ENERGETIC MODULATION OF NERVES

• US 20110092781A1
• Filed: 10/11/2010
• Published: 04/21/2011
• Est. Priority Date: 10/12/2009
• Status: Active Grant

• Current Assignee: Otsuka Medical Devices Co., Ltd. (Otsuka Holdings Company Limited)
• Original Assignee: Kona Medical, Inc.
• Inventors: GERTNER, Michael
• Granted Patent: US 9,174,065 B2
• Time in Patent Office: Days
• US Class Current: 600/301
• CPC Class Codes: A61B 17/320068 using mechanical vibrations, e.g. ultrasonic A61B17/22012 takes precedence; dental tooth drilling devices operated by vibration A61C3/03; removing intra-ocular material using mechanical vibrations A61F9/00745
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 18/18 by applying electromagnetic radiation, e.g. microwaves radiation therapy A61N5/00
• CPC Class Codes: A61B 2018/00404 Blood vessels other than those in or around the heart
• CPC Class Codes: A61B 2018/00434 Neural system
• CPC Class Codes: A61B 2018/00511 Kidney
• CPC Class Codes: A61B 2090/374 NMR or MRI
• CPC Class Codes: A61B 2090/3762 using computed tomography systems [CT]
• CPC Class Codes: A61B 2090/378 using ultrasound
• CPC Class Codes: A61B 5/0225 the pressure being controlled by electric signals, e.g. derived from Korotkoff sounds
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/4035 Evaluating the autonomic nervous system
• CPC Class Codes: A61B 5/4041 Evaluating nerves condition
• CPC Class Codes: A61B 5/4047 afferent nerves, i.e. nerves that relay impulses to the central nervous system
• CPC Class Codes: A61B 5/4052 efferent nerves, i.e. nerves that relay impulses from the central nervous system
• CPC Class Codes: A61B 5/412 Detecting or monitoring sepsis
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61B 5/489 Blood vessels
• CPC Class Codes: A61B 5/4893 Nerves
• CPC Class Codes: A61B 6/03 : Computed tomography [CT] echo-tomography A61B8/14
• CPC Class Codes: A61B 6/032 : Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/037 : Emission tomography
• CPC Class Codes: A61B 6/506 : for diagnosis of nerves
• CPC Class Codes: A61B 8/00 : Diagnosis using ultrasonic, sonic or infrasonic waves imaging of objects using sonar G01S15/00
• CPC Class Codes: A61B 8/06 : Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00
• CPC Class Codes: A61B 8/08 : Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• CPC Class Codes: A61B 8/4245 : involving determining the position of the probe, e.g. with respect to an external reference frame or to the patient
• CPC Class Codes: A61B 8/485 : involving measuring strain or elastic properties
• CPC Class Codes: A61B 90/37 : Surgical systems with images on a monitor during operation
• CPC Class Codes: A61N 1/0551 : Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 2/006 : for magnetic stimulation of nerve tissue
• CPC Class Codes: A61N 2005/063 : comprising light transmitting means, e.g. optical fibres
• CPC Class Codes: A61N 2007/0026 : Stimulation of nerve tissue
• CPC Class Codes: A61N 2007/003 : Destruction of nerve tissue
• CPC Class Codes: A61N 2007/0078 : with multiple treatment transducers
• CPC Class Codes: A61N 2007/025 : interstitial
• CPC Class Codes: A61N 5/00 : Radiation therapy ultrasound therapy A61N7/00; devices or apparatus applicable to both therapy and diagnosis A61B6/00
• 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
• CPC Class Codes: A61N 5/0622 : Optical stimulation for exciting neural tissue
• CPC Class Codes: A61N 7/00 : Ultrasound therapy lithotripsy A61B17/22, A61B17/225; massage using supersonic vibration A61H23/00 ; using ultrasound for introducing media into the body A61M37/0092
• CPC Class Codes: A61N 7/02 : Localised ultrasound hyperthermia hyperthermia in general A61F7/00

Abstract

In some examples, nerves surrounding arteries or leading to organs are targeted with energy sources to correct or modulate physiologic processes. In some examples, different types of energy sources are utilized singly or combined with one another. In some examples, bioactive agents or devices activated by the energy sources are delivered to the region of interest and the energy is enhanced by such agents or the agents are enhanced by the energy sources.

