Method and apparatus for carrying out the controlled heating of tissue in the region of dermis

• US 20080097557A1
• Filed: 10/19/2006
• Published: 04/24/2008
• Est. Priority Date: 10/19/2006
• Status: Abandoned Application

• Current Assignee: Apsara Medical Corporation
• Original Assignee: Apsara Medical Corporation
• Inventors: Eggers, Philip E., Eggers, Eric A., Eggers, Andrew R.
• Application Number:
  US11/583,621
• Publication Number:
  US 20080097557A1
• Time in Patent Office: Days
• US Class Current: 607/99
• CPC Class Codes: A61B 18/082 Probes or electrodes therefor
• CPC Class Codes: A61B 18/1477 Needle-like probes
• CPC Class Codes: A61B 2018/00452 Skin
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00797 measured by multiple temperature sensors
• CPC Class Codes: A61B 2018/00809 measured thermochromatically
• CPC Class Codes: A61B 2018/00815 measured by a thermistor

Abstract

Implant apparatus and method for effecting a controlled heating of tissue within the region of dermis of skin. The heater implants are configured with a thermally insulative generally flat support functioning as a thermal barrier. One surface of this thermal barrier carries one or more electrodes within a radiofrequency excitable circuit as well as an associated temperature sensing circuit. The implants are located within heating channels at the interface between skin dermis and the next adjacent subcutaneous tissue layer such that the electrodes are contactable with the lower region of dermis. During therapy a conformal heat sink is positioned against the skin above the implants and a slight tamponade is applied through the heat sink to assure uniform dermis contact with electrode surfaces. An adjuvant may be employed to infiltrate dermis to significantly lower the thermal threshold transition temperature for dermis or dermis component shrinkage.

Claims

1. Implant apparatus for effecting a controlled heating of tissue at the region of the dermis from a location generally at the interface of dermis and next adjacent subcutaneous tissue, comprising:

a thermally insulative generally flat support having a support surface and an oppositely disposed insulative surface, said support having a lengthwise dimension extending between leading and trailing ends and a widthwise dimension along an active length;

an electrode circuit supported from said support surface having one or more electrodes energizable from a radiofrequency source to generate heat within tissue at the region of the dermis; and

a lead assemblage extending from each electrode to a lead contact region adjacent said support trailing end.

2. The implant apparatus of claim 1 in which:

said lead assemblage is electrically insulated at least where contactable with tissue.

3. The implant apparatus of claim 1 in which:

said electrode circuit is located upon an electrically insulative electrode support substrate having an outer surface and an oppositely disposed inner surface supported from said support surface and extending to said trailing end.

4. The implant apparatus of claim 3 further comprising:

one or more electrically energizable resistor segments with a resistor lead assemblage extending therefrom located upon the outer surface of an electrically insulative resistor support substrate having an inner surface supported at said flat support surface and extending over said trailing end to expose a portion of said resistor lead assemblage at said insulative surface generally opposite said lead contact region; and

said electrode substrate inner surface being supported over said resistor support substrate outer surface.

5. The implant apparatus of claim 4 in which:

said resistor lead assemblage is configured to provide a four-point electrical connection with each resistor segment.

6. The implant apparatus of claim 3 further comprising:

one or more electrically energizable resistor segments supported from said support surface each being located in general alignment and thermal exchange relationship with an oppositely disposed electrode; and

a resistor lead assemblage extending from each said resistor segment to said lead contact region.

7. The implant apparatus of claim 6 in which:

said one or more resistor segments are supported upon said substrate inner surface; and

said thermally insulative support is configured with an opening extending therethrough at said trailing end shaped to provide electrical contact access with said resistor lead assemblage.

8. The implant apparatus of claim 6 in which:

said resistor lead assemblage is configured to provide a four-point electrical connection with each resistor segment.

9. The implant apparatus of claim 6 in which:

said one or more resistor segments are configured to provide a thermal output; and

said resistor lead assemblage is configured to effect the generation of said thermal output.

