Biomedical Engineering Associate Professor Yu Chen is working with a $200,000 grant from the National Science Foundation (NSF) to partner with the U.S. Food and Drug Administration (FDA) to undertake improvements in the clinical performance of pulse oximeters. Such improvements will positively impact patients undergoing surgical procedures, anesthesia, and other critical health conditions.
The pulse oximeter is an electronic device that measures the saturation of oxygen carried in your red blood cells. Pulse oximeters are powerful and inexpensive devices commonly used for early detection of health problems and monitoring of treatment. However, studies have shown that patient skin pigmentation levels and other physical factors can impact the measurement accuracy.
According to Chen, “This project will provide extensive insights into the factors influencing quantitative accuracy of pulse oximetry.”
Chen explains that a better understanding of the underlying mechanisms related to pulse oximeters will help the refinement of instrumentation and algorithms to improve the device performance.
Chen and his research team will be working with Dr. Joshua Pfefer of the FDA’s Office of Science and Engineering Labs to improve understanding of pulse oximeter light-tissue interactions through computational modeling. This work will include studying the impact of different biological and device design factors on detected optical signals and performing laboratory measurements of tissue-mimicking models to validate the computational modeling under well-controlled conditions.
As Chen says, “Such effective, least-burdensome evaluation of device performance has the potential to lead to improvements in clinical performance of oximeters. Furthermore, the planned research will be seamlessly integrated with educational, mentoring, and outreach activities.”
Chen’s project aims to develop and validate a series of test methods for pulse oximetry. As he says, “The work will involve fabricating physical models with biologically relevant properties of adult fingers, including epidermal layers with different pigmentation levels, bio-mimetic microvascular networks, and mock cardiovascular flow loop with tunable oxygenation to generate real-time physiological flow/pressure waveforms.”
In addition, Chen will develop in silico models of adult fingers of different sizes and perform Monte Carlo simulations – a mathematical technique used to estimate the possible outcomes of an uncertain event – to elucidate light-tissue interactions in pulse oximetry.
Finally, Chen’s research team will use computational models to validate spectroscopic measurements in finger-simulating physical models and investigate effects of epidermal melanin content along with other biological factors on key light-tissue interaction parameters and on estimated oxygen saturation measurement accuracy. (November 2022)