Bias‐Free Cardiac Monitoring Capsule

Cardiovascular disease (CVD) remains the leading cause of death worldwide. Patients often fail to recognize the early signs of CVDs, which display irregularities in cardiac contractility and may ultimately lead to heart failure. Therefore, continuously monitoring the abnormal changes in cardiac contractility may represent a novel approach to long‐term CVD surveillance. Here, a zero‐power consumption and implantable bias‐free cardiac monitoring capsule (BCMC) is introduced based on the triboelectric effect for cardiac contractility monitoring in situ. The output performance of BCMC is improved over 10 times with nanoparticle self‐adsorption method. This device can be implanted into the right ventricle of swine using catheter intervention to detect the change of cardiac contractility and the corresponding CVDs. The physiological signals can be wirelessly transmitted to a mobile terminal for analysis through the acquisition and transmission module. This work contributes to a new option for precise monitoring and early diagnosis of CVDs. A bias‐free cardiac monitoring capsule is developed as a zero‐power device implanted in animal models’ cardiac cavity through minimally invasive intervention. It enables continuous and accurate monitoring of cardiac contractility in situ, providing a stable signal, which may contribute to a new option for early diagnosis of heart failure and other cardiovascular diseases.