10. The implant apparatus of claim 9 in which:

said thermally insulative support is configured with an opening extending therethrough at said trailing end shaped to provide electrical contact access with said resistor lead assemblage.

11. The implant apparatus of claim 3 in which:

said electrodes are formed of gold plated copper having a thickness of between about 0.0003 inch and about 0.0014 inch.

12. The implant apparatus of claim 1 in which:

said electrodes are formed of a metal having a thickness effective to promote the spreading dispersion of thermal energy into the region of dermis.

13. The implant apparatus of claim 1 in which:

said electrodes are formed with copper having a thickness of between about 0.005 inch and about 0.020 inch.

14. The implant apparatus of claim 6 in which:

said resistor segments are formed of copper having a thickness of between about 0.003 inch and about 0.0014 inch.

15. The implant apparatus of claim 6 in which:

said one or more resistor segments are formed of a metal exhibiting a temperature coefficient of resistance greater than about 2000 ppm/°

C.

16. The implant apparatus of claim 3 in which:

said thermally insulative support comprises a polyimide material.

17. The implant apparatus of claim 1 in which:

said thermally insulative electrode support substrate comprises a polyetherimide resin.

18. The implant apparatus of claim 1 in which:

said thermally insulative support is formed of one or more polymeric materials having a thickness from about 0.02 inch to about 0.08 inch.

19. The implant apparatus of claim 1 in which:

said leading end of the thermally insulative support is surgically blunt.

20. The implant apparatus of claim 1 in which:

said leading end is slanted forwardly to an extent effective to provide a mechanical bias toward dermis when the implant is inserted into said interface.

21. The implant apparatus of claim 1 in which:

said thermally insulative generally flat support is configured with a bladed leading end effective to enter a skin entrance incision and guidably move under compressive urging along said interface between dermis and next adjacent subcutaneous tissue to form and be located within a heating channel.

22. The implant apparatus of claim 21 in which:

said bladed leading end is configured for blunt dissection along said interface.

23. The implant apparatus of claim 21 in which:

said leading end is slanted forwardly to an extent effective to provide a mechanical bias toward dermis when the implant is inserted into said interface.

24. The implant apparatus of claim 1 in which:

said lead assemblage is configured for effecting the radiofrequency energization of two or more electrodes of a common implant apparatus in bipolar fashion.

25. The implant apparatus of claim 1 in which:

said thermally insulative generally flat support lengthwise dimension is a fixed, consistent value; and

said electrode circuit has a fixed, consistent number of electrodes having a common length along said lengthwise dimension which may vary with respect to a given implant.

26. The implant apparatus of claim 25 in which:

said fixed, consistent value is about 7.5 inches.

27. The implant apparatus of claim 1 further comprising:

an adjuvant supported from said support surface releasable to disperse within dermis and effective when dispersed to lower the thermal transition temperature for carrying out the shrinkage of dermis or a component of dermis.

28. The implant apparatus of claim 1 further comprising:

implant insertion extent identifying visible indicia located forwardly from said flat support trailing end.

29. The method for effecting a controlled heating of tissue within the region of the dermis of skin, comprising the steps:

(a) determining a skin region for treatment;

(b) providing one or more heater implants each comprising a thermally insulative generally flat support having a support surface and an oppositely disposed insulative surface, a circuit mounted at the support surface having one or more electrodes;

(c) determining one or more heating channel locations along said skin region;

(d) locating each heater implant along a heating channel generally at the interface between dermis and next adjacent subcutaneous tissue in an orientation wherein said one or more electrodes are electrically contactable with dermis and in thermally insulative relationship with said next adjacent subcutaneous tissue;

(e) applying tamponade over at least a portion of said skin region to an extent effective to maintain substantially uniform and continuous electrical contact between dermis and said one or more electrodes;

(f) simultaneously controlling the temperature of the surface of skin within said region to an extent effective to protect the skin surface from thermal injury while permitting the derivation of effective therapeutic temperature at the said region of the dermis; and

(g) effecting an a radiofrequency energization of said electrodes toward a setpoint temperature.

30. The method of claim 29 in which:

step (b) provides two or more implants; and

step (g) effects said energization in bipolar fashion.

