Miniature implantable illuminator for photodynamic therapy

• US 6,622,049 B2
• Filed: 02/06/2002
• Issued: 09/16/2003
• Est. Priority Date: 10/16/2000
• Status: Expired due to Term

• Current Assignee: Remon Medical Technologies Ltd. (Boston Scientific Corporation)
• Original Assignee: Remon Medical Technologies Ltd. (Boston Scientific Corporation)
• Inventors: Doron, Eyal, Penner, Avl
• Primary Examiner(s): Walberg, Teresa
• Assistant Examiner(s): DAHBOUR, HENRY
• Application Number:
  US10/066,799
• Publication Number:
  US 20030074034A1
• Time in Patent Office: 587 Days
• Field of Search: 607/59, 607/60, 607/1, 607/2, 607/92, 607/96, 607/88, 607/32, 607/30, 607/31, 607/33, 607/61, 607/138, 128/898, 128/899, 128/903, 600/1, 600/2, 600/3, 604/19, 604/22, 606/201, 606/2, 606/3
• US Class Current: 607/59
• CPC Class Codes: A61B 2560/0219 of externally powered implanted units
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 2562/028 Microscale sensors, e.g. electromechanical sensors [MEMS]
• CPC Class Codes: A61B 5/0028 Body tissue as transmission medium, i.e. transmission systems where the medium is the human body
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/031 Intracranial pressure
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/076 Permanent implantations telemetry using implanted circuitry A61B5/0031; implanted stimulators for therapy A61N1/3605, A61N1/362, A61N1/372
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61N 1/37217 characterised by the communication link, e.g. acoustic or tactile
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: A61N 2005/0651 Diodes
• CPC Class Codes: A61N 5/0601 Apparatus for use inside the body
• CPC Class Codes: A61N 5/062 Photodynamic therapy, i.e. excitation of an agent

Abstract

A miniature implantable light source for providing light to an internal treatment site to effect a photodynamic therapy at the site, the light source is powered and/or controlled via acoustic energy transmitted from outside the body to an acoustic transducer in the light source.

Claims

1. A miniature light source for providing light to an internal treatment site to effect a photodynamic therapy at said site, comprising:

(a) a source of light that produces light of a desired wavelength, several discrete wavelengths or waveband when energized by an electrical current;

(b) an energy storage device operably coupled via an electrical circuit to said source of light;

(c) a switch operably coupled to said electrical circuit and said energy storage device; and

(d) an acoustic transducer coupled to said switch, said acoustic transducer being activatable upon acoustic excitation by an external acoustic energy source for closing the switch to allow current flow from said energy storage device to said source of light.

2. The miniature light source of claim 1, wherein the acoustic transducer is configured for receiving a first acoustic excitation signal and a second acoustic excitation signal, the switch being closed when the first acoustic excitation signal is received by the acoustic transducer, and the switch being opened when the second acoustic excitation signal is received by the acoustic transducer for discontinuing current flow from the energy storage device to the electrical circuit.

3. The miniature light source of claim 1, wherein the miniature light source is preprogrammed to shut off a predetermined time period following its activation.

4. The miniature light source of claim 1, wherein the miniature light source shuts off following a reception of an external shut off signal.

5. The miniature light source of claim 1, wherein the acoustic transducer comprises:

a cell member having a cavity;

a substantially flexible piezoelectric layer attached to the cell member, the piezoelectric layer having an external surface and an internal surface, the piezoelectric layer having predetermined dimensions for enabling fluctuations at its resonance frequency upon impinging of an external acoustic wave; and

a first electrode attached to the external surface and a second electrode attached to the internal surface.

6. The miniature light source of claim 1, wherein the energy storage device comprises a battery.

7. The miniature light source of claim 1, designed and operable to generate light pulses.

8. The miniature light source of claim 6, wherein the battery is a lithium battery.

9. The miniature light source of claim 1, wherein the energy storage device comprises a rechargeable device, the rechargeable device being rechargeable by a device external to the body.

10. The miniature light source of claim 1, further comprising a biocompatible, light transmitting, acoustic energy transmitting, material that encloses said source of light, said energy storage device, said electrical circuit, said switch and said acoustic transducer, to form a bead, said bead being thus adapted for insertion into the internal treatment site to effect the photodynamic therapy by providing light to the treatment site.

11. The miniature light source of claim 10, wherein the bead is generally spherical and less than 5 mm in diameter.

12. The miniature light source of claim 10, wherein the bead is generally semi-spherical, less than 5 mm in diameter and less than 2.5 mm in height.

13. The miniature light source of claim 1, wherein said source of light is selected from the group consisting of a LED, a fluorescent light source, an electroluminescent source and a LD.

14. The miniature light source of claim 1, further comprising a light diffuser disposed to diffuse the light emitted by the source of light.

