Electrical stimulator for the treatment of back pain and methods of use
Apparatus and methods for treating back pain are provided, in which an implantable stimulator is configured to communicate with an external control system, the implantable stimulator providing a neuromuscular electrical stimulation therapy designed to cause muscle contraction to rehabilitate the muscle, restore neural drive and restore spinal stability; the implantable stimulator further including one or more of a number of additional therapeutic modalities, including a module that provides analgesic stimulation; a module that monitors muscle performance and adjusts the muscle stimulation regime; and/or a module that provides longer term pain relief by selectively and repeatedly ablating nerve fibers. In an alternative embodiment, a standalone implantable RF ablation system is described.
1 . An electrical stimulation system for reducing back pain, the electrical stimulation system comprising:
a stimulator housing;
a first lead configured to be coupled to the stimulator housing and comprising a first electrode, the first electrode configured to be implanted adjacent to first tissue associated with a multifidus muscle within a back of a patient;
a second lead configured to be coupled to the stimulator housing and comprising a second electrode, the second electrode configured to be implanted adjacent to second tissue within the back of the patient;
first programming instructions for stimulating efferent nerve fibers associated with the first tissue associated with the multifidus muscle at a first frequency selected from within a range of 12-30 Hz;
second programming instructions for stimulating afferent nerve fibers associated with the second tissue within the back of the patient at a second frequency higher than the range having the first frequency; and
a controller within the stimulator housing, the controller configured to cause simultaneous delivery of electrical stimulation to the efferent nerve fibers via the first electrode responsive to the first programming instructions and electrical stimulation to the afferent nerve fibers via the second electrode responsive to the second programming instructions to effect pain relief or pain reduction in the patient,
wherein the first programming instructions are programmed in a first circuitry module operatively coupled to the first electrode and the second programming instructions are programmed in a second circuitry module operatively coupled to the second electrode.
2 . The electrical stimulation system of claim 1 , wherein the first electrode is configured to be implanted adjacent to a medial branch of a dorsal ramus nerve, and
wherein the controller is configured to cause delivery of the electrical stimulation to the efferent nerve fibers via the first electrode to electrically stimulate the medial branch of the dorsal ramus nerve to cause contraction of the multifidus muscle.
3 . The electrical stimulation system of claim 1 , wherein the second electrode is configured to be implanted adjacent to a peripheral nerve, and
wherein the controller is configured to cause delivery of the electrical stimulation to the afferent nerve fibers via the second electrode to electrically stimulate the peripheral nerve to block the pain signals traveling towards the human's brain from the human's spinal cord.
4 . The electrical stimulation system of claim 1 , wherein the controller is configured to cause delivery of the electrical stimulation via the first electrode to the efferent nervous tissue to improve muscle tone and neural drive.
5 . The electrical stimulation system of claim 1 , wherein the controller is configured to cause delivery of the electrical stimulation via the first electrode to the efferent nervous tissue to cause a series of muscle contractions during a predetermined number of sessions.
6 . The electrical stimulation system of claim 5 , wherein the predetermined number of sessions comprises one hour per day over a period of weeks.
7 . The electrical stimulation system of claim 1 , wherein the controller is configured to cause delivery of the electrical stimulation via the first electrode at an increasing stimulation pulse intensity to a predetermined maximum value to elicit a desired muscle contraction, and ramping down the electrical stimulation applied via the first electrode.
8 . The electrical stimulation system of claim 1 , wherein the controller is configured to cause delivery of the electrical stimulation via the first electrode at an increasing therapeutic dose of the electrical stimulation until a desired level is achieved, and decreasing the therapeutic dose of the electrical stimulation to zero.
9 . The electrical stimulation system of claim 8 , wherein the therapeutic dose comprises a number of muscle contractions within a therapy period.
10 . The electrical stimulation system of claim 1 , wherein the controller is configured to cause adjustment of parameters for the electrical stimulation, the controller further configured to cause delivery of the electrical stimulation via the first electrode or the second electrode at the adjusted parameters.
11 . The electrical stimulation system of claim 1 , wherein the stimulator housing is configured to be implanted within the patient.
12 . The electrical stimulation system of claim 11 , wherein the controller is configured to cause transmission of data to an external control system.
13 . The electrical stimulation system of claim 12 , wherein the stimulator housing is configured to receive power from the external control system to charge a battery within the stimulator housing.
14 . The electrical stimulation system of claim 12 , wherein the controller is configured to cause transmission of data to a computer running monitoring and control software.
15 . The electrical stimulation system of claim 1 , wherein the first lead has a first plurality of electrodes including the first electrode and the second lead has a second plurality of electrodes including the second electrode.
16 . The electrical stimulation system of claim 1 , wherein the controller is further configured to cause delivery of radiofrequency (RF) energy for repeated ablation of the tissue associated with the spine of the patient.
17 . The electrical stimulation system of claim 1 , further comprising a sensor within the stimulator housing, the sensor configured to monitor tissue temperature adjacent to the first electrode or the second electrode.
18 . The electrical stimulation system of claim 1 , further comprising a telemetry system disposed within the stimulator housing and operatively coupled to the controller.
19 . The electrical stimulation system of claim 18 , further comprising a battery within the stimulator housing,
wherein the controller is configured to transmit data indicative of at least one of impedance between the first electrode and another electrode on the first lead, temperature of the battery, or battery status of the battery to an external control system via the telemetry system.
20 . The electrical stimulation system of claim 1 , further comprising an electrode switching array disposed within the stimulator housing, the controller operatively coupled to the electrode switching array to select the first electrode to deliver neuromuscular stimulation to the efferent nerve fibers associated with the first tissue or to the second electrode to deliver analgesic stimulation to the afferent nerve fibers associated with the second tissue.
21 . The electrical stimulation system of claim 1 , further comprising a sensor configured to monitor tissue impedance.