Ultrasound guided high intensity focused ultrasound treatment of nerves

• US 20050240126A1
• Filed: 12/16/2004
• Published: 10/27/2005
• Est. Priority Date: 09/17/1999
• Status: Active Grant

• Current Assignee: University of Washington
• Original Assignee: University of Washington
• Inventors: Little, James W., Vaezy, Shahram, Foley, Jessica L.
• Granted Patent: US 7,510,536 B2
• Time in Patent Office: Days
• US Class Current: 601/2
• CPC Class Codes: A61B 2017/4216 Operations on uterus, e.g. endometrium
• CPC Class Codes: A61B 2018/00434 Neural system
• CPC Class Codes: A61B 2090/378 using ultrasound
• CPC Class Codes: A61B 8/06 Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00
• CPC Class Codes: A61B 8/0816 using echo-encephalography
• CPC Class Codes: A61B 8/0833 involving detecting or locating foreign bodies or organic structures
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/4209 by using holders, e.g. positioning frames
• CPC Class Codes: A61B 8/4254 using sensors mounted on the probe
• CPC Class Codes: A61B 8/4281 characterised by sound-transmitting media or devices for coupling the transducer to the tissue
• CPC Class Codes: A61B 8/4444 related to the probe
• CPC Class Codes: A61B 8/481 involving the use of contrast agent, e.g. microbubbles introduced into the bloodstream analysis of echo signal exploiting properties of a contrast enhancer in devices for short-range imaging with acoustic waves G01S7/52039
• CPC Class Codes: A61B 8/483 involving the acquisition of a 3D volume of data
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00

Abstract

A method for using high intensity focused ultrasound (HIFU) to treat neurological structures to achieve a desired therapeutic affect. Depending on the dosage of HIFU applied, it can have a reversible or irreversible effect on neural structures. For example, a relatively high dose of HIFU can be used to permanently block nerve function, to provide a non-invasive alternative to severing a nerve to treat severe spasticity. Relatively lower doses of HIFU can be used to reversible a block nerve function, to alleviate pain, to achieve an anesthetic effect, or to achieve a cosmetic effect. Where sensory nerves are not necessary for voluntary function, but are involved in pain associated with tumors or bone cancer, HIFU can be used to non-invasively destroy such sensory nerves to alleviate pain without drugs. Preferably, ultrasound imaging synchronized to the HIFU therapy is used to provide real-time ultrasound image guided HIFU therapy of neural structures.

Claims

1. A method for using high intensity focused ultrasound (HIFU) to provide therapy to a treatment site corresponding to a portion of a nervous system of a patient, the treatment site being spaced apart from a HIFU therapy device, comprising the steps of:

(a) determining an appropriate treatment site associated with the nervous system of the patient to be treated to achieve a desired non-permanent therapeutic effect;

(b) selecting a dose of HIFU required to achieve the desired non-permanent therapeutic effect;

(c) positioning the HIFU therapy device such that a focal point of the HIFU therapy device is disposed adjacent to the treatment site;

(d) verifying that the focal point of the HIFU therapy device is properly positioned relative to the treatment site, and if not repositioning the HIFU therapy device until the HIFU therapy device is properly positioned relative to the treatment site; and

(e) energizing the HIFU therapy device to provide the dose of HIFU required to achieve the desired non-permanent therapeutic effect.

2. The method of claim 1, further comprising the steps of:

(a) using ultrasound imaging to obtain an ultrasound image of the treatment site during therapy; and

(b) synchronizing the HIFU therapy device and the ultrasound imaging such that noise in the ultrasound image arising from the HIFU therapy device does not prevent visualization of the focal point in the ultrasound image during therapy.

3. The method of claim 1, wherein the non-permanent therapeutic effect comprises blocking nerve conduction to achieve a cosmetic effect.

4. The method of claim 1, wherein the non-permanent therapeutic effect comprises blocking nerve conduction to provide anesthesia of a nerve.