15. The miniature light source of claim 14, wherein said light diffuser is a lens disposed to diffuse the light emitted by the source of light.

16. A system for providing light of a desired wavelength, several discrete wavelengths or waveband to a treatment site disposed internally within a patient'"'"'s body, to effect a photodynamic therapy of the treatment site, comprising:

(a) a miniature light source which comprises;

(i) a source of light that produces light of a desired wavelength, several discrete wavelengths or waveband, several discrete wavelengths or waveband when energized by an electrical current;

(ii) an energy storage device operably coupled via an electrical circuit to said source of light;

(iii) a switch operably coupled to said electrical circuit and said energy storage device; and

(iv) an acoustic transducer coupled to said switch, said acoustic transducer being activatable upon acoustic excitation by an external acoustic energy source for closing the switch to allow current flow from said energy storage device to said source of light; and

(b) said external acoustic energy source for activating said acoustic transducer.

17. The system claim 16, wherein the miniature light source is preprogrammed to shut off a predetermined time period following its activation.

18. The system of claim 16, wherein the miniature light source shuts off following a reception of an external shut off signal.

19. The system of claim 16, wherein the acoustic transducer is configured for receiving a first acoustic excitation signal and a second acoustic excitation signal, the switch being closed when the first acoustic excitation signal is received by the acoustic transducer, and the switch being opened when the second acoustic excitation signal is received by the acoustic transducer for discontinuing current flow from the energy storage device to the electrical circuit.

20. The system of claim 16, wherein the acoustic transducer comprises:

a cell member having a cavity;

a substantially flexible piezoelectric layer attached to the cell member, the piezoelectric layer having an external surface and an internal surface, the piezoelectric layer having predetermined dimensions for enabling fluctuations at its resonance frequency upon impinging of an external acoustic wave; and

a first electrode attached to the external surface and a second electrode attached to the internal surface.

21. The system of claim 16, wherein the energy storage device comprises a battery.

22. The system of claim 21, wherein the miniature light source is designed and operable to generate light pulses.

23. The system of claim 21, wherein the battery is a lithium battery.

24. The system of claim 16, wherein the energy storage device comprises a rechargeable device, the rechargeable device being rechargeable by a device external to the body.

25. The system of claim 16, wherein the miniature light source further comprises a biocompatible, light transmitting, acoustic energy transmitting, material that encloses said source of light, said energy storage device, said electrical circuit, said switch and said acoustic transducer, to form a bead, said bead being thus adapted for insertion into the internal treatment site to effect the photodynamic therapy by providing light to the treatment site.

26. The system of claim 25, wherein the bead is generally spherical and less than 5 mm in diameter.

27. The system of claim 25, wherein the bead is generally semi-spherical, less than 5 mm in diameter and less than 2.5 mm in height.

28. The system of claim 16, wherein said source of light is selected from the group consisting of a LED, a fluorescent light source, an electroluminescent source and a LD.

29. The system of claim 16, wherein the miniature light source further comprises a light diffuser disposed to diffuse the light emitted by the source of light.

30. The system of claim 29, wherein said light diffuser is a lens disposed to diffuse the light emitted by the source of light.

31. A method for providing light of a desired wavelength, several discrete wavelengths or waveband to an internal treatment site to effect a photodynamic therapy, comprising:

(a) providing a miniature light source which comprises;

(i) a source of light that produces light of a desired wavelength, several discrete wavelengths or waveband when energized by an electrical current;

(ii) an energy storage device operably coupled via an electrical circuit to said source of light;

(iii) a switch operably coupled to said electrical circuit and said energy storage device; and

(iv) an acoustic transducer coupled to said switch, said acoustic transducer being activatable upon acoustic excitation by an external acoustic energy source for closing the switch to allow current flow from said energy storage device to said source of light;

(b) implanting said miniature light source at the internal treatment site of a subject in need thereof; and

(c) activating said acoustic transducer via said external acoustic energy source, thereby providing the light of the desired wavelength, several discrete wavelengths or waveband to the internal treatment site to effect the photodynamic therapy.

32. The method of claim 31, wherein the miniature light source is preprogrammed to shut off a predetermined time period following its activation.

33. The method of claim 31, wherein the miniature light source shuts off following a reception of an external shut off signal.

34. The method of claim 31, further comprising administering to the subject a therapeutically effective amount of a photodynamic therapy agent.

35. The method of claim 31, wherein the acoustic transducer is configured for receiving a first acoustic excitation signal and a second acoustic excitation signal, the switch being closed when the first acoustic excitation signal is received by the acoustic transducer, and the switch being opened when the second acoustic excitation signal is received by the acoustic transducer for discontinuing current flow from the energy storage device to the electrical circuit.

