Systems and Methods for Reducing Power Consumption in an Implantable Medical Device

• US 20150012062A1
• Filed: 07/01/2014
• Published: 01/08/2015
• Est. Priority Date: 07/02/2013
• Status: Active Grant

• Current Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Original Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Inventors: Chen, Joey, Bradley, Kerry, Halberg, Leslie
• Granted Patent: US 9,744,347 B2
• Time in Patent Office: Days
• US Class Current: 607/59
• CPC Class Codes: A61B 5/064 using markers A61B5/062 takes precedence
• CPC Class Codes: A61B 8/0841 for locating instruments
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/0553 Paddle shaped electrodes, e.g. for laminotomy
• CPC Class Codes: A61N 1/36017 with leads or electrodes penetrating the skin
• CPC Class Codes: A61N 1/36021 for treatment of pain
• CPC Class Codes: A61N 1/36071 Pain
• CPC Class Codes: A61N 1/36125 Details of circuitry or electric components
• CPC Class Codes: A61N 1/36139 with automatic adjustment
• CPC Class Codes: A61N 1/36146 specified by the stimulation parameters
• CPC Class Codes: A61N 1/36153 Voltage A61N1/3616 takes precedence
• CPC Class Codes: A61N 1/37223 Circuits for electromagnetic coupling
• CPC Class Codes: A61N 1/37235 Aspects of the external programmer
• CPC Class Codes: A61N 1/37252 Details of algorithms or data aspects of communication system, e.g. handshaking, transmitting specific data or segmenting data
• CPC Class Codes: A61N 1/3752 Details of casing-lead connections
• CPC Class Codes: A61N 1/3787 from an external energy source

Abstract

A medical device for providing a stimulation therapy includes stimulation circuitry configured to provide a plurality of electrical pulses to be delivered to a patient. The stimulation circuitry contains a microcontroller configured to generate the electrical pulses. Each electrical pulse includes a primary phase, an interphase after the primary phase, and a recovery phase after the primary phase. Consecutive electrical pulses are separated by a standby period. The microcontroller is configured to operate in an active mode during at least one of: the primary phase and the interphase. The microcontroller is configured to operate in a power-conservation mode during a substantial majority of the standby period. The microcontroller consumes substantially less power when operating in the power-conservation mode than in the active mode.

Claims

1. A medical device for providing an electrical stimulation therapy for a patient, the medical device comprising:

telemetry circuitry configured to receive programming instructions via telecommunications conducted with an electronic programmer;

stimulation circuitry configured to provide, in response to the received programming instructions, a plurality of electrical pulses to be delivered to the patient as a part of the electrical stimulation therapy, wherein the stimulation circuitry contains a microcontroller configured to generate the electrical pulses, wherein each electrical pulse includes a primary phase, an interphase after the primary phase, and a recovery phase after the primary phase, and wherein consecutive electrical pulses are separated by a standby period; and

power supply circuitry configured to provide electrical power to the telemetry circuitry and the stimulation circuitry;

wherein;

the microcontroller is configured to operate in an active mode during at least one of;

the primary phase and the interphase;

the microcontroller is configured to operate in a power-conservation mode during a substantial majority of the standby period; and

the microcontroller consumes substantially less power when operating in the power-conservation mode than in the active mode.

2. The medical device of claim 1, wherein:

the recovery phase is one of;

an active recovery phase or a passive recovery phase;

the microcontroller is configured to operate in the active mode during the active recovery phase; and

the microcontroller is configured to operate in the power-conservation mode during the passive recovery phase.

3. The medical device of claim 1, wherein:

the microcontroller contains a microcontroller core and a direct memory access (DMA) unit that is separate from the microcontroller core and consumes substantially less power than the microcontroller core;

the microcontroller core is turned on when the microcontroller operates in the active mode and is turned off when the microcontroller operates in the power-conservation mode; and

the DMA unit remains turned on when the microcontroller operates in the power-conservation mode.