5. The method of claim 1, wherein the non-permanent therapeutic effect comprises blocking nerve conduction to alleviate pain.

6. The method of claim 1, wherein the non-permanent therapeutic effect comprises blocking nerve conduction to treat spasticity.

7. The method of claim 1, wherein the step of determining the appropriate treatment site comprises the step of selecting a nerve as the treatment site.

8. The method of claim 1, wherein the step of determining the appropriate treatment site comprises the step of selecting a nerve ganglia as the treatment site.

9. The method of claim 1, wherein the step of selecting the dose of HIFU required to achieve the desired therapeutic effect comprises the step of determining the dose of HIFU required to partially block nerve conduction at the treatment site.

10. The method of claim 1, wherein the step of selecting the dose of HIFU required to achieve the desired therapeutic effect comprises the step of determining the dose of HIFU required to completely block nerve conduction at the treatment site.

11. The method of claim 1, wherein the step of verifying that the focal point of the HIFU therapy device is properly positioned relative to the treatment site comprises the step of using magnetic resonance imaging to determine a position of the focal point relative to the treatment site.

12. The method of claim 1, wherein the step of verifying that the focal point of the HIFU therapy device is properly positioned relative to the treatment site comprises the steps of:

(a) using ultrasound imaging to obtain an ultrasound image of the treatment site; and

(b) energizing the HIFU therapy device at a power level that is insufficient to induce damage at the treatment site, but is sufficient to enable the focal point to be visualized in the ultrasound image.

13. The method of claim 1, wherein the step of verifying that the focal point of the HIFU therapy device is properly positioned relative to the treatment site comprises the steps of:

(a) positioning an ultrasound imaging device and the HIFU therapy device such that the focal point lies within an image plane provided by the ultrasound imaging device;

(b) providing an indication of where the focal point lies within an ultrasound image generated by the ultrasound imaging device, such that the focal point can be visualized in the ultrasound image, even when the HIFU therapy device is not energized;

(c) fixing a position of the ultrasound imaging device relative to the HIFU therapy device, such that movement of either device will not move the focal point out of the image plane;

(d) obtaining the ultrasound image of the treatment site; and

(e) manipulating at least one of the ultrasound imaging device, the HIFU therapy device, and a frame used to secure the position of the ultrasound imaging device relative to the HIFU therapy device until the indication of the focal point is properly positioned relative to the treatment site.

14. The method of claim 1, wherein the step of verifying that the focal point of the HIFU therapy device is properly positioned relative to the treatment site comprises the steps of:

(a) identifying what type of physiological reaction should occur if the focal point of the HIFU therapy device is properly positioned relative to the treatment site when the HIFU therapy device is energized to stimulate the nervous system of the patient, to achieve an identified physiological reaction;

(b) energizing the HIFU therapy device at a power level that is insufficient to induce damage at the treatment site but is sufficient to stimulate the nervous system of the patient;

(c) observing any physiological reaction to achieve an observed physiological reaction; and

(d) determining if the identified physiological reaction corresponds to the observed physiological reaction, and if so, concluding that the focal point of the HIFU therapy device is properly positioned relative to the treatment site.

15. The method of claim 1, wherein the step of verifying that the focal point of the HIFU therapy device is properly positioned relative to the treatment site comprises the steps of:

(a) using an imaging device to obtain an image of the treatment site and adjacent areas;

(b) tracking a position of the imaging device;

(c) tracking a position of the HIFU therapy device;

(d) based on the positions of the imaging ultrasound transducer and the HIFU therapy device, introducing an icon into the image, the icon corresponding to a predicted position of the focal point based on the positions of the imaging device and the HIFU therapy device; and

(e) manipulating the position of at least one of the imaging device and the HIFU therapy device until the icon coincides with the treatment site in the image.

