ULTRASOUND THERAPY TRANSDUCER HEAD AND ULTRASOUND THERAPY SYSTEM INCORPORATING THE SAME

• US 20100063422A1
• Filed: 03/04/2009
• Published: 03/11/2010
• Est. Priority Date: 09/08/2008
• Status: Abandoned Application

• Current Assignee: Sunnybrook Health Sciences Centre
• Original Assignee: Sunnybrook Health Sciences Centre
• Inventors: Song, Junho, Hynynen, Kullervo H.
• Application Number:
  US12/397,984
• Publication Number:
  US 20100063422A1
• Time in Patent Office: Days
• US Class Current: 601/2
• CPC Class Codes: A61B 2018/00011 with fluids
• CPC Class Codes: A61B 2018/00642 with feedback, i.e. closed loop control
• CPC Class Codes: A61B 8/546 involving monitoring or regulation of device temperature
• CPC Class Codes: A61N 2007/0078 with multiple treatment transducers
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00
• CPC Class Codes: B06B 3/00 Methods or apparatus specially adapted for transmitting mechanical vibrations of infrasonic, sonic, or ultrasonic frequency

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.

Claims

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.