Claims

1. A method of treatment, comprising:

placing an energy source outside a patient;

operating the energy source so that an energy delivery path of the energy source is aimed towards a nerve inside the patient, wherein the nerve is a part of an autonomic nervous system; and

using the energy source to deliver treatment energy from outside the patient to the nerve located inside the patient to treat the nerve.

2. The method of claim 1, wherein the treatment energy comprises focused energy.

3. The method of claim 1, wherein the treatment energy comprises non-focused energy.

4. The method of claim 1, wherein the treatment energy comprises HIFU energy.

5. The method of claim 1, wherein the treatment energy comprises LIFU energy.

6. The method of claim 1, wherein the treatment energy is delivered to the nerve to achieve partial ablation of the nerve.

7. The method of claim 1, wherein the treatment energy is delivered to the nerve to achieve complete ablation of the nerve.

8. The method of claim 1, wherein the treatment energy is delivered to achieve paralysis of the nerve.

9. The method of claim 1, wherein the nerve leads to a kidney.

10. The method of claim 9, wherein the nerve comprises a renal nerve.

11. The method of claim 9, wherein the nerve comprises a sympathetic nerve connected to the kidney.

12. The method of claim 9, wherein the nerve comprises an afferent nerve connected to the kidney.

13. The method of claim 9, wherein the nerve comprises a renal sympathetic nerve at a renal pedicle.

14. The method of claim 1, wherein the nerve comprises a nerve trunk adjacent to a vertebra.

15. The method of claim 1, wherein the nerve comprises a ganglion adjacent to a vertebra.

16. The method of claim 1, wherein the nerve comprises a dorsal root nerve.

17. The method of claim 1, wherein the nerve leads to an adrenal gland.

18. The method of claim 1, wherein the nerve comprises a motor nerve.

19. The method of claim 1, wherein the nerve is next to a kidney.

20. The method of claim 1, wherein the nerve is behind an eye.

21. The method of claim 1, wherein the nerve comprises a celiac plexus.

22. The method of claim 1, wherein the nerve is within or around a vertebral column.

23. The method of claim 1, wherein the nerve extends to a facet joint

24. The method of claim 1, wherein the nerve comprises a celiac ganglion.

25. The method of claim 1, wherein the act of operating the energy source comprises positioning the energy source.

26. The method of claim 1, wherein the energy source comprises an ultrasound energy source.

27. The method of claim 26, wherein the ultrasound energy source is used to deliver the treatment energy to the nerve from multiple directions outside the patient.

28. The method of claim 1, wherein the treatment energy is delivered to modulate the nerve without damaging the nerve.

29. The method of claim 1, further comprising determining a position of a renal vessel using an imaging device located outside the patient.

30. The method of claim 29, wherein the position of the renal vessel is used to determine a position of the nerve.

31. The method of claim 29, wherein the imaging device comprises a CT device, an MRI device, a thermography device, an infrared imaging device, an optical coherence tomography device, a photoacoustic imaging device, a PET imaging device, a SPECT imaging device, or an ultrasound device.

32. The method of claim 1, further comprising determining a position of the nerve inside the patient.

33. The method of claim 32, wherein the act of determining the position of the nerve inside the patient comprises determining a position of a renal vessel to target the nerve that surrounds the renal vessel.

34. The method of claim 33, wherein the renal vessel comprises a renal artery.

35. The method of claim 32, wherein the act of determining the position of the nerve inside the patient comprises using a Doppler triangulation technique.

38. The method of claim 32, wherein the imaging device comprises a MRI device.

39. The method of claim 32, wherein the imaging device comprises a CT device.

40. The method of claim 32, wherein the treatment energy comprises HIFU energy, and the imaging device comprises a MRI device.

41. The method of claim 32, wherein the treatment energy comprises HIFU energy, and the imaging device comprises an ultrasound device.