16. A method for using high intensity focused ultrasound (HIFU) to provide therapy to a treatment site corresponding to a portion of a nervous system of a patient, the treatment site being spaced apart from a HIFU therapy device, comprising the steps of:

(a) determining an appropriate treatment site to be treated to achieve a desired therapeutic effect;

(b) selecting a dose of HIFU required to achieve the desired therapeutic effect, the desired therapeutic effect comprising blocking nerve conduction for at least one of the following purposes;

(i) to alleviate pain;

(ii) to provide a palliative treatment for cancer;

(iii) to treat spasticity;

(iv) to provide an anesthetic effect; and

(v) to provide a cosmetic effect;

(c) positioning the HIFU therapy device such that a focal point of the HIFU therapy device is disposed adjacent to the treatment site;

(d) verifying that the focal point of the HIFU therapy device is properly positioned relative to the treatment site, and if not, repositioning the HIFU therapy device until the HIFU therapy device is properly positioned relative to the treatment site; and

(e) energizing the HIFU therapy device to provide the dose of HIFU to the treatment site that is required to achieve the desired therapeutic effect.

17. The method of claim 16, further comprising the steps of:

(a) using ultrasound imaging to obtain an ultrasound image of the treatment site during therapy; and

(b) synchronizing the HIFU therapy device and the ultrasound imaging such that noise in the ultrasound image arising from the HIFU therapy device does not prevent visualization of the focal point in the ultrasound image during therapy.

18. The method of claim 16, wherein the step of determining the appropriate treatment site comprises the step of selecting at least one of a nerve and a nerve ganglia as the treatment site.

19. The method of claim 16, wherein the step of selecting the dose of HIFU required to achieve the desired therapeutic effect comprises the step of selecting the dose of HIFU required to partially block nerve conduction at the treatment site.

20. The method of claim 16, wherein the step of selecting the dose of HIFU required to achieve the desired therapeutic effect comprises the step of selecting the dose of HIFU required to completely block nerve conduction at the treatment site.

21. The method of claim 16, wherein the step of selecting the dose of HIFU required to achieve the desired therapeutic effect comprises the step of selecting the dose of HIFU required to permanently block nerve conduction at the treatment site.

22. The method of claim 16, wherein the step of selecting the dose of HIFU required to achieve the desired therapeutic effect comprises the step of selecting the dose of HIFU required to temporarily block nerve conduction at the treatment site.

23. The method of claim 16, wherein the step of verifying that the focal point of the HIFU therapy device is properly positioned relative to the treatment site comprises the steps of:

(a) using ultrasound imaging to obtain an ultrasound image of the treatment site; and

(b) energizing the HIFU therapy device at a power level that is insufficient to induce damage at the treatment site, but is sufficient to enable the focal point to be visualized in the ultrasound image.

24. The method of claim 16, wherein the step of verifying that the focal point of the HIFU therapy device is properly positioned relative to the treatment site comprises the steps of:

(a) identifying a type of physiological reaction that should occur if the focal point of the HIFU therapy device is properly positioned relative to the treatment site when the HIFU therapy device is energized to stimulate the nervous system of the patient, yielding an identified physiological reaction;

(b) energizing the HIFU therapy device at a power level that is insufficient to induce damage at the treatment site, but is sufficient to stimulate the nervous system of the patient;

(c) observing any physiological reaction to achieve an observed physiological reaction; and

(d) determining if the identified physiological reaction corresponds to the observed physiological reaction, and if so, concluding that the focal point of the HIFU therapy device is properly positioned relative to the treatment site.

25. The method of claim 16, wherein the step of verifying that the focal point of the HIFU therapy device is properly positioned relative to the treatment site comprises the steps of:

(a) positioning an ultrasound imaging device and the HIFU therapy device such that the focal point lies within an image plane provided by the ultrasound imaging device;

(b) providing an indication of where the focal point lies within the image plane, such that the focal point can be visualized in the image plane even when the HIFU therapy device is not energized;

(c) fixing a position of the ultrasound imaging device relative the HIFU therapy device, such that movement of either device will not move the focal point out of the image plane;

(d) obtaining an ultrasound image of the treatment site; and

(e) manipulating at least one of the ultrasound imaging device, the HIFU therapy device, and a frame used to secure the position of the ultrasound imaging device relative to the HIFU therapy device, until the indication of the focal point is properly positioned relative to the treatment site.

