Chaya Hirsch929 Moraga Ct, Palo Alto, CA 94303

5542916, Aug 6, 1996

Sep 28, 1994

8/314190

Chaya Hirsch - Palo Alto CA
Robert Hale - Plymouth, GB2
Bruno Strul - Palo Alto CA

Vidamed, Inc. - Menlo Park CA

A61B 1720

604 22

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.

6090105, Jul 18, 2000

Nov 17, 1997

8/971415

John Zepeda - Los Altos CA
Chaya Hirsch - Palo Alto CA
Kee Lee - Daly City CA
Edward J. Gough - Menlo Park CA

Rita Medical Systems, Inc. - Mountain View CA

A61B 1739

606 41

An ablation apparatus includes an introducer with a distal end sufficiently sharp to penetrate tissue. An energy delivery device is configured to be coupled to an energy source. The energy delivery device includes a first electrode and a second electrode each with a tissue piercing distal portion. The first and second electrodes are at least partially positionable in the introducer and deployable from the introducer at a selected tissue site to an expanded state. In the expanded state the deployed first and second electrodes distend laterally away from the introducer with a radius of curvature to form a shaped array of deployed electrodes at the tissue site when positioned at the selected tissue site. The first electrode distal portion and the second electrode distal portion are each at least partially made of a shaped memory alloy material that displays stress induced martensite behavior above body temperature. A cable couples the energy source to the energy delivery device.