36. The method of claim 31, wherein the acoustic transducer comprises:

a cell member having a cavity;

a substantially flexible piezoelectric layer attached to the cell member, the piezoelectric layer having an external surface and an internal surface, the piezoelectric layer having predetermined dimensions for enabling fluctuations at its resonance frequency upon impinging of an external acoustic wave; and

a first electrode attached to the external surface and a second electrode attached to the internal surface.

37. The method of claim 31, wherein the energy storage device comprises a battery.

38. The method of claim 31, wherein the miniature light source is designed and operable to generate light pulses.

39. The method of claim 37, wherein the battery is a lithium battery.

40. The method of claim 31, wherein the energy storage device comprises a rechargeable device, the rechargeable device being rechargeable by a device external to the body.

41. The method of claim 31, wherein the miniature light source further comprises a biocompatible, light transmitting, acoustic energy transmitting, material that encloses said source of light, said energy storage device, said electrical circuit, said switch and said acoustic transducer, to form a bead, said bead being thus adapted for insertion into the internal treatment site to effect the photodynamic therapy by providing light to the treatment site.

42. The method of claim 41, wherein the bead is generally spherical and less than 5 mm in diameter.

43. The method of claim 41, wherein the bead is generally semi-spherical, less than 5 mm in diameter and less than 2.5 mm in height.

44. The method of claim 31, wherein said source of light is selected from the group consisting of a LED, a fluorescent light source, an electroluminescent source and a LD.

45. The method of claim 31, wherein the miniature light source further comprises a light diffuser disposed to diffuse the light emitted by the source of light.

46. The method of claim 45, wherein said light diffuser is a lens disposed to diffuse the light emitted by the source of light.

47. The method of claim 31, wherein implanting said miniature light source at the internal treatment site is effected by injection or catheterization.

48. The method of claim 47, wherein said injecting comprises inserting a distal end of a needle that is connected to a syringe containing the miniature light source into the treatment site, and forcing the bead from the syringe into the treatment site through the needle.

49. The method of claim 31, wherein activating said acoustic transducer via said external acoustic energy source is effected by placing said external acoustic energy source against a body portion of a treated subject and activating said external acoustic energy source.

50. The method of claim 31, further comprising injecting a plurality of miniature light sources into the treatment site at spaced-apart locations.

51. A miniature light source for providing light to an internal treatment site to effect a photodynamic therapy at said site, comprising:

(a) a source of light that produces light of a desired wavelength, several discrete wavelengths or waveband when energized by an electrical current;

(b) an acoustic transducer being operably coupled via an electrical circuit to said source of light, said acoustic transducer being powered by acoustic energy providable by an external acoustic energy source to effect current flow to said source of light.

52. The miniature light source of claim 51, further comprising a capacitor in said electrical circuit, said capacitor being chargeable by said acoustic transducer and dischargeable so as to effect said current flow to said source of light.

53. The miniature light source of claim 51, further comprising a rectifier that is connected to the acoustic transducer, said rectifier converting an alternating current to a direct current, which is supplied to energize the light source.

54. The miniature light source of claim 51, wherein the miniature light source is preprogrammed to shut off a predetermined time period following its activation.

55. The miniature light source of claim 51, wherein the miniature light source shuts off following a reception of an external shut off signal.

56. The miniature light source of claim 51, wherein the acoustic transducer comprises:

a cell member having a cavity;

a substantially flexible piezoelectric layer attached to the cell member, the piezoelectric layer having an external surface and an internal surface, the piezoelectric layer having predetermined dimensions for enabling fluctuations at its resonance frequency upon impinging of an external acoustic wave; and

a first electrode attached to the external surface and a second electrode attached to the internal surface.

57. The miniature light source of claim 51, wherein said acoustic transducer comprises a transducer element adapted for converting acoustic wave energy transmitted through an external fluid medium into electric energy, said transducer element comprising:

a cell member having a cavity;

a substantially flexible piezoelectric layer peripherally attached to said cell member so as to isolate said cavity from the external fluid medium, said cavity containing gas and having a substantially lower acoustic impedance than said external fluid medium, a central portion of said piezoelectric layer not rigidly affixed with respect to said cavity, said piezoelectric layer having an external surface and an internal surface, said piezoelectric layer featuring such dimensions so as to enable fluctuations thereof in-and-out of said cavity at its resonance frequency upon impinging of an acoustic signal transmitted through the external fluid medium, said resonance frequency determined by the physical dimensions of said cavity and said piezoelectric layer wherein the wavelength of the acoustic signal is substantially larger than said dimensions; and

a first electrode attached to said external surface and a second electrode attached to said internal surface.

58. The miniature light source of claim 57, wherein said cavity is etched or drilled into a substrate.

59. The miniature light source of claim 58, wherein said substrate includes an electrically insulating layer and an electrically conducting layer.

