Method and system for neural tissue modification

• US 6,161,048 A
• Filed: 09/22/1999
• Issued: 12/12/2000
• Est. Priority Date: 06/26/1997
• Status: Expired

• Current Assignee: Covidien AG (Medtronic Plc)
• Original Assignee: Radionics, Inc. (Integra LifeSciences Holdings Corporation)
• Inventors: Cosman, Eric R., Rittman, William J. III, Sluijter, Menno E.
• Primary Examiner(s): O'Connor, Cary
• Assistant Examiner(s): CARTER, RYAN CHRISTOPHER
• Application Number:
  US09/297,316
• Time in Patent Office: 447 Days
• Field of Search: 607/89, 607/99-102, 607/113, 607/148, 606/34, 606/41, 600/547, 600/549, 600/373
• US Class Current: 607/100
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61N 1/36017 with leads or electrodes penetrating the skin
• CPC Class Codes: A61N 1/36021 for treatment of pain
• CPC Class Codes: A61N 1/36025 for treating a mental or cerebral condition
• CPC Class Codes: A61N 1/40 Applying electric fields by inductive or capacitive coupling microwave apparatus A61N5/00; Applying radio-frequency signals

Abstract

A method and apparatus for altering a function of neural tissue in a patient. An electromagnetic signal is applied to the neural tissue through an electrode. The electromagnetic signal has a frequency component above the physiological stimulation frequency range and an intensity sufficient to produce an alteration of the neural tissue, the alteration causing the patient to experience a reduction in pain, and a waveform that prevents lethal temperature elevation of the neural tissue during application of the electromagnetic signal to the neural tissue.

Claims

1. A system for altering a function of neural tissue in a patient comprising:

a) signal applicator adapted to apply an electrical signal output to said neural tissue;

b) a signal generator that generates a electrical signal output having at least one frequency component above a physiologic stimulation frequency range, said at least one frequency component producing an alteration of a function of at least a portion of said neural tissue, and said electrical signal output having a waveform that produces an average power deposition in the neural tissue corresponding to non-lethal average temperature elevation of said at least a portion of said neural tissue when said electrical signal output is applied to said neural tissue through said signal applicator; and

c) a signal coupler that couples said signal generator and said signal applicator.

2. The system of claim 1, further comprising:

a temperature sensor that senses temperature of said at least a portion of the neural tissue and produces an output signal representative of said temperature; and

a frequency component intensity control to adjust the intensity of the frequency component to maintain the temperature of the neural tissue below a lethal thermal level when said electrical signal is applied to said neural tissue.

3. The system of claim 1, wherein said electrical output signal is a radiofrequency signal.

4. A system for altering a function of neural tissue in a patient comprising:

a) an electrode adapted to apply an amplitude modulated electrical signal to the neural tissue of the patient;

b) a signal generator that generates an amplitude modulated electrical signal having at least one frequency component above a physiological stimulation frequency range, said amplitude modulated electrical signal producing an alteration of a function of the neural tissue while producing an average power deposition in the neural tissue corresponding to non-lethal temperature elevation of said neural tissue when the amplitude modulated electrical signal is applied to the neural tissue through said electrode; and

c) an electrical coupling between said signal generator and said electrode to apply said amplitude modulated electrical signal to said electrode.

5. The system of claim 4 further comprising:

a modulation amplitude control that adjusts the amplitude of said amplitude modulated electrical signal.

6. The system of claim 4 wherein the amplitude modulated electrical signal has a peak voltage in the range of 10 to 30 volts.

7. A method for altering the function of neural tissue in a patient comprising the steps of:

a) generating an electrical signal having at least one frequency component above a physiologic stimulation frequency range, said at least one frequency component producing an alteration of at least a portion of said neural tissue, and said electrical signal having a waveform that produces an average power deposition in the neural tissue corresponding to non-lethal average temperature elevation of said at least a portion of said neural tissue when said electrical signal is applied to said neural tissue; and

b) applying said electrical signal to said neural tissue.

8. The method of claim 7 further comprising the steps of:

a) sensing the temperature of said at least a portion of the neural tissue;

b) generating a temperature signal representative of the sensed temperature of said at least a portion of the neural tissue; and

,

c) adjusting the intensity of the at least one frequency component in response to said temperature signal in order to maintain the average temperature of said at least a portion of the neural tissue below lethal temperature levels when the electrical signal is applied to said neural tissue.

9. A system for altering a function of at least a portion of neural function of tissue in a patient comprising:

a) a generator that generates an electromagnetic signal having at least one high frequency component above a physiologic stimulation frequency range, said at least one high frequency component have a modulated waveform that produces alteration of the function of said at least a portion of said neural tissue when applied to said tissue through an electromagnetic signal applicator.