Portable device for heart rate monitoring based on impedance pletysmography

Abstract

The design of a portable device for heart rate monitoring is described in this work. The cardiac activity is detected through the noninvasively measurement of blood volume changes in the forearm. When blood volume arrives to the forearm from the left ventricle, the electrical properties of the body segment change. These changes, that mainly comprise the electrical impedance of the tissue, are measured through the injection of a safely ac current and the detection of the voltage changes due to blood flow. Such a method is known as electrical impedance plethysmography. A peak-detection-software is used in a microcontroller to estimate the heart rate. Results of measuring the heart rate have shown accuracy that accomplishes the AAMI standards for heart rate monitors.