A tale of camels, the sun and vaccine refrigeration

Yes, you read it right! There is in fact a thread of logic – very sound logic, if I may add – that connects camels, the sun (or solar panels to be precise), and vaccine refrigeration. Professor Winston (Wolé) Soboyejo, a professor of engineering at Princeton University, and a native of Nigeria, has devised a simple, yet elegant way to refrigerate vaccines as they are transported on camel back to remote places with no road access. In a must-see video, Professor Soboyejo describes the challenge. In these remote places, the only way for children to be vaccinated is for the vaccines to be brought in from the cities first by land rovers and then by camel trains. The roughly week-long journey in the places he studied (Kenya, Ethiopia) is not only arduous, but also wasteful. In current practice, the vaccines are kept refrigerated by ice packs. Once the vaccine container is opened, all the vaccine that is not used up before the ice melts, is wasted. Professor Soboyejo and collaborators thus came up with a simple (apparently!) plan – if Mohammed cannot go to the mountain, then bring the mountain to Mohammed! In other words, they decided that a self-sustained and economical powerpack will travel with the vaccines – on camelback. Deserts have ample sunlight. So, they decided to use solar panels to charge batteries, which would in turn keep the refrigerators cold at all times. They optimized their design on real camels – of all places – in the Bronx Zoo! In the development process, they had to overcome some unanticipated challenges, e.g., the variation in the hump sizes of camels! With exquisite forethought, the solar cells were designed to be lightweight and built with locally available material. For example, the frames are made of bamboo. The vision is that this technology will not only deliver vaccines safely to children in remote desert lands, but also spawn local industry which will manufacture the solar cells. Bravo!

More on disease diagnosis with a mobile phone

This is a quick follow up on an earlier post entitled "Did you say disease diagnosis with a mobile phone?" Newsweek recently did a story on this discovery entitled Dial "D" for Diagnosis. The story, for one, throws a human light on the discovery, by telling us that this potentially socially transforming technology came about from a challenge thrown to a class of Biomedical Engineering graduate students at University of California, Berkeley, by Professor Daniel Fletcher. He apparently asked the students to respond to an imaginary scenario where were hiking in a remote village where an unknown infectious disease was spreading, what could you build with only a camera cell phone and a backpack of lenses that might help identify the disease? This is a quick follow up on an earlier post entitled "Did you say disease diagnosis with a mobile phone?" Newsweek recently did a story on this discovery entitled Dial "D" for Diagnosis. The story, for one, throws a human light on the discovery, by telling us that this potentially socially transforming technology came about from a challenge thrown to a class of Biomedical Engineering graduate students at University of California, Berkeley, by Professor Daniel Fletcher. He apparently asked the students to respond to an imaginary scenario where they were hiking in a remote village where an unknown infectious disease was spreading, and they had to build a device that might help identify the disease, with only a camera cell phone and a backpack of lenses. The product: the Cellscope (please bear with the intro ad). Here is another link to a Youtube video.

Breslauer, D., Maamari, R., Switz, N., Lam, W., & Fletcher, D. (2009). Mobile Phone Based Clinical Microscopy for Global Health Applications PLoS ONE, 4 (7) DOI: 10.1371/journal.pone.0006320

Telemedicine with a twist: cutting costs for state-of-the-art medical imaging

It is not an exaggeration to day that medical imaging has revolutionized western medicine in the past two decades or so, with the frontiers being constantly pushed to allow better, earlier and faster diagnosis for a variety of diseases. The story is quite different, however, in the developing world where, according to recent WHO estimates, over 50% of medical equipment that is available is not being used because it is too sophisticated or in disrepair or because the health personnel are not trained to use it. WHO further estimates that some three quarters of the world population does not have access to medical imaging.

One problem that may be at least partially responsible for this discrepancy is that typical medical imaging equipment is large, non-portable, expensive, require multiple components to work in concert (viz., data acquisition, data analysis, image rendering and visual display), and require highly trained personnel to operate them optimally.

