Abstract: A medical device is described having a handle, a shaft coupled to the handle and an end effector coupled to the shaft. In one embodiment, the device includes an ultrasonic transducer and is arranged so that ultrasonic or electrical energy can be delivered to a vessel or tissue to be treated. Various novel sensing circuits are described to allow a measure of the drive signal to be measured and fed back to a controller. An active fuse circuit is also described for protecting one or more batteries of the device from an over-current situation.

Abstract: A medical device is described having a handle, a shaft coupled to the handle and an end effector coupled to the shaft. In one embodiment, the device includes an ultrasonic transducer and is arranged so that ultrasonic or electrical energy can be delivered to a vessel or tissue to be treated. Various novel sensing circuits are described to allow a measure of the drive signal to be measured and fed back to a controller. An active fuse circuit is also described for protecting one or more batteries of the device from an over-current situation.

Abstract: A medical device is described having a handle, a shaft coupled to the handle, an end effector coupled to the shaft and an ultrasonic transducer coupled to the end effector for delivering ultrasonic energy to tissue or a vessel to be treated. A drive circuit is provided for generating a drive signal that is applied to the ultrasonic transducer. In one embodiment, the drive circuit includes a resonant circuit and a controller that varies the period of the drive signal passed through the resonant circuit in order to control the power supplied to the ultrasonic transducer.

Abstract: A medical device is described having a handle, a shaft coupled to the handle and an end effector coupled to the shaft. In one embodiment, the device includes an ultrasonic transducer and is arranged so that ultrasonic or electrical energy can be delivered to a vessel or tissue to be treated. Various novel sensing circuits are described to allow a measure of the drive signal to be measured and fed back to a controller. An active fuse circuit is also described for protecting one or more batteries of the device from an over-current situation.

Abstract: A medical device is described having a handle, a shaft coupled to the handle and an end effector coupled to the shaft. In one embodiment, the device includes an ultrasonic transducer and is arranged so that ultrasonic or electrical energy can be delivered to a vessel or tissue to be treated. Various novel sensing circuits are described to allow a measure of the drive signal to be measured and fed back to a controller. An active fuse circuit is also described for protecting one or more batteries of the device from an over-current situation.

Abstract: A medical device is described having a handle, a shaft coupled to the handle, an end effector coupled to the shaft and an ultrasonic transducer coupled to the end effector for delivering ultrasonic energy to tissue or a vessel to be treated. A drive circuit is provided for generating a drive signal that is applied to the ultrasonic transducer. In one embodiment, the drive circuit includes a resonant circuit and a controller that varies the period of the drive signal passed through the resonant circuit in order to control the power supplied to the ultrasonic transducer.