Variation of Neural Stimulation Parameters

• US 20060190061A1
• Filed: 04/28/2006
• Published: 08/24/2006
• Est. Priority Date: 01/11/2002
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Stypulkowski, Paul H.
• Granted Patent: US 7,873,418 B2
• Time in Patent Office: Days
• US Class Current: 607/72
• CPC Class Codes: A61N 1/36071 Pain

Abstract

Techniques for varying stimulus parameters used in neural stimulation to improve therapy efficacy, minimize energy consumption, minimize undesired side effects, and minimize loss of therapeutic effectiveness due to physiologic tolerance to stimulation. Neural stimulation is provided having a stimulation amplitude, a stimulation frequency, a stimulation pulse duration, an electrode-firing pattern, and a set of electrode-firing-polarity conditions. At least one of the stimulation parameters is pseudo-randomly varied. A second stimulation parameter is changed based upon having pseudo-randomly varied the first stimulation parameter and based upon a predetermined relationship specifying how changes in the first parameter affect desirable values for the second parameter.

Claims

1. A neural-stimulation device comprising:

means for measuring a strength-duration curve for neural excitation for at least one of a patient'"'"'s neurons;

means for providing neural stimulation having a plurality of stimulation parameters including a stimulation amplitude, a stimulation frequency, a stimulation pulse duration, an electrode-firing pattern, and a set of one or more electrode-polarity-firing conditions;

means for pseudo-randomly varying at least a first of the stimulation parameters; and

means for changing a value of a second of the stimulation parameters based upon having pseudo-randomly varied the first stimulation parameter and based upon the measured strength-duration curve that specifies how changes in the first parameter affect desirable values for the second parameter.

2. The neural-stimulation device of claim 1 in which the means for pseudo-randomly varying at least the first of the stimulation parameters varies at least the first stimulation parameter within a predetermined range.

3. The neural-stimulation device of claim 1 in which:

the means for providing neural stimulation includes an implantable pulse generator and a lead having at least one electrode operatively coupled with the implantable pulse generator;

the means for pseudo-randomly varying at least the first of the stimulation parameters is implemented in software operatively associated with the implantable pulse generator; and

the means for changing a value of a second of the stimulation parameters based upon having pseudo-randomly varied the first stimulation parameter and based upon the measured strength-duration curve is implemented in software operatively associated with the implantable pulse generator.

4. The neural-stimulation device of claim 1 in which the means for providing neural stimulation includes a pulse generator and a lead having at least one electrode operatively coupled with the pulse generator.

5. The neural-stimulation device of claim 1, in which the means for pseudo-randomly varying at least a first of the stimulation parameters includes:

means for varying the first stimulation parameter to produce a neuron-firing pattern having a plurality of different interspike intervals measured either over an interspike-measurement duration or over a plurality of spikes.

6. The neural-stimulation device of claim 5, wherein the means for varying the first stimulation parameter to produce a neuron-firing pattern having a plurality of different interspike intervals comprises:

means for varying the first stimulation parameter to produce a plurality of neuron-firing patterns selected from the group consisting of;

a substantially-normal-distribution neural-firing pattern, a skew-left-distribution neural-firing pattern, a skew-right-distribution neural-firing pattern, and a bimodal-bursting-distribution neural-firing pattern.

7. The neural-stimulation device of claim 1, wherein at least one of the one or more electrode-polarity-firing conditions is selected from the group consisting of:

anode, cathode, and off.

8. The neural-stimulation device of claim 1 in which the means for pseudo-randomly varying at least a first of the stimulation parameters is adapted to vary at least a first of the stimulation parameters sufficiently to avoid development of physiological tolerance to the neural-stimulation.

9. The neural-stimulation device of claim 1 in which:

the means for pseudo-randomly varying at least a first of the stimulation parameters is adapted to vary at least a first stimulation parameter selected from the group consisting of stimulation amplitude, a stimulation pulse duration, an electrode-firing pattern, and a set of one or more electrode-polarity-firing conditions; and

the means for changing a value of a second stimulation parameter based upon having pseudo-randomly varied the first stimulation parameter and based upon the measured strength-duration curve that specifies how changes in the first parameter affect desirable values for the second parameter, the second parameter selected from the group consisting of stimulation amplitude, a stimulation frequency, a stimulation pulse duration, an electrode-firing pattern, and a set of one or more electrode-polarity-firing conditions.

