Electrosurgical apparatus
First Claim
1. An electrosurgical apparatus for cutting tissue and for ablating occlusions comprising:
- means for selectively generating a train of relatively high energy pulses and a train of relatively low energy pulses of electrical energy for application to a wire having an attached electrode, the means for selectively generating having a variable output impedance, a load impedance of the means for selectively generating comprising an impedance of the wire having an attached electrode;
means for sensing the load impedance relative to the output impedance in response to the train of low energy pulses applied to the wire and for adjusting the output impedance to match the load impedance in response to the sensed load impedance relative to the output impedance; and
means for controlling the means for selectively generating and the means for sensing and for adjusting to generate the train of low energy pulses and to match the output impedance to the load impedance and for subsequently generating the train of high energy pulses for producing an arc at the electrode to ablate an occlusion.
1 Assignment
0 Petitions
Accused Products
Abstract
An electrosurgical apparatus for cutting tissue and for ablating occlusions includes a pulse generator for selectively generating a train of pulses of electrical energy for application to a wire having an attached electrode, the generator having a variable output impedance, the wire and the electrode being at least part of a load impedance. The apparatus senses the load impedance relative to the output impedance and adjusts the output impedance to match the load impedance. The generator produces pulses of variable energy, measures the relative electrical energy produced by an arc in response to a pulse, compares the relative electrical energy to a predetermined value to determine an energy difference, and adjusts the energy of a subsequent pulse to reduce the energy difference for the subsequent pulse toward zero.
1217 Citations
22 Claims
-
1. An electrosurgical apparatus for cutting tissue and for ablating occlusions comprising:
-
means for selectively generating a train of relatively high energy pulses and a train of relatively low energy pulses of electrical energy for application to a wire having an attached electrode, the means for selectively generating having a variable output impedance, a load impedance of the means for selectively generating comprising an impedance of the wire having an attached electrode; means for sensing the load impedance relative to the output impedance in response to the train of low energy pulses applied to the wire and for adjusting the output impedance to match the load impedance in response to the sensed load impedance relative to the output impedance; and means for controlling the means for selectively generating and the means for sensing and for adjusting to generate the train of low energy pulses and to match the output impedance to the load impedance and for subsequently generating the train of high energy pulses for producing an arc at the electrode to ablate an occlusion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
-
-
17. An electrosurgical apparatus for cutting tissue and for ablating occlusions comprising:
-
means for generating a train of variable energy pulses of electrical energy for application to a wire connected to an output terminal of the means for generating and having an electrode attached to the wire for producing an arc in response to the pulses of electrical energy; means for measuring relative electrical energy produced by the arc at the electrode produced by a pulse including a filter connected to the output terminal in parallel with the wire and the attached electrode for rejecting a primary frequency and at least one harmonic frequency of the train of variable energy pulses of electrical energy; means for comparing the relative electrical energy produced by the arc to a predetermined value to determine an energy difference; and means for adjusting the electrical energy of a subsequent pulse in response to the energy difference to reduce the energy difference for the subsequent pulse toward zero. - View Dependent Claims (18, 19, 20, 21, 22)
-
Specification