Timed delivery of electrical stimulation therapy

• US 10,052,486 B2
• Filed: 03/16/2016
• Issued: 08/21/2018
• Est. Priority Date: 04/06/2015
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Denison, Timothy J., Stanslaski, Scott R.
• Primary Examiner(s): Johnson, Nicole F
• Assistant Examiner(s): Lavert, Nicole F.
• Application Number:
  US15/071,835
• Publication Number:
  US 20160287879A1
• Time in Patent Office: 888 Days
• Field of Search: 607 3, 607 62
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/1101 Detecting tremor
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/374 Detecting the frequency distribution of signals, e.g. detecting delta, theta, alpha, beta or gamma waves
• CPC Class Codes: A61B 5/4082 Diagnosing or monitoring movement diseases, e.g. Parkinson, Huntington or Tourette
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: A61N 1/0534 Electrodes for deep brain stimulation
• CPC Class Codes: A61N 1/36025 for treating a mental or cerebral condition
• CPC Class Codes: A61N 1/36053 adapted for vagal stimulation A61N1/36114 takes precedence
• CPC Class Codes: A61N 1/36064 Epilepsy
• CPC Class Codes: A61N 1/36067 Movement disorders, e.g. tremor or Parkinson disease stimulating motor muscle A61N1/36003
• CPC Class Codes: A61N 1/36082 Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease
• CPC Class Codes: A61N 1/36096 Mood disorders, e.g. depression, anxiety or panic disorder
• CPC Class Codes: A61N 1/36139 with automatic adjustment
• CPC Class Codes: A61N 1/36167 Timing, e.g. stimulation onset
• CPC Class Codes: A61N 1/36171 Frequency

Abstract

In some examples, a phase locked loop (PLL) circuit outputs a timing signal having a frequency and phase that is the same as a patient signal that is an input to the PLL circuit. The PLL circuit includes or is coupled to a storage circuit that stores information needed to cause the PLL circuit to maintain the frequency of the timing signal to the same frequency even after the patient signal is not available as an input.

Claims

1. A method comprising:

receiving, by a circuit, a patient signal indicative of a patient condition;

determining, by the circuit, a first timing signal having a frequency based on the patient signal;

controlling, by the circuit, delivery of a first instance of electrical stimulation therapy, with a stimulation generator, based on the first timing signal, wherein controlling delivery of the first instance of the electrical stimulation therapy comprises determining when to deliver the first instance of the electrical stimulation therapy based on the first timing signal, and wherein delivery of the first instance of the electrical stimulation therapy causes the patient signal to not be received for a duration;

during the duration when the patient signal is not being received, generating, by the circuit, a second timing signal having the same frequency as the frequency of the first timing signal that was determined based on the patient signal; and

controlling, by the circuit, delivery of a second instance of the electrical stimulation therapy, with the stimulation generator, based on the second timing signal during at least a portion of the duration when the patient signal is not being received, wherein controlling delivery of the second instance of the electrical stimulation therapy comprises determining when to deliver the second instance of the electrical stimulation therapy based on the second timing signal.

2. The method of claim 1, further comprising:

storing information for the first timing signal,

wherein generating the second timing signal comprises generating the second timing signal based on the stored information.

3. The method of claim 2, wherein storing information comprises storing, with an integrator, the information for the first timing signal.

4. The method of claim 2, wherein storing information comprises storing information representing a voltage level that causes a reference oscillator to output the second timing signal.

5. The method of claim 1, wherein receiving the patient signal comprises receiving, from an accelerometer, a signal representing patient tremor.

6. The method of claim 1, wherein the patient signal comprises a first patient signal, the method further comprising:

receiving a second patient signal indicative of the patient condition;

determining an updated timing signal based on the second patient signal;

during a duration when the second patient signal is not being received, outputting the updated timing signal;

controlling delivery of electrical stimulation therapy based on the updated timing signal during at least a portion of the duration when the second patient signal is not being received.

7. The method of claim 1, further comprising:

comparing a phase of the second timing signal to a threshold phase,

wherein controlling delivery of the second instance of the electrical stimulation therapy comprises controlling delivery of the second instance of the electrical stimulation therapy based on the comparison.

8. The method of claim 1, wherein controlling delivery of the second instance of the electrical stimulation therapy based on the second timing signal comprises delivering the second instance of the electrical stimulation therapy based on the second timing signal during the entire duration when the patient signal is not being received.

