Peltier unidirectional and selective nerve stimulation

• US 20080015667A1
• Filed: 07/13/2006
• Published: 01/17/2008
• Est. Priority Date: 07/13/2006
• Status: Active Grant

• Current Assignee: Rainbow Medical Ltd.
• Original Assignee: Yossi Gross
• Inventors: Gross, Yossi
• Granted Patent: US 7,761,168 B2
• Time in Patent Office: Days
• US Class Current: 607/113
• CPC Class Codes: A61F 2007/0075 using a Peltier element, e.g. near the spot to be heated or cooled
• CPC Class Codes: A61F 2007/126 for invasive application, e.g. for introducing into blood vessels
• CPC Class Codes: A61F 7/12 Devices for heating or cooling internal body cavities
• CPC Class Codes: F25B 21/02 using Peltier effect; using Nernst-Ettinghausen effect

Abstract

Apparatus is provided including an assembly (22) and a control unit (36). The assembly (22) includes a housing (34) configured to be applied to a nerve (20) of a subject, and at least one cathode (30) and at least one Peltier cooler (32), which are fixed to the housing (34). The control unit (36) is configured to drive the cathode (30) to apply an activating current to the nerve (20) that generates action potentials traveling in first and second directions (38 and 40) in the nerve (20), and the Peltier cooler (32) to cool the nerve (20) sufficiently to block propagation of at least a portion of the cathode-generated action potentials traveling in the second direction (40). Other embodiments are also described.

Claims

1. Apparatus comprising:

an assembly, which comprises;

a housing configured to be applied to a nerve of a subject; and

at least one cathode and at least one Peltier cooler, which are fixed to the housing; and

a control unit, which is configured to drive;

the cathode to apply an activating current to the nerve that generates action potentials traveling in first and second directions in the nerve, and

the Peltier cooler to cool the nerve sufficiently to block propagation of at least a portion of the cathode-generated action potentials traveling in the second direction.

2. The apparatus according to claim 1, wherein the control unit is configured to drive the Peltier cooler to cool the nerve sufficiently to block the propagation of substantially all of the cathode-generated action potentials traveling in the second direction.

3. The apparatus according to claim 1, wherein the assembly comprises a temperature sensor, positioned in a vicinity of the Peltier cooler, and wherein the control unit is configured to set at least one parameter responsively to the sensed temperature, the parameter selected from the group consisting of:

a parameter of the activating current, and a parameter of the cooling.

4. The apparatus according to claim 1, wherein the nerve includes a vagus nerve, wherein the assembly is configured to be applied to the vagus nerve, and wherein the control unit is configured to drive the cathode to generate the action potentials sufficient to reduce a heart rate of the subject.

5. The apparatus according to claim 1, wherein the nerve contains smaller- and larger-diameter fibers, and wherein the control unit is configured to drive the Peltier cooler to cool the nerve sufficiently to block the propagation of the portion of the cathode-generated action potentials traveling in the smaller-diameter fibers.

6. The apparatus according to claim 5, wherein the control unit is configured to drive the Peltier cooler to apply cooling substantially constantly while blocking the propagation of the portion of the cathode-generated action potentials traveling in the smaller-diameter fibers.

7. The apparatus according to claim 5,

wherein the Peltier cooler comprises a first Peltier cooler,

wherein the assembly comprises a second Peltier cooler fixed to the housing such that the cathode is longitudinally between the first and second Peltier coolers, and

wherein the control unit is configured to drive the second Peltier cooler to cool the nerve sufficiently to block propagation of at least a portion of the cathode-generated action potentials traveling in the first direction.

8. The apparatus according to claim 5,

wherein the assembly comprises an anode fixed to the housing such that the cathode is longitudinally between the anode and the Peltier cooler, and

wherein the control unit is configured to drive the anode to apply an inhibiting current to the nerve that blocks propagation of at least a portion of the cathode-generated action potentials traveling in the first direction.

9. The apparatus according to claim 1, wherein the assembly comprises at least one anode, and wherein the control unit is configured to drive the anode to apply an inhibiting current to the nerve that blocks the propagation of a portion of the cathode-generated action potentials traveling in the second direction.

