Abstract: In a method of controlling electrosurgical power delivery based on a comparison of sensed tissue impedance to various impedance threshold values, energy is delivered to tissue in a sealing cycle as a series of pulses. An initial pulse has a profile with a preset energy starting value that increases at a ramping rate to a preset end value. Sensed impedance data are monitored throughout each pulse and compared to an impedance threshold value for RF setpoint, an impedance threshold value for cumulative time, and an impedance threshold value for energy cutback. Based on sensed impedance during a pulse, the profile of a subsequent pulse can be modified. In a high impedance event that reflects low tissue presence, energy may be cutback. A sealing cycle is stopped when a cumulative amount of time with an impedance value over the impedance cumulative time threshold value reaches a sealing cycle duration limit.

Abstract: A method of controlling electrosurgical power delivery is based on a comparison of sensed tissue impedance to various impedance threshold values. Energy is delivered to tissue in a sealing cycle as a series of pulses. A pulse has a profile with a preset energy starting value that increases at a ramping rate to a preset end value. Sensed impedance data are monitored throughout each pulse and compared to each of an impedance threshold value for RF setpoint, an impedance threshold value for cumulative time, and an impedance threshold value for energy cutback. Based on sensed impedance during a pulse, the profile of a subsequent pulse can be modified. In the event of a high impedance event that reflects low tissue presence, energy may be cutback. A sealing cycle is stopped when a cumulative amount of time with an impedance value over the impedance cumulative time threshold value reaches a limit.

Abstract: In a method of controlling electrosurgical power delivery based on a comparison of sensed tissue impedance to various impedance threshold values, energy is delivered to tissue in a sealing cycle as a series of pulses. An initial pulse has a profile with a preset energy starting value that increases at a ramping rate to a preset end value. Sensed impedance data are monitored throughout each pulse and compared to an impedance threshold value for RF setpoint, an impedance threshold value for cumulative time, and an impedance threshold value for energy cutback. Based on sensed impedance during a pulse, the profile of a subsequent pulse can be modified. In a high impedance event that reflects low tissue presence, energy may be cutback. A sealing cycle is stopped when a cumulative amount of time with an impedance value over the impedance cumulative time threshold value reaches a sealing cycle duration limit.

Abstract: A method of controlling electrosurgical power delivery based on a comparison of sensed tissue impedance to various impedance threshold values is provided. Energy is delivered to tissue in a sealing cycle as a series of pulses. An initial pulse has a profile with a preset energy starting value that increases at a ramping rate to a preset end value. Sensed impedance data are monitored throughout each pulse and compared to each of an impedance threshold value for RF setpoint, an impedance threshold value for cumulative time, and an impedance threshold value for energy cutback. Based on sensed impedance during a pulse, the profile of a subsequent pulse can be modified. In the event of a high impedance event that reflects low tissue presence, energy may be cutback. A sealing cycle is stopped when a cumulative amount of time with an impedance value over the impedance cumulative time threshold value reaches a sealing cycle duration limit.

Abstract: A method of controlling electrosurgical power delivery is based on a comparison of sensed tissue impedance to various impedance threshold values. Energy is delivered to tissue in a sealing cycle as a series of pulses. A pulse has a profile with a preset energy starting value that increases at a ramping rate to a preset end value. Sensed impedance data are monitored throughout each pulse and compared to each of an impedance threshold value for RF setpoint, an impedance threshold value for cumulative time, and an impedance threshold value for energy cutback. Based on sensed impedance during a pulse, the profile of a subsequent pulse can be modified. In the event of a high impedance event that reflects low tissue presence, energy may be cutback. A sealing cycle is stopped when a cumulative amount of time with an impedance value over the impedance cumulative time threshold value reaches a limit.

Abstract: An adaptive algorithm monitors the rate of tissue impedance change during an electrosurgical procedure. Impedance levels are examined to determine an impedance ramp and/or slope rate, which indicates the rate at which a target tissue is undergoing a phase or state change. The level of electrosurgical energy applied to the target tissue is adjusted in real time. Energy is applied to the target tissue at levels that allow tissue phase or state change to occur in an optimum fashion. Undesired results such as thermal damage and defective sealing are mitigated. Another embodiment determines impedance achieved within a specific interval and adjusts the electrosurgical energy applied to the tissue after a threshold impedance has been maintained or exceeded for a predetermined interval. A further aspect of the invention provides mitigation during processing for partial tissue coverage of device electrodes or thin tissue.

Abstract: A method of controlling electrosurgical power delivery based on a comparison of sensed tissue impedance to various impedance threshold values is provided. Energy is delivered to tissue in a sealing cycle as a series of pulses. An initial pulse has a profile with a preset energy starting value that increases at a ramping rate to a preset end value. Sensed impedance data are monitored throughout each pulse and compared to each of an impedance threshold value for RF setpoint, an impedance threshold value for cumulative time, and an impedance threshold value for energy cutback. Based on sensed impedance during a pulse, the profile of a subsequent pulse can be modified. In the event of a high impedance event that reflects low tissue presence, energy may be cutback. A sealing cycle is stopped when a cumulative amount of time with an impedance value over the impedance cumulative time threshold value reaches a sealing cycle duration limit.

Abstract: An adaptive algorithm monitors, inter alia, the rate of tissue impedance change during an electrosurgical procedure. Impedance levels achieved within a specific timeframe are examined to determine an impedance ramp and/or slope rate, which indicates the rate at which a target tissue is undergoing a phase or state change and, thus, indicates a desired rate of tissue processing. The level of electrosurgical energy applied to the target tissue is adjusted in real time in accordance with such rate of impedance change and/or by predetermined values. Energy is thus applied to the target tissue at levels that allow tissue phase or state change to occur in an optimum fashion, for example allowing moisture to escape from the tissue slowly, and thus avoid thermal damage. As a result, such undesired results as thermal damage and defective sealing are mitigated.