Development of a Novel Cardiovascular Vessel Health Monitor; Medical Precedent and Treatment of Heart Disease: An Advocacy for ‘Interactive Innovation’ in Medical Device Development

Yao, Justin, School of Engineering and Applied Science, University of Virginia
Hossack, John, EN-Biomed Engr Dept, University of Virginia
Neeley, Kathryn, EN-Engineering and Society, University of Virginia

My STS and technical projects both focused on diagnostic devices and their implementation to lower the death rate of heart disease in the US. My technical project culminated in a device that uses routine vital measurements such as heart rate and pulse oximeter measurements to detect early signs of heart disease. My STS project explored how the current process of introducing medical devices shapes the approach doctors take to treat heart disease. Using these two perspectives on the heart disease problem I obtained insights on how a change in both discussion of medical treatment of heart disease and the direction of heart disease treatment research could lead to a lowering of the death rate due to heart disease.
In the US, the mortality rate of heart disease has been stagnant for many years because many people with heart disease are not diagnosed until the disease worsens. My technical project developed a device that takes routine vital measurements and turns those measurements into general measurements of metabolic capacity and arterial stiffness that cardiologists can use to make well-informed decisions on a patient’s treatment plan. The device uses pulse measurements of the heart from the ear and the index finger to calculate the pulse wave velocity (PWV) in the blood vessels as a quick indication of arterial stiffness which is an early indicator of heart disease. The device also calculates a patient’s METs or metabolic equivalents of task which are a measure of a patient’s energy expenditure rate relative to body mass which doctors use to get a general indication of whether a patient is fit for surgery. The process of designing the algorithm to calculate METs took several detours in which there was some discussion of building a rebreather mask to calculate oxygen consumption and measuring oxygen saturation of the blood. However, all those ideas limited the ease of operation of the device and were replaced by a simple formula that related METs with heart rate. The PWV was calculated using the time difference between the peaks of the ear and finger pulse oximeter waves. My team found that the measuring a patient’s METs would have the most practical use in the routine medical decisions of cardiologists. This is because the METs provides cardiologists with a more objective measurement of a person’s capabilities and allow for more accurate medical predictions of a patient’s survivability during surgery.
My team’s development of a medical device led me to examine the Food & Drug Association’s (FDA) process by which all medical devices are approved and introduced to market. Despite this process giving doctors useful tools for diagnosing and treating heart disease, the mortality rate is still stagnant in the US. My STS research investigated this contrast of heart disease treatment and the stagnation of heart disease mortality. My research utilized Pacey’s (1983) dichotomy of two kinds of innovation, “linear” and “interactive”, and the analogy of preventive care to infrastructure to analyze current medical practices and thought. The analysis suggests that the current process by which we introduce medical devices leads to researchers focusing too much on post-diagnosis treatment and improved technology to better the accuracy of diagnoses and not enough on developing earlier forms of care and detecting early signs of heart disease. This indicates that traditional approaches to treatment and diagnosis are preventing the lowering of the mortality rate rather than the accuracy and precision of the technology.
My technical and STS research projects complement each other by tackling the problem of lowering the heart disease mortality rate on both the technological and societal fronts. The technical project established a new method of detecting heart disease while the STS research explored how customary behaviors and mindsets of physicians and patients prevent these new avenues from being explored to their fullest. These projects show how non-technical factors such as bureaucratic processes and public consciousness prevent technical factors from being used in any new or creative ways. I discovered how much mental models can affect the interpretation of medical measurements and how decision about how technology is used are influenced by costs and time rather than technological availability. These projects present a picture of how medical technology needs to be improved to combat the stagnation in the mortality rate of heart disease, but even more than that, how cultural and organizational barriers as well as societal assumptions prevent technology from advancing in the right direction to achieve that goal.
I would like to acknowledge my Capstone team for helping me in improving our device so that it was able to record and calculate the required data. I would also like to thank all the advisors on both my technical and STS project for lending me aid and supporting me when everything seemed a bit overwhelming. It was difficult to fine tune the code to analyze the pulse oximeter data correctly and even more difficult to find a formula to measure METs indirectly. I would say that the greatest challenge was to find a scope that was not too large for my STS research and that using the technical project as inspiration allowed for a smoother transition between the two. It is also good to not be too engrossed by the developments of the technical project as it sometimes clouds the purpose of the STS research. I will admit that it was difficult to develop a conclusion that seemed fitting to the STS topic, but I was able to realize that sometimes conclusions are small but insightful and that not every conclusion has to be grandiose to be paradigm shifting. Overall, I am glad that I was able to finish and create such an interesting device to help medical professionals and to research more about how our medical system operates.

BS (Bachelor of Science)
Medical Precedent, Devices, Actor-network theory, Heart disease

School of Engineering and Applied Sciences
Bachelor of Science in Biomedical Engineering
Technical Advisor: John Hossack
STS Advisor: Kathryn Neeley
Technical Team Members: Daryl Brown, Brendan Kenefick, and Justin Yao

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