Rapid Charging And Power Management Of A Battery-Powered Fluid Analyte Meter

• US 20090146826A1
• Filed: 05/29/2008
• Published: 06/11/2009
• Est. Priority Date: 12/10/2007
• Status: Active Grant

• Current Assignee: Ascensia Diabetes Care Holdings AG (PHC Holdings Corporation)
• Original Assignee: Bayer Healthcare LLC (Bayer AG)
• Inventors: Chen, Jun, Gofman, Igor
• Granted Patent: US 8,164,468 B2
• Time in Patent Office: Days
• US Class Current: 340/636.200
• CPC Class Codes: A61B 2560/0214 of power generation or supply
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: G01N 33/48785 Electrical and electronic details of measuring devices for physical analysis of liquid biological material not specific to a particular test method, e.g. user interface or power supply
• CPC Class Codes: G01R 31/3646 for indicating electrical conditions or variables, e.g. visual or audible indicators
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: H02J 2310/23 The load being a medical device, a medical implant, or a life supporting device
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current
• CPC Class Codes: H02J 7/007192 in response to temperature
• CPC Class Codes: H02J 7/007194 of the battery

Abstract

A system and method is described for rapid charging and power management of a battery for a meter. A charger component is operably associated with the meter and is capable of executing a rapid charge algorithm for a rechargeable battery. The algorithm includes monitoring for a connection to an external power source and implementing a charging routine of a battery at a first charge rate and then at a second charge rate. The second charge rate is lower than the first charge rate. A temperature rise in the rechargeable battery due to the first charge rate has a negligible heat transfer effect on the fluid sample. The meter can also include a power switch for controlling current flow to a battery fuel gauge. The power switch is open when the meter enters into a sleep mode. The state of battery charge is determined after the meter exits the sleep mode.

Claims

1. A battery-powered meter adapted to determine an analyte concentration of a fluid sample using a test sensor, the meter comprising:

a port sized to receive at least a portion of the test sensor;

a front portion comprising a display operable to display said analyte concentration of said fluid sample;

a user-interaction mechanism operable to control said meter;

a housing for a rechargeable battery; and

a battery charger component operably associated with said meter, said battery charger component configured to execute a rapid charge algorithm for a rechargeable battery, said algorithm comprising;

(i) monitoring for a connection to an external power source; and

(ii) if said external power source is detected, implementing a charging routine for the rapid charging of said battery at a first charge rate until a first predetermined event occurs followed by charging said battery at a second charge rate until a second predetermined event occurs, said second charge rate being lower than said first charge rate.

2. The battery-powered meter of claim 1, wherein a temperature rise in said rechargeable battery due to said first charge rate has a negligible heat transfer effect on said fluid sample.

3. The battery-powered meter of claim 1, wherein said first charge rate has a range of 2C to 5C.

4. The battery-powered meter of claim 1, wherein said second charge rate is less than 1C.

5. The battery-powered meter of claim 1, wherein said battery charger component is part of an integrated circuit.

6. The battery-powered meter of claim 1, wherein said first predetermined event is a lapsing of a predetermined time period.

7. The battery-powered meter of claim 6, wherein said predetermined time period is approximately one minute or less.

8. The battery-powered meter of claim 1, wherein said first predetermined event is exceeding a predetermined charge voltage for said rechargeable battery.

9. The battery-powered meter of claim 1, wherein said first predetermined event is exceeding a threshold temperature in the rechargeable battery.

10. The battery-powered meter of claim 1, wherein said first predetermined event is exceeding a threshold temperature in the meter.

11. The battery-powered meter of claim 1, wherein said external power source is a port on a computing device.

12. The battery-powered meter of claim 1, wherein said rechargeable battery is periodically monitored for elevated temperature readings.

13. A method of rapid charging a battery in a fluid analyte meter, the method comprising:

monitoring for a connection to an external power source;

implementing a rapid charge routine for charging said battery at a first charge current rate over a first predetermined time period;

following said first predetermined time period, implementing a normal charge routine for charging said battery at a second charge current rate over a second predetermined time period, said first charge current rate being greater than said second charge current rate;

wherein said first predetermined time period is at least partially based on an estimated temperature rise in said battery due to a charge current associated with said first charge current rate.

14. The method of claim 13, wherein said first predetermined time period is further at least partially based on a threshold charge voltage.

15. The method of claim 13, wherein said first charge current rate and second charge current rate are generally constant.

16. The method of claim 13, further comprising notifying a user of said meter with a perceivable signal following said first predetermined time period.

