Abstract: Upon initial use of a catheter, a power control system writes data indicative of the date/time of the initial use to a memory device carried by the catheter. During continued use of the catheter the power control system periodically determines the difference between the stored date/time and the current date/time. For electrophysiological catheters, the power control system allows for an electrical interface with the catheter electrodes only when the difference is less than a set time period. The electrical interface may include the provision of ablation energy from the power control system to the electrodes or the receipt of signals from the electrodes indicative of electrical activity sensed by the electrodes. Alternatively, the power control system may provide a visual or audible overtime indication when the difference is greater than the set time period.

Abstract: An electrode and a voltage-measurement reference device are adapted to be positioned relative to a tissue load such that the load is generally located between the electrode and the reference device. A first wire and a second wire are electrically connected to the electrode. A power control system delivers RF current to the load through the first wire and measures the voltage across the load between the second wire and the reference device. The power control system measures the RF current through the first wire and determines the power delivered to the load using the measured current and voltage. The first and second wires function as thermocouple leads which, in combination with the electrode to which they are attached, form a thermocouple. The power control system monitors the voltage across the leads and determines the temperature at the electrode either during the delivery of current or alternatively, when current is not being delivered.