Patent ID: 7833258
Filing Date: 2010-11-16
Classification: A61N

Abstract:
1. A thermal therapy device comprising a transformer, an inverter circuit connected to the primary side of said transformer, a series resonance circuit having a resonance frequency, connected to the secondary side of said transformer and including a magnetic field generation coil and a resonance condenser and a controller for supplying a drive signal to said inverter circuit in such a way that the frequency of a current passing in said series resonance circuit conforms with the resonance frequency thereof, the device generating a magnetic field of high frequency toward a patient's affected portion; wherein said thermal therapy device comprises a current detecting means for detecting the current passing in said series resonance circuit; and said controller comprises a mode setting means for alternately switching between an operation mode during which a magnetic field of high frequency is generated toward the patient's affected portion and an measurement mode during which the resonance frequency of said series resonance circuit is measured to set the mode, a resonance frequency determining means for receiving an input of a signal of a current having been detected by said current detecting means and determining said resonance frequency based upon said signal during the measurement mode set by said mode setting means, and a drive signal supplying means for supplying a drive signal of a switching frequency to said inverter circuit using the resonance frequency having been determined by said resonance frequency determining means during the operation mode set by said mode setting means.