Development and Validation of a Wearable Ultrasonic Sensor for Noninvasive Beat-to-beat Blood Pressure Monitoring

PROJECT SUMMARY Hemodynamic monitoring is often carried out by invasive techniques. Noninvasive, continuous blood pressure monitoring is a major challenge in the multibillion-dollar healthcare industry. However, there is a clear lack of satisfactory noninvasive solution: blood pressure cuffs only provide intermittent data and can be irritating to patients, and other emerging non-invasive technologies require complex and frequent calibration procedures and oftentimes suffer from physiological or measurement artifacts. There is a critical need for new non-invasive technologies for blood pressure surveillance. The goal of this project is to develop an easy-to-use noninvasive blood pressure sensor prototype based on a proof-of-concept wearable device demonstrated by the team. The device records the human central blood pressure with a soft ultrasonic patch, which extracts blood vessel diameter based on A-mode ultrasound radiofrequency signals. The approach is enabled by stretchable electronic designs that allow conformal, seamless contact of a soft device with the human skin, eliminating the need for coupling gel at the device/skin interface. In this project, the current lab prototype will be redesigned to enable the device application in a clinical setting guided by physician interviews. The manufacturability will be enhanced to prepare for scale-up. The approach is innovative because it is the first-of-its-kind to acquire the blood pressure waveforms of major arteries non-invasively by a stretchable ultrasonic patch. In addition, because most existing devices on the market are either rigid or flexible but not stretchable, knowledge on stretchable device prototyping and packaging is critical to technological translation of similar wearable health monitoring sensors. The proposed research is significant because it aims to use a band-aid-like device to collect beat-to-beat pressure waveforms that are conventionally done invasively. Ultimately, the proposed approach has the potential to clear the roadblock to practical applications for cuffless blood pressure sensing and impact the clinical practice, which can eventually translate to improvements in patient outcomes and reductions in healthcare costs.