60. The miniature light source of claim 59, wherein said electrically insulating layer is made of a polymeric material.

61. The miniature light source of claim 57, wherein said piezoelectric layer is made of PVDF.

62. The transducer clement of claim 57, wherein said cavity is circular in cross section.

63. The transducer clement of claim 57, wherein said cavity is elliptical in cross section.

64. The miniature light source of claim 58, wherein said substrate includes a plurality of cell members.

65. The miniature light source of claim 51, wherein at least one of said first and second electrodes is specifically shaped so as to provide a maximal electrical output.

66. The miniature light source of claim 51, further comprising a biocompatible, light transmitting, acoustic energy transmitting, material that encloses said source of light and said acoustic transducer, to form a bead, said bead being thus adapted for insertion into the internal treatment site to effect the photodynamic therapy by providing light to the treatment site.

67. The miniature light source of claim 66, wherein the bead is generally spherical and less than 5 mm in diameter.

68. The miniature light source of claim 66, wherein the bead is generally semi-spherical, less than 5 mm in diameter and less than 2.5 mm in height.

69. The miniature light source of claim 51, wherein said source of light is selected from the group consisting of a LED, a fluorescent light source, an electroluminescent source and a LD.

70. The miniature light source of claim 51, further comprising a light diffuser disposed to diffuse the light emitted by the source of light.

71. The miniature light source of claim 70, wherein said light diffuser is a lens disposed to diffuse the light emitted by the source of light.

72. A system for providing light of a desired wavelength, several discrete wavelengths or waveband to a treatment site disposed internally within a patient'"'"'s body, to effect a photodynamic therapy of the treatment site, comprising:

(a) a miniature light source which comprises;

(i) a source of light that produces light of a desired wavelength, several discrete wavelengths or waveband when energized by an electrical current; and

(ii) an acoustic transducer being operably coupled via an electrical circuit to said source of light, said acoustic transducer being powered by acoustic energy providable by an external acoustic energy source to effect current flow to said source of light; and

(b) said external acoustic energy source for activating said acoustic transducer.

73. The system of claim 72, wherein said miniature light source further comprises a capacitor in said electrical circuit, said capacitor being chargeable by said acoustic transducer and dischargeable so as to effect said current flow to said source of light.

74. The system of claim 72, wherein said miniature light source further comprises a rectifier that is connected to the acoustic transducer, said rectifier converting an alternating current to a direct current, which is supplied to energize the light source.

75. The system of claim 72, wherein the miniature light source is preprogrammed to shut off a predetermined time period following its activation.

76. The system of claim 72, wherein the miniature light source shuts off following a reception of an external shut off signal.

77. The system of claim 72, wherein the acoustic transducer comprises:

a cell member having a cavity;

a substantially flexible piezoelectric layer attached to the cell member, the piezoelectric layer having an external surface and an internal surface, the piezoelectric layer having predetermined dimensions for enabling fluctuations at its resonance frequency upon impinging of an external acoustic wave; and

a first electrode attached to the external surface and a second electrode attached to the internal surface.

78. The system of claim 72, wherein said acoustic transducer comprises a transducer element adapted for converting acoustic wave energy transmitted through an external fluid medium into electric energy, said transducer element comprising:

a cell member having a cavity;

a substantially flexible piezoelectric layer peripherally attached to said cell member so as to isolate said cavity from the external fluid medium, said cavity containing gas and having a substantially lower acoustic impedance than said external fluid medium, a central portion of said piezoelectric layer not rigidly affixed with respect to said cavity, said piezoelectric layer having an external surface and an internal surface, said piezoelectric layer featuring such dimensions so as to enable fluctuations thereof in-and-out of said cavity at its resonance frequency upon impinging of an acoustic signal transmitted through the external fluid medium, said resonance frequency determined by the physical dimensions of said cavity and said piezoelectric layer wherein the wavelength of the acoustic signal is substantially larger than said dimensions; and

a first electrode attached to said external surface and a second electrode attached to said internal surface.

79. The system of claim 78, wherein said cavity is etched or drilled into a substrate.

80. The system of claim 79, wherein said substrate includes an electrically insulating layer and an electrically conducting layer.

81. The system of claim 80, wherein said electrically insulating layer is made of a polymeric material.

82. The system of claim 83, wherein a sealing connection is made of indium.

83. The system of claim 78, wherein said piezoelectric layer is made of PVDF.

84. The system of claim 78, wherein said cavity is circular in cross section.

85. The system of claim 78, wherein said cavity is elliptic in cross section.

86. The system of claim 79, wherein said substrate includes a plurality of cell members.

87. The system of claim 78, wherein at least one of said first and second electrodes is specifically shaped so as to provide a maximal electrical output.

