Chronic threshold of stimulating electrodes: comparison of activated vitreous carbon with conventional platinum-iridium electrodes in animal tests.
Electrodes made of vitreous carbon are inert, corrosion-resistant, inactive to electrocatalytic reactions and are especially biocompatible. Upon activation, they attain a capacitance of 20 to 40 mF and become "non-polarizable". Therefore, they should be particularly suitable as stimulating and sensing electrodes for cardiac pacemakers. The connective tissue layer that develops around the electrode because of the foreign-body reaction is less than 100 micron thick. The threshold rise, through lower than that of conventional Pt-Ir or ELGILOY electrodes, cannot be attributed exclusively to the connective tissue layer that is formed. Under favourable conditions, the threshold in animal experiments remains below 525 mV. Blood-spaces adjoining the electrodes are found at higher chronic threshold values.
D000818:Animals; D002244:Carbon; D004285:Dogs; D004553:Electric Conductivity; D004558:Electric Stimulation; D004566:Electrodes; D006321:Heart / Q000502:physiology; D007495:Iridium; D009132:Muscles / Q000502:physiology; D009206:Myocardium / Q000378:metabolism; D009417:Nerve Tissue / Q000502:physiology; D010984:Platinum
D007495:Iridium; D010984:Platinum; D002244:Carbon