9. The method of claim 1, wherein the first instance of the electrical stimulation therapy comprises one or more pulses of the electrical stimulation therapy, and wherein the second instance of the electrical stimulation therapy comprises one or more pulses of the electrical stimulation therapy.

10. A medical device comprising:

an electrical stimulation generator; and

a circuit configured to;

receive a patient signal indicative of a patient condition;

determine a first timing signal having a frequency based on the patient signal; and

determine when the electrical stimulation generator is to deliver a first instance of electrical stimulation therapy based on the first timing signal,

wherein the electrical stimulation generator is configured to deliver the first instance of the electrical stimulation therapy based on the determination of when to deliver the first instance of the electrical stimulation therapy, and wherein delivery of the first instance of the electrical stimulation therapy causes the patient signal to not be received for a duration,

wherein the circuit is configured to;

during the duration when the patient signal is not being received, generate a second timing signal having the same frequency as the frequency of the first timing signal that was determined based on the patient signal; and

determine when the electrical stimulation generator is to deliver a second instance of the electrical stimulation therapy based on the second timing signal,

wherein the electrical stimulation generator is configured to deliver the second instance of the electrical stimulation therapy, during at least a portion of the duration when the patient signal is not being received, based on the determination of when to deliver the second instance of the electrical stimulation therapy.

11. The medical device of claim 10, wherein the circuit comprises a phase locked loop (PLL) circuit.

12. The medical device of claim 10, further comprising:

a storage circuit configured to store information for the first timing signal,

wherein to generate the second timing signal, the circuit is configured to generate the second timing signal based on the stored information.

13. The medical device of claim 12, wherein the storage circuit comprises an integrator.

14. The medical device of claim 12, wherein the circuit comprises a reference oscillator, and wherein the storage circuit is configured to store information representing a voltage level that causes the reference oscillator to output the second timing signal.

15. The medical device of claim 10, wherein to receive the patient signal, the circuit is configured to receive, from an accelerometer, a signal representing patient tremor.

16. The medical device of claim 10, wherein the patient signal comprises a first patient signal, wherein the circuit is configured to:

receive a second patient signal indicative of the patient condition;

determine an updated timing signal based on the second patient signal; and

during a duration when the second patient signal is not being received, output the updated timing signal, and

wherein the electrical stimulation generator is configured to deliver electrical stimulation therapy based on the updated timing signal during at least a portion of the duration when the second patient signal is not being received.

17. The medical device of claim 10, further comprising:

a comparator circuit configured to compare a phase of the second timing signal to a threshold phase,

wherein the stimulation generator is configured to deliver the second instance of the electrical stimulation therapy based on the comparison.

18. The medical device of claim 10, wherein to deliver the second instance of the electrical stimulation therapy based on the second signal, the stimulation generator is configured to deliver the second instance of the electrical stimulation therapy based on the second timing signal during the entire duration when the patient signal is not being received.

19. A medical device comprising:

a stimulation generator; and

circuitry comprising;

means for receiving a patient signal indicative of a patient condition;

means for determining a first timing signal having a frequency based on the patient signal; and

means for determining when the electrical stimulation generator is to deliver a first instance of electrical stimulation therapy based on the first timing signal,

wherein the electrical stimulation generator is configured to deliver the first instance of the electrical stimulation therapy based on the determination of when to deliver the first instance of the electrical stimulation therapy, and wherein delivery of the first instance of the electrical stimulation therapy causes the patient signal to not be received for a duration,

wherein the circuitry further comprises;

means for generating a second timing signal having the same frequency as the frequency of the first timing signal that was determined based on the patient signal during the duration when the patient signal is not being received; and

means for determining when the electrical stimulation generator is to deliver a second instance of the electrical stimulation therapy based on the generated second timing signal,

wherein the stimulation generator is configured to deliver the second instance of the electrical stimulation therapy, during at least a portion of the duration when the patient signal is not being received, based on the determination of when to deliver the second instance of the electrical stimulation therapy.

20. The medical device of claim 19, wherein the circuitry further comprises:

means for storing information needed to generate the second timing signal having the same frequency as the frequency of the first timing signal that was determined from the patient signal,

wherein the means for generating the second timing signal comprises means for generating the second timing signal based on the stored information.