Ultrasound therapy transducer head and ultrasound therapy system incorporating the same

Abstract

An ultrasound therapy transducer head comprises an ultrasound source emitting ultrasonic radiation, the ultrasound source comprising a plurality of transducer elements, integrated driving electronics coupled to the transducer elements, the electronics generating at least one output ultrasound waveform and driving at least some of the transducer elements independently based on the at least one output ultrasound waveform and temperature control structure providing cooling for the electronics.

1 . An ultrasound therapy transducer head comprising:
 an ultrasound source emitting ultrasonic radiation, said ultrasound source comprising a plurality of transducer elements;   integrated driving electronics coupled to said transducer elements, said electronics generating at least one output ultrasound waveform and driving at least some of said transducer elements independently based on said at least one output ultrasound waveform; and   temperature control structure providing cooling for said electronics.   
     
     
         2 . An ultrasound therapy transducer head according to  claim 1  wherein said electronics drives each of said transducer elements independently. 
     
     
         3 . An ultrasound therapy transducer head according to  claim 2  wherein said electronics comprise digital and analog circuit components. 
     
     
         4 . An ultrasound therapy transducer head according to  claim 3  wherein said transducer elements are arranged in groups and wherein circuitry is provided for each group of transducer elements, each said circuitry comprising digital and analog circuit components. 
     
     
         5 . An ultrasound therapy transducer head according to  claim 4  wherein each said circuitry comprises a digital circuit and an analog circuit. 
     
     
         6 . An ultrasound therapy transducer head according to  claim 5  wherein for each group, said digital circuit comprises digital memory storing a digital waveform for each transducer element of said group and at least one digital to analog converter to convert each digital waveform output by said digital memory to an analog signal and wherein said analog circuit comprises at least one amplification stage receiving the analog signal output of said at least one digital to analog converter and providing a variable driving signal to each transducer element of said group. 
     
     
         7 . An ultrasound therapy transducer head according to  claim 6  wherein said digital circuit comprises a digital memory and a digital to analog converter for each transducer element of said group and wherein said analog circuit comprises at least one amplification stage for each transducer element of said group. 
     
     
         8 . An ultrasound therapy transducer head according to  claim 7  wherein each analog circuit comprises a pair of serially connected amplification stages. 
     
     
         9 . An ultrasound therapy transducer head according to  claim 8  wherein each analog circuit further comprises a high-pass filter between said amplification stages. 
     
     
         10 . An ultrasound therapy transducer head according to  claim 9  wherein a first of said amplification stages applies a voltage gain to the analog signal output of the associated digital to analog converter and the second of said amplification stages generates a high current analog output signal based on the high-pass filtered output of the first of said amplification stages. 
     
     
         11 . An ultrasound therapy transducer head according to  claim 7  wherein for each group, said digital circuit further comprises addressing circuitry communicating with each of the digital memories, said addressing circuitry controlling output of the digital waveforms by said digital memories and the loading of the digital waveforms into the digital memories. 
     
     
         12 . An ultrasound therapy transducer head according to  claim 11  wherein said addressing circuitry comprises memory storing count values and an address counter responsive to said memory for conditioning said digital memories to output the digital waveforms. 
     
     
         13 . An ultrasound therapy transducer head according to  claim 11  wherein said digital circuit further comprises a reference voltage source communicating with each of the digital to analog converters. 
     
     
         14 . An ultrasound therapy transducer head according to  claim 7  wherein for each group, said digital circuit and analog circuit are implemented on at least one integrated circuit chip. 
     
     
         15 . An ultrasound therapy transducer head according to  claim 14  wherein said digital circuit and analog circuit are implemented on separate integrated circuit chips. 
     
     
         16 . An ultrasound therapy transducer head according to  claim 15  wherein each of said integrated circuit chips is an application specific integrated circuit chip. 
     
     
         17 . An ultrasound therapy transducer head according to  claim 14  wherein said digital circuit and analog circuit are implemented on a single integrated circuit chip. 
     
     
         18 . An ultrasound therapy transducer head according to  claim 17  wherein said single integrated circuit chip is formed using a multi-chip package process. 
     
     
         19 . An ultrasound therapy transducer head according to  claim 2  wherein said temperature control structure comprises a heat exchanger for cooling said electronics. 
     
