| 摘要 |
PURPOSE:To prevent the thermal damage of a patient by the malfunction of the device and an increase in high-frequency leak current and to improve safety by canceling the floating capacity component generated in an ultrasonic surgical knife device at the time of introducing a high-frequency disposition signal to the front end of a hand piece for ultrasonic disposition device and making high-frequency disposition. CONSTITUTION:The high-frequency disposition signal from an electric surgical knife device 3 passes the affected part A point of the patient 15 on a bed 14 according to the route shown by a solid line (a) and flows through a counter electrode plate 11. Whereas, the high-frequency disposition signal is passed through the ground according to the route shown by a broken line (b) by the floating capacity Cc generated in the ultrasonic surgical knife device 2 and is passed through the part, such as, for example, the contact point B of the patient 15 and the bed 14, via the bed 14, which is in contact with the ground, by which the current flowing through the counter electrode plate 11 is generated and the thermal damage is eventually generated. The means 16 for canceling the floating capacity Cs is, therefore, provided in the ultrasonic surgical knife device 2. The means 16 for canceling the above-mentioned capacity is a parallel resonance circuit constituted of a coil L and a capacitor C and the shunt generated by the floating capacity Cc is decreased by the frequency characteristics of this circuit. |
