System for Dissociation and Removal of Proteinaceous Tissue

• US 20100331911A1
• Filed: 09/14/2010
• Published: 12/30/2010
• Est. Priority Date: 01/03/2006
• Status: Abandoned Application

• Current Assignee: Novartis Ag
• Original Assignee: Novartis Ag
• Inventors: Huculak, John C., Kovalcheck, Steven W.
• Application Number:
  US12/881,302
• Publication Number:
  US 20100331911A1
• Time in Patent Office: Days
• US Class Current: 607/53
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61F 9/00736 Instruments for removal of intra-ocular material or intra-ocular injection, e.g. cataract instruments A61F9/008 takes precedence

Abstract

An apparatus and method for the dissociation of soft proteinaceous tissue using pulsed rapid variable direction energy field flow fractionization is disclosed. The pulsed rapid disruptive energy field is created by the use of a probe which surrounds the soft proteinaceous tissue to be removed. Once the adhesive mechanism between tissue constituents has been compromised, fluidic techniques are used to remove the dissociated tissue.

Claims

1. A system for applying high-intensity pulsed electric fields to ocular tissue in order to change the state and increase the fluidity of the ocular tissue, the system comprising:

a probe for applying a stressing pulsed electric field to ocular tissue; and

an electric field generator for creating the stressing pulsed electric field with the probe;

wherein the pulsed electric field stresses and partially liquefies a proteinaceous complex to cause dissociation and increased fluidity of the ocular tissue and further wherein the pulsed electric field is insufficient to create an electron avalanche.

2. The system of claim 1, further comprising an aspiration system.

3. The system of claim 2, wherein the aspiration system removes dissociated ocular tissue.

4. The system of claim 1, wherein the probe includes at least two electrodes.

5. The system of claim 1, wherein the electric field traverses the ocular tissue to be dissociated.

6. The system of claim 1, wherein the direction of the electric field is varied.

7. The system of claim 3, wherein the electric field is generated from a first set of electrodes to a second set of electrodes by applying a pulsed voltage across the electrodes.

8. The system of claim 7, wherein the pulsed voltage is switchable between the first set of electrodes and the set of second electrodes.

9. The system of claim 7, wherein the pulsed voltage is repeatedly reversed between the first set of electrodes and the second set of electrodes.

10. The system of claim 7, wherein electrical activity between the first set of electrodes and the second set of electrodes is sequentially changed.

11. The system of claim 6, wherein the direction of the electric field is varied by repeated reversal of electrode potential, repeated switching of active electrodes or a combination of both.

12. The system of claim 7, further comprising:

a liquid medium in which the electrodes are immersed.

13. The system of claim 12, wherein the liquid medium has electrically conductive properties.

14. The system of claim 1, further comprising:

an irrigation system.

15. The system of claim 14, wherein the irrigation system supplies fluid with electrically conductive properties.

16. The system of claim 1, wherein the electric field has a pulse shape, pulse pattern, pulse repetition rate, and pulse train length that is disruptive to the tissue to be dissociated.

17. The system of claim 1, wherein the field strength of the electric field is larger than 1 kV/cm.

18. A method for dissociative liquefaction and for increasing fluidity of a macroscopic volume of proteinaceous ocular tissue, the method comprising the step of:

creating a weakened proteinaceous liquid complex by establishing a confined, localized, stressing pulsed electric field within the extracellular matrix of the proteinaceous tissue without creation of an electron avalanche.

19. The method of claim 18, wherein the creation of a confined, localized, stressing pulsed electric field within the extracellular matrix of the proteinaceous tissue causes dissociation of the proteinaceous complexes and local liquefaction of the macroscopic volume of proteinaceous tissue.

20. The method of claim 18, wherein the creation of a confined, localized stressing pulsed electric field within the tissue weakens the adhesive and structural relations between tissue components.

21. The method of claim 18, wherein the creation of the electric field within tissues promotes separation and detachment of tissue components from adjacent structures.

22. The method of claim 18, wherein the creation of the electric field within tissues weakens the hydrophobic and hydrostatic bonds within the tissue.

23. The method of claim 19, wherein the stressing pulsed electric field is advanced into the volume of tissue.

24. The method of claim 19, further comprising:

aspirating tissue.

25. The method of claim 24, wherein aspirating tissue further comprises entraining macroscopic volumes of tissue into the electric field.

26. The method of claim 24, wherein aspirating tissue further comprises removing a volume of tissue.

27. The method of claim 19, comprising:

irrigating tissue.

28. The method of claim 18, wherein the electric field is created by use of microwaves.

29. The method of claim 18, wherein the electric field is created by use of a laser.

30. The method of claim 29, wherein the laser operates with pulse duration in the femtosecond range and at substantially the peak absorption frequency of water.

