Tuesday, May 26, 2015

Medical Research Ethics

This op-ed appeared in today's NY Times:


Pretty interesting. Academics like to see ourselves as being trustworthy, upstanding people. But I guess is that the reality is we're just human in that we're corruptible by money, power, and pressure, just like everyone else...

Saturday, May 23, 2015

Nicaragua - Day 6

The autoclave in the
 Granada hospital. Note
the two pieces of wood
holding up the autoclave door!
Well, my first work week has come to an end. On Wednesday, I did a lecture about batteries and power supplies, which was pretty straightforward. We also did a lab where students got to make some basic circuit measurements including on a transformer. The students always get a kick out of watching someone stick the multimeter probes directly into the wall outlet to verify whether we are getting the correct line voltage. This is especially relevant since some of the outlets in our class don't seem to work quite right, which means that the transformers won't work right either!

But I digress. By far the most fun we had was hospital visits on Thursday and Friday. On Thursday, we took half the class to the local Granada public hospital, which is the same hospital he worked at last year. The technicians and engineers were super excited to see me again, and it was a happy reunion. They gave us a tour of the hospital, and also gave us some equipment to take apart, clean, and in some cases repair. We took apart and repaired a handful of nebulizers that weren't working for a variety of reasons.
A nebulizer under repair. The
two-sided pressure chamber is
opened up (bottom right).
One of them seem to have just been clogged with some debris. Another one had a frayed wire that needed replacing. These experiences are helpful, because the students gain confidence opening and troubleshooting the various pieces of equipment while having someone around to supervise. We also got to take a look at the hospital's autoclave, which is an enormous piece of equipment that can sterilize maybe cubic yards worth of supplies at once. Although the control electronics and mechanics look complicated, method of operation is fairly simple. Water is boiled into steam and forced into the chamber at pressure. The temperature and pressure do the job. We also took a look at some electrosurgery devices, and even did a fair amount of menial work such as cleaning ceiling fans! All of it is good experience, especially the social aspects wherein our students learn how to interact with staff, how to work at their pace, and how to work at their direction. 
A team effort!
At some point after lunch, I got roped into helping the technicians carry an enormous water reservoir bucket up a long ladder to place on a scaffolding. This is fairly commonly used as a water backup tank around here. How five of us got that tank up the ladder is anyone's guess, but nobody fell off and I felt pretty good about it afterwards!

Yesterday, Friday, we took the other half of the class to a hospital in Nandaime which is a village about 35 minutes outside of Granada. The hospital was very small, and although the staff seemed fairly knowledgeable, they were certainly resource deficient.
They had no engineering staff of their own, which meant there was a lot of equipment sitting around that needed repairing. They happily handed us a couple of autoclaves, an ECG machine, an infant incubator, and some common scales. We did the best we could and had a good deal of fun in the process. The infant incubator was fairly easy to repair. In fact I'm not even really sure what we did to fix it! We took it apart, cleaned a few ports, put it back together, and the alarm that had been going off magically stopped! The students cleaned and polished it until it looks like new, and we gave it back to the doctor, who was extremely happy. Apparently it was their only one in the hospital, and they hadn't been able to use it for a couple of years.

Sizing up the incubator.
The ECG machine had some sort of quirky electronics problem which we were unable to diagnose or repair. That was a little unfortunate, but to be expected given our relatively meager tools. The students who tackled the scales had a real adventure! They managed to get a decent number of the scales built up and functioning moderately well, but calibrating them was a complete headache. The scales were not very precise, and our efforts to calibrate against our own (known) body weights didn't get us very far. Well, better than nothing I suppose. We learned that once the springs in scales are shot, they're pretty much shot for good.
Calibrating the scales was a real challenge!
The autoclaves turned out to be a real challenge. I spent a lot of time studying the piping and electrical lines in an attempt to sort out how the devices work. Unlike the system in Granada, these were smaller benchtop models. Water from a tank gets pumped into the main chamber where heating elements turn it to steam at high pressure. Once the instruments are sterilized, the steam is released, passed through a condenser, and returned as water to the tank. One of the devices also had a vacuum pump which somehow accelerated drying and/or cooling  in the main chamber. The high pressure piping is a bit intimidating to mess with, and clogs with water scaling are apparently common. Judging from the condition of the autoclaves, both of them need a thorough scrubbing, especially with wire brushes inside the pipes, since there were mineral deposits everywhere. Unfortunately, we didn't have the right tools (and we ran out of time) so we'll have to try again next week when we go back.
The insides of an autoclave. The water tank (grey, left) pipes water into the tank (silver, right). The tubing is all high pressure, meaning we'd better put it back together properly, or else!
The people at the hospital were very good sports and seemed content to have us take apart their equipment and make a mess of the spare room they set us up in. The hospital director was very involved and wanted to know which equipment was fixed and what couldn't be salvaged. A few doctors poked their heads in too to watch the progress and ask questions. We're very fortunate to have our coordinator Inka who speaks very good Spanish, as well as a student who is a native speaker. So language wasn't a huge barrier. One gentleman from the lab hunted me down, telling me he had an electrical problem with his two microscopes. Turns out they just needed light bulbs, which of course we didn't have. I'm going to try to hunt them down in Granada this week and hopefully get him going next Friday. It was an interesting example of the problems EWH tries to solve. The microscopes were beautiful high quality ones, donated from abroad. But once their bulbs burned out, they were basically useless to this guy. Anyways, the hospital director had the lunch ladies treat us to a big meal of chicken and rice which was delicious and filling. I'm looking forwards to being back next week!
A well-earned lunch!

