Measurement of Cuffless Blood Pressure by Using a Magnetoplethysmogram Pulsimeter

Abstract

A wearable wrist magnetoplethysmogram (MPG) pulsimeter was developed for blood pressure (BP) monitoring using a magnetic field-sensing semiconductor Hall device. The pulsimeter contains a permanent magnet attached to silicon housing at the centre of a radial artery. BP and pulse rate were measured without using a cuff, utilizing an MPG pulsimeter consisting of a small and portable apparatus containing the measurement system with hardware and software for transforming the measured radial artery pulse waves into voltage signals. To acquire precise BP, the signals generated by the MPG pulsimeter were simultaneously compared with systole and diastole areas in the radial artery pulse wave. The pulse wave data for three clinical participants (normal BP, hypotension, and hypertension) were analysed. Analysis of pulse waves measured during testing of the arterial pulsimeter was conducted using two BP equations. The BP values calculated from these equations for the radial artery pulse wave data acquired during a 5-s-long window by using the MPG pulsimeter were compared to the BP values measured using electronic or liquid mercury BP meters. Our results are likely to be useful for developing a biomedical signal storage device for mobile U-healthcare applications.