Stress can impact the cardiovascular system, so it's essential to monitor it for diagnosis and treatment. Heart sounds provide critical data for understanding the heart's mechanical activities. Auscultation, also known as phonocardiography (PCG), is a medical technique that can be used to monitor the cardiovascular system by collecting and analyzing the mechanical vibrations on the chest wall created by the heart sounds.
Heart sounds were introduced as a biometric for security purposes by Beritelli and Spadaccini. They used the chirp-z transform (CZT) for feature extraction and Euclidean distance (ED) for classification. While other biometrics have been used in the past, they each have their flaws, such as susceptibility, replicability, danger in use, invasiveness of continuous scanning, and cost. Heart biometrics have the lowest cost and highest permanence and are the only biometric that enables continuous verification for users, offering reliable biometric identification based on vulnerability, acceptability, usability, and uniqueness.
This presentation highlights the use of S1 and S2 peak signals from heart sounds, captured through a microelectromechanical (MEMS) microphone placed on the Erb's point of the chest, as a continuous biometric for security purposes. The MEMS microphone contains a small silicon membrane that converts sound pressure vibrations to capacitance or voltage. The microphone is integrated with a flexible printed circuit board (PCB) made of copper traces and flexible polyimide, and the device is encapsulated with bio-compatible silicone for use as a cardiac patch. This system offers a non-invasive, continuous, and cost-effective solution for human identification based on heart sounds, providing a reliable and unique biometric for security purposes. This material is based on research sponsored by Army Research Laboratory under agreement number W911NF-19-2-0345. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation thereon. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of Army Research Laboratory (ARL) or the U.S. Government.
