An ultrasonic medical treatment device has a probe, a transducer for mechanically vibrating the probe at an ultrasonic frequency, a voltage source for energizing the transducer, and another electrical voltage source for feeding to the probe a high-frequency alternating waveform of limited current and limited voltage to be conducted into a patient through the operative tip of the probe after placement of the operative tip into contact with the patient. The alternating waveform has a current and a voltage so limited as to prevent damage to organic tissues while stimulating nerves to reduce or suppress pain.