42. The method of claim 32, wherein the nerve leads to a kidney, and the imaging device comprises a MRI device.

43. The method of claim 32, wherein the nerve leads to a kidney, and the imaging device comprises an ultrasound device.

44. The method of claim 32, wherein the nerve leads to a kidney, and the imaging device is used to obtain a doppler signal.

45. The method of claim 1, wherein the treatment energy is delivered to a kidney to decrease a sympathetic stimulus to the kidney, decrease an afferent signal from the kidney to an autonomic nervous system, or both.

46. The method of claim 1, further comprising delivering testing energy to the patient to determine if there is a reaction resulted therefrom, wherein the testing energy is delivered before the treatment energy is delivered from the energy source.

47. The method of claim 46, wherein the testing energy comprises heat or vibratory energy, and the method further comprises performing a test to detect sympathetic nerve activity.

48. The method of claim 46, wherein the testing energy comprises a stimulus applied to a skin, and the method further comprises detecting an output from the patient.

49. The method of claim 48, wherein the output comprises a heart rate.

50. The method of claim 46, wherein the test energy is delivered to stimulate a baroreceptor complex, and wherein the method further comprises:

applying pressure to a carotid artery; and

determining whether a blood pressure decreases after application of the pressure to the carotid artery.

51. The method of claim 50, wherein the test energy is delivered using an ultrasound device that is placed outside the patient.

52. The method of claim 50, wherein the treatment energy from the energy source is delivered if the blood pressure decreases or if the blood pressure decreases at a rate that is above a prescribed threshold.

53. The method of claim 1, wherein the treatment energy is delivered to treat hypertension.

54. The method of claim 1, wherein the treatment energy is delivered to treat glaucoma.

55. The method of claim 1, wherein the energy source is operated so that the energy source aims at a direction that aligns with a vessel that is next to the nerve.

56. The method of claim 1, further comprising tracking a movement of a treatment region containing the nerve.

57. The method of claim 1, wherein the energy delivery path of the energy source is aimed towards the nerve by using a position of a blood vessel that is surrounded by the nerve.

58. The method of claim 1, further comprising:

delivering a device inside the patient; and

using the device to determine a position of the nerve inside the patient;

wherein the energy source is operated based at least in part on the determined position so that the energy delivery path is aimed towards the nerve.

59. The method of claim 58, wherein the device is placed inside a vessel that is surrounded by the nerve, and the position of the nerve is determined indirectly by determining a position of the vessel.

60. A system for treatment, comprising:

an energy source for placement outside a patient;

wherein the energy source is configured to aim an energy delivery path towards a nerve that is a part of an autonomic nervous system inside the patient; and

wherein the energy source is configured to deliver treatment energy from outside the patient to the nerve located inside the patient to treat the nerve.

61. The system of claim 60, wherein the energy source is configured to provide focused energy.

62. The system of claim 60, wherein the energy source is configured to provide non-focused energy.

63. The system of claim 60, wherein the energy source is configured to provide HIFU energy.

64. The system of claim 60, wherein the energy source is configured to provide LIFU energy.

65. The system of claim 60, wherein the energy source is configured to provide the treatment energy to achieve partial ablation of the nerve.

66. The system of claim 60, wherein the energy source is configured to deliver the treatment energy to achieve complete ablation of the nerve.

67. The system of claim 60, wherein the energy source is configured to deliver the treatment energy to achieve paralysis of the nerve.

68. The system of claim 60, wherein the energy source comprises an ultrasound energy source.

69. The system of claim 68, wherein the ultrasound energy source is configured to deliver the treatment energy to the nerve from multiple directions outside the patient while the ultrasound energy source is stationary relative to the patient.

70. The system of claim 60, wherein the energy source is configured to deliver the treatment energy to modulate the nerve without damaging tissues that are within a path of the treatment energy to the nerve.

71. The system of claim 60, wherein the nerve comprises a renal nerve, and the system further comprises a processor located outside the patient, wherein the processor is configured for:

receiving an input related to a position of a renal artery;

determining an output related to a position of the renal nerve based on a model that associates artery position with nerve position; and

providing the output to a positioning system for the energy source so that the positioning system can cause the energy source to deliver the treatment energy from the outside of the patient to the renal nerve to treat the renal nerve.