     
         20 . An ultrasound therapy transducer head according to  claim 19  further comprising a coupling fluid reservoir containing coupling fluid positioned adjacent said ultrasound source through which emitted ultrasonic radiation passes before exiting said ultrasound therapy transducer head. 
     
     
         21 . An ultrasound therapy transducer head according to  claim 20  wherein said heat exchanger also cools said coupling fluid. 
     
     
         22 . An ultrasound therapy transducer head according to  claim 21  wherein a wall of said coupling fluid reservoir is an acoustically transparent membrane forming an external surface of said ultrasound therapy transducer head. 
     
     
         23 . An ultrasound therapy transducer head according to  claim 22  wherein said transducer elements are immersed in said coupling fluid. 
     
     
         24 . An ultrasound therapy transducer head according to  claim 22  further comprising at least one sensor monitoring the temperature of said coupling fluid. 
     
     
         25 . An ultrasound therapy transducer head according to  claim 23  wherein said heat exchanger cools said coupling fluid in response to said at least one sensor. 
     
     
         26 . An ultrasound therapy transducer head according to  claim 2  further comprising an acoustic power sensing arrangement positioned adjacent said ultrasound source through which emitted ultrasonic radiation passes before exiting said ultrasound therapy transducer head, said acoustic power sensing arrangement sensing the acoustic power of the emitted ultrasonic radiation. 
     
     
         27 . An ultrasound therapy transducer head according to  claim 26  wherein said acoustic power sensing arrangement senses the acoustic power of ultrasonic radiation generated by each transducer element. 
     
     
         28 . An ultrasound therapy transducer head according to  claim 27  wherein said acoustic power sensing arrangement comprises a pressure sensitive layer and an electrode pair generally aligned with each transducer element, the electrodes of each electrode pair being positioned on opposite sides of said pressure sensitive layer. 
     
     
         29 . An ultrasound therapy transducer head according to  claim 28  wherein said pressure sensitive layer is a piezoelectric membrane and wherein each electrode pair develops a potential voltage between the electrodes thereof generally proportional to the power of the ultrasonic radiation emitted by the associated transducer element. 
     
     
         30 . An ultrasound therapy transducer head according to  claim 29  further comprising readout circuitry for reading out the potential voltages developed by the electrode pairs. 
     
     
         31 . An ultrasound therapy transducer head according to  claim 30  wherein the readout circuitry selectively reads out the potential voltages developed by the electrode pairs. 
     
     
         32 . An ultrasound therapy transducer head according to  claim 31  further comprising control circuitry communicating with said readout circuitry and said electronics, said control circuitry providing feedback to said electronics based on the potential voltages readout by said readout circuitry. 
     
     
         33 . An ultrasound therapy transducer head according to  claim 32  wherein said temperature control structure provides cooling to said electronics based on said feedback. 
     
     
         34 . An ultrasound therapy transducer head according to  claim 28  further comprising a coupling fluid reservoir containing coupling fluid positioned adjacent said ultrasound source through which emitted ultrasonic radiation passes before exiting said transducer head. 
     
     
         35 . An ultrasound therapy transducer head according to  claim 34  wherein a wall of said coupling fluid reservoir is an acoustically transparent membrane forming an external surface of said ultrasound transducer head. 
     
     
         36 . An ultrasound therapy transducer head according to  claim 35  wherein said transducer elements and said acoustic power sensing arrangement are immersed in said coupling fluid. 
     
     
         37 . An ultrasound therapy transducer head according to  claim 36  further comprising readout circuitry for reading the sensed, ultrasonic radiation acoustic power. 
     
     
         38 . An ultrasound therapy transducer head according to  claim 37  further comprising control circuitry communicating with said readout circuitry and said electronics, said control circuitry providing feedback to said electronics based on the sensed, ultrasonic radiation acoustic power readout by said readout circuitry. 
     
     
         39 . An ultrasound therapy transducer head comprising:
 an ultrasound source comprising at least one transducer element for generating an ultrasound beam; and   an acoustic power sensing arrangement through which said ultrasound beam passes, said acoustic power sensing arrangement sensing the acoustic power of the ultrasound beam generated by said at least one transducer element.   
     