26. The method of claim 16, wherein the step of verifying that the focal point of the HIFU therapy device is properly positioned relative to the treatment site comprises the steps of:

(a) using an imaging device to obtain an image of the treatment site;

(b) tracking a position of the imaging device;

(c) tracking a position of the HIFU therapy device;

(d) based on the positions of the imaging device and the HIFU therapy device, introducing an icon into the image, the icon corresponding to a predicted position of the focal point based on the positions of the imaging device and the HIFU therapy device; and

(d) manipulating the position of at least one of the imaging device and the HIFU therapy device until the icon coincides with the treatment site in the image.

27. A method for using ultrasound to simultaneously image a target area and to provide therapy to a treatment site disposed within said target area, the treatment site corresponding to a portion of a nervous system, thereby inducing a desired therapeutic effect, comprising the steps of:

(a) positioning an imaging ultrasound transducer so as to enable an image of the target area to be obtained, and positioning a therapeutic ultrasound transducer so that a focal point corresponding to the therapeutic ultrasound transducer generally coincides with a portion of the target area;

(b) energizing the imaging ultrasound transducer to generate an ultrasound image of the target area;

(c) selecting the treatment site from within the ultrasound image;

(d) energizing the therapeutic ultrasound transducer to produce pulses of high intensity focused ultrasound (HIFU) therapeutic waves to induce the desired therapeutic effect;

(e) synchronizing the HIFU therapeutic waves relative to imaging waves produced by the imaging ultrasound transducer, such that noise in the ultrasound image from the HIFU therapeutic waves is displayed in a specific portion of the displayed target area; and

(f) enabling a user to shift the noise arising from the HIFU therapeutic waves to a portion of the ultrasound image that does not correspond to the treatment site, thereby enabling the treatment site to be observed in real-time as the HIFU therapeutic waves are administered to the treatment site.

28. The method of claim 27, wherein the desired therapeutic effect comprises blocking nerve conduction for at least one of the following purposes:

(a) to alleviate pain;

(b) to treat spasticity;

(c) to provide an anesthetic effect; and

(d) to provide a cosmetic effect.

29. The method of claim 27, further comprising a step of selecting a dose of HIFU required to achieve the desired therapeutic effect before energizing the therapeutic ultrasound transducer.

30. The method of claim 27, wherein the step of selecting a dose of HIFU required to achieve the desired therapeutic effect comprises the step of selecting a dose that will result in a temporary therapeutic effect.

31. The method of claim 27, wherein the step of selecting a dose of HIFU required to achieve the desired therapeutic effect comprises the step of selecting a dose that will result in a partial blockage of nerve conduction.

32. The method of claim 27, further comprising a step of verifying a position of the focal point relative to the target area before energizing the therapeutic ultrasound transducer to induce the desired therapeutic effect, to reduce a risk that non-target structures will be damaged.

33. The method of claim 32, wherein the step of verifying a position of the focal point relative to the target area comprises the steps of:

(a) tracking a position of the imaging ultrasound transducer while producing the ultrasound image of the target area;

(b) tracking a position of the therapeutic ultrasound transducer,

(c) based on the positions of the imaging ultrasound transducer and the therapeutic ultrasound transducer, introducing an icon into the ultrasound image, the icon corresponding to a predicted position of the focal point based on the positions of the imaging ultrasound transducer and the therapeutic ultrasound transducer; and

(d) manipulating the position of at least one of the imaging ultrasound transducer and the therapeutic ultrasound transducer until the icon coincides with the treatment site in the ultrasound image.