10. The apparatus according to claim 9, wherein the nerve contains smaller-, intermediate-, and larger-diameter fibers, and wherein the control unit is configured to:

configure the inhibiting current to block the propagation of the portion of the cathode-generated action potentials traveling in the larger-diameter fibers, and

drive the Peltier cooler to cool the nerve sufficiently to block the propagation of the portion of the cathode-generated action potentials traveling in the smaller-diameter fibers.

11. The apparatus according to claim 10,

wherein the Peltier cooler comprises a first Peltier cooler,

wherein the assembly comprises a second Peltier cooler fixed to the housing such that the cathode is longitudinally between the first and second Peltier coolers, and

wherein the control unit is configured to drive the second Peltier cooler to cool the nerve sufficiently to block propagation of at least a portion of the cathode-generated action potentials traveling in the first direction.

12. The apparatus according to claim 10,

wherein the anode comprises a first anode and the inhibiting current includes a first inhibiting current,

wherein the assembly comprises a second anode fixed to the housing such that the cathode is longitudinally between the second anode, on the one hand, and the first anode and the Peltier cooler, on the other hand, and

wherein the control unit is configured to drive the second anode to apply a second inhibiting current to the nerve that blocks propagation of at least a portion of the cathode-generated action potentials traveling in the first direction.

13. The apparatus according to claim 1, wherein the control unit is configured to:

configure the activating current to generate the action potentials in fibers of the nerve up to a first depth from a surface of the nerve, and

drive the Peltier cooler to cool fibers of the nerve up to a second depth less than the first depth, thereby blocking the propagation of the cathode-generated action potentials traveling in the second direction in the fibers of the nerve up to the second depth.

14. The apparatus according to claim 13, wherein the first depth is substantially equal to a radius of the nerve, and wherein the control unit is configured to configure the activating current to generate the action potentials in the fibers of the nerve at substantially all depths.

15. The apparatus according to claim 13,

wherein the Peltier cooler comprises a first Peltier cooler,

wherein the assembly comprises a second Peltier cooler fixed to the housing such that the cathode is longitudinally between the first and second Peltier coolers, and

wherein the control unit is configured to drive the second Peltier cooler to cool the nerve sufficiently to block propagation of at least a portion of the cathode-generated action potentials traveling in the first direction.

16. The apparatus according to claim 13, wherein the control unit is configured to drive the Peltier cooler to applying cooling to the nerve in a series of pulses having an average duration of less than 5 seconds.

17-61. -61. (canceled)

62. A method comprising:

applying, to a nerve of a subject, an activating current that generates action potentials traveling in first and second directions in the nerve; and

Peltier-cooling the nerve sufficiently to block propagation of at least a portion of the action potentials traveling in the second direction.

63. The method according to claim 62, wherein Peltier-cooling the nerve comprises Peltier-cooling the nerve sufficiently to block the propagation of substantially all of the cathode-generated action potentials traveling in the second direction.

64. The method according to claim 62, wherein Peltier-cooling the nerve comprises:

sensing a temperature in a vicinity of a site at which the nerve is Peltier-cooled; and

setting at least one parameter responsively to the sensed temperature, the parameter selected from the group consisting of;

a parameter of the activating current, and a parameter of the Peltier-cooling.

65. The method according to claim 62, wherein the nerve includes a vagus nerve, and wherein applying the activating current comprises applying, to the vagus nerve, the activating current that generates the action potentials sufficiently to reduce a heart rate of the subject.

66. The method according to claim 62, comprising identifying that the subject suffers from a condition selected from the group consisting of:

Parkinson'"'"'s disease, erectile dysfunction, premature ejaculation, tinnitus, obesity, heart failure, and cerebral palsy, wherein applying the activating current and Peltier-cooling the nerve comprise applying the activating current and Peltier-cooling the nerve responsively to the identifying.

