VITALS: an implantable sensor network for postoperative cardiac monitoring in heart failure patients

Heart Failure (HF) is a global epidemic, with high readmission rates and significant morbidity persisting due to gaps in post-acute care.Traditional follow-up often misses gradual postoperative cardiac deterioration occurring outside hospital settings. While advances in remote patient monitoring show promise, practical, continuous, and sensitive methods remain lacking. Building on previous work introducing a durable, soft strain sensor, this research presents VITALS, an implantable strain sensing network that enables continuous biventricular, multiaxial monitoring of cardiac function. The sensor's design demonstrates improved fatigue life in bechtop testing compared to other soft, large-deformation strain sensors, while effectively minimizing shear loading effects to enhance accuracy. Additionally, the network integrates a sensor on the aorta for synchronous systolic pressure monitoring. Acute animal studies demonstrate the potential of VITALS' to track epicardial strain, detect preload changes rapidly, and differentiate inotropic states. Validation against echocardiographic chamber volumes and GLS provides preliminary support of the sensor's clinical relevance.