An Implanted Closed-loop Chip System for Heart Rate Control: System Design and Effects in Conscious Rats()

OBJECTIVE: To evaluate the efficiency of an implanted chip system for the control of heart rate (HR). METHODS: The HR was recorded in six conscious Sprague-Dawley (SD) rats. An implanted chip system was designed to regulate the HR by stimulating the right cervical vagus nerve according to the feedback of real time HR. Each rat was subjected to 30-min regulation and 30-min recovery. The change of HR during the regulation period was compared with the control. The ECG was recorded during the experiment for 24 h. RESULTS: The ECG signals were successfully recorded during the experiment. The HR was significantly decreased during the period of regulation compared with control (-79.3 ±34.5, P < 0.01, n = 6) and then recovered to normal after regulation. CONCLUSION: The described implanted chip system can regulate the HR to a designated set point.