31. The method of claim 39 in which:

step (g) is carried out to effect a controlled shrinkage of dermis or a component of dermis.

32. The method of claim 29 in which:

step (g) is carried out to effect a therapeutic treatment of a capillary malformation.

33. The method of claim 29 further comprising the step:

(h) monitoring the temperature of said electrodes during step (g);

34. The method of claim 29 in which:

step (b) provides said circuit as having a polymeric substrate with an outward face supporting one or more electrodes, and an inward face supported from said support surface.

35. The method of claim 34 in which:

step (b) provides said flexible circuit as supporting one or more temperature sensors each having a temperature responsive condition adjacent to said inward face in thermal exchange adjacency with a said electrode; and

step (h) carries out said monitoring of temperature by monitoring the said temperature responsive condition of each temperature sensor.

36. The method of claim 35 in which:

step (b) provides each said flexible circuit supported temperature sensor as a resistor; and

step (h) carries out said monitoring of temperature in a manner wherein said temperature responsive condition is electrical resistance.

37. The method of claim 33 in which:

step (b) provides two or more implants;

step (g) effects said energization in bipolar fashion and reduces the power level to a bipolar electrode pair in response to a setpoint temperature attained input; and

step (h) derives said setpoint temperature attained input in correspondence with each bipolar electrode pair.

38. The method of claim 29 in which:

step (b) provides said circuit as a circuit having a polymeric substrate with an outward face supporting one or more said electrodes, and an inward face supporting one or more heater resistor segments generally aligned with said one or more electrodes, said inward face being adhesively coupled with said support surface; and

step (g) further effects a heat deriving energization of said heater resistor segments.

39. The method of claim 38 further comprising the step:

(h) monitoring the combined temperature of each electrode and resistor segment during step (g).

40. The method of claim 39 in which:

step (h) is carried out by intermittently monitoring the resistance value of each resistor segment.

41. The method of claim 40 in which:

step (h) further is carried out by comparing the monitored resistance value with a target value of resistance corresponding with a setpoint temperature.

42. The method of claim 41 in which:

step (b) provides three or more implants including two outwardly disposed border implants and one or more inwardly disposed implants, only said outwardly disposed border implants being configured with heater resistor segments; and

step (g) effects said radiofrequency energization of said electrodes in bipolar fashion.

43. The method of claim 42 in which:

step (g) effects said radiofrequency energization in a sequence of paired implants extending from a border implant to an opposite border implant under a duty cycle regimen.

44. The method of claim 43 in which:

step (g) effects said radiofrequency energization under about a 50% duty cycle.

45. The method of claim 43 in which:

step (g) effects a heat deriving energization of said heater resistor segments at said border implants to an extent effective to substantially equalize the thermal output of border implants with those of inwardly disposed implants.

46. The method of claim 29 in which:

step (f) is carried out with a container of liquid located against said skin region.

47. The method of claim 46 in which:

step (f) is carried out with a conformal polymeric container having a contact surface located against skin at said skin region.

48. The method of claim 47 in which:

step (e) is carried out by applying pressure at said skin region with said container.

49. The method of claim 47 in which:

step (f) is further carried out by locating heat transferring liquid intermediate the surface of skin at said skin region and the contact surface of the container.

50. The method of claim 47 in which:

step (f) is further carried out by effecting an agitation of liquid within said container adjacent skin at said skin region.

51. The method of claim 47 in which:

step (f) is carried out with liquid within said container at a temperature between about 15°

C. and about 25°

C.

52. The method of claim 31 in which:

step (f) is carried out with a conformal polymeric container having a transparency effective to permit viewing of skin surface at said skin region.

53. The method of claim 52 further comprising the steps:

(i) providing a pattern of visible indicia at said skin region prior to steps (e), (f) and (g), and providing a corresponding pattern of visible indicia adjacent said container contact surface, and

(j) monitoring the extent of skin shrinkage during step (g) by comparing said pattern of visible indicia at said skin region with said pattern of visible indicia at said container contact surface.