A collaborative group of researchers based at the University of California at Berkeley and at the Hebrew University in Jerusalem have come up with an ingenious solution to this intractable problem. These authors propose that one reason why medical imaging equipment are typically so expensive and complicated to use is that they are designed to be self contained units that combine all aspects of imaging, namely: (a) the data acquisition hardware which is in contact with the patient, (b) the imaging processing hardware and software, and (b) the image display unit. This causes substantial duplication in expensive components and places increased demands on operator training.

To make medical imaging feasible in regions of the world with minimal infrastructure, the authors propose to decentralize the different aspects of medical imaging, and generate a new medical imaging system made of two independent components connected through cellular phone technology which, as pointed out earlier in other posts, is quite ubiquitously available even in the remotest parts of the globe. The independent units of this proposed decentralized imaging system are: (a) a data acquisition device (DAD) at a remote patient site that is simple, with limited controls and no image display capability, and (b) an advanced image reconstruction and hardware control multiserver unit at a central site. The vision is that cellular phone technology will transmit unprocessed raw data from the patient site DAD. These will then be processed at a central location, which can have cutting edge image processing and rendering equipment and algorithms. Furthermore, being located at one or a few central site(s), they can be easily upgraded and kept current with the world standards. The final rendered images will then be sent back to the patient site via cell phone, where they can be displayed and reviewed. Of course, this format will also be accessible to real time expert consultation via “conventional” telemedicine.

In this initial report, the authors have confirmed the feasibility of this concept both for diagnostic as well as interventional imaging, by using a laboratory model of human breast cancer.

The next step in the journey, of course, will be to work out the logistics of getting such a system to work in the field. However, it is a great beginning, and this commentator surely hopes that this approach can be translated to real world public health scenarios in the near future.

Mere paper and scotch tape to diagnose disease in the field

It is eminently clear that for diagnostics to work effectively in the developing world, they have to be cheap, rugged, lightweight, portable, and work without needing additional infrastructure. Well, what could be simpler and cheaper than paper and scotch tape?

The laboratory of Professor George Whitesides at Harvard University has generated a prototype “lab-on-a-chip” microfluidic device, made out of water-absorbent paper and water-repellent double sided scotch tape. Microfluidic devices, simply put, are devices composed of channels that conduct fluid from a given point of application to one or more location(s) where some event (e.g., a chemical reaction or an enzymatic action) takes place. These devices are often made from glass or other polymers, and frequently use external pumps to conduct the fluid through the channels.

In this unique new design, the Whitesides group has used the natural absorbance of paper (and its ability to “wick” fluid), along with the water repellent nature of scotch tape to create a diagnostic lab-on-a-chip. Each stamp size device is composed of several alternating layers of paper and tape. The paper is first treated with a photoresist material in a micropatterned fashion using a mask (the photoresist material makes the paper in the treated parts water repellent). This results in the creation of channels that funnel liquid (such as test urine or sputum). Two adjacent micropatterned paper strips are separated by water-repellent scotch tape, where tiny holes punched in the tape serve as conduits for the liquid to flow from one paper strip to the next. Through these microchannels, the liquid is conducted to tiny wells coated with proteins or antibodies, where a color reaction can take place to provide the needed diagnosis (e.g., whether a bacteria or virus is present, or whether the specimen has high, medium or low sugar content).

The prototype (which the authors call 3D microPAD) was recently described in the prestigious journal, Proceedings of the National Academy of Sciences. This particular prototype tests 4 different samples for up to 4 different analytes and displays the results of the assays in a side-by-side configuration for easy comparison. The diagnostic results are color coded for easy reading, and are of a size that can be easily seen by naked eye, and photographed by mobile phones to allow telemedicine.

And the production cost? 3 cents/device!