88. The system of claim 72, wherein the miniature light source further comprises a biocompatible, light transmitting, acoustic energy transmitting, material that encloses said source of light and said acoustic transducer, to form a bead, said bead being thus adapted for insertion into the internal treatment site to effect the photodynamic therapy by providing light to the treatment site.

89. The system of claim 88, wherein the bead is generally spherical and less than 5 mm in diameter.

90. The system of claim 88, wherein the bead is generally semi-spherical, less than 5 mm in diameter and less than 2.5 mm in height.

91. The system of claim 72, wherein said source of light is selected from the group consisting of a LED, a fluorescent light source, an electroluminescent source and a LD.

92. The system of claim 72, wherein the miniature light source further comprises a light diffuser disposed to diffuse the light emitted by the source of light.

93. The system of claim 92, wherein said light diffuser is a lens disposed to diffuse the light emitted by the source of light.

94. A method for providing light of a desired wavelength, several discrete wavelengths or waveband to an internal treatment site to effect a photodynamic therapy, comprising:

(a) providing a miniature light source which comprises;

(i) a source of light that produces light of a desired wavelength, several discrete wavelengths or waveband when energized by an electrical current; and

(ii) an acoustic transducer being operably coupled via an electrical circuit to said source of light, said acoustic transducer being powered by acoustic energy providable by an external acoustic energy source to effect current flow to said source of light;

(b) implanting said miniature light source at the internal treatment site of a subject in need thereof; and

(c) powering said acoustic transducer via said external acoustic energy source, thereby providing the light of the desired wavelength, several discrete wavelengths or waveband to the internal treatment site to effect the photodynamic therapy.

95. The method of claim 94, wherein said miniature light source further comprises a capacitor in said electrical circuit, said capacitor being chargeable by said acoustic transducer and dischargeable so as to effect said current flow to said source of light.

96. The method of claim 94, further comprising administering to the subject a therapeutically effective amount of a photodynamic therapy agent.

97. The method of claim 94, wherein the miniature light source is preprogrammed to shut off a predetermined time period following its activation.

98. The method of claim 94, wherein the miniature light source shuts off following a reception of an external shut off signal.

99. The method of claim 94, wherein said miniature light source further comprises a rectifier that is connected to the acoustic transducer, said rectifier converting an alternating current to a direct current, which is supplied to energize the light source.

100. The method of claim 94, wherein the miniature light source further comprises a biocompatible, light transmitting, acoustic energy transmitting, material that encloses said source of light and said acoustic transducer, to form a bead, said bead being thus adapted for insertion into the internal treatment site to effect the photodynamic therapy by providing light to the treatment site.

101. The method of claim 100, wherein the bead is generally spherical and less than 5 mm in diameter.

102. The method of claim 100, wherein the bead is generally semi-spherical, less than 5 mm in diameter and less than 2.5 mm in height.

103. The method of claim 94, wherein said source of light is selected from the group consisting of a LED, a fluorescent light source, an electroluminescent source and a LD.

104. The method of claim 94, wherein the miniature light source further comprises a light diffuser disposed to diffuse the light emitted by the source of light.

105. The method of claim 104, wherein said light diffuser is a lens disposed to diffuse the light emitted by the source of light.

106. The method of claim 94, wherein implanting said miniature light source at the internal treatment site is effected by injection or catheterization.

107. The method of claim 106, wherein said injecting comprises inserting a distal end of a needle that is connected to a syringe containing the miniature light source into the treatment site, and forcing the bead from the syringe into the treatment site through the needle.

108. The method of claim 94, wherein activating said acoustic transducer via said external acoustic energy source is effected by placing said external acoustic energy source against a body portion of a treated subject and activating said external acoustic energy source.

109. The method of claim 94, further comprising injecting a plurality of miniature light sources into the treatment site at spaced-apart locations.

110. The method of claim 94, wherein the acoustic transducer comprises:

a cell member having a cavity;

a substantially flexible piezoelectric layer attached to the cell member, the piezoelectric layer having an external surface and an internal surface, the piezoelectric layer having predetermined dimensions for enabling fluctuations at its resonance frequency upon impinging of an external acoustic wave; and

a first electrode attached to the external surface and a second electrode attached to the internal surface.

111. The method of claim 94, wherein said acoustic transducer comprises a transducer element adapted for converting acoustic wave energy transmitted through an external fluid medium into electric energy, said transducer element comprising:

a cell member having a cavity;

a substantially flexible piezoelectric layer peripherally attached to said cell member so as to isolate said cavity from the external fluid medium, said cavity containing gas and having a substantially lower acoustic impedance than said external fluid medium, a central portion of said piezoelectric layer not rigidly affixed with respect to said cavity, said piezoelectric layer having an external surface and an internal surface, said piezoelectric layer featuring such dimensions so as to enable fluctuations thereof in-and-out of said cavity at its resonance frequency upon impinging of an acoustic signal transmitted through the external fluid medium, said resonance frequency determined by the physical dimensions of said cavity and said piezoelectric layer wherein the wavelength of the acoustic signal is substantially larger than said dimensions; and

a first electrode attached to said external surface and a second electrode attached to said internal surface.

