Apple Inc.
Blood Pressure Measurement Using Device with Piezoelectric Sensor

Abstract:

A blood pressure measurement device may include one or more piezoelectric sensors (e.g., differential piezoelectric sensors) for detecting blood flow through a limb of a user as part of determining blood pressure measurements. The piezoelectric sensor(s) may additionally or alternatively be used to determine one or more biological parameters of users (e.g., a ballistocardiogram, a heart rate, a heart rate variability, and a pulse wave velocity). The blood pressure measurement device may additionally or alternatively include a capacitive sensor for determining a pressure applied to the limb of the user by the blood pressure measurement device and/or operational states of the blood pressure measurement devices (off-arm, on-arm, inflating, deflating, tightness, and the like).