초록 ▼

The apparatus comprises: a comparator for comparing the voltage at which the constant current pulses are being supplied to the load with an increasing reference voltage; a counter for counting the number of voltage pulses that are greater in magnitude than the increasing reference voltage over a sam

The apparatus comprises: a comparator for comparing the voltage at which the constant current pulses are being supplied to the load with an increasing reference voltage; a counter for counting the number of voltage pulses that are greater in magnitude than the increasing reference voltage over a sampling period; and signal processing circuitry for correlating the count of pulses over the sampling period with the impedance of the load required to generate that number of constant current pulses at the voltage required for same.

대표청구항 ▼

In a neural stimulating apparatus of the type comprising a cathode adapted to be juxtaposed to the spinal cord in a body, in anode adapted to be placed in contact with the body, means for generating constant current output pulses which are supplied to the cathode, a cathode lead coupled between the

In a neural stimulating apparatus of the type comprising a cathode adapted to be juxtaposed to the spinal cord in a body, in anode adapted to be placed in contact with the body, means for generating constant current output pulses which are supplied to the cathode, a cathode lead coupled between the pulse generating means and the cathode for carrying the pulses to the cathode and means for controlling (a) the generation of pulses and (b) the supplying of pulses to the cathode, the improvement comprising means coupled to the cathode lead for measuring changes in the cathode impedance at the connection of said pulse generating means to the cathode lead, said means for measuring changes in the cathode impedance comprising means for comparing the voltage pulses at which the constant current pulses are being supplied to the load with an increasing reference voltage, means for counting the number of voltage pulses that are greater in magnitude than the increasing reference voltage over a sampling period, and means for correlating said count of pulses over the sampling period with the impedance of the load presented by the lead and connections to tissue required to generate that number of constant current pulses at the voltage required for same.