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US 5,542,916 AGranted
Dual-channel RF power delivery system
AssigneeVidamed, Inc.
InventorsChaya Hirsch, Robert Hale, Bruno Strul
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AssigneeVidamed, Inc.
InventorsChaya Hirsch, Robert Hale, Bruno Strul
Estimating the term…
A dual-channel RF power delivery system for applying RF energy to dual electrodes of an RF ablation device with independent control of the power level, frequency, phase, and time duration of the RF energy applied to each electrode to more accurately control the ablation of a target tissue. The power delivery system supplies a first controlled RF signal having a first power level, frequency, phase, and time duration to the electrode of a first flexible stylet and a second controlled RF signal having a second power level frequency, phase, and time duration to the electrode of a second flexible stylet. The difference between the first and second power levels and the temperature of the tissue between the first and second stylers are monitored to control the ablation of the target tissue. The supply of the first RF signal is terminated when the monitored temperature of the first stylet exceeds a first predetermined value and the supply of the second RF signal is terminated when the monitored temperature of the second stylet exceeds a second predetermined value. By adjusting the frequency and/or phase of the first and second RF signals, the relative amounts of bipolar and monopolar ablation can be adjusted for accurate control of the lesion volume. The lesion volume can also be controlled by varying the deployment length of the electrodes.
Apparatus for the treatment by radio frequency ablation of a target volume of tissue of a prostate in a human male having a bladder with a base and a penis with a urethra therein formed by a urethral wall extending into the base of the bladder along a longitudinal axis with the tissue of the prostate surrounding the urethra near the base of the bladder comprising an indifferent electrode adapted to be placed in contact with the human male, an elongate probe member having proximal and distal extremities and being sized so that It can be introduced into the urethra and having a length so that when the distal extremity of the elongate probe member is disposed in the vicinity of the prostate, the proximal extremity extends out of the urethra, a control handle coupled to the proximal extremity of the elongate probe member, first and second stylers carried by the elongate probe member and being movable through the urethral wall into the target volume of tissue in the prostate, each of the stylers having an electrode and an insulating sleeve surrounding the electrode, radio frequency power supply means having first and second output channels of radio frequency energy, means coupling the first output channel to the electrode of the first styler and coupling the second output channel to the electrode of the second stylet, additional means coupling the indifferent electrode to the radio frequency power supply means, said radio frequency power supply means including control means for supplying radio frequency power simultaneously to the electrodes of the first and second stylets so that simultaneous ablation occurs in the target volume of the tissue in the prostate so that the lesion volume is approximately doubled over that which would be created by a single electrode for the same amount of time or conversely for the same lesion volume, the time required is reduced by approximately one-half.
A method for the treatment by radio frequency ablation of a target volume of tissue of a prostate in a human male having a bladder with a base and a penis with a urethra therein formed by a urethral wall extending into the base of the bladder along a longitudinal axis with the tissue of the prostate surrounding the urethra near the base of the bladder by the use of an indifferent electrode in contact with the human male and an elongate probe member having proximal and distal extremities and sized so that it can be introduced into the urethra and having a length so that when the distal extremity of the elongate probe member is disposed in the vicinity of the prostate, the proximal extremity is proximal of the urethra, a control handle coupled to the proximal extremity of the elongate probe member, the elongate probe member having first and second stylets carried thereby and being movable through the urethral wall into the target volume of tissue in the prostate, each of the stylets having an electrode and an insulating sleeve surrounding the electrode and a radio frequency power supply having first and second output channels of radio frequency energy, means coupling the first output channel to the electrode of the first stylet and coupling the second output channel to the electrode of the second stylet comprising the steps of introducing the first and second stylets through the urethral wall and into the target volume of tissue in the prostate, supplying radio frequency energy from the first and second output channels simultaneously to the electrodes of the first and second stylets so that simultaneous ablation occurs at both of the electrodes to create a lesion volume which is approximately twice as great as that which can be created by a single electrode during the same period of time or conversely the same lesion volume can be created in approximately one-half of the time in comparison to the use of a single electrode.
Dependencies are inferred from the claim text.