34. The method of claim 32, wherein the step of verifying a position of the focal point relative to the target area comprises a steps of:

(a) identifying a type of physiological reaction that should occur if the focal point of the therapeutic ultrasound transducer is properly positioned relative to the treatment site and the therapeutic ultrasound transducer is energized to stimulate the nervous system, yielding an identified physiological reaction;

(b) energizing the therapeutic ultrasound transducer at a power level that is insufficient to induce damage but is sufficient to stimulate the nervous system;

(c) observing any physiological reaction to achieve an observed physiological reaction; and

(d) determining if the identified physiological reaction corresponds to the observed physiological reaction, and if so, concluding that the focal point of the therapeutic ultrasound transducer is properly positioned relative to the treatment site.

35. The method of claim 32, wherein the step of verifying a position of the focal point relative to the target area comprises the step of energizing the therapeutic ultrasound transducer at a power level that is insufficient to induce damage, but is sufficient to enable the focal point to be visualized in the ultrasound, before energizing the therapeutic ultrasound transducer at a power level sufficient to achieve the desired therapeutic effect.

36. The method of claim 32, wherein the step of verifying a position of the focal point relative to the target area comprises the steps of:

(a) positioning the imaging ultrasound transducer and the therapeutic ultrasound transducer such that the focal point lies within an image plane provided by the imaging ultrasound transducer;

(b) providing an indication of where the focal point lies within the ultrasound image, such that the focal point can be visualized in the ultrasound image even when the therapeutic ultrasound transducer is not energized;

(c) fixing a position of the imaging ultrasound transducer relative to the therapeutic ultrasound transducer, such that movement of either device will not move the focal point out of the ultrasound image; and

(d) manipulating at least one of the imaging ultrasound transducer, the therapeutic ultrasound transducer, and a frame used to secure the position of the imaging ultrasound transducer relative to the therapeutic ultrasound transducer until the indication of the focal point is properly positioned relative to the treatment site.

37. A method for using ultrasound to simultaneously image a target area and to provide therapy to a treatment site disposed within said target area, the treatment site comprising a portion of the nervous system, comprising the steps of:

(a) using an imaging ultrasound transducer to obtain an ultrasound image of the target area;

(b) selecting the treatment site from the ultrasound image; and

(c) using an therapeutic ultrasound transducer to direct high intensity focused ultrasound (HIFU) at the treatment site, the therapeutic ultrasound transducer and the imaging ultrasound transducer being synchronized such that any noise in the ultrasound image arising from the HIFU does not obscure visualization of the treatment site in the ultrasound image, enabling the treatment site to be observed in real-time as the HIFU is administered to the treatment site.

38. The method of claim 37, wherein the therapy comprises blocking nerve conduction.

39. The method of claim 38, wherein the nerve conduction is blocked temporarily.

40. The method of claim 38, wherein the nerve conduction is blocked to alleviate pain.

41. The method of claim 38, wherein the nerve conduction is blocked to treat spasticity.

42. The method of claim 38, wherein the nerve conduction is blocked to provide an anesthetic effect.

43. The method of claim 38, wherein the nerve conduction is blocked to provide a cosmetic effect.

44. The method of claim 37, further comprising a step of verifying a position of a focal point of the therapeutic ultrasound transducer relative to the treatment site before energizing the therapeutic ultrasound transducer to provide therapy, to reduce a risk that non-target structures will be damaged.

45. The method of claim 44, wherein the step of verifying a position of the focal point relative to the treatment site comprises the steps of:

(a) tracking a position of the imaging ultrasound transducer while producing the ultrasound image;

(b) tracking a position of the therapeutic ultrasound transducer;

(c) based on the positions of the imaging ultrasound transducer and the therapeutic ultrasound transducer, introducing an icon into the ultrasound image, the icon corresponding to a predicted position of the focal point based on the positions of the imaging ultrasound transducer and the therapeutic ultrasound transducer; and

(d) manipulating the position of at least one of the imaging ultrasound transducer and the therapeutic ultrasound transducer until the icon coincides with the treatment site in the ultrasound image.