54. The method of claim 29 in which:

step (f) controls the temperature of the skin within said region within a temperature range of from about 30°

C. to about 37°

C.

55. The method of claim 29 in which:

step (f) is carried out with a temperature controlled metal assembly having an electrically insulative contact surface which is located in thermal exchange relationship with the surface of skin at said skin region.

56. The method of claim 29 further comprising the step:

(j) precooling said next adjacent subcutaneous tissue through the surface of skin at said skin region prior to steps (d) through (g).

57. The method of claim 29 in which:

step (f) is continued subsequent to step (h) for an interval effective to alter the temperature of heated dermis toward human body temperature.

58. The method of claim 29 in which:

step (b) provides three or more implants;

step (g) effects said energization in bipolar fashion under a duty cycle regimen.

59. The method of claim 29 further comprising the steps:

(k) providing a current diffusing return electrode; and

(l) positioning the return electrode in electrical return relationship against epidermis over those implants located by step (d); and

wherein step (g) effects said radiofrequency energization between the electrode or electrodes of said one or more heater implants and said return electrode to effect said controlled heating of tissue.

60. The method of claim 59 in which:

step (k) provides the return electrode as an electrically conductive conformal surface.

61. The method of claim 59 in which:

step (l) is further carried out by locating an energy transferring liquid between the return electrode and epidermis.

62. The method of claim 60 in which:

step (k) provides the return electrode as a conformal polymeric container of liquid functioning as a heat sink; and

step (e) is carried out of applying pressure at said skin region with said container.

63. The method of claim 60 in which:

step (g) is carried out to effect a therapeutic treatment of a capillary malformation.

64. The method of claim 63 in which:

step (g) is carried out to effect an irreversible vascular coagulation with a setpoint temperature atraumatic to dermis.

65. The method of claim 31 further comprising the step:

(m) administering an adjuvant generally to dermis at said skin region effective to lower the thermal transition temperature for carrying out the shrinkage of dermis or a component of dermis.

66. The method of claim 65 in which:

step (m) administers said adjuvant topically at said skin region.

67. The method of claim 65 in which:

step (b) provides one or more implants as carrying said adjuvant at a location for dispersion within dermis from the heating channel.

68. The method of claim 29 in which:

step (b) provides two or more heater implants wherein said thermally insulative generally flat support exhibits a lengthwise dimension which is a fixed, consistent value, and said circuit has a fixed consistent number of electrodes having a common length which may vary among given implants.

69. The method of claim 68 in which:

step (b) provides said two or more implants as exhibiting a lengthwise dimension of about 7.5 inches.

70. The method of claim 29 in which:

step (b) provides said one or more heater implants with one or more electrodes formed of a metal having a thickness effective to promote the spreading dispersion of thermal energy into the region of dermis.

71. The method of claim 70 in which:

step (b) provides said one or more implants with one or more electrodes formed with copper having a thickness of between about 0.005 inch and about 0.020 inch.

72. The method for effecting a controlled heating of tissue within the region of the dermis of skin, comprising the steps:

(a) determining a skin region for treatment;

(b) providing two or more heater implants each comprising a thermally insulative generally flat support having a support surface and an oppositely disposed insulative surface, the support having a lengthwise dimension extending between leading and trailing ends, a widthwise dimension, a circuit mounted at the support surface having one or more electrodes;

(c) determining two or more heating channel locations at said skin region, each having a channel entrance location;

(d) forming an entrance incision at each channel entrance location;

(e) inserting a heater implant leading end through each entrance incision to locate it within a heating channel, the trailing end remaining outside the surface of said skin region, and the one or more electrodes being located for contact with adjacent dermis;

(f) applying tamponade over at least a portion of said skin region to an extent effective to maintain uniform electrical contact between the one or more electrodes of each implant and adjacent dermis;

(g) applying bipolar radiofrequency energization to the one or more electrodes of the inserted implants from the trailing ends thereof for a therapy interval; and

(h) removing the implant active area through the corresponding entrance incision.

