Treatment of shoulder dysfunction using a percutaneous intramuscular stimulation system

• US 8,249,713 B2
• Filed: 11/05/2007
• Issued: 08/21/2012
• Est. Priority Date: 06/03/1998
• Status: Expired due to Term

• Current Assignee: SPR Therapeutics, Inc.
• Original Assignee: SPR Therapeutics, LLC (SPR Therapeutics, Inc.)
• Inventors: Fang, Zi-Ping, Walker, Maria E.
• Primary Examiner(s): Patel, Niketa
• Assistant Examiner(s): STOKLOSA, JOSEPH A
• Application Number:
  US11/982,789
• Publication Number:
  US 20080065171A1
• Time in Patent Office: 1,751 Days
• Field of Search: 607/116, 607/118, 607/46, 607/48, 607/50
• US Class Current: 607/46
• CPC Class Codes: A61N 1/36003 of motor muscles, e.g. for walking assistance
• CPC Class Codes: A61N 1/36017 with leads or electrodes penetrating the skin

Abstract

A method of treating shoulder dysfunction involves the use of a percutaneous, intramuscular stimulation system. A plurality of intramuscular stimulation electrodes are implanted directly into select shoulder muscles of a patient who has suffered a disruption of the central nervous system such as a stroke, traumatic brain injury, spinal cord injury or cerebral palsy. An external microprocessor based multi-channel stimulation pulse train generator is used for generating select electrical stimulation pulse train signals. A plurality of insulated electrode leads percutaneously, electrically interconnect the plurality of intramuscular stimulation electrodes to the external stimulation pulse train generator, respectively. Stimulation pulse train parameters for each of the stimulation pulse train output channels are selected independently of the other channels. The shoulder is evaluated for subluxation in more than one dimension. More than one muscle or muscle group is simultaneously subjected to a pulse train dosage. Preferably, the at least two dosages are delivered asynchronously to two muscle groups comprising the supraspinatus in combination with the middle deltoid, and the trapezious in combination with the posterior deltoid.

Claims

1. A method of treating chronic shoulder pain in an individual comprising:

(i) identifying in the individual a site of chronic shoulder pain;

(ii) targeting for electrical stimulation a region of shoulder muscle tissue near the site;

(iii) providing an electrode that is size and configured for insertion into the targeted region of shoulder muscle tissue through an introducer without surgical exposure of the shoulder muscle tissue, the electrode including a component to anchor the electrode in the shoulder muscle tissue, the electrode being electrically coupled to an electrode lead that is sized and configured to extend from the electrode, when inserted into the targeted region of shoulder muscle tissue, percutaneously through the skin and including a portion that, in use, exits the skin and is exposed outside the individual;

(iv) providing an external electrical stimulation pulse generator that is sized an configured, in use, to be carried outside the individual, the electrical pulse generator including a connector for electrically coupling to the portion of the electrode lead exposed outside the individual;

(v) inserting the electrode through the introducer and skin into the targeted region of the shoulder muscle tissue without surgical exposure of the shoulder muscle tissue, wherein the electrode lead extends percutaneously through the skin of the individual with the section exiting the skin and exposed outside the individual;

(vi) electrically coupling the connector of the external stimulation pulse generator to the section of the electrode lead exposed outside the individual;

(vii) operating the external stimulation pulse generator according to a prescribed treatment regiment to deliver electrical stimulation pulses to the electrode via the electrode lead to cause contraction of the shoulder muscle tissue at the site;

(viii) treating the chronic shoulder pain by

(a) temporarily performing (vii) during a prescribed stimulation period of at least one week to achieve by the end of the prescribed stimulation period a statistically significant reduction in the chronic shoulder pain, as measured according to a pain rating index, and

(b) terminating (vii) at the end of the prescribed stimulation period to cease delivery of electrical stimulation pulses to the site, wherein no statistically significant increase in the pain rating index, as measured at the termination of the prescribed stimulation period, occurs at the site for a period of at least three months after termination of the prescribed stimulation period.

2. A method as defined in claim 1

wherein the prescribed treatment regiment includes a stimulation pulse train pattern including at least one stimulation cycle defining a stimulation pulse train envelope defined by at least a ramp-up phase of a first select duration in which the pulses of a stimulus pulse train pattern progressively increase in charge, a hold phase of a second select duration in which the pulses of the stimulus pulse train pattern are substantially constant charge, and a ramp down phase of a third select duration in which the pulses of the stimulus pulse train pattern progressively decrease in charge.

3. A method as defined in claim 1

wherein (ii) includes targeting plural regions of shoulder muscle tissue near the site of chronic shoulder pain;

wherein (iii) includes providing, for each one of the targeted plural regions, an electrode that is sized and configured for insertion into the respective targeted region of shoulder muscle tissue without surgical exposure of the shoulder muscle tissue, the electrode being electrically coupled to an electrode lead that is sized and configured to extend from the electrode, when inserted into the respective targeted region of shoulder muscle tissue, percutaneously through the skin of the individual and including an exposed portion that, in use, exits the skin outside the individual;

wherein (v) comprises inserting one of the electrodes through the skin into each of the targeted plural regions of the shoulder muscle tissue;

wherein (vi) includes electrically coupling the connector of the external stimulation pulse generator to the exposed section of each electrode lead outside the individual; and

wherein (vii) includes operating the external stimulation pulse generator according to the prescribed treatment regiment to deliver electrical stimulation pulses to the electrodes via the respective electrode leads to cause contraction of the shoulder muscle tissue.

4. A method as defined in claim 3

wherein the plural regions include a first muscle group and a second muscle group.

5. A method as defined in claim 2

wherein the ramp-up phase duration is from about 2 to about 8 seconds, the hold phase duration is from about 5 to about 15 seconds, and the ramp-down phase duration is from about 2 to about 8 seconds.

6. A method as defined in claim 5, wherein the ramp-up phase duration is from about 5±

1 seconds, the hold phase duration is from about 10±

2 seconds, and the ramp-down phase duration is from about 5±

1 seconds.

7. A method according to claim 1

wherein die electrode comprises a spiral or helix to accommodate stress due to muscle flexure and/or extension.

8. A method according to claim 1

wherein the electrode comprises a component to anchor the electrode in the shoulder muscle tissue.

9. A method according to claim 8

wherein the component comprises a barb.