International BME Research Essay

[collegebum1989]

Hi everyone,

I plan to apply for the Whitaker International Scholars Program after my Masters at Cornell. Please provide any helpful feedback. I appreciate all the positive (and negative criticism)

Question (2 pages)

Describe scientific research activities in which you have participated within the last 5 years. Provide details on the title of the research project, the dates it took place, and your role in the research, if it was a group project. In addition, list any publications or presentations that you have authored or coauthored within the last 5 years. If you have no research experience, describe your understanding of biomedical engineering research and why you expect to succeed in this field.

I have had the chance to participate in multiple research disciplines throughout my undergraduate career. Although each has given me a unique experience in a specific field, I feel that the strength of my research experiences comes from understanding the weaknesses and failures which I faced during each project I have been involved with.

I began my first research experience during my sophomore year at _ in January 2009. I worked as a research assistant in the neuropharmacology and neuroimaging laboratory under Dr. _ at _ National Laboratory. I was one of the select few students to participate in first-hand experience to preclinical research. I performed in vitro autoradiography on rodent brains to assess the binding of radioactively-labeled ligands to assess neurotransmitter levels after drug abuse. While simple in concept, I learned that these imaging techniques were fundamentally challenging in practice. This was clearly represented by the seven months of planning I had to do for an hour-long binding experiment. During those seven months, I conducted various literature reviews, and often times fell into a daze after reading an eloquent research article and then picking up another article which completely contracted it. Inexperienced in the neuroscience field, my mentor was my sole means of guidance through the critical analysis process. It was then how I learned how the intricate apprenticeship relationship is fundamental to the progress of research.

As I learned more about radioactive labeling of neurotransmitters, I began to work with a beta-imager to measure binding levels of tritiated dopamine receptor ligands to quantify how neurotransmitter levels were affected after cocaine abuse. I then analyzed radiation profiles using specific software to localize dopamine D3 receptor binding. I also learned experimental behavior paradigms for drug abuse such as the forced swim test for sleep deprivation and the self-administration for quantifying drug addiction. With the guidance of my mentor and my principle investigator, I was able to present my work on the effects of cocaine addiction, abstinence and extinction on dopamine D3 receptor levels at the Annual Society for Neuroscience Conference 2010 in October 2009 in Chicago, IL.

While I enjoyed the models of cocaine abuse in mice and the implications they may have for drug addiction in society, by my senior year I was more intrigued by the real-world applications of biomedical engineering. Specifically, I was interested in innovative cost-effective medical instruments for global health application. My senior design project starting September 2010 further developed this interest in instrumentation by providing an excellent opportunity to analyze the etiology of tuberculosis in tropical regions of the world. Our senior design team focused on developing a cost-effective diagnostic screening device for tuberculosis which needed to be capable of functioning at the point-of-care. While in my previous research, the fundamental challenge was controlling for confounding variables, and creating a controlled experimental model, this project was a true engineering challenge: designing an instrument through design constraints. I learned for the first time, that in science, sometimes it isn’t the technology which can be challenging, but finding a way to optimize it for a particular application.

In our case, tuberculosis is a disease which is often treatable in developed nations due to the advancements in diagnostic medicine. However, in developing nations, diagnosis is practically impossible due to population crowding increasing transfection rates, making it difficult to predict. Understanding our constraints, we developed an optics-based system which utilized fluorescence as a means of preferentially exciting bacterial cells within patients’ blood. We characterized the resolution of our device using negative-targeting blocks. We then developed alternative designs along our design path and realized how constraints can sometimes lead to uncompromising dead ends. Constraints, of course, are the guidelines by which engineers live by, and it is this challenge that makes this field so alluring.

Our final design was a laboratory prototype which consisted of a inexpensive complementary metal-oxide sensor (CMOS) found in common cellphones to detect light through a two-lens system to detect fluorescence emitted from bacterial cells excited by a laboratory-grade laser. Ironically, the simplicity of our design resulted from a complex design process which made us truly appreciate the beauty of our device. We used fluorescent beads of known sizes and fluorescently-labeled e.coli bacteria as a proof-of-concept to represent the resolving power of our microscope, which was sufficient enough to detect the morphology of tuberculosis bacteria. Our efforts earned us _ University College of Engineering’s Most Socially Responsible Design from all the engineering disciplines. This was a symbolic moment for my teammates and I, and a pivotal moment where we truly understood the implications of the field of Biomedical Engineering to human healthcare.

After graduating from _ in May 2011 and understanding my interests in medical imaging technology, I came to Cornell University as a master’s student to learn more the implications of imaging modalities towards biomedical research. I started my masters design project with two other students with Dr. _ in August 2011, working on a project focusing on using two-photon laser microscopy (2PLM) to develop a novel rodent model for cardiac microinfarcts. While cardiovascular diseases are a widely studied within biomedical research, our project is the first to look at in vivo changes in microvasculature following a microinfarct. Our research strategy primarily focuses on using femtosecond laser ablation to create a disease model for microinfarcts by differentially ablating vessels of interest. Then, using 2PLM, we can use non-linear optics to represent in vivo changes in network architecture resulting from infarcts and perform some exciting experiments to see how local blood flow is affected.

While our project has the potential to create a new paradigm within biomedical optics research, my experience within the project has been a little more humbling. The number of complex procedures involved in the process of analyzing infarct tissue has currently limited previous success in creating a stable disease model. One of complications which occur is motion artifacts associated with conflicting motions between breathing and heartbeats. To solve this, we performed tracheotomies on the rodent and artificially ventilate it according to the EKG signal. We also found that motion artifacts are reduced and produce the most stable signal within the QRS peak in the EKG cycle. Consequently, we have built an electrophysiological trigger circuit which utilizes hysteresis to send a signal to the microscope only when the input voltage from the EKG is greater than the threshold voltage we set to the trigger circuit. This allows us to preferentially image specific phases of EKG, often known as phase-synchronized imaging. Our next goal for this upcoming year is to be able to create EKG-trigged image stacks of microvessels following ablation to reconstruct three-dimensional images of vessel architecture following microinfarcts.

My research experiences have broadened my exposure of biomedical research from various disciplines. Likewise, my experiences have taught me to think from a larger perspective. Biomedical engineering represents an integration of small breakthroughs, all motivated by unmet clinical demands. As an undergraduate, I tested established preclinical models of drug addiction, and as a master’s student I am working to hopefully create a new paradigm for a preclinical model of cardiac microinfarcts. Through the Whitaker International Scholars Program, I hope not only to take these research experiences to a larger global context, but I hope to apply everything I’ve learned through my experiences to a new direction of biomedical research in Bangladesh.

Edited December 9, 2011 by collegebum1989