Differential temperature measurement for ultrasound transducer thermal control

A method for determining and controlling the surface temperature of tissue adjacent to a transducer that applies energy to the tissue, comprising the steps of:

• measuring a first temperature representative of the temperature of the transducer;
• measuring a second temperature representative of the ambient temperature of the tissue in a region that is isolated from the transducer;
• and
• calculating the surface temperature of the tissue adjacent to the transducer from the first measured temperature and the second measured temperature;
• and
• controlling the energy applied to said transducer in response to said calculated surface temperature.

Apparatus for determining the surface temperature of tissue adjacent to a transducer that applies energy to the tissue, comprising:

• means for measuring a first temperature representative of the temperature of the transducer;
• means for measuring a second temperature representative of the ambient temperature of the tissue in a region that is thermally isolated from the transducer;
• and
• means for calculating the surface temperature of the tissue adjacent to the transducer from the first measured temperature and the second measured temperature.

Apparatus for application of ultrasound energy to biological tissue, comprising:

• a probe having an ultrasound transducer mounted therein;
• a first temperature sensor mounted in said probe for sensing a first temperature representative of the temperature of an emitting face of said ultrasound transducer;
• a second temperature sensor mounted in said probe for sensing a second temperature representative of the ambient temperature of the biological tissue in a region that is thermally isolated from the ultrasound transducer;
• a power source for energizing said ultrasound transducer;
• and
• means for calculating the surface temperature of the tissue adjacent to the ultrasound transducer from the first sensed temperature and the second sensed temperature

A method for controlling the surface temperature of tissue adjacent to an ultrasound transducer that applies ultrasound energy to the tissue, comprising the steps of:

• measuring a first temperature representative of the temperature of the ultrasound transducer;
• measuring a second temperature representative of the ambient temperature of the tissue in a region that is thermally isolated from the ultrasound transducer;
• calculating the surface temperature of the tissue adjacent to the ultrasound transducer from the first measured temperature and the second measured temperature;
• and
• reducing the ultrasound energy transmitted by said ultrasound transducer when said calculated surface temperature exceeds a temperature limit.