     
         40 . An ultrasound therapy transducer head according to  claim 39  wherein said ultrasound source comprises an array of transducer elements and wherein said acoustic power sensing arrangement senses the acoustic power of the ultrasound beam generated by each transducer element. 
     
     
         41 . An ultrasound therapy transducer head according to  claim 40  wherein said acoustic power sensing arrangement comprises a pressure sensitive layer and an electrode pair generally aligned with each transducer element, the electrodes of each electrode pair being positioned on opposite sides of said pressure sensitive layer. 
     
     
         42 . An ultrasound therapy transducer head according to  claim 41  wherein said pressure sensitive layer is a piezoelectric membrane and wherein each electrode pair develops a potential voltage between the electrodes thereof generally proportional to the power of the ultrasound beam generated by the associated transducer element. 
     
     
         43 . An ultrasound therapy transducer head according to  claim 42  further comprising readout circuitry for reading out the potential voltages developed by the electrode pairs. 
     
     
         44 . An ultrasound therapy transducer head according to  claim 43  wherein the readout circuitry selectively reads out the potential voltages developed by the electrode pairs. 
     
     
         45 . An ultrasound therapy transducer head according to  claim 44  further comprising control circuitry communicating with said readout circuitry and said ultrasound source, said control circuitry providing feedback to said ultrasound source based on the potential voltages readout by said readout circuitry. 
     
     
         46 . An ultrasound therapy transducer head according to  claim 40  further comprising a coupling fluid reservoir containing coupling fluid positioned adjacent said ultrasound source through which the generated ultrasound beams pass before exiting said ultrasound therapy transducer head. 
     
     
         47 . An ultrasound therapy transducer head according to  claim 46  wherein a wall of said coupling fluid reservoir is an acoustically transparent membrane forming an external surface of said ultrasound transducer head. 
     
     
         48 . An ultrasound therapy transducer head according to  claim 47  wherein said transducer elements and said acoustic power sensing arrangement are immersed in said coupling fluid. 
     
     
         49 . An ultrasound therapy transducer head according to  claim 48  further comprising readout circuitry for reading sensed the ultrasound beam powers. 
     
     
         50 . An ultrasound therapy transducer head according to  claim 49  further comprising control circuitry communicating with said readout circuitry and said ultrasound source, said control circuitry providing feedback to said ultrasound source based on the read ultrasound beam powers. 
     
     
         51 . An ultrasound therapy transducer head according to  claim 46  further comprising a heat exchanger for cooling said coupling fluid. 
     
     
         52 . An ultrasound therapy transducer head according to  claim 51  further comprising at least one first sensor monitoring the temperature of said coupling fluid. 
     
     
         53 . An ultrasound therapy transducer head according to  claim 52  wherein said heat exchanger cools said coupling fluid in response to said at least one first sensor. 
     
     
         54 . An ultrasound therapy transducer head according to  claim 53  further comprising at least one second sensor monitoring the temperature of said ultrasound source. 
     
     
         55 . An ultrasound therapy transducer head according to  claim 54  wherein said heat exchanger cools said ultrasound source in response said at least one second sensor. 
     
     
         56 . An ultrasound therapy transducer head comprising:
 an ultrasound source comprising at least one transducer element for generating an ultrasound beam; and   temperature control structure to control temperature within said ultrasound therapy transducer head.   
     
     
         57 . An ultrasound therapy transducer head according to  claim 56  further comprising a coupling fluid reservoir containing coupling fluid positioned adjacent said ultrasound source through which the ultrasound beam passes before exiting said transducer head. 
     
     
         58 . An ultrasound therapy transducer head according to  claim 57  further comprising a heat exchanger for cooling said coupling fluid. 
     
     
         59 . An ultrasound therapy transducer head according to  claim 58  further comprising at least one first sensor monitoring the temperature of said coupling fluid. 
     
     
         60 . An ultrasound therapy transducer head according to  claim 59  wherein said heat exchanger cools said coupling fluid in response to said at least one first sensor. 
     
     
         61 . An ultrasound therapy transducer head according to  claim 60  further comprising at least one second sensor monitoring the temperature of said ultrasound source. 
     
     
         62 . An ultrasound therapy transducer head according to  claim 61  wherein said heat exchanger cools said ultrasound source in response to said at least one second sensor.