Thermometer, electronic device having a thermometer, and method for measuring body temperature

• US 20060056487A1
• Filed: 09/13/2005
• Published: 03/16/2006
• Est. Priority Date: 09/15/2004
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Kuroda, Masao, Kobayashi, Yutaka, Ishibashi, Naoki
• Granted Patent: US 7,249,883 B2
• Time in Patent Office: Days
• US Class Current: 374/179
• CPC Class Codes: G01K 1/165 for application in zero heat flux sensors
• CPC Class Codes: G01K 13/20 Clinical contact thermometers for use with humans or animals
• CPC Class Codes: G01K 7/427 Temperature calculation based on spatial modeling, e.g. spatial inter- or extrapolation

Abstract

A deep-area temperature calculating device 441 calculates the temperature T_core of a deep area on the basis of a first body-surface temperature and second body-surface temperature from body-surface sensors 31A and 31B, and on the basis of a first intermediate temperature and second intermediate temperature from intermediate sensors 32A and 32B. Since the temperature T_core of the deep area is determined from two body-surface temperatures and two intermediate temperatures, the temperature T_core of the deep area can be calculated regardless of the heat resistance of the thermometer without making any assumptions regarding the heat resistance of the area that extends from the deep area of the human body to the body surface. Thereby, the temperature T_core of the deep area can be calculated and the body temperature can be measured with high precision regardless of differences in the body type or contact with clothing or bedding.

Claims

1. A thermometer comprising:

first temperature measuring device being configured to contact a first body surface of an organism, said first temperature measuring device having

a first base temperature measuring unit to measure a first base temperature from said first body surface at a first base temperature measuring position having a first heat resistance, and

a first heat flux measuring unit to measure a first heat flux at said first base temperature measuring position;

second temperature measuring device being configured to contact a second body surface at a position different from said first body surface, said second temperature measuring device having

a second base temperature measuring unit to measure a second base temperature from said second body surface at a second base temperature measuring position having a second heat resistance having an unknown ratio to said first heat resistance, and

a second heat flux measuring unit to measure a second heat flux at said second base temperature measuring position;

a heat flux adjusting device being configured to set said first heat flux and said second heat flux at different values; and

a deep-area temperature calculating device being configured to calculate the temperature of a deep area in the organism using the ratios of said first and second base temperatures, said first and second heat flux, and said first and second heat resistance.

2. The thermometer according to claim 1, wherein

said first temperature measuring device has a first reference temperature measuring unit to measure the temperature of a first reference temperature measuring position where the heat resistance from said first body surface is different from said first heat resistance as a first reference temperature,

said second temperature measuring device has a second reference temperature measuring unit to measure the temperature of a second reference temperature measuring position where the heat resistance from said second body surface is different from said second heat resistance as a second reference temperature,

said first heat flux measuring unit calculates said first heat flux on the basis of said first base temperature, said first reference temperature, and said heat resistance between said first base temperature measuring position and said first reference temperature measuring position,

said second heat flux measuring unit calculates said second heat flux on the basis of said second base temperature, said second reference temperature, and heat resistance between said second base temperature measuring position and said second reference temperature measuring position, and

a ratio of the heat resistance between said first base temperature measuring position and said first reference temperature measuring position, and said heat resistance between said second base temperature measuring position and said second reference temperature measuring position is known.

3. The thermometer according to claim 2, wherein

thermal insulating materials having a common heat resistance are disposed between said first base temperature measuring position and said first reference temperature measuring position, and between said second base temperature measuring position and said second reference temperature measuring position, and

said heat flux adjusting device has a first thermal insulating material disposed between said first reference temperature measuring position and the outside air, and a second thermal insulating material disposed between said second reference temperature measuring position and the outside air and provided with a different heat resistance from the heat resistance of said first thermal insulating material.

4. The thermometer according to claim 2, wherein

said heat flux adjustment device has

a first thermal insulating material disposed between said first base temperature measuring position and said first reference temperature measuring position, and

a second thermal insulating material disposed between said second base temperature measuring position and said second reference temperature measuring position, and wherein

said first thermal insulating material and said second thermal insulating material have a common thermal conductivity and cross section, and

a thickness of said first thermal insulating material and a thickness of said second thermal insulating material are different.

5. The thermometer according to claim 2, wherein

said first heat resistance and said second heat resistance are the same, and

a formula,

$\mathrm{Tcore}=\frac{\{\mathrm{Tb3}·}{}$

(Tb1-Tb2)-α

·

Tb1·

(Tb3-Tb4)}{(Tb1-Tb2)-α

·

(Tb3-Tb4)},

is stored in said deep-area temperature calculating device to calculate a temperature T_core of said deep area, T_b1 is a first base temperature, T_b2 is a first reference temperature, T_b3 is a second base temperature, T_b4 is a second reference temperature, and α

is a ratio of heat resistance between said first base temperature measuring position and said first reference temperature measuring position, and the heat resistance between said second base temperature measuring position and said second reference temperature measuring position.

