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Miller ’16 Critical Thinking in PROFUSA Lab

Michael Miller ’16 – This summer I am the Biology Intern in College Station, Texas for PROFUSA Corp. PROFUSA Corp. is a company, based out of San Francisco, California that makes medical prototypes. Here in Texas, we work on preclinical testing of these prototypes on pigs. My first day on the job I was sat down and given two major projects to work on for the 8 weeks that I am here. The first; to find a better way to adhere one of these prototypes to the body of the pig. The second; to work on a way to measure blood profusion called laser speckle contrast imaging.

Finding a new adhesive might sound pretty trivial and effortless on the surface, but finding a tape/combination of tapes that will hold weight onto a pig’s skin for up to 8 hours has proven to be difficult. In my research I found 9 different tapes ranging from medical grade to electrical tapes that I thought would perform well in a series of 10 “in vitro” (not on the pig) tests. After running these tests multiple times I was able to eliminate 7 but found that the combination of two tapes, a double-sided and a single-sided tape, was also a strong candidate. I then tested the remaining four tapes on the pig and achieved my goal of finding a way to be both space efficient, and time efficient while also sticking to the pig for a prolonged period of time. Below, you can see one of the tests that I ran, not on the pig, but on myself to insure that we were not causing any unnecessary pain to the pig.

Michael Miller SBIF 2014 Profusa1.docx

Miller ’16 experiments with adhesives

PROFUSA's laser speckle equipment

PROFUSA’s laser speckle equipment

Laser speckle contrast imaging equipment is usually very expensive, but here at PROFUSA, we have found an inexpensive and easy way to achieve the same goal. Our laser speckle system, shown above (right), consists of a laser that penetrates into the skin a little bit and then bounces back, and a webcam with special lenses. We have a computer program that will only pick up the red pixels from the images that we gather and from there we can calculate blood movement. Here is how we calculate this: the movement of blood causes the light from the laser to bounce around which can be observed by the naked eye. If there is a lot of blood movement, the blurring will increase and the standard deviation of the intensity, which is calculated by the computer program, will decrease, and consequently the speckle contrast will be lower because it is calculated by the ratio between the standard deviation of the intensity and the mean of the intensity. On the contrary, if there is no movement, the speckle contrast will be larger since the blurring will decrease and the standard deviation will increase. The mean intensity will remain unchanged. Using this tool, I have found that we can observe the effects that different tapes, different sized needles, or even temperature have on the pig, because blood profusion is directly proportionate to irritation and pain. Being able to determine these effects insures that nothing we do in the lab or on the pig is going to cause the pig any unnecessary harm or discomfort.

I have learned and built on new lab skills, learned about diseases like diabetes, and built upon my critical thinking skills throughout my time here with PROFUSA. This experience has also taught me a few non-internship skills, such as shopping for my own groceries and living 100% on my own that I really didn’t think about before coming here. Having never been west of Chicago before, I drove here by myself. I have gotten a nice look at the culture of not only the west and Texas, but also a big college town. I have met a lot of great people here both in the company and at Texas A&M that I hope to keep in touch with. Although I do not have an abundance of time left here, there is still a lot of progress to be made and a lot of experiments to be run that I am very excited about. I want to thank Career Services and everyone that has put forth effort or money to support the Small Business Internship Fund for making this possible and helping me get here.