4. The medical device of claim 3, wherein:

the microcontroller contains a system clock that is running at a first frequency;

the stimulation circuitry further comprises an oscillator that is external to the microcontroller, the oscillator running at a second frequency that is substantially lower than the first frequency;

the microcontroller is driven by the system clock when operating in the active mode; and

the DMA unit is driven by the oscillator when the microcontroller operates in the power-conservation mode.

5. The medical device of claim 4, wherein when operating in the power-conservation mode, the microcontroller is configured to be woken up by an interrupt signal immediately before a subsequent electrical pulse needs to be generated, such that the microcontroller operates in the active mode after being woken up, wherein the interrupt signal is generated by a timer clocked by the oscillator.

6. The medical device of claim 1, wherein:

the power supply circuitry comprises;

an inductive charging mechanism configured to receive an inductive energy;

a charging circuit configured to convert the inductive energy into a direct current (DC) signal;

a battery charged by the charging circuit to provides a first DC voltage;

a voltage down-converter that down-converts the first DC voltage to a second DC voltage smaller than the first DC voltage, the second DC voltage being a voltage supply for at least the microcontroller; and

a voltage up-converter that up-converts the first DC voltage to a third DC voltage that is greater than the first DC voltage, the third voltage being a voltage supply for the stimulation circuitry; and

the stimulation circuitry further comprises;

a stimulation driver that amplifies the electrical pulses generated by the microcontroller; and

an array of multiplexers coupled between the stimulation driver and an external lead that includes a plurality of electrodes configured to deliver the electrical stimulation therapy to the patient.

7. The medical device of claim 6, further comprising a switch coupled between the voltage up-converter and the stimulation driver, wherein the switch is configured to disconnect the stimulation driver from the voltage up-converter during the standby period in between consecutive electrical pulses.

8. The medical device of claim 6, wherein, for each pulse:

if the pulse has a passive recovery phase, the voltage up-converter and the array of multiplexers are enabled before the primary phase and disabled during the interphase; and

if the pulse has an active recovery phase, the voltage up-converter and the array of multiplexers are enabled before the primary phase and disabled after the active recovery phase.

9. A medical system for providing an electrical stimulation therapy for a patient, the medical system comprising:

an electronic programmer configured to generate stimulation programming instructions for an implantable pulse generator (IPG); and

the IPG, wherein the IPG comprises;

telemetry circuitry configured to receive the programming instructions via telecommunications conducted with the electronic programmer;

stimulation circuitry configured to provide, in response to the received programming instructions, a plurality of electrical pulses to be delivered to the patient as a part of the electrical stimulation therapy, wherein the stimulation circuitry contains a microcontroller configured to generate the electrical pulses, wherein each electrical pulse includes a primary phase, an interphase after the primary phase, and a recovery phase after the primary phase, and wherein consecutive electrical pulses are separated by a standby period; and

power supply circuitry configured to provide electrical power to the telemetry circuitry and the stimulation circuitry;

wherein;

the microcontroller is configured to operate in an active mode during at least one of;

the primary phase and the interphase;

the microcontroller is configured to operate in a power-conservation mode during a substantial majority of the standby period; and

the microcontroller consumes substantially less power when operating in the power-conservation mode than in the active mode.

10. The medical system of claim 9, further comprising:

an implantable lead configured to be attached to the IPG, wherein the implantable lead contains a plurality of electrodes configured to deliver the electrical pulses generated by the IPG to a peripheral nerve of the patient.

11. The medical system of claim 9, wherein:

the power supply circuitry comprises;

an inductive charging mechanism configured to receive an inductive energy;

a charging circuit configured to convert the inductive energy into a direct current (DC) signal;

a battery charged by the charging circuit to provides a first DC voltage;

a voltage down-converter that down-converts the first DC voltage to a second DC voltage smaller than the first DC voltage, the second DC voltage being a voltage supply for at least the microcontroller; and

a voltage up-converter that up-converts the first DC voltage to a third DC voltage that is greater than the first DC voltage, the third voltage being a voltage supply for the stimulation circuitry; and

the stimulation circuitry further comprises;

a stimulation driver that amplifies the electrical pulses generated by the microcontroller; and

an array of multiplexers coupled between the stimulation driver and an external lead that includes a plurality of electrodes configured to deliver the electrical stimulation therapy to the patient.

