(19)
(11) EP 1 932 487 A8

(12) CORRECTED EUROPEAN PATENT APPLICATION
Note: Bibliography reflects the latest situation

(15) Correction information:
Corrected version no 1 (W1 A2)

(48) Corrigendum issued on:
09.06.2010 Bulletin 2010/23

(43) Date of publication:
18.06.2008 Bulletin 2008/25

(21) Application number: 08004974.5

(22) Date of filing: 07.10.2005
(51) International Patent Classification (IPC): 
A61B 18/12(2006.01)
(84) Designated Contracting States:
DE ES FR GB IE IT

(30) Priority: 08.10.2004 US 616971 P
03.10.2005 US 242391

(62) Application number of the earlier application in accordance with Art. 76 EPC:
05021935.1 / 1645234

(71) Applicant: Covidien AG
8212 Neuhausen am Rheinfall (CH)

(72) Inventors:
  • Heard, David N.
    Boulder Colorado 80305 (US)
  • Dobbins, Gary Lee
    Longmont Colorado 80503 (US)
  • Gay, Brandon
    Superior Colorado 80027 (US)
  • Buysse, Steven P.
    Longmont Colorado 80501 (US)
  • McPherson, James W.
    Boulder Colorado 80301 (US)

(74) Representative: HOFFMANN EITLE 
Patent- und Rechtsanwälte Arabellastrasse 4
81925 München
81925 München (DE)

 
Remarks:
This application was filed on 17-03-2008 as a divisional application to the application mentioned under INID code 62.
 


(54) Electrosurgical system employing multiple electrodes


(57) A system and method for heat ablation of tissue in which energy is sequentially applied to at least two electrodes inserted into tissue. The system is comprised of a radiofrequency (RF) source for supplying RF energy, at least two electrodes configured to apply RF energy to tissue, at least one return electrode for returning the RF energy to the RF source, and a controller configured to sequentially apply the RF energy to each of the at least two electrodes. The sequential delivery of energy is determined by the measured current and voltage, the calculated impedance at each of the electrodes and the timing for each electrode. An internal load may be activated with the previously activated channel and remain on until the next channel is activated to avoid the generator from having an open circuit.