31. The method of claim 18, wherein the electric field is created by use of ultrasound.

32. The method of claim 18, wherein the electric field is created by the use of pulsed voltage.

33. The method of claim 18, wherein the electric field is created by the use of pulsed DC voltage.

34. The method of claim 18, wherein the electric field is created by the use of gated AC voltage.

35. A method of using high-intensity pulsed electric fields to change the state and increase the fluidity of ocular tissue, the method comprising:

providing a hollow probe for insertion into a posterior region of an eye;

engaging a volume of ocular tissue with the hollow probe;

creating a high-intensity pulsed electric field with electrodes located within the probe to partially liquefy the ocular tissue; and

removing a volume of the ocular tissue;

wherein the high-intensity pulsed electric field is insufficient to create an electron avalanche.

36. The method of claim 35, wherein the high-intensity pulsed electric field is substantially orthogonal to the volume of tissue to be dissociated.

37. The method of claim 35, wherein the high-intensity pulsed electric field traverses the volume of tissue to be dissociated.

38. The method of claim 35, wherein the volume of tissue is removed by aspiration.

39. The method of claim 35, further comprising:

irrigating the ocular tissue with irrigation fluid.

40. The method of claim 39, wherein the irrigation fluid is electrically conductive.

41. The method of claim 35, wherein the pulses in the high-intensity-pulsed electric field are used to dissociated proteinaceous components of tissue.

42. The method of claim 38, wherein irrigation fluid is used with aspiration.

43. The method of claim 42, wherein the flow of the aspiration and the irrigation are matched in order that the volume and pressure within the eye is maintained within physiological limits.

44. The method of claim 38, wherein the aspiration flow rate is matched to the fluidity of the ocular tissue.

45. A system for creating a high-intensity pulsed electric field between electrodes of a surgical probe in order to change the state and increase the fluidity of ocular tissue, the system comprising:

a surgical probe with at least two electrodes;

at least one pulse generator;

a control circuit, the control circuit for controlling a duration, a repetition, a polarity, and an amplitude of electrical pulses delivered to the electrodes of the surgical probe; and

an electrical conductor, the electrical conductor connecting the pulse generator, the control circuit, and the electrodes;

wherein a high-intensity, pulsed, electric field formed at a tip of the surgical probe is sufficient to create a weakened proteinaceous liquid complex from the volume of ocular tissue and further wherein pulse strength of the high-intensity pulsed electric field is insufficient to create an electron avalanche.

46. The system of claim 45, wherein the pulse generator further comprises a pulse forming circuit.

47. The system of claim 45, further comprising:

a switch circuit.

48. The system of claim 45, wherein the pulse generator has one or more output channels.

49. The system of claim 45, wherein the pulse generator delivers pulsed DC voltage.

50. The system of claim 45, wherein the pulse generator delivers gated AC voltage.

51. The system of claim 45, wherein the control circuit changes a parameter selected from the group consisting of:

the pulse-shape, the pulse-repetition-rate, the pulse-duration, the pulse train-length, the pulse-pattern, the pulse amplitude, and the number of pulses.

52. The system of claim 45, wherein the control circuit changes the activation sequence of the electrodes.

53. The system of claim 52, wherein the output sequence of the pulse generator is selected from the group consisting of:

a sequence of ordered pulses and a sequence of random pulses.

54. The system of claim 47, wherein the control circuit changes the polarity of the pulsed electric field created between the electrodes.

55. The system of claim 47, wherein the control circuit changes the direction of the pulsed electric field created between the electrodes.

56. The system of claim 45, further comprising:

an electrically conducting medium located between the electrodes.

57. The system of claim 45, further comprising:

a fluid located between the electrodes that maintains a stable electrical environment.

58. The system of claim 45, wherein the surgical probe has one or more through lumens.

59. The system of claim 45, further comprising:

an irrigation system to deliver a fluid between the electrodes.

60. The system of claim 58, wherein a number of the lumens are for irrigation.

61. The system of claim 45, further comprising:

an aspiration system to remove dissociated tissue.

62. The system of claim 58, wherein the number of the lumens are for aspiration.

63. The system of claim 45, where the pulse generator delivers one or more pulses in bursts.

64. The system of claim 63, wherein the control circuit changes the time between the pulses in a burst.

65. The system of claim 63, wherein the control circuit changes the pulse train length.

66. The system of claim 63, wherein the control circuit changes the burst frequency.

67. The system of claim 45, further comprising:

irrigation fluid with pH properties conducive to a pulsed electric field induced increase of the fluidity of the tissue.

68. The system of claim 45, further comprising:

irrigation fluid combined with ingredients conducive to a pulsed electric field induced increase of the fluidity of the tissue.

69. The system of claim 68, wherein the ingredients in the irrigation fluid has enzymatic properties.

70. A method of using high-intensity pulsed electric fields to change the state and to increase the fluidity of a macroscopic volume of ocular tissue, the method comprising:

applying a localized pulsed electric field to the tissue without causing an electron avalanche;

wherein the localized pulsed electric field comprises pulses that have a pulse-shape, a pulse-repetition-rate, and a pulse-duration;

wherein the pulses are grouped into bursts or pulse-trains; and

wherein the pulse-trains have a pulse-train-length, and a pulse-pattern.

