The present invention belongs to the technical field related to
cardiac monitoring, and discloses a passive sensor for real-time
cardiac monitoring and its application. The passive sensor includes a monitoring unit, a flexible substrate, and a
signal receiving unit, wherein: the monitoring unit is a thin film composed of a material with an electric double layer effect. Thus, cations and anions in the
interstitial fluid around the heart are adsorbed on the surface of the monitoring unit to form an electric double layer structure. When the
cardiac muscle relaxes and contracts or the
blood flow signal is transmitted, the change in pressure will further cause the change in the effective charge adsorption area, resulting in the change of the current
signal; the flexible substrate is used to isolate the monitoring unit and the signal receiving unit; the signal receiving unit is connected to the monitoring unit for receiving the charge change on the surface of the monitoring unit, and serves as a counter
electrode to form a
closed loop with the monitoring unit. This application can realize the real-time monitoring and
signal acquisition of cardiac mechanical signals, with high sensitivity and high accuracy.