73. The method of claim 72 further comprising the step:

(i) simultaneously with step (g) controlling the temperature of the surface of skin within said skin region to an extent effective to protect the skin surface from thermal injury.

74. The method of claim 73 in which:

step (i) controls the temperature of the skin surface within said region within a temperature range of from about 37°

C. to about 40°

C.

75. The method of claim 72 in which:

step (g) is carried out to effect a controlled shrinkage of dermis or a component of dermis.

76. The method of claim 72 in which:

step (g) is carried out to effect a therapeutic treatment of a capillary malformation.

77. The method of claim 75 further comprising the step:

(j) during and/or after step (g) and before step (h) determining an extent of skin shrinkage.

78. The method of claim 77 in which:

step (j) provides a pattern of visible indicia at said skin region prior to step (f) and visually determines the extent of relative movement of said indicia.

79. The method of claim 73 in which:

step (i) is continued subsequent to step (g) for an interval effective to alter the temperature of heated dermis toward human body temperature.

80. The method of claim 72 further comprising the step:

(k) precooling the next adjacent subcutaneous tissue to dermis through the surface of skin at said skin region prior to steps (d) through (h).

81. The method of claim 73 in which:

step (i) is carried out with a liquid containing conformal polymeric container having a contact surface located against skin at said skin region.

82. The method of claim 81 in which:

step (i) promotes a thermal exchange by agitation of said liquid adjacent said contact surface.

83. The method of claim 81 in which:

step (i) is further carried out by locating a heat transferring liquid lubricant intermediate the surface of skin at said skin region and the contact surface of the container.

84. The method of claim 73 in which:

step (i) is carried out with a temperature controlled metal heat sink having an electrically insulated contact surface which is located in thermal exchange relationship with the surface of skin at said skin region.

85. The method of claim 75 in which:

step (g) is carried out after having generally predetermined said therapy interval with respect to a desired extent of skin shrinkage and setpoint temperature.

86. The method of claim 76 further comprising the step:

(p) administering an adjuvant generally to dermis at said skin region effective to lower the thermal transition temperature for carrying out the shrinkage of dermis or a component of dermis.

87. The method of claim 86 further comprising the step:

step (b) provides one or more implants as carrying said adjuvant at a location for dispersion within dermis from the heating channel.

88. The method of claim 86 in which:

the thermal transition temperature lowering adjuvant of step (l) is one or more of salt, an enzyme, a detergent, a lipophile, a denaturing solvent, an organic denaturant, and acidic solution, or a basic solution.

89. The method of claim 88 wherein the enzyme is one or more of hyaluronidase, lysozyme, muramidase, or collagenase.

90. The method of claim 86 wherein said adjuvant is administered one or more of topically, transdermally, intradermally, subdermally, or hypodermally.

91. The method of claim 88 wherein said adjuvant is administered subdermally by release from a heater implant.

92. The method of claim 72 in which:

step (b) provides said two or more heater implants wherein said thermally insulative generally flat support lengthwise dimension is a fixed, consistent value, and said circuit has a fixed, consistent number of electrodes having a common length which may vary among given implants.

93. The method of claim 92 in which:

step (b) provides said two or more implants as having a flat support exhibiting a lengthwise dimension of about 7.5 inches.

94. The method of claim 72 in which:

step (b) provides said two or more implants with one or more electrodes formed of a metal having a thickness effective to promote the spreading dispersion of thermal energy into the region of dermis.

95. The method of claim 94 in which:

step (b) provides said two or more implants with one or more electrodes formed with copper having a thickness of between about 0.005 inch and about 0.020 inch.

96. The method of claim 72 in which:

step (b) provides said two or more implants with visible insertion indicia located forwardly from said flat support trailing end with a configuration effective to determine the extent of insertion of the implant within a heating channel.

97. The method of claim 96 in which:

step (e) inserts a heater implant within a heating channel to an extent identified by visually comparing said insertion indicia with said entrance incision.

98. The method of claim 76 in which:

step (g) is carried out to effect an irreversible vascular coagulation with a setpoint temperature and therapy interval atraumatic to dermis.

