video. Anyways, that was a first for me. Good luck seeing that in the university classroom!<br />
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In a more humbling moment, we were handed a handheld ultrasonic fetal heartbeat monitor. The doctor told us that it worked but gave noisy measurements and that the measured heart rates were definitely off. She told us to be careful since it was their only working one. The problem seemed pretty clear in that the connector between the ultrasonic wand and the base unit were hopelessly frayed and degraded.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi_seYGK1TrnPZcPNLJPCzv1gCz4CQfyZ6negjnwwiMqxgrz6kO3HLZ3ZCOEUsIf0qYeiwauzSBffV_IJG-Bi3UzZJYHhej12N2F46ZD-FAWSElfbmo_Dfb_MuCbme-TjjRPlNa_EX-fr1r/s1600/IMG_20150528_115327411.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi_seYGK1TrnPZcPNLJPCzv1gCz4CQfyZ6negjnwwiMqxgrz6kO3HLZ3ZCOEUsIf0qYeiwauzSBffV_IJG-Bi3UzZJYHhej12N2F46ZD-FAWSElfbmo_Dfb_MuCbme-TjjRPlNa_EX-fr1r/s320/IMG_20150528_115327411.jpg" width="180" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">the frayed ultrasound wand cable</td></tr>
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We tried to re-shield the cable from the ultrasonic wand using some tin foil. Then I decided that we needed to replace the connector where the wand plugged into the base circuit board. After much effort, we were able to desolder and remove the connector.<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj0T3pZsMMmVJBQB-dr4VSCNj3t2tROo6a_Owm5Slz4KyxyBoH5yhAS5QVNjyMcOLMmk-dC20sHAmG6MZEnHABk_ro4WGUIXdrTArNN88Ghyn20YsqzHqYIAetMlD-Pvs_m09fXd49Pe_ie/s1600/IMG_20150528_122102144.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj0T3pZsMMmVJBQB-dr4VSCNj3t2tROo6a_Owm5Slz4KyxyBoH5yhAS5QVNjyMcOLMmk-dC20sHAmG6MZEnHABk_ro4WGUIXdrTArNN88Ghyn20YsqzHqYIAetMlD-Pvs_m09fXd49Pe_ie/s320/IMG_20150528_122102144.jpg" width="180" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The USB style connector was in pretty bad shape. At least two pins were probably not consistently making contact.</td></tr>
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Unfortunately, after visiting about six or seven different shops, we were unable to buy a replacement connector. Finally I decided it was time to put the original connector back into the circuit board. However, no matter what I tried, the connector wouldn't go back in cleanly. After an incredibly aggravating couple of hours, it was time for us to leave, and I had to accept the fact that the connector wasn't going back into circuit board properly. We tried turning the device on, but it no longer recognized the wand. With my tail between my legs, we went to hand it back to the doctor. It's hard to tell whether she was really upset or not, but she thanked us for trying and sent us on our way. I feel pretty guilty that we ruined their sensor, and now I'm consumed with trying to get them new one, which will apparently involve a trip to Managua at some point. In hindsight, I should have taken a much more conservative approach with this instrument since it was their only working one. I think my hubris got the better of me, and I really only considered the best case scenario. I will try to communicate this lesson to my students today. I think it can be instructive when students see their instructor fail, and try to learn from that failure. Perhaps some good will come of this.<br />
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Anyways, despite that, it has been a fairly successful few days, and everyone seems to be learning and having fun. Hopefully next week we will get to visit a facility in Managua where they collect broken medical equipment from across the entire country. I am really looking forward to that!<br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh5L9_5-LMRhOw4lqGUixssn37wfhKwV2Pdy7qeXKnlKrAfEP2Rd1py1JtWWHVsmFdlL4z_UfStdPeTcTaukq99kP0ROkkD0VV1vo7lS77LiTRyT-VTCKXbZiLWcdK38jPhchpdSDNhyuy8/s1600/IMG_20150528_135349949.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="180" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh5L9_5-LMRhOw4lqGUixssn37wfhKwV2Pdy7qeXKnlKrAfEP2Rd1py1JtWWHVsmFdlL4z_UfStdPeTcTaukq99kP0ROkkD0VV1vo7lS77LiTRyT-VTCKXbZiLWcdK38jPhchpdSDNhyuy8/s320/IMG_20150528_135349949.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Our hard work was rewarded with a nice pile of coconuts which we had to learn to open ourselves with the hospital's machete!</td></tr>
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<br />iyadhttp://www.blogger.com/profile/04161354219540180195noreply@blogger.com1