A wireless ECG recording system for small animal models of heart regeneration

Heart failure afflicts the developed world, causing mortality more than any other diseases. This is due to the fact that humans' heart possesses a very limited capacity to regenerate. Heart attacks or myocardial infarction (MI) could result in an irreversible loss of cardiomyocytes and consequently heart failure. Besides, zebrafish and neonatal mice are well-known for their magical capacity to recover after ventricular amputation, thus becoming precious models for heart regeneration studies. In this work, we report the first wireless electrocardiography (ECG) recording system for small animal models of heart regeneration. The system consists of a microelectrode array (MEA) and electronic components for wireless powering, signal processing and data communication. The MEA is based on a biocompatible and flexible polymer so it could conform to non-planar anatomical surfaces. The power transfer is achieved using inductive coupling between two solenoids and the ECG signals are sent through an optical link. The wireless operation can free the animal, eliminating anesthesia during experiments and thus minimizing unwanted side effects. The first generation of the device was demonstrated successfully with neonatal mice, revealing awake ECG signals with all features, thereby paving the way to physiologically investigate heart regeneration in long-term without disrupting the animals' normal activities.