Well it's the weekend now, which means exploring around Granada, and maybe going zip lining tomorrow. Tomorrow is also a very big religious holiday here, the feast day of Mary Help of Christians. There have been a lot of parades and loud music, and fireworks that don't make any light but make these very loud explosion popping sounds. It's kind of nice, except that the firework explosions go on literally through the night.

I'm looking forward to next week's work schedule. We start talking more about specific pieces of hospital equipment, and the labs get more interesting too. I think considering the success we had in the hospital this week, students will be pretty engaged with the lectures as they start to see the physical principles underlying the various pieces of equipment that they saw at the hospitals.

Wednesday, May 20, 2015

Nicaragua - Day 3

I'm back in Nicaragua this summer! As I did last year, I'm working as the instructor for the Engineering World Health Summer Institute. The program brings about 25 students from the US, Canada, and other locations and trains them can Spanish and medical instrumentation for one month. At the end of that month, they move to local regional hospitals in various towns and villages around the country, and spend a month preparing whatever medical equipment they can and otherwise trying to be useful in the hospital. As we discovered last year, the students' primary asset might be their ability to speak English, since things like instruction manuals and on-screen instructions might be in English. Many hospitals around here already have a good engineering staff that handle many of these issues, but there are also a lot of smaller regional hospitals that could really use the help.

The toaster oven plug! The plastic at the base of the right-most
 prong is pretty melted. The plug was super hot whenever I
went to unplug it!
My job is a bit of a challenge, because I have to get students to actually be useful in a hospital. Theoretical knowledge will only get you so far. At the end of the day, it's your ability to roll up your sleeves, think creatively, and troubleshoot that will lead to success. Four days a week, my students get a lecture, followed by a hands-on lab. The lectures are designed to expose students to the fundamentals of operation of a variety of types of medical equipment which they are likely to encounter in the developing world. This means that we spend a lot of time on relatively humble pieces of equipment like oxygen concentrators and suction pumps, and zero time on things like MRI's and CT scans. So far, I'm two lectures in. The first lecture was about the basics of circuit theory and signal processing. The second lecture covered electrical safety and ground loops. Today's lecture will cover power supplies and batteries. Yesterday, I told a fun anecdote about how at my home stay in Nicaragua last year, I discovered that the plug for the toaster oven in the kitchen had a short circuit that was making the plug get so hot that the plastic was melting! This happened because people kept on unplugging the toaster oven by yanking on the cord, and not by pulling from the actual plug, which is what you're supposed to do. All that yanking on the cable eventually led to the wires coming loose inside the plug and starting to short. I'm guessing eventually it would have started a fire! Luckily it was an easy fix.

I'm pretty excited because tomorrow is the first of our weekly hospital trips. We take our students to a hospital every week where they get some hands-on experience taking apart, cleaning, repairing, and putting back together various pieces of hospital equipment with me there to supervise and help. Last year, the experience was really valuable for me as well as the students. The hospital I'll be going to tomorrow is actually more of a centralized facility in Managua where they collect broken equipment from across the country, repair whatever they can, and then return it to service. I'm looking forward to seeing how all that works.

Monday, September 15, 2014

Neuroinformatics 2014

Last month I attended the 2014 Neuroinformatics conference in Leiden, Netherlands. This was a new meeting for me - I'm new to the community - and it was a real eye opener. It was very helpful to be in the presence of a community who've spent so much time and energy thinking about how to manage and analyze enormous sets of biomedical data. Happily, some kind soul video taped basically the whole thing. The videos are available here:

A great set of conference photos is up on Flikr too.