10. The neural-stimulation device of claim 1 in which:

the means for pseudo-randomly varying at least a first of the stimulation parameters is adapted to vary at least a first stimulation parameter selected from the group consisting of stimulation amplitude and stimulation pulse duration; and

the means for changing a value of a second stimulation parameter based upon having pseudo-randomly varied the first stimulation parameter and based upon the measured strength-duration curve that specifies how changes in the first parameter affect desirable values for the second parameter, the second parameter selected from the group consisting of stimulation amplitude, a stimulation frequency, a stimulation pulse duration, an electrode-firing pattern, and a set of one or more electrode-polarity-firing conditions.

11. A neural-stimulation system comprising:

at least one neural-stimulation lead, wherein at least one of the leads has at least one neural-stimulation electrode; and

a neural-stimulation device operatively coupled to the at least one neural-stimulation lead, wherein the neural-stimulation device;

provides neural stimulation having a plurality of stimulation parameters including a stimulation amplitude, a stimulation frequency, a stimulation pulse duration, an electrode-firing pattern, and a set of one or more electrode-polarity-firing conditions,

pseudo-randomly varying at least a first of the stimulation parameters, and

changes a value of a second of the stimulation parameters based upon having varied the first stimulation parameter and based upon a strength-duration curve of neural excitation to achieve a desirable clinical outcome.

12. The neural-stimulation system of claim 11 in which the neural stimulation device pseudo-randomly varies at least the first of the stimulation parameters within a predetermined range.

13. The neural-stimulation system of claim 11 in which the neural stimulation device pseudo-randomly varies at least the first of the stimulation parameter to produce a plurality of neuron-firing patterns selected from the group consisting of:

a substantially-normal-distribution neural-firing pattern, a skew-left-distribution neural-firing pattern, a skew-right-distribution neural-firing pattern, and a bimodal-bursting-distribution neural-firing pattern.

14. The neural-stimulation system of claim 11 in which the neural stimulation device pseudo-randomly varies at least the first of the stimulation parameter sufficiently to avoid development of physiological tolerance to the neural-stimulation.

15. A neural-stimulation method comprising:

measuring a strength-duration curve for neural excitation and observing whether a desired clinical outcome is achieved, the desired clinical outcome including the reduction of tremor via thalamic stimulation;

providing neural stimulation having a plurality of stimulation parameters;

pseudo-randomly varying at least a first of the stimulation parameters; and

changing a value of a second of the stimulation parameters based upon having pseudo-randomly varied the first stimulation parameter and based upon a predetermined relationship that specifies how changes in the first parameter affect desirable values for the second parameter, the predetermined relationship substantially similar to the strength-duration curve for neural excitation.

16. The method of claim 15 wherein the plurality of stimulation parameters includes a stimulation amplitude, a stimulation frequency, a stimulation pulse duration, an electrode-firing pattern, and a set of one or more electrode-polarity-firing conditions

17. The neural-stimulation method of claim 15, further comprising:

varying the first stimulation parameter to produce a neuron-firing pattern, the neuron-firing pattern having a plurality of different interspike intervals measured either over an interspike-measurement duration or over a plurality of spikes.

18. The neural-stimulation method of claim 17, wherein the neuron-firing pattern is selected from the group consisting of:

a substantially-normal-distribution neural-firing pattern, a skew-left-distribution neural-firing pattern, a skew-right-distribution neural-firing pattern, and a bimodal-bursting-distribution neural-firing pattern.

19. The neural-stimulation method of claim 16, wherein at least one of the one or more electrode-polarity-firing conditions is selected from the group consisting of:

anode, cathode, and off.

20. The neural-stimulation method of claim 16, wherein pseudo-randomly varying or changing the set of one or more electrode-polarity-firing conditions changes a spatial pattern of neurons affected by the neural stimulation.