Vagal nerve action potential recording for the control of an artificial heart

An Artificial heart needs to react for demand of organism precisely. Information from the biological system is necessary for that purpose. In this study, an autonomic nerve activity was recorded for this purpose. Recording of the vagal nerve activity in the awake condition aiming at the artificial heart control was tried in this study. Various electrodes including stainless steel electrodes for the functional electrical stimulation (FES), which electrode will lasting for over a year, was tested in this study. Healthy adult goats were anesthetized with Halothene inhalation, hemodynamic parameters were continuously monitored. Incision were made to the left neck and left vagal nerve were separated. Various electrodes were inserted into the vagal nerve and fixed by the plasticizer. After an incision was closed, the goats were transferred to the cage and extubated after waking. Hemodynamic parameters and vagal nerve activity were measured in the awake condition. The results showed that clear observation of the vagal nerve action potential was embodied by this experimental system. The vagal nerve discharges were synchronized with heart beat and respiration. Tonus of the vagal nerve were significantly altered in advance to the body motion. These interesting results suggest the feasibility of the predictive control of an artificial heart system based on an activity of an autonomic nervous system. Physiological control of an artificial heart system may be possible in future.