Power supply having means for extending the operating time of an implantable medical device

• US 5,949,632 A
• Filed: 12/01/1998
• Issued: 09/07/1999
• Est. Priority Date: 12/01/1998
• Status: Expired due to Fees

• Current Assignee: Exonix Corporation
• Original Assignee: Exonix Corporation
• Inventors: Echarri, Roberto, Echarri, Guillermo, Barreras, Francisco Jose Sr.
• Primary Examiner(s): NGUYEN, MATTHEW VAN
• Application Number:
  US09/203,275
• Time in Patent Office: 280 Days
• Field of Search: 363/50, 361/18, 361/54, 361/56, 361/90, 307/116, 307/126, 307/130, 607/33, 607/61
• US Class Current: 361/90
• CPC Class Codes: A61M 2205/8212 with means or measures taken for minimising energy consumption
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 2310/23 The load being a medical device, a medical implant, or a life supporting device
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators

Abstract

A power supply comprising: a power source including a capacitive, nuclear or an electrochemical device for storing electrical energy; sensing circuitry for sensing when the voltage on power source is above or below a certain level; a DC-DC converter coupled to the power source switching circuitry coupled to the sensing circuitry and operable to connect the DC-DC converter to an output load and disconnect the power source from the output load when the voltage on the power source falls below a certain level and for connecting the power source to the output load and disconnecting the DC-DC converter from the output load when the voltage on the power source rises above a certain level; circuitry for activating the DC to DC Converter when the voltage on the power source falls below a certain level; and circuitry means for shutting down the DC to DC Converter when the voltage on the power source rises above a certain level.

The method for extending the operating time of a capacitive, nuclear or electrochemical power source includes the steps of: sensing when the voltage level on the power source is below or above a certain level; producing a first logic signal when the voltage on the power source falls below a certain level and producing a second logic signal when the voltage on the power source is above a certain level; providing a DC-DC converter coupled to the output of the power source; switching the connections to an output load from the power source to the DC-DC converter when the first logic signal is produced; connecting the power source to an output load and disconnecting the DC-DC converter from the output load when the second logic signal is produced; activating the DC to DC Converter when the first logic signal is produced; and shutting down the DC to DC Converter when the second logic signal is produced.

Claims

1. An implantable medical device having a power supply comprising:

power source means for storing or generating electrical energy selected essentially from the class comprising;

a large value capacitor, an electrochemical cell (rechargeable or non-rechargeable), or a nuclear cell;

sensing means for sensing when the voltage on said power source means is above or below a certain level;

a DC-DC converter coupled to said power source means;

switching means coupled to said sensing means and operable to connect said DC-DC converter to an output load and disconnect said power source means from the output load when the voltage on said power source means falls below a certain level and for connecting said power source means to the output load and disconnecting said DC-DC converter from the output load when the voltage on said power source means rises above a certain level;

means for activating said DC to DC Converter when the voltage on said power source falls below a certain level; and

means for shutting down said DC to DC Converter when the voltage on said power source rises above a certain level.

2. The implantable medical device of claim 1 wherein said sensing means comprises a comparator having a positive input coupled to a voltage reference and a negative input coupled to a voltage source representing a fraction of the voltage on said power source means.

3. The implantable medical device of claim 2 wherein said comparator outputs a logic high when the voltage on said power source means falls below a certain level and outputs logic low when the voltage on said power source means exceeds a certain level.

4. The implantable medical device of claim 1 wherein said switching means comprises a first electronic switch for closing a first circuit and opening a second circuit when said switching means receives a logic high and a second electronic switch for opening said first circuit and closing said second circuit when said switching means receives a logic low signal.

5. The implantable medical device of claim 4 wherein said electronic switch means comprises two PMOS transistors.

6. The implantable medical device of claim 4 wherein said electronic switch means comprises two Schottky diodes.

7. The implantable medical device of claim 1 wherein said switching means is defined by an inductor and transistor connected in series between said power source means and a common or ground for said power supply and an oscillator connected to a base of said transistor and receiving an input from said sensing means;

and wherein a junction between said inductor and transistor being coupled through a diode to said implantable medical device.

8. The implantable medical device of claim 7 including a storage capacitor connected to the output and said diode being a Schottky diode.

9. A power supply comprising:

capacitive, electrochemical or nuclear means for storing or generating electrical energy;

sensing means for sensing when the voltage on said power source means is above or below a certain level;

a DC-DC converter coupled to said power source means;

switching means coupled to said sensing means and operable to connect said DC-DC converter to an output load and disconnect said power source means from the output load when the voltage on said power source means falls below a certain level and for connecting said power source means to the output load and disconnecting said DC-DC converter from the output load when the voltage on said power source means rises above a certain level;

activating means for activating said DC to DC Converter when the voltage on said power source falls below a certain level; and

shutting down means for shutting down said DC to DC Converter when the voltage on said power source rises above a certain level.

10. The power supply of claim 9 wherein said sensing means comprises a comparator having a positive input coupled to a voltage reference and a negative input coupled to a voltage source representative of the voltage on said power source means.

11. The power supply of claim 10 wherein said comparator outputs a logic high when the voltage on said power source means falls below a certain level and outputs logic low when the voltage on said power source means exceeds a certain level.

12. The power supply of claim 9 wherein said switching means comprises an electronic switch for closing a first circuit and opening a second circuit when said electronic switching circuit receives a logic high signal and for opening said first circuit and closing said second circuit when said electronic switching circuit receives a logic low signal.

13. The power supply of claim 9 wherein said switching means comprises two PMOS transistors.

14. The power supply of claim 9 wherein said switching means comprises two Schottky diodes.

15. The power supply means of claim 9 wherein said switching means is defined by an inductor and transistor connected in series between said power source means and a common or ground for said power supply and an oscillator connected to a base of said transistor and receiving an input from said sensing means;

and wherein a junction between said inductor and transistor being coupled through a diode to said implantable medical device.

16. The power supply of claim 9 including a storage capacitor connected to the output of said diode and said diode being a Schottky diode.

17. A method for extending the operating time of a capacitive or electrochemical power source including the steps of:

sensing when the voltage level on said power source is below or above a certain level;

producing a first logic signal when the voltage on said power source falls below a certain level and producing a second logic signal when the voltage on said power source is above a certain level;

providing a DC-DC converter coupled to the output of said power source;

switching the connections to an output load from said power source to the DC-DC converter when a first logic signal is produced; and

connecting said power source to an output load the disconnecting the DC-DC converter from the output load when a second logic signal is produced;

activating said DC to DC Converter when said first logic signal is produced; and

shutting down said DC to DC Converter when said second logic signal is produced.

18. A method for extending the operating time of a capacitive, electrochemical or nuclear power source in an implantable medical device including the steps of:

sensing when the voltage level on said power source is below or above a certain level;

producing a first logic signal when the voltage on said power source falls below a certain level and producing a second logic signal when the voltage on said power source is above a certain level;

providing a DC-DC converter coupled to the output of said power source;

switching the connections to an output load from said power source to the DC-DC converter when a first logic signal is produced; and

connecting said power source to an output load and disconnecting the DC-DC converter from the output load when a second logic signal is produced;

activating said DC to DC Converter when said first logic signal is produced; and

shutting down said DC to DC Converter when said second logic signal is produced.