112. The method of claim 111, wherein said cavity is etched or drilled into a substrate.

113. The method of claim 112, wherein said substrate includes an electrically insulating layer and an electrically conducting layer.

114. The method of claim 113, wherein said electrically insulating layer is made of a polymeric material.

115. The method of claim 111, wherein a sealing connection is made of indium.

116. The method of claim 111, wherein said piezoelectric layer is made of PVDF.

117. The method of claim 111, wherein said cavity is circular in cross section.

118. The method of claim 111, wherein said cavity is elliptic in cross section.

119. The method of claim 112, wherein said substrate includes a plurality of cell members.

120. The method of claim 111, wherein at least one of said first and second electrodes is specifically shaped so as to provide a maximal electrical output.

121. A miniature light source for providing light to an internal treatment site to effect a photodynamic therapy at said site, comprising:

(a) a source of light that produces light of a desired wavelength, several discrete wavelengths or waveband when energized by an electrical current;

(b) a rechargeable energy storage device operably coupled via an electrical circuit to said source of light;

(c) an acoustic transducer coupled to said rechargeable energy storage device, said acoustic transducer being activatable upon acoustic signal by an external acoustic energy source for recharging said rechargeable energy storage device.

122. The system of claim 121, wherein said rechargeable energy storage device is selected from the group consisting of a rechargeable battery and a capacitor.

123. The miniature light source of claim 121, further comprising a rectifier that is connected to the acoustic transducer, said rectifier converting an alternating current to a direct current, which is supplied to said rechargeable energy storage device.

124. The miniature light source of claim 121, wherein the miniature light source is preprogrammed to shut off a predetermined time period following its activation.

125. The miniature light source of claim 121, wherein the miniature light source shuts off following a reception of an external shut off signal.

126. The miniature light source of claim 121, wherein the acoustic transducer comprises:

a cell member having a cavity;

a substantially flexible piezoelectric layer attached to the cell member, the piezoelectric layer having an external surface and an internal surface, the piezoelectric layer having predetermined dimensions for enabling fluctuations at its resonance frequency upon impinging of an external acoustic wave; and

a first electrode attached to the external surface and a second electrode attached to the internal surface.

127. The miniature light source of claim 121, wherein said acoustic transducer comprises a transducer element adapted for converting acoustic wave energy transmitted through an external fluid medium into electric energy, said transducer element comprising:

a cell member having a cavity;

a substantially flexible piezoelectric layer peripherally attached to said cell member so as to isolate said cavity from the external fluid medium, said cavity containing gas and having a substantially lower acoustic impedance than said external fluid medium, a central portion of said piezoelectric layer not rigidly affixed with respect to said cavity, said piezoelectric layer having an external surface and an internal surface, said piezoelectric layer featuring such dimensions so as to enable fluctuations thereof in-and-out of said cavity at its resonance frequency upon impinging of an acoustic signal transmitted through the external fluid medium, said resonance frequency determined by the physical dimensions of said cavity and said piezoelectric layer wherein the wavelength of the acoustic signal is substantially larger than said dimensions; and

a first electrode attached to said external surface and a second electrode attached to said internal surface.

128. The miniature light source of claim 127, wherein said cavity is etched or drilled into a substrate.

129. The miniature light source of claim 128, wherein said substrate includes an electrically insulating layer and an electrically conducting layer.

130. The miniature light source of claim 129, wherein said electrically insulating layer is made of a polymeric material.

131. The miniature light source of claim 121, wherein a sealing connection is made of indium.

132. The miniature light source of claim 127, wherein said piezoelectric layer is made of PVDF.

133. The miniature light source of claim 127, wherein said cavity is circular in cross section.

134. The miniature light source of claim 127, wherein said cavity is elliptic in cross section.

135. The miniature light source of claim 128, wherein said substrate includes a plurality of cell members.

136. The miniature light source of claim 121, wherein at least one of said first and second electrodes is specifically shaped so as to provide a maximal electrical output.

137. The miniature light source of claim 121, further comprising a biocompatible, light transmitting, acoustic energy transmitting, material that encloses said source of light and said acoustic transducer, to form a bead, said bead being thus adapted for insertion into the internal treatment site to effect the photodynamic therapy by providing light to the treatment site.

138. The miniature light source of claim 137, wherein the bead is generally spherical an less than 5 mm in diameter.

139. The miniature light source of claim 137, wherein the bead is generally semi-spherical, less than 5 mm in diameter and less than 2.5 mm in height.