46. The method of claim 44, wherein the step of verifying a position of the focal point relative to the treatment site comprises the steps of:

(a) identifying what type of physiological reaction should occur if the focal point of the therapeutic ultrasound transducer is properly positioned relative to the treatment site and the therapeutic ultrasound transducer is energized to stimulate the nervous system, yielding an identified physiological reaction;

(b) energizing the therapeutic ultrasound transducer at a power level that is insufficient to induce damage but is sufficient to stimulate the nervous system;

(c) observing any physiological reaction to achieve an observed physiological reaction; and

(d) determining if the identified physiological reaction corresponds to the observed physiological reaction, and if so, concluding that the focal point of the therapeutic ultrasound transducer is properly positioned relative to the treatment site.

47. The method of claim 44, wherein the step of verifying a position of the focal point relative to the target area comprises the step of energizing the therapeutic ultrasound transducer at a power level that is insufficient to induce damage at the treatment site, but is sufficient to enable the focal point to be visualized in the image provided by the imaging ultrasound transducer, before energizing the therapeutic ultrasound transducer at a power level sufficient to achieve the desired therapeutic effect.

48. A method for using high intensity focused ultrasound (HIFU) to provide therapy to a treatment site associated with a nervous system of a patient, the treatment site being spaced apart from a HIFU therapy device, comprising the steps of:

(a) determining an appropriate treatment site associated with the nervous system of the patient to be treated to achieve a desired therapeutic effect;

(b) selecting a dose of HIFU required to achieve a desired therapeutic effect;

(c) using an ultrasound imaging device to obtain an image of the treatment site;

(d) positioning the HIFU therapy device such that a focal point of the HIFU therapy device is disposed adjacent to the treatment site;

(e) energizing the HIFU therapy device at a power level that is insufficient to induce damage at the treatment site, but is sufficient to enable the focal point to be visualized in the image provided by the ultrasound imaging device to verify that the focal point of the HIFU therapy device is properly positioned relative to the treatment site, and if not, repositioning the HIFU therapy device until the HIFU therapy device is properly positioned relative to the treatment site; and

(f) energizing the HIFU therapy device to provide the dose of HIFU required to achieve the desired therapeutic effect.

49. A method for using high intensity focused ultrasound (HIFU) to treat spasticity by applying HIFU to a treatment site corresponding to a portion of a nervous system of a patient, the treatment site being spaced apart from a HIFU therapy device, comprising the steps of:

(a) determining an appropriate treatment site associated with the nervous system of the patient to treat spasticity;

(b) selecting a dose of HIFU required to achieve a desired therapeutic effect;

(c) positioning the HIFU therapy device such that a focal point of the HIFU therapy device is disposed adjacent to the treatment site;

(d) verifying that the focal point of the HIFU therapy device is properly positioned relative to the treatment site, and if not, repositioning the HIFU therapy device until the HIFU therapy device is properly positioned relative to the treatment site; and

(e) energizing the HIFU therapy device to provide the dose of HIFU required to achieve the desired therapeutic effect.

50. A method for using high intensity focused ultrasound (HIFU) to alleviate pain by applying HIFU to a treatment site corresponding to a portion of a nervous system of a patient, the treatment site being spaced apart from a HIFU therapy device, comprising the steps of:

(a) determining an appropriate treatment site associated with the nervous system of the patient to alleviate pain;

(b) selecting a dose of HIFU required to achieve a desired therapeutic effect;

(c) positioning the HIFU therapy device such that a focal point of the HIFU therapy device is disposed adjacent to the treatment site;

(d) verifying that the focal point of the HIFU therapy device is properly positioned relative to the treatment site, and if not, repositioning the HIFU therapy device until the HIFU therapy device is properly positioned relative to the treatment site; and

(e) energizing the HIFU therapy device to provide the dose of HIFU required to achieve the desired therapeutic effect.