71. The method of claim 70, wherein the pulse-shape is tuned to structural properties of the ocular tissue and its surroundings.

72. The method of claim 71, wherein the pulse-repetition rate is tuned to structural properties of the ocular tissue and its surroundings.

73. The method of claim 70, wherein the pulse-duration is tuned to structural properties of the ocular tissue and its surroundings.

74. The method of claim 70, wherein the pulse-pattern is tuned to structural properties of the ocular tissue and its surroundings.

75. The method of claim 70, wherein the pulse-train-length is tuned to structural properties of the ocular tissue and its surroundings.

76. A device for distributing a high-intensity pulsed electric field to ocular tissue for changing the state and increasing the fluidity of ocular tissue, the device comprising:

a probe having a handle and a shaft for engaging ocular tissue, the probe shaft having a first number of electrodes;

a distal termination of each electrode being spatially positioned to provide a contained region wherein a penetrating disruptive electric field is created and applied to a volume of the ocular tissue;

the electrode terminations being shaped to concentrate a pulsed electric field within the ocular tissue; and

a connection to an electrical system that generates ultra short high-intensity electric pulses;

the connection delivering the high-intensity electric pulses to the probe;

77. The device of claim 76, wherein outside diameter of the probe shaft is less than 0.04 inches.

78. The device of claim 76, wherein the distal termination of one or more of the electrodes is shaped to concentrate the electric field to ocular tissue between the electrodes.

79. The device of claim 76, wherein two or more of the electrodes are axially arranged around the center longitudinal axis of the probe shaft.

80. The device of claim 76, wherein the electrodes are axially positioned so that one or more of the electrodes terminates at different lengths or different axial positions.

81. The device of claim 76, wherein the distal termination of one or more of the electrodes is pointed.

82. The device of claim 76, wherein the distal termination of one or more of the electrodes is angled.

83. The device of claim 76, wherein the electrodes are made of wires, a portion of the wires being round shaped.

84. The device of claim 76, wherein the electrodes are made of wires, a portion of the wires being ovular shaped.

85. The device of claim 76, wherein the electrode terminations are not insulated.

86. The device of claim 76, wherein the distance between the electrode terminations is less the 0.5 millimeters.

87. The device of claim 76, wherein the distal termination of one or more of the electrodes is shaped to concentrate a pulsed rapid electric field to ocular tissue in the vicinity of the electrodes.

88. The device of claim 76, wherein one or more edges of the electrode terminations are rounded.

89. The device of claim 76, wherein the distal termination of one or more of the electrodes is triangular.

90. The device of claim 89, wherein the apex of the triangular distal termination is pointed towards the center of an orifice of the probe.

91. The device of claim 76, wherein the distal termination of one or more of the electrodes has one or more sharp edges.

92. The device of claim 91, wherein one or more of the sharp edges are directed toward a longitudinal axis of the probe.

93. The device of claim 76, wherein a portion of the electrodes are flat ribbon shaped.

94. The device of claim 93, wherein one or more of the electrodes are orientated with a wider side tangent to the circumference of the probe shaft.

95. The device of claim 93, wherein one or more of the electrodes are orientated with a narrower side tangent to the circumference of the probe shaft.

96. The device of claim 76, wherein the distal end of the probe terminates in an atraumatic tip.

97. The device of claim 96, wherein the atraumatic tip comprises a formed polymer over-sheath on the distal end of the probe shaft.

98. The device of claim 97, wherein the atraumatic tip encases a treatment zone within which the electric field is directed and ocular tissue is engaged.

99. The device of claim 76, wherein the location of the distal electrode terminations creates a region of ocular tissue encirclement.

100. The device of claim 76, wherein the electrode termination shape is selected from the group of shapes consisting of:

straight edges, corners, curvatures and combination thereof.

101. The device of claim 76, wherein the probe is hollow.

102. The device of claim 101, wherein the shaft of the probe terminates in an axial orifice for engagement of ocular tissue.

103. The device of claim 101, wherein the shaft of the probe terminates in a lateral orifice for engagement of ocular tissue.

104. The device of claim 101, wherein the hollow in the shaft comprises one or more lumens through the probe shaft.

105. The device of claim 104, wherein one or more of the lumens are for aspiration.

106. The device of claim 104, wherein one or more of the lumens are for fluid irrigation.

107. The device of claim 104, wherein one or more of the lumens are for passage of an instrument.

108. The device of claim 104, wherein one or more of the lumens are for passage of an optical fiber.

109. The device of claim 104, wherein aspiration is provided through an independent cannula.

110. The device of claim 76, wherein irrigation is provided through an independent cannula.