72. The system of claim 60, further comprising a processor for determining a position of a renal vessel located outside the patient.

73. The system of claim 72, further comprising an imaging device for providing an image signal, wherein the processor is configured to determine the position based on the image signal.

74. The system of claim 73, wherein the imaging device comprises a CT device, a MRI device, a thermography device, an infrared imaging device, an optical coherence tomography device, a photoacoustic imaging device, a PET imaging device, a SPECT imaging device, or an ultrasound device.

75. The system of claim 72, wherein the position of the renal vessel is used during the treatment energy delivery to target the nerve that surrounds the renal vessel.

76. The system of claim 72, wherein the position is determined using a Doppler triangulation technique.

77. The system of claim 72, wherein the renal vessel comprises a renal artery.

78. The system of claim 60, wherein treatment energy is delivered to a kidney to decrease a sympathetic stimulus to the kidney, decrease an afferent signal from the kidney to an autonomic nervous system, or both.

79. The system of claim 60, wherein the energy source is also configured to deliver testing energy to the patient to determine if there is a reaction resulted therefrom.

80. The system of claim 60, wherein the energy source is configured to deliver the treatment energy to treat hypertension.

81. The system of claim 60, wherein the energy source is configured to deliver the treatment energy to treat glaucoma.

82. The system of claim 60, wherein the energy source has an orientation so that the energy source aims at a direction that aligns with a vessel that is next to the nerve.

83. The system of claim 60, wherein the energy source is configured to track a movement of the nerve.

84. The system of claim 83, wherein the energy source is configured to track the movement of the nerve by tracking a movement of a blood vessel next to the nerve.

85. The system of claim 60, wherein the energy source is configured to aim at the nerve by aiming at a vessel that is surrounded by the nerve.

86. The system of claim 60, further comprising:

a device for placement inside the patient; and

a processor for determining a position using the device;

wherein the energy source is configured to aim the energy delivery path towards the nerve inside the patient based at least in part on the determined position.

87. The system of claim 86, wherein the device is sized for insertion into a vessel that is surrounded by the nerve.

88. A system to deliver energy from a position outside a skin of a patient to a nerve surrounding a blood vessel inside the patient, comprising:

a processor configured to receive image signal, and determine a three dimensional coordinate of a blood vessel based on the image signal; and

an energy source configured to deliver energy from the position outside the skin of the patient to the nerve surrounding the blood vessel;

wherein the processor is also configured to control the energy source based on the determined coordinate.

89. The system of claim 88, further comprising an imaging device for providing the image signal.

90. The system of claim 89, wherein the imaging device comprises a MRI device.

91. The system of claim 89, wherein the imaging device comprises an ultrasound device.

92. The system of claim 88, wherein the energy comprises focused energy.

93. The system of claim 88, wherein the energy comprises focused ultrasound.

94. The system of claim 88, wherein the energy source comprises an ultrasound array that is aligned with the vessel.

95. The system of claim 88, further comprising an imaging device for providing a B-mode ultrasound for imaging the blood vessel.

96. A system to deliver energy from a position outside a skin of a patient to a nerve surrounding a blood vessel comprising:

a fiducial for placement inside the blood vessel;

a detection device to detect the fiducial inside the blood vessel;

a processor configured to determine a three dimensional coordinate of the detected fiducial; and

an energy source configured to transmit energy through the skin and to focus the energy at the region of the blood vessel;

wherein the processor is configured to operate the energy source based on the determined three dimensional coordinate of the fiducial, and information regarding the blood vessel.

97. The system of claim 96, wherein the energy source comprises an ultrasound device, and wherein the blood vessel is a renal artery.

98. The system of claim 96, further comprising an ultrasound imaging system.

99. The system of claim 96, wherein the fiducial is placed inside the blood vessel and is attached to an intravascular catheter.

100. The system of claim 96, wherein the fiducial is a passive fidicial that is configured to respond to an external signal.

101. The system of claim 96, wherein the fiducial is an active ficucial, transmitting its position to the detection device.

102. A method to treat hypertension in a patient comprising:

obtaining an imaging signal from a blood vessel in the patient;

planning a delivery of energy to a wall of the blood vessel; and

delivering energy from outside a skin of the patient to an autonomic nerve surrounding the blood vessel.

