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US Patent 5540684 - Method and apparatus for electrosurgically treating tissue
US Patent Issued on July 30, 1996
Estimated Patent Expiration Date:
July 28, 2014Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
Estimated Patent Expiration Date:
July 28, 2014Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.AbstractTissue impedance or tissue impedance in combination with tissue temperature is used to control electrosurgical tissue treatment. Tissue impedance alone provides better control of electrosurgical treatment by determining an initial maximum tissue impedance, a minimum tissue impedance selecting a point between the maximum and minimum impedances, preferably the average, as an impedance threshold, and turning off rf power to the electrosurgical instrument when the impedance reaches the threshold as it rises from the minimum. Control may also be by the combination of tissue impedance and temperature. Temperature is controlled to maintain a selected preferred temperature and a maximum temperature is also selected so that if the tissue reaches the maximum temperature, power is turned off. Impedance control is combined with temperature control so that the temperature of the instrument is maintained at a selected preferred temperature unless a maximum temperature is exceeded, which normally will not happen. The impedance is also monitored with maximum and minimum values being determined as well as a threshold impedance between the max and the min. When the threshold, preferably the average impedance, is reached, power is removed from the instrument. | InventorApplicationNo. 282522 filed on 07/28/1994US Classes:606/40, Coagulation606/38, With feed back control606/51With forceps or tweezersField of Search606/37, Combined cutting-coagulation606/38, With feed back control606/39, Cutting606/40, Coagulation606/51, With forceps or tweezers606/52With forceps or tweezersExaminersPrimary: Cohen, Lee S.US Patent References3651811, 4232676, Surgical cutting instrumentIssued on: 11/11/1980 Inventor: Herczog4248231, Surgical cutting instrument Issued on: 02/03/1981 Inventor: Herczog , et al.4474179, Method and apparatus for the high frequency coagulation of protein for surgical purposes Issued on: 10/02/1984 Inventor: Koch4651280, Electrosurgical control system using tissue conductivity Issued on: 03/17/1987 Inventor: Chang , et al.4658819, Electrosurgical generator Issued on: 04/21/1987 Inventor: Harris , et al.4685459, Device for bipolar high-frequency coagulation of biological tissue Issued on: 08/11/1987 Inventor: Koch , et al.4903696, Electrosurgical generator Issued on: 02/27/1990 Inventor: Stasz, et al.4938761, Bipolar electrosurgical forceps Issued on: 07/03/1990 Inventor: Ensslin5057099, Method for laser surgery Issued on: 10/15/1991 Inventor: Rink5122137, Temperature controlled RF coagulation Issued on: 06/16/1992 Inventor: Lennox5342357, Fluid cooled electrosurgical cauterization system Issued on: 08/30/1994 Inventor: Nardella5403312Electrosurgical hemostatic device Issued on: 04/04/1995 Inventor: Yates, et al. Foreign Patent References
International ClassA61B 017/39 |