67. The method according to claim 62, wherein the nerve contains smaller- and larger-diameter fibers, and wherein Peltier-cooling comprises Peltier-cooling the nerve sufficiently to block the propagation of the portion of the cathode-generated action potentials traveling in the smaller-diameter fibers.

68. The method according to claim 67, wherein Peltier-cooling comprises Peltier-cooling substantially constantly while blocking the propagation of the portion of the cathode-generated action potentials traveling in the smaller-diameter fibers.

69. The method according to claim 67,

wherein Peltier-cooling comprises Peltier-cooling at a first cooling site of the nerve,

wherein applying the activating current comprises applying the activating current at an activation site of the nerve, and

comprising Peltier-cooling the nerve at a second cooling site of the nerve sufficiently to block propagation of at least a portion of the cathode-generated action potentials traveling in the first direction, wherein the activation site is longitudinally between the first and second cooling sites.

70. The method according to claim 67,

wherein Peltier-cooling comprises Peltier-cooling at a cooling site of the nerve,

wherein applying the activating current comprises applying the activating current at an activation site of the nerve, and

comprising applying, to the nerve at an inhibition site of the nerve, an inhibiting current that blocks propagation of at least a portion of the cathode-generated action potentials traveling in the first direction, wherein the activation site is longitudinally between the inhibition site and the cooling site.

71. The method according to claim 62, comprising applying an inhibiting current to the nerve that blocks the propagation of a portion of the cathode-generated action potentials traveling in the second direction.

72. The method according to claim 71,

wherein the nerve contains smaller-, intermediate-, and larger-diameter fibers, and

wherein applying the inhibiting current comprises configuring the inhibiting current to block the propagation of the portion of the cathode-generated action potentials traveling in the larger-diameter fibers, and

wherein Peltier-cooling comprises Peltier-cooling the nerve sufficiently to block the propagation of the portion of the cathode-generated action potentials traveling in the smaller-diameter fibers.

73. The method according to claim 72,

wherein Peltier-cooling comprises Peltier-cooling at a first cooling site of the nerve,

wherein applying the activating current comprises applying the activating current at an activation site of the nerve, and

comprising Peltier-cooling the nerve at a second cooling site sufficiently to block propagation of at least a portion of the cathode-generated action potentials traveling in the first direction, wherein the activation site is longitudinally between the first and second cooling sites.

74. The method according to claim 72,

wherein applying the inhibiting current comprises applying a first inhibiting current at a first inhibition site of the nerve,

wherein Peltier-cooling comprises Peltier-cooling at a cooling site of the nerve,

wherein applying the activating current comprises applying the activating current at an activation site of the nerve, and

comprising applying, to the nerve at a second inhibition site of the nerve, a second inhibiting current that blocks propagation of at least a portion of the cathode-generated action potentials traveling in the first direction, wherein the activation site is longitudinally between the second inhibition site, on the one hand, and the first inhibition site and the cooling site, on the other hand.

75. The method according to claim 62,

wherein applying the activating current comprises configuring the activating current to generate the action potentials in fibers of the nerve up to a first depth from a surface of the nerve, and

wherein Peltier-cooling comprises Peltier-cooling the nerve sufficiently to cool fibers of the nerve up to a second depth less than the first depth, thereby blocking the propagation of the cathode-generated action potentials traveling in the second direction in the fibers of the nerve up to the second depth.

76. The method according to claim 75, wherein the first depth is substantially equal to a radius of the nerve, and wherein applying the activating current comprises configuring the activating current to generate the action potentials in the fibers of the nerve at substantially all depths.

77. The method according to claim 75,

wherein Peltier-cooling comprises Peltier-cooling at a first cooling site of the nerve,

wherein applying the activating current comprises applying the activating current at an activation site of the nerve, and

comprising Peltier-cooling the nerve at a second cooling site of the nerve sufficiently to block propagation of at least a portion of the cathode-generated action potentials traveling in the first direction, wherein the activation site is longitudinally between the first and second Peltier cooling sites.

78. The method according to claim 75, wherein Peltier-cooling comprises Peltier-cooling the nerve in a series of pulses having an average duration of less than 5 seconds.

79-119. -119. (canceled)