17. The method of claim 13, further comprising implementing a termination charge routine following said second predetermined time period that charges said battery at a third current rate until a predetermined event occurs, said third charge current rate being lower than said second charge current rate.

18. The method of claim 17, wherein said third charge current rate is continuously decreasing.

19. A computer-readable memory medium having stored thereon instructions for directing a rapid charge of a battery for a meter operable to determine an analyte concentration of a fluid sample, said instructions comprising:

monitoring for a connection to an external power source;

implementing a rapid charge routine for charging said battery at a first charge current until a first predetermined event occurs;

following said occurrence of said first predetermined event, implementing a normal charge routine for charging said battery at a second charge current until a second predetermined event occurs, said first charge current being greater than said second charge current;

monitoring a temperature rise for at least one of said battery and said meter, said monitoring occurring at one or more predetermined time intervals; and

if said temperature rise in said at least one of said battery and said meter exceed a predetermined threshold value, canceling at least one of said rapid charge routine and said normal charge routine.

20. A portable meter having a circuit configured with a battery to provide power to a sensing element within said circuit, the meter comprising:

a processor powered by said circuit, said processor configured to operate said meter in an active mode and a sleep mode;

a fuel gauge powered by said circuit, said fuel gauge configured to track state of battery charge data received from said battery during active mode operation of said meter;

an interface configured to transfer state of battery charge data from said fuel gauge to said processor; and

a power switch for controlling current flow to said fuel gauge, said power switch configured to be open and closed by said processor, said processor signals said power switch to an open position if said meter enters into said sleep mode and said processor signals said power switch to a closed position if said meter enters into an active mode, wherein prior to entering said sleep mode, said processor is configured to record a first state of battery charge for said battery and a first time reference immediately prior to said meter entering said sleep mode, said processor further configured to determine a second state of battery charge at a second reference time immediately after said meter exits from said sleep mode into said active mode, said second state of battery charge determined based on said recorded first state of charge, said first reference time, said second reference time, and a predetermined energy usage rate of said meter during said sleep mode.

21. The portable meter of claim 20, wherein said fuel gauge continuously tracks state of battery charge during active mode of operation of said meter.

22. The portable meter of claim 20, wherein the fuel gauge is an integrated circuit.

23. The portable meter of claim 20, further comprising a display coupled to said processor, said display configured to display the present state of battery charge.

24. The portable meter of claim 20, wherein said processor is a microcontroller.

25. The portable meter of claim 20, wherein said battery is a rechargeable battery.

26. The portable meter of claim 25, wherein said portable meter enters into said active mode when a primary power source is charging said battery.

27. A method of power management in a battery-powered meter that is configured to operate in an active mode and a standby mode, said batter-powered meter including a battery fuel gauge and a microcontroller, said method comprising the steps of:

receiving a first request to enter into said standby mode;

recording a first state of charge for a battery of said meter, said recording occurring at a first reference time immediately after said first request is received;

recording said first reference time using said microcontroller;

entering said meter into said standby mode, wherein power to said battery fuel gauge is switched off in said standby mode;

receiving a second request at a second reference time to exit said standby mode and enter said active mode, said second reference time occurring after said first reference time,

wherein in response to said second request, a second reference time is immediately recorded and said microcontroller determines a second state of battery charge based on said first reference time, said second reference time, a standby mode current and a standby mode voltage of said meter.

28. The method of claim 27, wherein said battery-powered meter is a blood glucose meter.

29. The method of claim 27, wherein said first state of battery charge for said battery is determined using said battery fuel gauge.

30. The method of claim 27, wherein said battery-powered meter is initially in said active mode.

31. The method of claim 30, further comprising, if said meter is in an active mode, updating a state of battery charge using battery charge data received by said microcontroller from said battery fuel gauge.

32. The method of claim 31, wherein said updating is continuous.

33. The method of claim 31, further comprising displaying said state of battery charge on a display gauge.

34. A computer-readable memory medium having stored thereon instructions for managing the power of a battery-powered meter operating in an active mode and a sleep mode, said instructions comprising the following steps:

receiving a first request to enter into said sleep mode;

recording a first state of charge for a battery of said meter, said recording occurring at a first reference time immediately after said first request is received;

recording said first reference time;

entering said meter into said standby mode, wherein power to a battery fuel gauge is switched off in said standby mode;

receiving a second request at a second reference time to exit said sleep mode and enter said active mode, said second reference time occurring after said first reference time;

immediately after said second request, recording a second reference time; and

determining a second state of battery charge based on said first reference time, said second reference time, a sleep mode current, and a sleep mode voltage.