Determination of stimulation output capabilities throughout power source voltage range

• US 8,219,196 B2
• Filed: 01/29/2009
• Issued: 07/10/2012
• Est. Priority Date: 10/31/2008
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Torgerson, Nathan A.
• Primary Examiner(s): Lavert, Nicole F
• Application Number:
  US12/362,167
• Publication Number:
  US 20100114257A1
• Time in Patent Office: 1,258 Days
• Field of Search: 607/27, 607 30- 33, 607 60- 62, 607/116
• US Class Current: 607/27
• CPC Class Codes: A61N 1/0531 Brain cortex electrodes
• CPC Class Codes: A61N 1/0534 Electrodes for deep brain stimulation
• CPC Class Codes: A61N 1/36082 Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease
• CPC Class Codes: A61N 1/37258 Alerting the patient
• CPC Class Codes: A61N 1/378 Electrical supply
• CPC Class Codes: G01R 31/3647 for determining the ability of a battery to perform a critical function, e.g. cranking

Abstract

Techniques for determining whether a medical device will be able to deliver stimulation according to a particular program throughout a useable voltage range of a power source of the medical device are described. According to some examples, the medical device configures a DC to DC converter of the medical device in a specified output configuration and delivers electrical stimulation from the medical device according to a program while at the specified output configuration. Whether the medical device will be able to deliver stimulation according to the program when the power source is at a power source voltage level lower than a present voltage level used during therapy delivery is determined based on a value of a voltage drop across a regulator module determined while delivering the electrical stimulation according to the program. The determination for a program may be performed, as an example, when the program is created or modified.

Claims

1. A medical device comprising:

a power source at a present power source voltage level;

a signal generator that generates electrical stimulation, wherein the signal generator comprises;

a DC to DC converter coupled to the power source; and

a regulator module coupled to the DC to DC converter; and

a processor that controls the signal generator to configure the DC to DC converter in a specified output configuration and deliver stimulation according to a program while at the specified output configuration, determines a value of a voltage drop across the regulator module during the delivery of electrical stimulation according to the program, and determines whether the medical device will be able to deliver stimulation according to the program at a power source voltage level lower than the present voltage level of the power source based on the determined value of the voltage drop.

2. The medical device of claim 1, further comprising a transceiver that is configured to communicate with a programming device that is located external to the medical device, wherein the processor sends an indication via the transceiver of whether the medical device will be able to deliver stimulation according to the program at the lower power source voltage level based on the determined value of the voltage drop.

3. The medical device of claim 2, wherein the indication comprises an indication that the medical device is not able to deliver electrical stimulation according to the program at the lower power source voltage level, wherein the power source comprises a rechargeable power source, and wherein the indication further comprises a minimum recharge frequency required for the program.

4. The medical device of claim 3, wherein the processor rescales a gauge of a power source voltage level indicator based on the minimum recharge frequency required for the program.

5. The medical device of claim 2, wherein the indication comprises an indication that the medical device is not able to deliver electrical stimulation according to the program at the lower power source voltage level, wherein the power source comprises a non-rechargeable power source, and wherein the indication further comprises a modified power source replacement schedule required for the program.

6. The medical device of claim 2, wherein the regulator module comprises a plurality of regulators, and wherein the processor determines a value of a voltage drop across the regulator module by measuring a first output of a first regulator configured as a cathode, measuring a second output of a second regulator configured as an anode, and calculating a difference between the first output and the second output.

7. The medical device of claim 1, wherein the medical device comprises an implantable medical device.

8. The medical device of claim 1, wherein the power source comprises a battery.

9. The medical device of claim 1, wherein the power source is rechargeable.

10. The medical device of claim 1, wherein the processor measures the present power source voltage level.

11. The medical device of claim 1, wherein the lower power source voltage level comprises a minimum threshold voltage of the power source below which therapy delivery by the medical device will cease.

12. The medical device of claim 1, wherein the processor calculates a minimum voltage level required to deliver stimulation according to the program based on the determined voltage drop value and compares the minimum required voltage level to the lower power source voltage level to determine whether the medical device will be able to deliver stimulation according to the program at the lower power source voltage level.

13. The medical device of claim 1, wherein the processor calculates an expected decrease in a level of voltage input into the regulator module as the present voltage level depletes to the lower voltage level and determines whether the medical device will be able to deliver stimulation according to the program at the lower power source voltage level based on the determined value of the voltage drop and the expected decrease in input voltage.

14. The medical device of claim 1, wherein the DC to DC converter comprises a capacitor module, the specified output configuration comprises a specified stack configuration, and delivering electrical stimulation comprises discharging the capacitor module through the regulator module.

15. The medical device of claim 1, wherein the specified output configuration comprises a maximum output configuration.

16. A medical device comprising:

means for configuring a DC to DC converter in a specified output configuration;

means for delivering electrical stimulation according to a program while at the specified output configuration;

means for determining a value of a voltage drop across a regulator module within the medical device while delivering the electrical stimulation according to the program; and

means for determining whether the medical device will be able to deliver stimulation according to the program at a power source voltage level lower than a present voltage level of a power source based on the determined value of the voltage drop.

17. A medical device comprising:

a power source at a present power source voltage level;

a signal generator that generates electrical stimulation, wherein the signal generator comprises;

a DC to DC converter coupled to the power source; and

a regulator module coupled to the DC to DC converter; and

a processor that controls the signal generator to configure the DC to DC converter in a specified output configuration and deliver stimulation according to a program while at the specified output configuration, determines a first output of the DC to DC converter at the specified output configuration and the present battery power source voltage level, determines a second output of the DC to DC converter at a maximum output configuration and a power source voltage level lower than the present voltage level of the power source, compares the first and second outputs, and determines whether the medical device will be able to deliver stimulation according to the program at the power source voltage level lower than the present voltage level of the power source based on the comparison.

18. The medical device of claim 17, wherein the processor determines that the medical device will be able to deliver stimulation according to the program when the second output is at least one of greater than or equal to the first output.

19. The medical device of claim 17, wherein, when the second output is less than the first output, the processor determines a voltage drop across the regulator module at the second output of the DC to DC converter at the maximum output configuration and the power source voltage level lower than the present voltage level of the power source, and determines whether the medical device will be able to deliver stimulation according to the program at the power source voltage level lower than the present voltage level of a power source based on the determined value of the voltage drop.