The Whitesides group has launched a nonprofit, Diagnostics for All (DFA), to commercialize this technology. DFA was recently designated subcontractor in a 5-year grant from the Bill and Melinda Gates Foundation awarded to Harvard University for the invention of a diagnostics platforms for use in developing countries. They also won the Massachusetts Institute of Technology (MIT) $100K Entrepreneurship Competition in 2008, being the competition’s first ever non-profit winner.

Did you say disease diagnosis with a mobile phone?

A group of researchers from University of California at Berkeley and San Francisco have built a fascinating new device, which should make disease diagnosis in the field in the developing world a lot more feasible. The new device takes advantage of the recent penetration of mobile telephones in the remotest parts of the world – places where there are few health amenities, or even reliable roads and power. Most mobile telephones today have built-in cameras which, although they may not be the dream of a professional photographer, can nevertheless produce digital images at sufficient resolution for diagnostic pathology.

The researchers have combined a camera-equipped mobile phone with a simple light microscope, and packaged it into a simple, portable and rugged “diagnostic field microscope” (for technical details, please see here). This new-fangled contraption can not only take diagnostic images (e.g., from blood smears prepared from patients suspected to have malaria or sickle cell anemia), but can also transmit those images to trained Pathologists anywhere in the globe for professional diagnosis. And all this can be achieved, logistics permitting, in real time. As anyone who has any experience of healthcare in the remotest parts of the developing world knows, this latter is really a make or break factor. In many places, the patient and his/her family may have travelled for days, sometimes on foot, to see a doctor. The probability that the patient can be sent home, and then be expected to return in a week for diagnosis and follow up treatment is next to nil. Thus, this device, if deployed in the field, can potentially increase the rate of treatment by very large proportions, and may in fact help control the spread of epidemics such as malaria, by timely administration of treatment to an initially infected cluster.

The researchers have gone one more step, and have equipped this system not only for bright-field microscopy (e.g., taking photographs of blood smears that can be done using ambient light), but also for fluorescence microscopy using an inexpensive LED (light emitting diode) as the illumination source. They have tested the feasibility of using fluorescence microscopy to diagnose Tuberculosis from sputum samples, stained with a fluorescent dye that helps in the identification of the tubercolusis-causing bacteria. They have also tested ways in which the images obtained can be processed automatically, and have confirmed that the phone computational resources are sufficient for such processing.

After this initial and very exciting report, it will be great to see a translation of this technology to the real world, wherein a company comes up with a business model that’ll ensure sustainable production and distribution of these mobile phone microscopes to places where they can really make a difference in the lives of people.

I would love to hear ideas about translation. Please post comments below.

Diagnostic lab-in-a-backpack

Imagine a remote spot in the developing world - be it in Africa, Asia or South America, where the only way to reach your patients is a day's trek over harsh terrain. Once you get there, you can be assured that there'll be no power, no refrigeration and no sterile setup. Now imagine that a large proportion of your patients have HIV/AIDS or tuberculosis or diabetes. "Oh, that's too bad," you'll say, "this is a situation beyond redress."

In come the student volunteers from Rice University's "Beyond Traditional Borders" program, equipped with a backpack that carries everything you need: a stethoscope, an otoscope and an ophthalmoscope, a glucose monitoring kit, an urinalysis kit, a pulse oxymeter, a hematocrit centrifuge, a microscope with a 100x oil-immersion objective, and all manner of power cords, battery chargers, head lights and the like. Plus, three rows of compartmented boxes holding just the appropriate medication.

Yes, this is not a pipe dream - it is a reality today. Meet Rice University's proprietory lab-in-a-backpack, developed by students and faculty from a unique program of study - "Beyond Traditional Borders." This program draws students and faculty from disparate fields of specialization such as engineering, design, economics and the like.

And the whole program is spearheaded by the visionary scientist and social entrepreneur, Dr. Rebecca Richards-Kortum.

For more details on this project, please visit here.