Multiscale Cardiac Monitoring with No Physical Contact: An Investigation Using Impulse Radio Ultra-Wideband Radar
Currently, the most common methods for detecting cardiac information are electrocardiography (ECG) and photoplethysmography (PPG). ECG uses metal electrodes placed on the body to detect electrical signals, while PPG uses optical sensors at the wrist or finger to detect changes in blood volume. While these methods are widely used in clinical settings, they require physical contact and may not be suitable for continuous, real-time monitoring in certain situations. To address this, researchers are exploring the development of a contactless method for detecting cardiac information that could be used for next-generation medical monitoring and home healthcare. Such a method would have many potential applications and could improve the accuracy and accessibility of cardiac monitoring.
In a paper published this month, a new method for measuring cardiac motion using impulse radio ultra-wideband (IR-UWB) radar at a center frequency of 7.29 GHz is proposed.
This method aims to improve upon traditional state-of-the-art methods, such as electrocardiography (ECG), heart sound, and ultrasound, which have drawbacks including the need for physical contact and incomplete information about the cardiac cycle.
The proposed method involves using the IR-UWB radar to take anteroposterior and along-the-arc measurements from healthy subjects lying down or prone and comparing the results to simultaneous ECG monitoring. The results show that the proposed method is able to detect cardiac motion from the front more accurately in terms of amplitude and is most effective at a detection angle of 120°. Importantly, the proposed method is able to detect all ECG information, as well as previously "blind" segments of cardiac motion information, during the entire cardiac cycle. This makes it a potentially significant tool for fast and accurate assessment and diagnosis of cardiac diseases, with potential applications in contactless online cardiac monitoring and in-home healthcare.
Qiao JH, Qi FG, Liang FL, Ma J, Lv H, Yu X, Xue HJ, An Q, Yan KD, Shi D, Qiao YH, Wang JQ, Zhang Y. Contactless multiscale measurement of cardiac motion using biomedical radar sensor. Front Cardiovasc Med. 2022 Dec 13;9:1057195. doi: 10.3389/fcvm.2022.1057195. PMID: 36582736; PMCID: PMC9792510.