51. The method of claim 50, wherein the step of selecting the dose of HIFU required to achieve the desired therapeutic effect comprises the step of selecting a dose of HIFU that will result in both thermal and mechanical interactions with the treatment site.

52. A method for using high intensity focused ultrasound (HIFU) to provide an anesthetic effect by applying HIFU to a treatment site corresponding to a portion of a nervous system of a patient, the treatment site being spaced apart from a HIFU therapy device, comprising the steps of:

(a) determining an appropriate treatment site associated with the nervous system of the patient to provide the anesthetic effect;

(b) selecting a dose of HIFU required to achieve a desired therapeutic effect;

(c) positioning the HIFU therapy device such that a focal point of the HIFU therapy device is disposed adjacent to the treatment site;

(d) verifying that the focal point of the HIFU therapy device is properly positioned relative to the treatment site, and if not, repositioning the HIFU therapy device until the HIFU therapy device is properly positioned relative to the treatment site; and

(e) energizing the HIFU therapy device to provide the dose of HIFU required to achieve the desired therapeutic effect.

53. A method for using high intensity focused ultrasound (HIFU) to provide a cosmetic effect by applying HIFU to a treatment site corresponding to a portion of a nervous system of a patient, the treatment site being spaced apart from a HIFU therapy device, comprising the steps of:

(a) determining an appropriate treatment site associated with the nervous system of the patient to provide the cosmetic effect;

(b) selecting a dose of HIFU required to achieve a desired therapeutic effect;

(c) positioning the HIFU therapy device such that a focal point of the HIFU therapy device is disposed adjacent to the treatment site;

(d) verifying that the focal point of the HIFU therapy device is properly positioned relative to the treatment site, and if not, repositioning the HIFU therapy device until the HIFU therapy device is properly positioned relative to the treatment site; and

(e) energizing the HIFU therapy device to provide the dose of HIFU required to achieve the desired therapeutic effect.

54. The method of claim 53, were in the step of determining an appropriate treatment site associated with the nervous system of a patient comprises the steps of:

(a) identifying musculature associated with the cosmetic effect to be achieved; and

(b) identifying the portion of the nervous system controlling the musculature so identified, the portion so identified being determined to be the appropriate treatment site.

55. A probe for administering high intensity focused ultrasound (HIFU) therapy to a neural structure within a patient'"'"'s body, wherein a tissue mass is disposed between the probe and the neural structure, comprising:

(a) a supporting structure; and

(b) a HIFU transducer disposed at the distal end of the supporting structure, the HIFU transducer having been configured to achieve a focal region that is larger than a cross-sectional area of the neural structure to be treated, such that a lesion induced by a single application of HIFU will substantially encompass a portion of the neural structure coinciding with the focal region, so that only a single application of HIFU is required to block conduction of the neural structure.

56. A method for using high intensity focused ultrasound (HIFU) to provide therapy to a treatment site corresponding to a portion of a nervous system of a patient, the treatment site being disposed substantially adjacent to a HIFU therapy device, comprising the steps of:

(a) determining an appropriate treatment site associated with the nervous system of the patient to be treated to achieve a desired non-permanent therapeutic effect;

(b) selecting a dose of HIFU required to achieve the desired non-permanent therapeutic effect;

(c) positioning the HIFU therapy device such that the HIFU therapy device is substantially adjacent to do treatment site and a focal point of the HIFU therapy device coincides with the treatment site;

(d) visually verifying that the focal point of the HIFU therapy device is properly positioned relative to the treatment site, a distal portion of the HIFU therapy device generally coinciding with the focal point of the HIFU therapy device, and if not, repositioning the HIFU therapy device until the HIFU therapy device is properly positioned relative to the treatment site; and

(e) energizing the HIFU therapy device to provide the dose of HIFU required to achieve the desired non-permanent therapeutic effect.