140. The miniature light source of claim 121, wherein said source of light is selected from the group consisting of a LED, a fluorescent light source, an electroluminescent source and a LD.

141. The miniature light source of claim 121, further comprising a light diffuser disposed to diffuse the light emitted by the source of light.

142. The miniature light source of claim 141, wherein said light diffuser is a lens disposed to diffuse the light emitted by the source of light.

143. A system for providing light of a desired wavelength, several discrete wavelengths or waveband to a treatment site disposed internally within a patient'"'"'s body, to effect a photodynamic therapy of the treatment site, comprising:

(a) a miniature light source which comprises;

(i) a source of light that produces light of a desired wavelength, several discrete wavelengths or waveband when energized by an electrical current;

(ii) a rechargeable energy storage device operably coupled via an electrical circuit to said source of light;

(iii) an acoustic transducer coupled to said rechargeable energy storage device, said acoustic transducer being activatable upon acoustic signal by an external acoustic energy source for recharging said rechargeable energy storage device; and

(b) said external acoustic energy source for recharging said rechargeable energy storage device.

144. The system of claim 143, wherein said rechargeable energy storage device is selected from the group consisting of a rechargeable battery and a capacitor.

145. The system of claim 143, wherein said miniature light source further comprising a rectifier that is connected to the acoustic transducer, said rectifier converting an alternating current to a direct current, which is supplied to said rechargeable energy storage device.

146. The system of claim 143, wherein the miniature light source is preprogrammed to shut off a predetermined time period following its activation.

147. The system of claim 143, wherein the miniature light source shuts off following a reception of an external shut off signal.

148. The system of claim 143, wherein the acoustic transducer comprises:

a cell member having a cavity;

a substantially flexible piezoelectric layer attached to the cell member, the piezoelectric layer having an external surface and an internal surface, the piezoelectric layer having predetermined dimensions for enabling fluctuations at its resonance frequency upon impinging of an external acoustic wave; and

a first electrode attached to the external surface and a second electrode attached to the internal surface.

149. The system of claim 143, wherein said acoustic transducer comprises a transducer element adapted for converting acoustic wave energy transmitted through an external fluid medium into electric energy, said transducer element comprising:

a cell member having a cavity;

a substantially flexible piezoelectric layer peripherally attached to said cell member so as to isolate said cavity from the external fluid medium, said cavity containing gas and having a substantially lower acoustic impedance than said external fluid medium, a central portion of said piezoelectric layer not rigidly affixed with respect to said cavity, said piezoelectric layer having an external surface and an internal surface, said piezoelectric layer featuring such dimensions so as to enable fluctuations thereof in-and-out of said cavity at its resonance frequency upon impinging of an acoustic signal transmitted through the external fluid medium, said resonance frequency determined by the physical dimensions of said cavity and said piezoelectric layer wherein the wavelength of the acoustic signal is substantially larger than said dimensions; and

a first electrode attached to said external surface and a second electrode attached to said internal surface.

150. The system of claim 149, wherein said cavity is etched or drilled into a substrate.

151. The system of claim 150, wherein said substrate includes an electrically insulating layer and an electrically conducting layer.

152. The system of claim 151, wherein said electrically insulating layer is made of a polymeric material.

153. The system of claim 143, wherein a sealing connection is made of indium.

154. The system of claim 149, wherein said piezoelectric layer is made of PVDF.

155. The system of claim 149, wherein said cavity is circular in cross section.

156. The system of claim 149, wherein said cavity is elliptic in cross section.

157. The system of claim 150, wherein said substrate includes a plurality of cell members.

158. The system of claim 149, wherein at least one of said first and second electrodes is specifically shaped so as to provide a maximal electrical output.

159. The system of claim 143, wherein the miniature light source further comprises a biocompatible, light transmitting, acoustic energy transmitting, material that encloses said source of light and said acoustic transducer, to form a bead, said bead being thus adapted for insertion into the internal treatment site to effect the photodynamic therapy by providing light to the treatment site.

160. The system of claim 159, wherein the bead is generally spherical and less than 5 mm in diameter.

161. The system of claim 159, wherein the bead is generally semi-spherical, less than 5 mm in diameter and less than 2.5 mm in height.

162. The system of claim 143, wherein said source of light is selected from the group consisting of a LED, a fluorescent light source, an electroluminescent source and a LD.

163. The system of claim 143, wherein the miniature light source further comprises a light diffuser disposed to diffuse the light emitted by the source of light.

164. The system of claim 163, wherein said light diffuser is a lens disposed to diffuse the light emitted by the source of light.