12. The medical system of claim 11, further comprising a switch coupled between the voltage up-converter and the stimulation driver, wherein the switch is configured to disconnect the stimulation driver from the voltage up-converter during the standby period in between consecutive electrical pulses.

13. The medical system of claim 11, wherein, for each pulse:

if the pulse has a passive recovery phase, the voltage up-converter and the array of multiplexers are enabled before the primary phase and disabled during the interphase, and the microcontroller is configured to operate in the power-conservation mode during the passive recovery phase; and

if the pulse has an active recovery phase, the voltage up-converter and the array of multiplexers are enabled before the primary phase and disabled after the active recovery phase, and the microcontroller is configured to operate in the active mode during the active recovery phase.

14. A method of providing an electrical stimulation therapy for a patient, the method comprising:

receiving programming instructions from an electronic programmer; and

generating, via a microcontroller and in response to the received programming instructions, a plurality of electrical pulses to be delivered to the patient as a part of the electrical stimulation therapy, wherein each electrical pulse includes a primary phase, an interphase after the primary phase, and a recovery phase after the primary phase, wherein consecutive electrical pulses are separated by a standby period, and wherein the generating of the electrical pulses comprises;

operating the microcontroller in an active mode during at least one of;

the primary phase and the interphase;

operating the microcontroller in a power-conservation mode during a substantial majority of the standby period; and

wherein the microcontroller consumes substantially less power when operating in the power-conservation mode than in the active mode.

15. The method of claim 14, wherein:

the microcontroller contains a microcontroller core and a direct memory access (DMA) unit that is separate from the microcontroller core and consumes substantially less power than the microcontroller core;

the operating of the microcontroller comprises;

turning on the microcontroller core in the active mode;

turning off the microcontroller core in the power-conservation mode; and

keeping the DMA unit turned on in the power-conservation mode.

16. The method of claim 15, wherein:

the microcontroller contains a system clock that is running at a first frequency;

the stimulation circuitry further comprises an oscillator that is external to the microcontroller, the oscillator running at a second frequency that is substantially lower than the first frequency;

the operating of the microcontroller comprises driving the microcontroller with the system clock in the active mode; and

driving the DMA unit with the oscillator in the power-conservation mode.

17. The method of claim 16, further comprising:

generating an interrupt signal with a timer unit that is clocked by the oscillator; and

waking up the microcontroller from the power-conservation mode via the interrupt signal immediately before a subsequent electrical pulse needs to be generated.

18. The method of claim 14, further comprising:

receiving an inductive energy;

converting the inductive energy into a direct current (DC) signal;

charging a battery with the DC signal, thereby providing a first DC voltage via the battery;

down-converting the first DC voltage to a second DC voltage smaller than the first DC voltage;

providing the second DC voltage as a voltage supply for at least the microcontroller;

up-converting the first DC voltage to a third DC voltage greater than the first DC voltage;

providing the third DC voltage as a voltage supply for a stimulation driver and an array of multiplexers coupled to the stimulation driver;

amplifying, via the stimulation driver, the electrical pulses generated by the microcontroller; and

delivering the amplified electrical pulses to the patient at least in part by configuring the array of multiplexers.

19. The method of claim 18, further comprising:

disconnecting the stimulation driver from the voltage up-converter during the standby period between consecutive electrical pulses.

20. The method of claim 18, further comprising, for each pulse:

if said pulse has a passive recovery phase;

enabling the voltage up-converter and the array of multiplexers before the primary phase;

disabling the voltage up-converter and the array of multiplexers during the interphase; and

operating the microcontroller in the power-conservation mode during the passive recovery phase; and

if said pulse has an active recovery phase;

enabling the voltage up-converter and the array of multiplexers before the primary phase;

disabling the voltage up-converter and the array of multiplexers after the active recovery phase; and

operating the microcontroller in the active mode during the active recovery phase.