103. The method of claim 102, further comprising selectively modulating an afferent nerve within a sympathetic nerve bundle.

104. The method of claim 102, further comprising utilizing microneurography after the delivery of the energy to determine an effect of the energy delivery on a sympathetic nervous system.

105. The method of claim 102, wherein the blood vessel extends to or from a kidney, and the method further comprises locating the blood vessel with doppler ultrasound.

106. A system to modulate an autonomic nerve in a patient utilizing transcutaneous energy delivery, the system comprising:

a processor comprising;

an input for receiving information regarding energy and power to be delivered to a treatment region containing the nerve; and

an output for outputting a signal;

wherein the processor is configured to determine a position of a reference target from outside the patient to localize the nerve relative to the reference target;

a therapeutic energy device comprising;

a transducer for delivering energy from outside the patient;

a controller to control an aiming of the transducer based at least in part on the signal from the processor; and

an imaging system coupled to the processor or the therapeutic energy device.

107. The system of claim 106, wherein the processor is configured to determine the position during an operation of the therapeutic energy device.

108. The system of claim 106, further comprising a patient interface configured to position the therapeutic device so that the transducer is aimed toward a blood vessel connected to a kidney from a position between ribs superiorly, a iliac crest inferiorly, and a vertebral column medially.

109. The system of claim 106, wherein the therapeutic energy device is configured to deliver focused ultrasound.

110. The system of claim 106, wherein the reference target is at least a portion of a blood vessel traveling to or from a kidney, and the nerve is a renal nerve.

111. The system of claim 110, wherein the transducer is configured to focus energy at a distance from 6 cm to 18 cm.

112. The system of claim 106, wherein the transducer is configured to deliver the energy in a form of focused ultrasound to a renal blood vessel at an angle ranging between about −

10 degrees and about −

48 degrees relative to a horizontal line connecting transverse processes of a spinal column.

113. The system of claim 106, wherein the energy from the therapeutic energy device ranges between 100 W/cm2 and 2500 W/cm2.

114. The system of claim 106, wherein the reference target is an indwelling vascular catheter.

115. The system of claim 106, wherein the imaging system is a magnetic resonance imaging system and the therapeutic energy device is an ultrasound device.

116. The system of claim 106, wherein the imaging system is an ultrasound imaging system.

117. The system of claim 106, wherein the processor is a part of the therapeutic energy device.

118. The system of claim 106, wherein the processor is a part of the imaging system.

119. A method to deliver energy from a position outside the skin of a patient to a nerve surrounding a blood vessel, comprising:

placing a device inferior to ribs, superior to an iliac crest, and lateral to a spine;

using the device to maintain an energy delivery system at a desired position relative to the patient so that the energy delivery system can deliver energy through the skin without traversing bone.

120. The method of claim 119, wherein the energy delivery system comprises a focused ultrasound delivery system.

121. A device for use in a system to deliver focused ultrasound energy from a position outside a skin of a patient to a nerve surrounding a blood vessel, comprising:

a positioning device configured to maintain an energy delivery system at a desired position relative to the patient so that the energy delivery system can deliver energy through the skin without traversing bone;

wherein the positioning device is configured to be placed inferior to ribs, superior to an iliac crest, and lateral to a spine.

122. The device of claim 121, wherein the energy delivery system comprises a focused ultrasound delivery system.

123. The device of claim 122, wherein the positioning device is configured to maintain an angle of the focused ultrasound delivery system such that bony structures are not include in an ultrasound field.

124. A system for treatment, comprising:

a treatment device configured to deliver energy from outside a patient to a nerve inside the patient;

a catheter configured for placement inside a vessel surrounded by the nerve, the catheter configured to transmit a signal; and

a processor configured to receive the signal and determine a reference position in the vessel;

wherein the treatment device is configured deliver the energy to the nerve based on the determined reference position.