Note: Albert Einstein once lectured in that very same room - and the University of Leiden has been around since 1575 I believe. Pretty amazing.

Dirichlet Process Clustering

We've been looking at Dirichlet Process Clustering recently as a great data-driven approach for learning patterns in data. This discussion is about as lucid of a discussion on the topic as I've seen.

(Note, following this link might require that you become a registered user at quora.com - which is an awesome site that you should follow anyways...)

Wednesday, July 16, 2014

Wednesday, June 25, 2014

Nicaragua - Engineering World Health Summer Institute

I recently spent a month in Nicaragua as an instructor for the Engineering World Health (EWH) Summer Institute (SI). EWH is an amazing not-for-profit whose goal is to help hospitals in the developing world have access to expertise for maintaining and repairing their equipment. EWH's research has shown that while a respectable amount of equipment is donated to hospitals in the developing world, there is practically zero support for installing, maintaining, or repairing it. As such equipment donations often fail to make the desired impact because:
  • no one knows how to install it
  • no one knows how to use it
  • the donation comes without an instruction manual
  • the instructions aren't in the local language
  • the device was donated from a 50Hz country and cannot work without modification in a 60Hz country
  • the device uses consumables (pads, hoses, etc) which aren't provided and that are hard or impossible to procure locally
  • there is no local expertise for what to do when the equipment fails
EWH seeks to fill this void in a number of ways. The Summer Institute is a program where US students travel to a developing nation for two months. During Month 1, they learn the local language and receive training on medical device operation, troubleshooting, and repair. During Month 2, the students transition to regional hospitals where they work to support the hospital's medical equipment needs in any way they can. They also perform a detailed inventory of equipment to assist EWH in forecasting how to improve their support.

This summer, EWH is operating SI's in Nicaragua, Tanzania, and Rwanda. I was the instructor for the Nicaragua program during Month 1. Now that it's Month 2, I have returned home and the students are hard at work in their respective hospitals.

Our classroom! Always hot and often noisy. A big departure from the relatively
cozy confines of Temple's College of Engineering.
This was a wonderful teaching assignment for me because it was tough and therefore I was forced to learn a lot. I have a lot of general and theoretical expertise in medical instrumentation, but I haven't personally disassembled any ventilators or defibrillators so I was fairly worried about my ability to instruct others to do so. Fortunately, I had a lot of good support, including a former instructor with a zillion years of expertise who patiently answered all my late-night email questions. I did a total of sixteen lectures, (four per week for four weeks) and we covered the following subjects:
  • Lecture 1: Basic Circuit Theory
  • Lecture 2: Electrical Safety and Transformers
  • Lecture 3: Power Supplies and Batteries
  • Lecture 4: Ventilators and Oxygen Concentrators
  • Lecture 5: Pumps, Pulse Oximetry, and Blood Pressure
  • Lecture 6: ECG
  • Lecture 7: Defibrillators
  • Lecture 8: Fetal Heart Monitoring
  • Lecture 9: Infant Incubators and Warmers
  • Lecture 10: Lighting
  • Lecture 11: Apnea Monitor and Signal Detection Theory
  • Lecture 12: Electrosurgery
  • Lecture 13: Suction and Medical Gasses
  • Lecture 14: Anesthesia
  • Lecture 15: Autoclaves
  • Lecture 16: Motors

Did I mention it was hot?

There was also a series of (very!) hands-on labs where students had to solder, wire, debug, measure, and calculate any number of circuits relevant to medical electronics. The labs started out fairly straightforward (make an extension cord) but quickly got complicated (build a power supply and use it to charge a battery). The labs were a ton of fun and a good opportunity to show the students some hands on skills.

Practicing hands-on skills during lab.

Perhaps the best part of the experience was our weekly visits to the hospital, whose full name is "Hospital Amistad JapĆ³n - Nicaragua". As the name suggests, the hospital was built through a collaboration with the Japanese government. We were told that the Japanese have done a lot of philanthropic work in Nicaragua including overhauling the drinking water supply. Good for them. But I digress. The point of the hospital visits was to give the students hands on experience taking apart, reassembling, and troubleshooting medical equipment. The engineering staff there was excellent and incredibly knowledgeable. They already know full well how every piece of equipment in the hospital works and how to repair it. We were there to learn from them, not vice versa. They were very generous with their time and expertise and soon had us doing all sorts of tasks ranging from menial to sophisticated and 100% educational.