165. A method for providing light of a desired wavelength, several discrete wavelengths or waveband to an internal treatment site to effect a photodynamic therapy, comprising:

(a) providing a miniature light source which comprises;

(i) a source of light that produces light of a desired wavelength, several discrete wavelengths or waveband when energized by an electrical current;

(ii) a rechargeable energy storage device operably coupled via an electrical circuit to said source of light;

(iii) an acoustic transducer coupled to said rechargeable energy storage device, said acoustic transducer being activatable upon acoustic signal by an external acoustic energy source for recharging said rechargeable energy storage device;

(b) implanting said miniature light source at the internal treatment site of a subject in need thereof; and

(c) recharging said rechargeable energy storage device via said acoustic transducer and said external acoustic energy source.

166. The method of claim 165, wherein said rechargeable energy storage device is selected from the group consisting of a rechargeable battery and a capacitor.

167. The method of claim 165, further comprising administering to the subject a therapeutically effective amount of a photodynamic therapy agent.

168. The method of claim 165, wherein the miniature light source is preprogrammed to shut off a predetermined time period following its activation.

169. The method of claim 165, wherein the miniature light source shuts off following a reception of an external shut off signal.

170. The method of claim 165, wherein said miniature light source further comprising a rectifier that is connected to the acoustic transducer, said rectifier converting an alternating current to a direct current, which is supplied to said rechargeable energy storage device.

171. The method of claim 165, wherein the miniature light source further comprises a biocompatible, light transmitting, acoustic energy transmitting, material that encloses said source of light and said acoustic transducer, to form a bead, said bead being thus adapted for insertion into the internal treatment site to effect the photodynamic therapy by providing light to the treatment site.

172. The method of claim 171, wherein the bead is generally spherical and less than 5 mm in diameter.

173. The method of claim 171, wherein the bead is generally semi-spherical, less than 5 mm in diameter and less than 2.5 mm in height.

174. The method of claim 165, wherein said source of light is selected from the group consisting of a LED, a fluorescent light source, an electroluminescent source and a LD.

175. The method of claim 165, wherein the miniature light source further comprises a light diffuser disposed to diffuse the light emitted by the source of light.

176. The method of claim 175, wherein said light diffuser is a lens disposed to diffuse the light emitted by the source of light.

177. The method of claim 165, wherein implanting said miniature light source at the internal treatment site is effected by injection or catheterization.

178. The method of claim 177, wherein said injecting comprises inserting a distal end of a needle that is connected to a syringe containing the miniature light source into the treatment site, and forcing the bead from the syringe into the treatment site through the needle.

179. The method of claim 165, wherein activating said acoustic transducer via said external acoustic energy source is effected by placing said external acoustic energy source against a body portion of a treated subject and activating said external acoustic energy source.

180. The method of claim 165, further comprising injecting a plurality of miniature light sources into the treatment site at spaced-apart locations.

181. The method of claim 165, wherein the acoustic transducer comprises:

a cell member having a cavity;

a substantially flexible piezoelectric layer attached to the cell member, the piezoelectric layer having an external surface and an internal surface, the piezoelectric layer having predetermined dimensions for enabling fluctuations at its resonance frequency upon impinging of an external acoustic wave; and

a first electrode attached to the external surface and a second electrode attached to the internal surface.

182. The method of claim 165, wherein said acoustic transducer comprises a transducer element adapted for converting acoustic wave energy transmitted through an external fluid medium into electric energy, said transducer element comprising:

a cell member having a cavity;

a substantially flexible piezoelectric layer peripherally attached to said cell member so as to isolate said cavity from the external fluid medium, said cavity containing gas and having a substantially lower acoustic impedance than said external fluid medium, a central portion of said piezoelectric layer not rigidly affixed with respect to said cavity, said piezoelectric layer having an external surface and an internal surface, said piezoelectric layer featuring such dimensions so as to enable fluctuations thereof in-and-out of said cavity at its resonance frequency upon impinging of an acoustic signal transmitted through the external fluid medium, said resonance frequency determined by the physical dimensions of said cavity and said piezoelectric layer wherein the wavelength of the acoustic signal is substantially larger than said dimensions; and

a first electrode attached to said external surface and a second electrode attached to said internal surface.

183. The method of claim 182, wherein said cavity is etched or drilled into a substrate.

184. The method of claim 183, wherein said substrate includes an electrically insulating layer and an electrically conducting layer.

185. The method of claim 184, wherein said electrically insulating layer is made of a polymeric material.

186. The method of claim 182, wherein said piezoelectric layer is made of PVDF.

187. The method of claim 182, wherein said cavity is circular in cross section.

188. The method of claim 182, wherein said cavity is elliptical in cross section.

189. The method of claim 183, wherein said substrate includes a plurality of cell members.

190. The method of claim 182, wherein at least one of said first and second electrodes is specifically shaped so as to provide a maximal electrical output.