125. The system of claim 124, wherein the treatment device comprises an ultrasound device.

126. A method of inhibiting the function of a nerve traveling with an artery comprising:

providing an external imaging modality to determine the location of the artery of a patient;

placing the artery in a first three dimensional coordinate reference based on the imaging;

placing or associating a therapeutic energy generation source in the first three dimensional coordinate reference frame;

modeling the delivery of energy to the adventitial region of the artery or a region adjacent to the artery where a nerve travels;

delivering therapeutic energy from the therapeutic energy source, from at least two different angles, through the skin of a patient, to intersect at the artery or the region adjacent to the artery;

and, at least partially inhibiting the function of the nerve traveling with the artery.

127. The method of claim 126, wherein the imaging modality is one of:

ultrasound, MRI, and CT.

128. The method of claim 126, wherein the therapeutic energy is ultrasound.

129. The method of claim 126, wherein the artery is a renal artery.

130. The method of claim 126, wherein placing the artery in a three dimensional reference frame comprises locating the artery using a doppler ultrasound signal.

131. The method of claim 126, further comprising:

utilizing a fiducial wherein the fiducial is placed internal to the patient.

132. The method of claim 131, wherein said fiducial is temporarily placed in a position internal to the patient.

133. The method of claim 131, wherein said fiducial is a catheter placed in the artery of the patient.

134. The method of claim 133, wherein said catheter is detectable using a radiofrequency signal and said imaging modality is ultrasound.

135. The method of claim 126, wherein the therapeutic energy from the energy source is delivered in a distribution along the length of the artery.

136. The method of claim 126, wherein the therapeutic energy is ionizing radiation.

137. A system to inhibit the function of a nerve traveling with a renal artery comprising:

a detector to determine the location of the renal artery and renal nerve from a position external to a patient;

an ultrasound component to deliver therapeutic energy through the skin from at least two directions to the nerve surrounding the renal artery;

a modeling algorithm comprising an input and an output, said input to the modeling algorithm comprising a three dimensional coordinate space containing a therapeutic energy source and the position of the renal artery in the three dimensional coordinate space; and

,

said output from the modeling algorithm comprising;

the direction and energy level of the ultrasound component;

a fiducial, locatable from a position outside a patient, adapted to be temporarily placed in the artery of the patient and communicate with the detector to determine the location of the renal artery in a three dimensional reference frame, the information regarding the location transmittable as the input to the model.

138. The system of claim 137, wherein the fiducial is a passive reflector of ultrasound.

139. The system of claim 137, wherein the fiducial generates radiofrequency energy.

140. The system of claim 137, wherein the fiducial is activated to transmit energy based on a signal from an ultrasound or magnetic field generator.

141. The system of claim 137, wherein the output from the model instructs the ultrasound component to deliver a lesion on the artery in which the major axis of the lesion is longitudinal along the length of the artery.

142. The system of claim 141, wherein the output from the model instructs the ultrasound component to deliver multiple lesions around an artery simultaneously.

143. The system of claim 137, wherein the output from the model instructs the ultrasound component to deliver a circumferential lesion around the artery.

144. The system of claim 141, wherein the lesion is placed around the renal artery just proximal to the bifurcation of the artery in the hilum of the kidney.

145. A method to stimulate or inhibit the function of a nerve traveling to or from the kidney comprising:

a. Identifying an acoustic window at the posterior region of a patient in which the renal arteries can be visualized;

b. transmitting a first energy through the skin of a patient from the posterior region of the patient;

c. imaging an arterial region using the first transmitted energy;

d. applying a second transmitted energy to the arterial adventitia by coupling the imaging and the second transmitted energy.

146. The method of claim 145, further comprising:

tracking the image created by the first transmitted energy.

147. A method to locate the position of a blood vessel in the body of a patient comprising:

applying a first wave of ultrasound, from a first direction, to a region of a blood vessel from outside of the patient and detecting its return signal;

comparing the applied first wave and its return signal;

simultaneously, or sequentially, applying a second wave of ultrasound from a second direction to the blood vessel and detecting a its return signal;

integrating the return signals from the first wave and the return signals from the second wave to determine the position, in a three dimensional coordinate reference, of the blood vessel.

148. The method of claim 147, further comprising the step of instructing a therapeutic ultrasound transducer to apply energy to the position of the blood vessel.