Method and apparatus for photothermal treatment of tissue at depth

• US 7,351,252 B2
• Filed: 06/19/2003
• Issued: 04/01/2008
• Est. Priority Date: 06/19/2002
• Status: Active Grant

• Current Assignee: Palomar Medical Technologies Incorporated (Hologic Incorporated), The General Hospital Corporation (Mass General Brigham, Inc.)
• Original Assignee: Palomar Medical Technologies Incorporated (Hologic Incorporated)
• Inventors: Radl, Andrew, Manstein, Dieter, Altshuler, Gregory B., Zenzie, Henry H., Anderson, R. Rox, Smirnov, Michael Z., Burke, James III, Erofeev, Andrei V.
• Primary Examiner(s): FARAH, AHMED M
• Application Number:
  US10/465,137
• Publication Number:
  US 20040093042A1
• Time in Patent Office: 1,748 Days
• Field of Search: 607 88- 92, 606 3- 29
• US Class Current: 607/88
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 18/203 applying laser energy to the outside of the body
• CPC Class Codes: A61B 2018/00005 Cooling or heating of the probe or tissue immediately surrounding the probe
• CPC Class Codes: A61B 2018/00011 with fluids
• CPC Class Codes: A61B 2018/00452 Skin
• CPC Class Codes: A61B 2018/00458 Deeper parts of the skin, e.g. treatment of vascular disorders or port wine stains
• CPC Class Codes: A61B 2018/00476 Hair follicles
• CPC Class Codes: A61N 1/32 alternating or intermittent currents applying electric fields by inductive or capacitive coupling A61N1/40; microwave apparatus A61N5/02
• CPC Class Codes: A61N 2007/0008 Destruction of fat cells
• CPC Class Codes: A61N 5/0613 Apparatus adapted for a specific treatment
• CPC Class Codes: A61N 7/00 Ultrasound therapy lithotripsy A61B17/22, A61B17/225; massage using supersonic vibration A61H23/00 ; using ultrasound for introducing media into the body A61M37/0092

Abstract

The present invention provides method and apparatus for treating tissue in a region at depth by applying optical radiation thereto of a wavelength able to reach the depth of the region and of a selected relatively low power for a duration sufficient for the radiation to effect the desired treatment while concurrently cooling tissue above the selected region to protect such tissue. Treatment may be enhanced by applying mechanical, acoustic or electrical stimulation to the region.

Claims

1. Apparatus for treating at least a selected region at depth of a patient while protecting tissue above the selected region, comprising:

an optical radiation source for delivering optical radiation at a power of between 0.2-50 W/cm² to the patient'"'"'s skin, said optical radiation being applied to said selected region for at least approximately 2 seconds;

wherein said source includes a broadband optical radiation source, and a filter through which radiation from said broadband source is passed;

wherein said filter includes a water filter to at least attenuate wavelengths from said broadband source which are selectively absorbed by water; and

a cooling mechanism for cooling tissue above said selected region to a temperature below that of said selected region.

2. Apparatus as claimed in claim 1 wherein said water filter includes chilled water flowing between said broadband source and the patient'"'"'s body, said flowing chilled water also functioning as part of said mechanism for cooling.

3. Apparatus as claimed in claim 1 wherein said cooling mechanism also cools said filter.

4. Apparatus as claimed in claim 1 including a mechanism for removing heat from said filter.

5. Apparatus as claimed in claim 1 wherein said source includes adjustable optics for shaping radiation to be delivered to said selected region.

6. Apparatus as claimed in claim 1 wherein said source is at least primarily at one or more wavelengths between about 600 nm and about 1850 nm.

7. Apparatus as claimed in claim 6 wherein said source is at least primarily at one or more wavelengths between about 800 nm and about 1350 nm.

8. Apparatus as claimed in claim 6 wherein said source is at least primarily at one or more wavelengths between about 1050 nm and about 1250 nm.

9. Apparatus as claimed in claim 1 wherein said optical radiation source and said mechanism are concurrently operated for a period of at least two seconds.

10. Apparatus as claimed in claim 9 wherein said optical radiation source and said mechanism are concurrently operated for a period of at least five seconds.

11. Apparatus as claimed in claim 9 including a precooling mechanism which cools tissue above said selected region prior to the concurrent operation of said source and said cooling mechanism.

12. Apparatus as claimed in claim 11 wherein said cooling mechanism and said precooling mechanism are the same mechanism.

13. Apparatus as claimed in claim 11 wherein said optical radiation power and said period of concurrent operation vary dependent on whether said precooling mechanism is operated.

14. Apparatus as claimed in claim 1 wherein said optical radiation source and said mechanism are concurrently operated for a period of between about two seconds and two hours.

15. Apparatus as claimed in claim 1 wherein at least 50% of the filtered light having wavelengths between 900 nm and 1400 nm such that said apparatus is an apparatus for fat reduction, said radiation heating subdermal fat tissue.

16. Apparatus as claimed in claim 1 including a mechanism for stimulating tissue in said selected region.

17. Apparatus as claimed in claim 16 wherein said mechanism for providing stimulation is at least one of a mechanical stimulator, acoustic stimulator and an electrical stimulator.

18. Apparatus as claimed in claim 1 wherein said selected region contains at least one hair bulb, wherein parameters for said apparatus, including said source, are selected to slowly damage said bulb, and wherein the treatment time for the apparatus is approximately 15 minutes.

19. The apparatus of claim 1, wherein the optical radiation source is capable of delivering radiation at a power of between 0.2-5 W/cm² to the patient'"'"'s skin for a duration between two seconds and two hours, both said power and said duration increasing with increased depth for said selected regions.

