Arrangement for measuring the body temperature of a living organism

• US 20060173375A1
• Filed: 01/26/2006
• Published: 08/03/2006
• Est. Priority Date: 02/03/2005
• Status: Active Grant

• Current Assignee: Draeger Safety AG and Co KGaA (Draegerwerk AG & Co KGaA)
• Original Assignee: Draeger Safety Incorporated (FPS Vermögensverwaltung GmbH)
• Inventors: Koch, Jochim
• Granted Patent: US 7,299,090 B2
• Time in Patent Office: Days
• US Class Current: 600/549
• 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 13/20 Clinical contact thermometers for use with humans or animals
• 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

Abstract

An arrangement for measuring the body temperature of a living organism includes a sensor housing containing a first temperature sensor for measuring the skin temperature of the living organism, a second temperature sensor and an evaluation unit. The first temperature sensor is placed on the skin of the body and the second temperature sensor is arranged thermally insulated on the side of the first temperature sensor facing away from the skin and is at a spacing relative to the first temperature sensor. The evaluation unit computes the body temperature in accordance with a pregiven temperature formula which contains a temperature difference from the temperatures measured by the first temperature sensor and the second temperature sensor. A compensation unit is provided in such a manner that a lost heat flow (q_sa) is considered which occurs during the measurement operation.

Claims

1. An arrangement for measuring the body temperature of a living organism, the arrangement comprising:

a housing;

a first sensor mounted in said housing and disposed in contact engagement with the skin of the living organism for measuring a first temperature;

a second sensor mounted in said housing for measuring a second temperature;

said first sensor having a side facing away from said skin;

said second sensor being mounted at a distance from said side of said first sensor;

insulating means disposed between said first and second sensors for thermally insulating said first and second sensors from each other and conducting a main thermal flow therebetween from which a thermal loss flow (q_sa) branches off while measuring said body temperature;

compensation means for determining or estimating said thermal loss flow (q_sa); and

,

an evaluation unit operatively connected to said compensation means so as to permit consideration of said thermal loss flow (q_sa) thereby increasing the accuracy of the measurement of said body temperature.

2. The arrangement of claim 1, wherein said evaluation unit determines said body temperature with the aid of a formula and said compensation means is a compensation term which expands said formula.

3. The arrangement of claim 2, wherein said housing has an outer wall;

and, said compensation term is dependent upon at least one of a boundary temperature (t_sa) at said outer wall of said housing and a thermal conductance (α

) between said housing and the ambient (U).

4. The arrangement of claim 3, said housing having an outer wall;

and, said arrangement further comprising a third sensor mounted in the region of said outer wall for measuring said boundary temperature and said compensation term being formed in dependence upon said boundary temperature (t_sa) measured by said third sensor.

5. The arrangement of claim 4, said first sensor and said second sensor conjointly defining an imaginary connecting line therebetween and said third sensor being mounted in a side region laterally of said connecting line.

6. The arrangement of claim 3, wherein said compensation term is formed exclusively by coupling of constant parameters (K_iso, K_g, A_iso, A_s, α

, K_s) and the skin temperature (T_h1) measured by said first sensor and the further temperature (T_h2) measured by said second sensor.

7. The arrangement of claim 6, wherein said housing has an outer wall;

said constant parameter (α

) is a thermal conductance constant (α

) representing the thermal conductance between said outer wall of said housing and the ambient (U); and

, said compensation term is dependent upon said thermal conductance constant (α

).

8. The arrangement of claim 6, wherein said boundary temperature (t_sa) is computed from a boundary temperature formula in dependence upon constant parameters (α

, K_s, K_iso) and in dependence upon said skin temperature (T_h1) measured by said first temperature sensor and said further temperature (T_h2) measured by said second temperature sensor.

9. The arrangement of claim 6, wherein said thermal conductance constant (α

) is assigned a value in a range of 10 W/m² K to 30 W/m² K.