Friday, May 25, 2018

Guatemala, Day 5

We'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.

Wiring together our extension cords

Wrangling the soldering iron
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.
Hospital main entrance

Waiting to be allowed on-site
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.

One of the bigger autoclaves
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.

Does anyone know how to change the air filter on a fume hood?
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.
The air compressors that weren't quite doing their job
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.
Surgical lights with burned out bulbs

An operating room

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.
Taco lunch: $3

Tuesday, May 22, 2018

Guatemala, Day 2

Minerva Temple
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.

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.

Nachos for dinner!

Fried banana goodness
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.

Below are a few photos I snapped of the town today. Enjoy!

I want to guess these are walnuts but I'm not sure.

The courtyard at our school

The coffee shop where I drink tasty espresso drinks

Monday, May 21, 2018

Guatemala, Day 1

Greetings 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.

Central Park

The view from the door of our school building.

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!

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.

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.

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.

Lunch! Soup, shredded beef, boiled veggies.

Dinner! Shredded beef empanadas. Delicious!

My new buddy, Bidoo.

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!

Monday, September 19, 2016

3D Printing

I'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 hackathon we're running this weekend (more details on that soon). We've been using headset designs from OpenBCI. 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:

The scaffolding is manually removed using a pressure washer to strip it all away:

The finished products are firm and very cleanly articulated:


I'll post some pictures of the headsets once they're completely put together. Overall though, its a really neat process!

Thursday, March 10, 2016

Brain Efficiency

I'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.

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.

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:

  • The average adult consumes about 2,000 calories per day
  • 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
  • Of those, about 20%, or 260 calories, are consumed by your brain
  • 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.

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.

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.

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.

Wednesday, February 3, 2016


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.


On the plus side, DARPA is willing to throw up to $60M on the problem. So there's that.

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.

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.

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.

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.

Anyways, the full DARAPA call for proposals (or Broad Agency Announcement - BAA in the DARPA parlance) can be found here.

Monday, January 25, 2016

Remembering Marvin Minsky

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.

The Washington Post obit:

The New York Times obit:

His textbook was pretty excellent, too. I recommend it highly!