99. The method of claim 98 in which:

step (g) is carried out with a setpoint temperature within the range from about 45°

C. to about 60°

C.

100. A method for thermally remodeling skin, the improvement of which comprises remodeling skin in the presence of an effective amount of a collagen thermal transition temperature lowering adjuvant.

101. The method of claim 100 wherein the thermal transition temperature lowering adjuvant is one or more of a salt, an enzyme, a detergent, a lipophile, a denaturing solvent, an organic denaturant, an acidic solution, or a basic solution.

102. The method of claim 101 wherein the enzyme is one or more of hyaluronidase, lysozyme, muramidase, or collagenase.

103. The method of claim 101 wherein the denaturing solvent is one or more of an alcohol, an ether, monomethyl sulfoxide or DMSO.

104. The method of claim 101 wherein the organic denaturant is urea.

105. The method of claim 101 wherein two or more thermal transition temperature lowering adjuvants are present in a therapeutically effective combination.

106. The method of claim 100 wherein said adjuvant is administered one or more of topically, transdermally, intradermally, subdermally, or hypodermally.

107. The method of claim 106 wherein said adjuvant is administered subdermally by release from a heater implant.

108. The method for effecting a controlled heating of a capillary malformation within a skin region comprising the steps:

(a) determining the degree of vascular ectasia at said region;

(b) providing one or more heater implants each comprising a thermally insulative generally flat support having a support surface and an oppositely disposed insulative surface, the support having an active length, a circuit mounted at the support surface having one or more electrodes along the active length;

(c) determining one or more heating channel locations within said region each having an entrance location;

(d) locating each heater implant along a heating channel generally at the interface between dermis and next adjacent subcutaneous tissue in an orientation wherein said one or more electrodes are electrically contactable with dermis and in thermally insulative relationship with said next adjacent subcutaneous tissue;

(e) applying tamponade over at least a portion of said skin region to an extent effective to maintain substantially uniform and continuous electrical contact between dermis and said one or more electrodes;

(f) simultaneously controlling the temperature of the surface of skin within said region to an extent effective to protect the skin surface from thermal injury while permitting the derivation of effective therapeutic temperature at the said skin region dermis; and

(g) effecting a radiofrequency energization of said electrodes heating them toward a setpoint temperature atraumatic to dermis while effecting an irreversible vascular coagulation at the skin region.

109. The method of claim 108 in which:

step (g) effects said energization of said electrodes toward a setpoint temperature within a range of between about 45°

C. and about 60°

C.

110. The method of claim 108 furthering comprising the step:

(h) monitoring the temperature of each said electrode during step (g).

111. The method of claim 110 in which:

step (b) provides said implants as having one or more temperature sensors, each having a temperature responsive condition corresponding with the temperature of an electrode; and

step (h) carries out the monitoring of temperature by monitoring said temperature responsive condition.

112. The method of claim 108 in which:

step (f) is carried out with a container of liquid located against said skin region.

113. The method of claim 112 in which:

step (f) is carried out with a conformal polymeric container having a contact surface located against skin at said skin region.

114. The method of claim 113 in which:

step (e) is carried out by applying pressure at said skin region with said container.

115. The method of claim 108 in which:

step (b) provides two or more implants; and

step (g) effects said energization in bipolar fashion.

116. The method of claim 108 further comprising the steps:

(i) providing a current diffusing return electrode; and

(j) positioning the return electrode in electrical return relationship against epidermis over those implants heated by step (d); and

wherein step (g) effects said radiofrequency energization between the electrode or electrodes of said one or more heater implants and said return electrode to effect controlled heating at the capillary malformation.

117. The method of claim 108 further comprising the steps:

(k) subsequent to step (g) removing said one or more implants from each heating channel;

(l) waiting a clearance interval at least effective for the resorption of tissue at said skin region which has undergone irreversible vascular coagulation; and

(m) then repeating step (a).

118. The method of claim 117 further comprising the steps:

(n) where step (m) determines that any remaining capillary malformation is equivalent to a type 1 lesion, treating the remaining capillary malformation using laser-based therapy.