Method and system for ultrasound induced hyperthermia with microwave thermometry feedback

Abstract

A device for providing hyperthermia treatment includes an ultrasound energy generator configured to apply low intensity ultrasound to target tissue. The low intensity ultrasound energy induces therapeutic heating in the tissue at or below the surface of the skin. In order to control the temperature of the tissue during therapy, a microwave radiometer, such as a Dicke radiometer, can be used to measure the temperature of the tissue and feed back the temperature measurement to the ultrasound energy generator to control ultrasonic energy produced and control the temperature of the target tissue.

What is claimed is: 
     
         1 . A system for providing ultrasound based heating comprising:
 an ultrasound transducer coupled to an ultrasound generator, the ultrasound generator being configured to generate a low intensity ultrasound signal and direct ultrasound energy at a target tissue;   a microwave radiometer including a microwave antenna and a digital signal processor configured to receive and process microwave energy received from the target tissue;   wherein the digital signal processor determines a temperature of the target tissue and the digital signal processor is connected to the ultrasound generator to send a signal representative of the temperature of the target tissue to control the low intensity ultrasound generated by the ultrasound generator.   
     
     
         2 . The system according to  claim 1  wherein the ultrasound transducer produces ultrasonic energy at a predefined frequency within a range from 0.5 MHz to 5.0 MHz. 
     
     
         3 . The system according to  claim 1  wherein the ultrasonic transducer produces ultrasonic energy at a predefined intensity within a range from 0.1 Watts per cubic centimeter to 3.0 Watts per cubic centimeter. 
     
     
         4 . The system according to  claim 1  wherein the ultrasonic transducer heats the target tissue to a predefined temperature in a range from 38 to 44 degrees Celsius. 
     
     
         5 . The system according to  claim 4  wherein the ultrasonic transducer heats a portion of the target tissue at least 2.0 centimeters below a surface of the target tissue to a predefined temperature in a range from 38 to 44 degrees Celsius. 
     
     
         6 . A method of providing ultrasound based heating comprising:
 providing an ultrasound transducer coupled to an ultrasound generator,   using the ultrasound generator to generate a low intensity ultrasound signal and the ultrasound transducer to direct ultrasound energy at a target tissue;   providing a microwave radiometer including a microwave antenna and a digital signal processor;   positioning the microwave radiometer to receive microwave energy from the target tissue;   process the received microwave energy by digital signal processor to determine a temperature of the target tissue;   send a signal representative of the temperature of the target tissue to the ultrasound generator and cause the ultrasound generator to change at least one of an output power and a signal frequency of the low intensity ultrasound signal.   
     
     
         7 . The method according to  claim 6  wherein the ultrasound transducer produces ultrasonic energy at a predefined frequency within a range from 0.5 MHz to 5.0 MHz. 
     
     
         8 . The method according to  claim 6  wherein the ultrasonic transducer produces ultrasonic energy at a predefined intensity within a range from 0.1 Watts per cubic centimeter to 3.0 Watts per cubic centimeter. 
     
     
         9 . The method according to  claim 6  wherein the ultrasonic transducer heats the target tissue to a predefined temperature in a range from 38 to 44 degrees Celsius. 
     
     
         10 . The method according to  claim 9  wherein the ultrasonic transducer heats a portion of the target tissue at least 2.0 centimeters below a surface of the target tissue to a predefined temperature in a range from 38 to 44 degrees Celsius.