Apparatus and method for blocking activation of tissue or conduction of action potentials while other tissue is being therapeutically activated

• US 20050149148A1
• Filed: 02/10/2005
• Published: 07/07/2005
• Est. Priority Date: 05/17/2001
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: King, Gary W.
• Granted Patent: US 7,433,734 B2
• Time in Patent Office: Days
• US Class Current: 607/70
• CPC Class Codes: A61N 1/36007 of urogenital or gastrointestinal organs, e.g. for incontinence control
• CPC Class Codes: A61N 1/36071 Pain
• CPC Class Codes: A61N 1/39624 Pain reduction therapy

Abstract

A desired effect is produced by therapeutically activating tissue at a first site within a patient'"'"'s body and a corresponding undesired side effect is reduced by blocking activation of tissue or conduction of action potentials at a second site within the patient'"'"'s body by applying high frequency stimulation and/or direct current pulses at or near the second site. Time-varying DC pulses may be used before or after a high frequency blocking signal. The high frequency stimulation may begin before and continue during the therapeutic activation. The high frequency stimulation may begin with a relatively low amplitude, and the amplitude may be gradually increased. The desired effect may be promotion of micturition or defecation and the undesired side effect may be sphincter contraction. The desired effect may be defibrillation of the patient'"'"'s atria or defibrillation of the patient'"'"'s ventricles, and the undesired side effect may be pain.

Claims

1. Apparatus for producing a desired effect by activating tissue at a first predetermined site within a body and for reducing a corresponding undesired side effect by blocking activation of tissue or conduction of action potentials at a second predetermined site within the body, the apparatus comprising:

first generator means for producing low frequency stimulation;

second generator means for producing high frequency and/or direct current pulse stimulation; and

a first electrode operatively coupled to the first generator means, the first electrode being adapted to activate tissue at the first predetermined site by applying low frequency stimulation; and

a second electrode coupled to the second generator means, the second electrode being adapted to block activation of electrically excitable tissue at the second site by applying high frequency stimulation or one or more direct current pulses, or both high frequency stimulation and one or more direct current pulses, at or near the second site such that the high frequency stimulation and/or the direct current pulses prevent the low frequency stimulation applied at the first site from activating the electrically excitable tissue, or causing conduction of action potentials, at the second site.

2. The apparatus of claim 1 wherein:

the first generator means comprises a first signal generator for producing low frequency stimulation; and

the second generator means comprises a second signal generator for producing high frequency and/or direct current pulse stimulation.

3. The apparatus of claim 2 further including at least one implantable lead operatively coupling the first and second electrode with the first and second signal generators.

4. The apparatus of claim 2 further including a first implantable lead operatively coupling the first electrode with the first signal generator, and a second implantable lead operatively coupling the second electrode with the second signal generator.

5. The apparatus of claim 1 wherein the first generator means and the second generator means comprise at least one signal generator capable of simultaneously producing both low frequency stimulation and high frequency stimulation or direct current pulses.

6. The apparatus of claim 5 further including at least one implantable lead operatively coupling the first and second electrode with the signal generator.

7. The apparatus of claim 5 further including a first implantable lead operatively coupling the first electrode with the signal generator, and a second implantable lead operatively coupling the second electrode with the signal generator.

8. The apparatus of claim 5, wherein the second generator means further includes means for beginning before, and continuing during the activation, the high frequency stimulation or the direct current pulses or both the high frequency stimulation and the direct current pulses.

9. The apparatus of claims 8, wherein the second generator means further includes means for beginning the high frequency stimulation or the direct current pulses or both the high frequency stimulation and the direct current pulses with a relatively low amplitude and gradually increasing the amplitude.

10. The apparatus of claim 1, wherein the second generator means further includes means for beginning before, and continuing during the activation, the high frequency stimulation or the direct current pulses or both the high frequency stimulation and the direct current pulses.

11. The apparatus of claim 10, wherein the second generator means further includes means for beginning the high frequency stimulation or the direct current pulses or both the high frequency stimulation and the direct current pulses with a relatively low amplitude and gradually increasing the amplitude.

12. The apparatus of claim 11, wherein the second generator means further includes means for terminating the high frequency stimulation or the direct current pulses or both the high frequency stimulation and the direct current pulses by gradually reducing the amplitude of the high frequency stimulation or the direct current pulses or both the high frequency stimulation and the direct current pulses.

13. The apparatus of claim 12, further comprising:

a sensor for sensing at the second site or at a site that is remote from both the first site and the second site; and

means, responsive to the sensor, for adjusting at least one parameter of the high frequency stimulation or the direct current pulses or both the high frequency stimulation and the direct current pulses, the parameter being selected from the group consisting of;

pulse amplitude, pulse width, pulse frequency, pulse duty cycle, pulse polarity, and pulse waveform.

14. The apparatus of claim 12, further comprising:

a sensor for sensing at the second site or at a site that is remote from both the first site and the second site; and

means, responsive to an indication from the sensor of activation at the second site or at the remote site, for applying the high frequency stimulation or the direct current pulses or both the high frequency stimulation and the direct current pulses to the second site.

15. The apparatus of claim 1, wherein the second generator means further includes means for terminating the high frequency stimulation or the direct current pulses or both the high frequency stimulation and the direct current pulses by gradually reducing the amplitude of the high frequency stimulation or the direct current pulses or both the high frequency stimulation and the direct current pulses.

16. The apparatus of claim 1, further comprising:

a sensor for sensing at the second site or at a site that is remote from both the first site and the second site; and

means, responsive to the sensor, for adjusting at least one parameter of the high frequency stimulation or the direct current pulses or both the high frequency stimulation and the direct current pulses, the parameter being selected from the group consisting of;

pulse amplitude, pulse width, pulse frequency, pulse duty cycle, pulse polarity, and pulse waveform.

17. The apparatus of claim 1, further comprising:

a sensor for sensing at the second site or at a site that is remote from both the first site and the second site; and

means, responsive to an indication from the sensor of activation at the second site or at the remote site, for applying the high frequency stimulation or the direct current pulses or both the high frequency stimulation and the direct current pulses to the second site.

18. The apparatus of claim 1, further comprising:

a sensor for sensing at the second site or at a site that is remote from both the first site and the second site; and

means, responsive to an indication from the sensor of activation at the second site or at the remote site, for applying the high frequency stimulation or the direct current pulses or both the high frequency stimulation and the direct current pulses to the second site.

19. The apparatus of claim 1, wherein the first generator means produces stimulation at a frequency less than 100 Hertz, and the second generator means produces stimulation at a frequency greater than 100 Hertz.

20. The apparatus of claim 19, wherein the second generator means produces stimulation at a frequency greater than 100 but less than 185 Hertz.

21. The apparatus of claim 20, wherein the second generator means produces stimulation at a frequency of at least 250 Hertz.