6. A thermometer comprising:

a first temperature measuring device being configured to contact a first body surface of an organism, said first temperature measuring device being configured from a plurality of measuring units configured to measure temperature at positions having mutually different heat resistances from said first body surface;

a second temperature measuring device being configured to contact a second body surface at a position different from said first body surface, said second temperature measuring device being configured from a plurality of measuring units configured to measure temperature at positions having mutually different heat resistances from said second body surface;

a heat flux adjusting device being configured to set a heat flux of said first temperature measuring device and a heat flux of said second temperature measuring device at different values;

a temperature distribution calculating device being configured to calculate a first temperature distribution from a curve approximation using temperatures determined by measuring units of said first temperature measuring device and heat resistances in said measuring units, said temperature distribution calculating device being configured to calculate a second temperature distribution from a curve approximation using the temperatures determined by said measuring units of said second temperature measuring means and heat resistances in said measuring units; and

a deep-area temperature calculating device being configured to calculate the temperature of a deep area in the organism from said first temperature distribution and said second temperature distribution.

7. The thermometer according to claim 6, wherein

said temperature distribution calculating device is configured to calculate the temperature distributions by polynomial approximations.

8. The thermometer according to claim 6, wherein

at least one of said measuring units contacts said body surface of the organism and measures the temperature of said body surface.

9. The thermometer according to claim 6, further comprising

a display device having a display unit to display the temperature of said deep area calculated by said deep-area temperature calculating device, and

a thermometer main body having a first temperature measuring device and a second temperature measuring device, wherein

said display device and said thermometer main body are configured as separate units.

10. The thermometer according to claim 9, wherein

said deep-area temperature calculating device is provided on or in said display device.

11. The thermometer according to claim 9, wherein

said display device and said thermometer main body both have a transceiver configured to exchange information with each other by wireless communication.

12. A thermometer, comprising:

a base temperature measuring unit being configured to measure the base temperature from the body surface of an organism at a specific base temperature measuring position;

a heat flux measuring unit being configured to measure heat flux at said base temperature measuring position;

a heat resistance calculating device being configured to calculate a surface-layer heat resistance from a deep area in the organism to said base temperature measuring position based on a for-calculation deep-area temperature of said deep area in the organism measured at the same time as a for-calculation base temperature measured by said base temperature measuring unit and a for-calculation heat flux measured by said heat flux measuring unit;

a storage device being configured to store surface heat resistance calculated by said heat resistance calculating device; and

a deep-area temperature calculating device being configured to calculate the temperature of said deep area using said base temperature measured by said base temperature measuring unit, said heat flux measured by said heat flux measuring unit, and said surface-layer heat resistance stored in said storage device during body temperature measurement.

13. The thermometer according to claim 12, wherein

said heat flux measuring unit has a reference temperature measuring unit to measure, as a reference temperature, the temperature at said reference temperature measuring position, which is different from said base temperature measuring position, wherein the heat resistance between the base temperature measuring position is known, and

said heat flux value is measured based on said base temperature, said reference temperature, and known heat resistance.

17. The thermometer according to claims 12, further comprising

a display device having a display unit to display the temperature of said deep area calculated by said deep-area temperature calculating device, and

a thermometer main body having said first temperature measuring device and said second temperature measuring device, wherein

said display device and said thermometer main body are configured as separate units.

18. The thermometer according to claim 17, wherein

said heat resistance calculating device and said deep-area temperature calculating device are provided in or on said display device.

19. The thermometer according to claim 18, wherein

said display device and said thermometer main body both include a transceiver capable of exchanging information with each other by wireless communication.

20. The thermometer according to claim 19, wherein

said transceiver is configured to receive information about for-calculation deep-area temperature measured by a known thermometer.

14. A thermometer comprising:

a temperature measuring device being configured to contact a body surface of an organism, said temperature measuring device being configured from a plurality of measuring units configured to measure the temperature at positions having mutually different heat resistances from said body surface;

a temperature distribution calculating device being configured to calculate a relationship between heat resistance and temperature as a temperature distribution from a curve approximation using the temperature determined by said temperature measuring means and a plurality of heat resistances;

a deep-area temperature calculating device being configured to calculate the temperature of a deep area in the organism using said temperature distribution obtained by said temperature distribution calculating device;

a heat resistance calculating device being configured to calculate surface heat resistance from said deep area in the organism to a measuring unit nearest to said body surface by performing a curve approximation using the temperature determined by said temperature measuring device, said heat resistance, and a for-calculation deep-area temperature of said deep area in the organism measured at the same time as the temperature; and

a storage device being configured to store said surface heat resistance calculated by said heat resistance calculating device,

said deep-area temperature calculating device being configured to calculate the temperature of said deep area of the organism using said temperature calculated by said temperature distribution calculating device and said surface heat resistance stored in said storage device.

