Title:  Hermetically-Encapsulated Precision Accelerometer Contact Microphones for Wearable Medical Devices

Committee:

Dr. Farrokh Ayazi, ECE, Chair , Advisor

Dr. Omer Inan, ECE

Dr. Azadeh Ansari, ECE

Dr. Pamela Bhatti, ECE

Dr. Wilbur Lam, BME

Abstract: Mechano-acoustic signals emanating from the heart and lungs contain valuable information about the cardiopulmonary system. Unobtrusive wearable sensors capable of monitoring these signals longitudinally can detect early pathological signatures and titrate care accordingly. This thesis presents a wearable, hermetically-sealed high-precision accelerometer contact microphone (ACM) to acquire wideband mechano-acoustic physiological signals and enable simultaneous monitoring of multiple health factors associated with the cardiopulmonary system including heart and respiratory rate, heart sounds, lung sounds, and body motion and position of an individual. The encapsulated sensor utilizes nano-gap transduction technology to achieve extraordinary sensitivity in a wide bandwidth with high dynamic range. The performance of the developed sensors in recording physical biomarkers, such as heart and lungs sounds, is validated by comparing the recorded signals with state-of-art electronic stethoscopes. The accuracy of the system in detection of vital signs is also evaluated by comparing it against a medical-grade ECG system. Feasibility of the sensor in clinical applications is studied by deploying the ACM to capture the weak mechano-acoustic signals such as pathological heart sounds in patients with preexisting cardiopulmonary conditions. The sensor and methods presented in this work can potentially detect abnormal sounds and symptoms of cardiopulmonary diseases in early stages and provides a unique solution for disease screening and longitudinal monitoring. This inexpensive wearable sensing technology has the potential to enhance remote healthcare delivery and improve the quality of life and outcome in patients with chronic diseases and reduce overall health care costs.