Hypertension is a major risk factor for chronic diseases such as heart disease and stroke, which cost billions of dollars in health care expenses in America. Long-term and continuous blood monitoring system is an effective way for blood pressure management to reduce the risk of adverse health outcomes. However, the current cuff inflation-based monitoring schemes are cumbersome and inconvenient, which leads to limited ambulatory blood pressure monitoring for patients to only 24 to 48 hours.
Ultrasound has been used in medical applications for a long time, known for its harmless nature and good tissue penetrative performances. This dissertation focuses on the development of a subcutaneous continuous blood pressure monitoring system without a cuff, utilizing AlN-based piezoelectric micromachined ultrasonic transducers (PMUTs).