USE OF A CATECHOLAMINE SENSOR IN THE CONTROL OF AN ARTIFICIAL-HEART SYSTEM

An electrochemical sensor system to allow real-time measurement and fe edback of catecholamine concentrations was developed for use in the co ntrol of artificial hearts. Electrochemical analyses were carried out using a carbon fiber working electrode, an Ag-AgCl reference electrode , and a potentiostat. The operating parameters of the pneumatically-dr iven artificial heart system were altered in accordance with the algor ithm for changes in the catecholamine concentration. The minimum detec table concentrations of both adrenaline and noradrenaline in a mock ci rculatory system using a phosphate-buffered solution were approximatel y 1-2 ng/ml (10(8) mol/L). An artificial heart control system utilizin g this set-up performed satisfactorily without delay, although sensor sensitivity decreased when placed in goat plasma instead of a phosphat e-buffered solution, due to the adsorption of various substances such as plasma proteins onto the electrodes. This study demonstrated the fu ture feasibility of a feedback control system for artificial hearts us ing catecholamine concentrations.