20. The apparatus of claim 1, wherein the optical radiation source is capable of delivering radiation of a wavelength between 600 nm and 1850 nm and at a power of between 0.2-5W/cm² to the patient'"'"'s skin, the wavelength and the power both varying as a function of the depth of the selected region.

21. The apparatus of claim 1, wherein the optical radiation source is capable of delivering radiation of a wavelength between about 600 nm and about 1850 nm, at a power of between 0.2-5 W/cm² to the patient'"'"'s skin for a duration between two seconds and two hours, the wavelength, duration and power all varying as a function of the depth of the selected region.

22. Apparatus as claimed in claim 1 wherein said filtered radiation is at least primarily at one or more wavelengths between about 600 nm and about 1850 nm.

23. Apparatus as claimed in claim 1 wherein said filtered radiation is at least primarily at one or more wavelengths between about 800 nm and about 1350 nm.

24. Apparatus as claimed in claim 1 wherein said filtered radiation is at least primarily at one or more wavelengths between about 1050 nm and about 1250 nm.

25. Apparatus for treating at least a selected region at depth of a patient while protecting tissue above the selected region, comprising:

an optical radiation source for delivering optical radiation at a power of between 0.2-50 W/cm² to the patient'"'"'s skin, said power varying at least in part as a function of the depth of said selected region, said optical radiation being applied to said selected region for at least approximately 2 seconds;

a cooling mechanism for cooling tissue above said selected region to a temperature below that of said selected region; and

wherein parameters for said optical radiation source and for said cooling mechanism are selected to achieve a selected temperature as indicated by equation 10 at a selected depth z max determined by equation 11.

26. Apparatus as claimed in claim 25 wherein the minimum treatment time for the apparatus is determined in accordance with equation 12.

27. A method of fat reduction for treating at least a selected region at depth of a patient'"'"'s body while protecting tissue above the selected region, comprising:

(a) selectively delivering optical radiation at a power between approximately 0.2 and 5 W/cm² to the patient'"'"'s body above said selected region, said optical radiation being applied to said selected region for at least approximately 2 seconds; and

(b) concurrently cooling patient tissue above said selected region to a temperature below that of the selected region, wherein said radiation heats subdermal fat tissue.

28. A method as claimed in claim 27 wherein said power is 0.5-5 W/cm².

29. A method as claimed in claim 27 wherein step (a) includes generating broad band optical radiation, and filtering said broad band radiation before delivering it to said patient'"'"'s body.

30. The method of claim 27, wherein the optical radiation is at least primarily at one or more wavelengths between about 600 nm and about 1850 nm.

31. The method of claim 30, wherein the optical radiation is at least primarily at one or more wavelengths between about 800 nm and about 1350 nm.

32. The method of claim 30 wherein the electromagnetic energy is at least primarily at one or more wavelengths between about 1050 nm and about 1250 nm.

33. The method of claim 27 wherein step (a) and step (b) are performed concurrently for a period of at least two seconds.

34. The method of claim 33 wherein step (a) and step (b) are performed concurrently for a period of at least five seconds.

35. The method of claim 27 wherein step (a) and step (b) are performed concurrently for a period of between about two seconds and about two hours.

36. The method of claim 27 including the step of precooling tissue above said selected region.

37. The method of claim 27 wherein said method is a method for fat reduction, subdermal fat tissue being heated during step (a).

38. The method of claim 27 including the step of stimulating tissue in said selected region.

39. The method of claim 38 wherein said step of providing stimulation provides at least one of mechanical stimulation, acoustic stimulation and electrical stimulation.

40. A method for treating at least a selected region at depth of a patient'"'"'s body while Protecting tissue above the selected region, comprising:

precooling tissue above said selected region;

selectively delivering optical radiation at a power between approximately 0.2 and 5 W/cm² to the patient'"'"'s body above said selected region, said optical radiation being applied to said selected region for at least approximately 2 seconds; and

concurrently cooling patient tissue above said selected region to a temperature below that of the selected region, The method of claim 38 wherein said optical radiation power and said period of concurrent operation vary dependent on whether said precooling step is performed.

41. The method of claim 40 wherein said selected region is heated during the step of selectively delivering optical radiation.

42. The method of claim 40, wherein step of selectively delivering radiation at a power between approximately 0.2 and 5 W/cm² to the patient'"'"'s body above said selected region further comprises delivering said radiation for a duration of two seconds to two hours, both said power and said duration varying with the depth of said selected region;

and

cooling step further comprises maintaining a surface temperature below 32°

C.

43. The method of claim 40, wherein the step of selectively delivering radiation further comprises delivering a wavelength between about 600 nm and about 1850 nm such that both said power and wavelength varying as a function of the depth of said selected region.

44. The method of claim 40, wherein said radiation being selected so as not to be scattered or absorbed by tissue above said selected region sufficiently to prevent sufficient radiation from reaching the selected region to effect a desired treatment.

45. A method as claimed in claim 44 wherein said selected region contains subdermal fat;

and wherein said radiation at least includes at least one wavelength selectively absorbed by fat.

46. A method for treating at least a selected region at depth of a patient'"'"'s body while protecting tissue above the selected region, comprising:

(a) selectively delivering optical radiation at a power between approximately 0.2 and 50 W/cm² to the patient'"'"'s body above said selected region, said power varying at least in part as a function of the depth of said selected region, said optical radiation being applied to said selected region for at least approximately 2 seconds;

(b) concurrently cooling patient tissue above said selected region to a temperature below that of the selected region; and

wherein parameters for said optical radiation and for said cooling are selected to achieve a selected temperature as indicated by equation 10 at a selected depth z max determined by equation 11.

47. The method of claim 46 wherein the minimum treatment time for the method is determined in accordance with equation 12.