System and apparatus for determining ambient temperatures for a fluid analyte system

• US 8,801,275 B2
• Filed: 09/16/2011
• Issued: 08/12/2014
• Est. Priority Date: 09/23/2010
• Status: Active Grant

• Current Assignee: Ascensia Diabetes Care Holdings AG (PHC Holdings Corporation)
• Original Assignee: Bayer Healthcare LLC (Bayer AG)
• Inventors: Wu, Mu
• Primary Examiner(s): KAPLAN VERBITSKY, GAIL
• Application Number:
  US13/234,268
• Publication Number:
  US 20120076171A1
• Time in Patent Office: 1,061 Days
• Field of Search: 374/10, 374/4, 374/5, 374/100, 374/163, 374/1, 374/29, 374/30, 374/45, 374/141, 374/147, 374/148, 73/232, 73/232.5, 73/250.1, 733/350.3, 73/310.1, 73/614.6, 205/775, 204/400, 422/82.12, 600/322, 600/347, 600/364, 600/366, 600/549, 702/130
• US Class Current: 374/109
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: G01K 1/20 Compensating for effects of temperature changes other than those to be measured, e.g. changes in ambient temperature
• CPC Class Codes: G01K 7/42 Circuits effecting compensation of thermal inertia; Circuits for predicting the stationary value of a temperature
• CPC Class Codes: G01K 7/427 Temperature calculation based on spatial modeling, e.g. spatial inter- or extrapolation
• 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

Abstract

A system and method for rapidly determining ambient temperature in a fluid-analyte meter. The meter includes a housing defining an interior space and an area for receiving a fluid sample. A processor and a first temperature sensor are disposed within the interior space of said the housing. A second temperature sensor is disposed on the housing. One or more processors are configured to determine a first temperature value from temperature data received from the first temperature sensor. The processor(s) are also configured to apply a variable current to a temperature-adjustment source such that the second temperature sensor is adjusted to a predetermined steady-state temperature value different from the first temperature value. The processor(s) are further configured to determine an ambient temperature of an exterior space of the housing based on the applied variable current, pre-determined steady-state temperature, and received first temperature values.

Claims

1. A fluid-analyte meter configured to rapidly determine ambient temperature, the meter comprising:

a housing defining an interior space and an exterior ambient space;

a processor disposed within said housing;

a controller disposed within said housing, said controller communicatively connected to said processor;

a first temperature sensor disposed within said interior space of said housing;

a second temperature sensor disposed on said housing, said second temperature sensor communicatively connected to said controller; and

a temperature-adjustment source disposed on said housing, said temperature-adjustment source configured to create a convective zone about said second temperature sensor,

wherein said controller is configured to transmit instructions for supplying a variable current to said temperature-adjustment source such that said temperature-adjustment source adjusts said second temperature sensor to a predetermined steady-state temperature value different from a first temperature value, said first temperature value based on first temperature data received via said controller from said first temperature sensor, said controller further configured to receive second temperature data from said second temperature sensor, said controller or said processor configured to determine an ambient temperature of said exterior ambient space based on said supplied variable current, predetermined steady-state temperature, and first temperature values.

2. The meter of claim 1, wherein said ambient temperature is further determined using the relationship:

φ

_AMBIENT=φ

_TOTAL−

φ

_INSIDE

with the heat flux from said second temperature sensor to said interior space of said housing, φ

_INSIDE, being approximately constant and the heat flux from said second temperature sensor to said exterior ambient space, φ

_AMBIENT, being greater than φ

_INSIDE.

3. The meter of claim 1, wherein said second temperature sensor and said temperature-adjustment source are a single element.

4. The meter of claim 3, wherein said second temperature sensor is an RTD sensor.

5. The meter of claim 1, wherein said temperature-adjustment source is a heat source and said pre-determined steady-state temperature value is greater than said first temperature value.

6. The meter of claim 1, wherein said temperature-adjustment source is a thermoelectric cooler and said pre-determined steady-state temperature value is less than said first temperature value.

7. The meter of claim 1, wherein said ambient temperature of said exterior space is determined in less than one minute.

8. The meter of claim 1, wherein said ambient temperature of said exterior space is determined in less than twenty seconds.

9. The meter of claim 1, wherein said second temperature sensor is embedded in an interior surface of said housing.

10. The meter of claim 1, wherein said second temperature sensor is embedded in an exterior surface of said housing.

11. The meter of claim 1, wherein said second temperature sensor is at least partially embedded in a metal layer, said metal layer being at least partially embedded in said housing.

12. The meter of claim 1, further comprising a printed circuit board disposed in said interior space of said housing, said first temperature sensor being disposed on said printed circuit board.

13. A method for rapidly determining ambient temperature in a fluid-analyte meter, the method comprising:

providing a meter including a housing, a first temperature sensor disposed within an interior space of said housing, a second temperature sensor disposed on said housing, and a temperature-adjustment source disposed near said second temperature sensor;

determining a first temperature value from first temperature data received via said first temperature sensor;

applying a variable current to said temperature-adjustment source such that said second temperature sensor is adjusted to a predetermined equilibrium temperature value different from said first temperature value;

determining a second temperature value from second temperature data received from said second temperature sensor; and

determining, via one or more processors, an ambient temperature of an exterior space of said fluid-analyte meter based on said variable current and said determined first and second temperature values.

14. The method of claim 13, wherein said second temperature sensor and said temperature-adjustment source are a single element.

15. The method of claim 13, further comprising providing a printed circuit board disposed in said interior space of said housing, said first temperature sensor being disposed on said printed circuit board.