The hospital in Granada.

Because medical equipment is expensive and hard to come by (apparently all purchases must be approved by the national health ministry...) the engineering staff takes extraordinary precautions to keep their equipment operational. Every day they take perfectly functional equipment off the floor so that it can be cleaned and serviced. Preventative maintenance is in their DNA. This ethos extended beyond autoclaves and centrifuges - they also care for their ceiling fans, air conditioning units, and refrigerators with the same devotion. 

Even the motor from a lowly floor fan can teach you a lot!

Our students took apart and cleaned a lot of air conditioners and fans. But they also got to service baby incubators, centrifuges, autoclaves, ventilators, suction pumps, and nebulizers amongst others. In each case, we'd strip the device down as far as possible and then figure out how it worked as we cleaned it and put it back together. I thought the suction pumps were especially neat since their method of operation is elegantly simple. I also learned that a nebulizer is basically as suction pump running in reverse. Sometimes the lessons came from unexpected places. By taking a fan apart, I learned what permanent split capacitor motor is, and by taking apart a motor from a cafeteria meat grinder, I learned what a centrifugal switch is and why the motor needs it (the switch disengages a startup coil once the motor spins up to speed).

Taking apart an infant incubator to see how it works. The black
element radiates heat. The white disc object on the left is a fan
that moves the warm air into the infant chamber.
Taking apart a particularly dirty suction machine. The black stuff
inside the suction chamber is dried blood! At the bottom,
you can see the rubber diaphragm attached to the motor piston.
Its pumping motion is what creates a vacuum in the suction chamber.

Watching the engineering staff fix an x-ray film developing unit! With a
little cleaning and some oil, they got this thing up and running. I took
a photography class in high school and amazingly still remembered a bit
about the film developing process, so I was able to explain it to our students
who must have thought I grew up in the stone age.

One team tried putting a broken industrial dryer back into service. One of our savvy students found an english language warning sticker on the back of the dryer indicating that the gas would automatically be cut off if the exhaust duct was clogged. Of course their engineering staff couldn't read this warning and so had not thought to check the duct. Our students took it apart and sure enough it was very much clogged! They were able to clear a lot of the clog out - the dryer still isn't working but I'm pretty sure its a lot closer to functional than it was a month ago.

Mid-morning mango break!

We had one especially fulfilling experience where we were able to repair an infant incubator which had been on the fritz for over a year. The engineering staff had already repaired it but had somehow missed one connection (which to their credit was very hard to spot). I showed the students how to draw a circuit diagram by studying the circuit board, and together we determined that one of the connections on the circuit diagram had been overlooked during the original repair. A single soldered wire allowed us to turn the machine on! Then we noticed that the fuse kept blowing. Que tal? Our on-the-ground-coordinator (and lab instructor, and former EWH-SI student) remembered that its not uncommon for people to put the wrong fuse in a device. Sure enough, the incubator needed a 5 amp fuse but someone had put a 1 amp in instead. We swapped up to a properly rated fuse and lo and behold, the thing was functional. As far as I know that machine is back on the floor now, warming babies. That was a highlight of the trip, for sure.

Fixing the faulty circuit board in the infant incubator. As you
can see, the staff had already made a repair (after the board
overheated and partially burned!). We were fortunate enough
to spot a single unconnected trace and correct it.
Analyzing the circuit board.

My only regret is that I'm not around for Month 2 to visit students and keep learning about all these superbly interesting medical devices! And I'm also a bit jealous that they get to keep practicing Spanish - I'm worried I'm going to forget a lot of what I learned :-/

One final thought ... for the first time in a long time, I got to be a student again. We had Spanish lessons four days a week for four hours. I forgot that its sometimes hard work to be a student. Its hard work to sit and listen to someone speak at you. The classes were a lot easier to digest and a lot more fun when the learning was interactive. I noticed that after about two weeks of Spanish, I would have rather stopped learning new Spanish and instead focussed on becoming proficient at what I'd already learned. I suspect there's a lesson for me there in terms of how I approach teaching engineering. I try to be an upbeat and entertaining lecturer, but there's really no substitute for getting students to practice and become proficient, even if it means potentially teaching less material.

My Spanish notebook!

So that was that. A fulfilling and exciting chapter of my professional life. I hope EWH will have me back to teach again one day. Africa? Middle East? Sign me up!