Systems and methods for precharging circuitry for pulse generation

• US 20050245978A1
• Filed: 04/12/2005
• Published: 11/03/2005
• Est. Priority Date: 04/12/2004
• Status: Active Grant

• Current Assignee: Advanced Neuromodulation Systems Incorporated (Abbott Laboratories)
• Original Assignee: Advanced Neuromodulation Systems Incorporated (Abbott Laboratories)
• Inventors: Tranchina, Benjamin A., Varrichio, Anthony J.
• Granted Patent: US 7,450,987 B2
• Time in Patent Office: Days
• US Class Current: 607/11
• CPC Class Codes: A61N 1/36125 Details of circuitry or electric components
• CPC Class Codes: A61N 1/3782 producing a voltage above the power source level
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps
• CPC Class Codes: H02M 3/072 adapted to generate an output voltage whose value is lower than the input voltage
• CPC Class Codes: H02M 3/073 Charge pumps of the Schenkel-type

Abstract

A low power (and lower cost) implementation for amplifier used in delivering a stimulation pulse is provided according to embodiments through use of a pre-charge period for each pulse. For example, a voltage at a variable output terminal of a digital-to-analog converter is increased on the leading edge of PULSE and INVERTCLK signals to result in an output of an operational amplifier increasing to a predetermined voltage prior to output of a stimulation pulse, according to an embodiment. A shunt path may be implemented to shunt current away from a load during the pre-charge period.

Claims

1. A system comprising:

an amplifier controlling a magnitude of an output pulse; and

a controller initiating, prior to delivery of the output pulse, pre-charging of the amplifier.

2. The system of claim 1, wherein during pre-charging of said amplifier the amplifier output is powered up to a predetermined voltage.

3. The system of claim 2, wherein during pre-charging of said amplifier the amplifier provides a low output current.

4. The system of claim 1, wherein said pre-charging of said amplifier is accomplished during an amplifier pre-charge period which is programmable.

5. The system of claim 1, wherein a current resulting from said pre-charging of said amplifier is shunted from a load to which said output pulse is delivered.

6. The system of claim 5, further comprising:

a field effect transistor coupled to the output of said amplifier within a current sink path used in shunting said current resulting from said pre-charging of said amplifier.

7. The system of claim 6, wherein said field effect transistor comprises a low voltage device, and wherein a high voltage field effect transistor is disposed to isolate said low voltage field effect transistor from a voltage of said output pulse.

8. The system of claim 1, wherein said amplifier and controller comprise a stimulation system for providing therapeutic stimulation to a patient, and wherein a current resulting from said pre-charging of said amplifier is shunted so as not to be delivered to the patient.

9. The system of claim 1 wherein said amplifier comprises an operational amplifier, said system further comprising:

a digital-to-analog converter programmably setting one input to the operational amplifier; and

a scale circuit within the electrical path through the electrode connectors, programmably setting an other input to the operational amplifier, wherein said controller initiates pre-charging of the operational amplifier through control of the digital-to-analog converter and the scale circuit.

10. The system of claim 1, wherein a resistance of the scale circuit is programmably set during pre-charging to minimize power dissipation by the stimulation pulse delivery system.

11. A method comprising:

controlling a magnitude of an output pulse using an amplifier; and

pre-charging the amplifier prior to delivery of the output pulse.

12. The method of claim 11, wherein said pre-charging of said amplifier comprises:

powering said amplifier to a predetermined output voltage.

13. The method of claim 11, wherein said pre-charging of said amplifier comprises:

outputting a current by said amplifier; and

controlling said current output by said amplifier.

14. The method of claim 13, wherein said controlling said current comprises:

setting a resistance provided by said scale circuit to a largest resistance value which results in a desirable rise time with respect to said amplifier.

15. The method of claim 11, wherein pre-charging of said amplifier comprises:

providing an amplifier pre-charge period during which said pre-charging is accomplished; and

programmably selecting said amplifier pre-charging period.

16. The method of claim 11, further comprising:

shunting a current resulting from said pre-charging of said amplifier from a load to which said output pulse is delivered.

17. The method of claim 11, further comprising:

providing therapeutic stimulation to a patient using said output pulse; and

shunting a current resulting from said pre-charging of said amplifier so as not to be delivered to the patient.

18. A stimulation pulse delivery system comprising:

a stimulation pulse generation circuit; and

a shunt path selectively shunting current resulting from said stimulation pulse generation circuit from a load to which a stimulation pulse is to be delivered.

19. The system of claim 18, further comprising:

a controller in communication with said shunt path and controlling said shunt path to shunt said current during a pre-charge operational period of said stimulation pulse generation circuit.

20. The system of claim 18, wherein said stimulation pulse generation circuit comprises:

an amplifier controlling a magnitude of said stimulation pulse; and

a controller initiating, prior to delivery of the stimulation pulse, pre-charging of the amplifier.