Project Summary This project aims to develop a low-cost, comfortable, and easy-to-use wearable alert system that tracks continuous BP non-invasively in patients to notify caregivers of hypotensive events in the postoperative setting. Postoperative hypotension (POH), when a patient’s mean arterial pressure (MAP) falls to unsafe levels, commonly <70 mmHg, can occur frequently in the time span between leaving the operating room and prior to discharge from the hospital. POH is a serious and common condition that has been shown to be independently associated with poor patient outcomes such as acute kidney injury, stroke, hospital re-admission, myocardial injury, and death.1–9 During surgery and recovery in the post anesthesia care unit (PACU) or the intensive care unit (ICU), a patient’s hemodynamics are closely monitored to support timely interventions and treatment. However, once the patient is transferred to a lower ward for recovery, patient monitoring is dramatically reduced. The current method to monitor a patient’s BP in the general ward, which relies on intermittent spot-checks performed manually every 4-6 hours by the nurse using an oscillometric BP cuff, is insufficient for detecting POH events. A recent study showed that almost 50% of hypotensive events went undetected by routine vital assessments. There is an unmet need for a technology that comfortably monitors a patient’s BP in the postoperative setting. Our core technology is able to non-invasively measure rapid BP changes at any location with a palpable pulse. The proposed project aims build upon the core technology to create a wearable alert system that informs caregivers of postoperative hypotensive episodes. To do so, a machine learning (ML) classifier for detection of hypotensive episodes will be developed through monitoring in the ICU. This ML classifier will undergo feasibility testing in the PACU and then a pilot study in the general ward. Successful completion of the proposed aims will result in a proof- of-concept wearable alert system that continuously monitors BP in the postoperative environment in a low-profile, wireless, and comfortable manner. Such a technology has huge potential to change clinical practice through earlier detection of patient deterioration, allowing more timely intervention and ultimately improved patient outcomes.