15. The thermometer according to claim 14, wherein

said temperature distribution calculating device is configured to calculate said 20 temperature distribution by polynomial approximation.

16. The thermometer according to claim 15, wherein

at least one of said measuring units contacts said body surface of the organism and measures the temperature of said body surface.

21. The thermometer according to claim 14, wherein

said storage device is configured to store the surface heat resistance for multiple organisms.

22. The thermometer according to claim 14, wherein

said thermometer main body is configured to be attached to said body surface of an organism.

23. An electronic device having the thermometer according to claim 14.

24. A method for measuring body temperature in a deep area in an organism, comprising:

measuring a first base temperature at a first base temperature measuring position having a first heat resistance from a first body surface of the organism;

measuring a first heat flux at the first base temperature measuring position;

measuring a second base temperature at a second base temperature measuring position having a second heat resistance whose ratio to the first heat resistance is known from a second body surface that is different from the first body surface;

measuring a second heat flux at the second base temperature measuring position; and

calculating a deep-area temperature in the organism using the ratios of the first and second base temperatures, the first and second heat fluxes, and the first and second heat resistance.

25. The body temperature measuring method according to claim 24, wherein

measuring the first heat flux such that the temperature at a first reference temperature measuring position, where the heat resistance from the first body surface is different from the first heat resistance, is measured as the first reference temperature, and the first heat flux is calculated based on the first base temperature, the first reference temperature, and the heat flux value between the first base temperature measuring position and the first reference temperature measuring position, and

measuring the second heat flux such that the temperature at a second reference temperature measuring position, where the heat resistance from the second body surface is different from the second heat resistance, is measured as the second reference temperature, and the second heat flux is calculated based on the second base temperature, the second reference temperature, and the heat flux value between the second base temperature measuring position and the second reference temperature measuring position.

26. The method for measuring body temperature according to claim 24, wherein

the first heat resistance and the second heat resistance have the same value, and

calculating the deep area temperature, the temperature T_core of the deep area is calculated by the formula

$\mathrm{Tcore}=\frac{\{\mathrm{Tb3}·}{}$

(Tb1-Tb2)-α

·

Tb1·

(Tb3-Tb4)}{(Tb1-Tb2)-α

·

(Tb3-Tb4)}

where T_b1 is a first base temperature, T_b2 is a first reference temperature, T_b3 is a second base temperature, T_b4 is a second reference temperature, and α

is the ratio of the heat resistance between the first base temperature measuring position and the first reference temperature measuring position, and the heat resistance between the second base temperature measuring position and the second reference temperature measuring position.

27. A method for measuring body temperature in a deep area in an organism, comprising:

calculating and storing a surface-layer heat resistance from a deep area in the organism to a base temperature measuring position; and

calculating the temperature of the deep area using the surface-layer heat resistance,

calculating and storing the surface-layer heat resistance includes measuring the for-calculation base temperature of the organism, measuring the for-calculation heat flux at the base temperature measuring position, calculating the surface heat resistance from the deep area in the organism to the base temperature measuring position on the basis of the for-calculation deep-area temperature of the deep area in the organism measured at the same time as the for-calculation base temperature and the for-calculation heat flux, and storing the surface heat resistance calculated in the heat resistance calculation step; and

calculating the temperature of the deep area includes the base temperature, measuring the heat flux, and calculating the temperature of the deep area on the basis of the base temperature, the heat flux, and the surface heat resistance stored in the storage step.

28. The method for measuring body temperature according to claim 27, wherein

measuring the heat flux such that the temperature at a reference temperature measuring position, which is different than the base temperature measuring position and has a known heat resistance with respect to the base temperature measuring position, is measured as a reference temperature, and

the heat flux value is calculated based on the base temperature, the reference temperature, and the known heat resistance.

29. A method for measuring body temperature in a deep area of an organism, comprising:

measuring the temperature at positions having mutually different heat resistances from the body surface of the organism;

calculating the relationship between heat resistance and temperature as a temperature distribution by curve approximation using the multiple heat resistances and a plurality of temperatures previously measured; and

calculating the temperature in a deep area of the organism using the temperature distribution calculated in the temperature distribution calculating step.