Vagal nerve activity suggests a new control method of an artificial heart

Background: In order to develop the autonomic control algorithm for the total artificial heart (TAH) from a physiological viewpoint, the neural interface is thought to be useful. Method: Seven healthy adult goats were used in this study. Under general anesthesia, fifth-rib resection was performed. The electrocardiogram (ECG), aortic pressure (AoP), and other hemodynamic parameters were continuously measured. The vagal nerve was exposed at the left neck, and bipolar electrodes attached. After the anesthesia was terminated, hemodynamic time series data and vagal nerve activity were recorded. The goats were then anesthetized again, and the vagal nerves were cut at the distal point of the electrode. After the anesthesia was terminated, the time series data were recorded again. Results: Before the vagus was cut, vagal nerve activity did not significantly correlate with AoP. However, after the distal end of the vagal nerve was cut, the activity correlated with the alteration of AoP and increased before the animals began standing up. Discussion: Results of this study suggest that body motion and AoP are affected by vagal nerve activity. Monitoring of vagal nerve activity may be useful for the physiological autonomic control algorithm of the TAH.