A Wearable Device for Continuous Cardiorespiratory System Monitoring

This paper describes the design and implementation of a wearable monitoring device for performing a continuous inspection on the cardiorespiratory system based on the Heart Rates (HR) and Respiration Rates (RR). The HR and RR are the two vital signs as relevant indicators to show the functionality and wellness of the cardiorespiratory system. The device consists of a bell-shaped stethoscope, which is attached to a capacitive microphone, and a FM radio transceiver to establish a wireless connection between the measuring sensor and collecting device which is held off body. In order to obtain the HR values a simple peak detection scheme is applied to the measured sound signals to count the number of Beats Per Minute (BPM). In contrary to the direct measurement used for obtaining the HR values, the interaction between the heart and lungs (i.e., Mechanical modulation of the heart by the lungs) was considered. Such modulation leads to eliminating the need for of a respiration sensor. Also, the HRR value, which is introduced as the ratio of the HR and RR value, is used to assess the health condition of the cardiorespiratory system.