Multi-frequency ultrasound therapy systems and methods

A multi-frequency ultrasound therapy device comprising:

• a generator/control unit, comprising:
• a precision oscillator having wave shaping circuitry for generating a wave-form at multiple frequencies;
• a microprocessor for controlling and monitoring a generation and output of said wave-form at any one selected frequency of said multiple frequencies, said microprocessor operably interfacing with said precision oscillator;
• and
• at least one output amplifier for amplifying the generated wave-form;
• an applicator sound head operably coupled to said generator/control unit;
• means associated with said output amplifier for supplying the amplified wave-form to the applicator sound head as electrical signals;
• a thermistor interfaced with the microprocessor for monitoring an operating temperature of the applicator sound head and disabling the precision oscillator when the operating temperature of the applicator sound head exceeds a safety level;
• at least two electrodes having an electrical connection leading from the generator/control unit;
• an aluminum alloy applicator member;
• a crystal transducer formed of a ceramic and bonded to said applicator member, the crystal transducer being operably coupled to said electrodes for converting said electrical signals into multi-frequency ultrasound waves, the crystal transducer and the applicator member in association with the applicator sound head for operating at a first desired resonant frequency, a second desired resonant frequency and a third desired resonant frequency.

A method for calibrating a multi-frequency sound head, the method comprising the steps of:

• obtaining an applicator sound head having a transducer providing a natural resonance at a first desired frequency, with additional resonances at a second desired frequency and a third desired frequency;
• scanning the applicator sound head at a first temperature through at least three output frequencies;
• determining a specific driving frequency of maximum efficiency at each of said output frequencies;
• calculating an impedance of the applicator sound head from detected output voltage and current at each of said output frequencies;
• scanning the applicator sound head at a second temperature being higher than the first temperature;
• detecting a change in said driving frequency of maximum efficiency at each of said scanned output frequencies;
• storing for each of said three output frequencies the head impedance and the driving frequency change;
• generating a multi-frequency wave-form;
• amplifying said multi-frequency wave-form;
• delivering the amplified multi-frequency wave-form to the applicator sound head as high-frequency electrical signals;
• converting the high-frequency electrical signals into ultrasonic waves;
• monitoring the temperature and output current of the applicator sound head;
• and
• calibrating the driving frequency to maintain a level of optimum ultrasonic output.