Electronic thermometer and temperature prediction method therefor

• US 6,439,768 B1
• Filed: 12/27/1999
• Issued: 08/27/2002
• Est. Priority Date: 11/30/1999
• Status: Expired due to Fees

• Current Assignee: Tai DOC Tech Corporation
• Original Assignee: Taidoc Corporation Limited
• Inventors: Jan, Tung-Chuang, Wu, Shu-Mei, Chen, Chao-Wang
• Primary Examiner(s): Gutierrez, Diego
• Assistant Examiner(s): DEJESUS, LYDIA M
• Application Number:
  US09/472,746
• Time in Patent Office: 974 Days
• Field of Search: 374/169, 374/208, 374/102, 702/131
• US Class Current: 374/169
• CPC Class Codes: G01K 7/42 Circuits effecting compensation of thermal inertia; Circuits for predicting the stationary value of a temperature

Abstract

A thermometer having a symmetrical probe with a sensor for sensing temperatures and a processor, a method for calculating temperature of an object by a second-order differential equation comprises the steps of obtaining temperatures from object, performing a first temperature calculation to obtain an initial prediction of temperature of object, adding a compensation coefficient, generating a compensated temperature based on a combination of initial prediction of temperature of object and compensated coefficient, and calculating a stabilized prediction of temperature of object based on compensated temperature before sensor has reached temperature of object. This thermometer can effectively decreasing error during heat transfer process.

Claims

1. An electronic thermometer for determining the temperature of a human body, comprising:

a symmetrically shaped probe having a symmetrical point;

a sensor provided in the symmetrical point in the probe for sensing temperatures of the human body and outputting the sensed temperatures; and

a processor for sampling the sensed temperatures at a plurality of times, performing a first temperature calculation to obtain an initial prediction of temperature, and applying a selected compensation coefficient in a first first-order differential equation (A) to calculate a compensated temperature, and using the calculated compensated temperature in a second first-order differential equation (B) to calculate a final prediction of temperature, wherein;

the compensation coefficient is selected from a plurality of different compensation coefficients, based on a rate of change of the sensed temperatures, different parts of the human body having different compensation coefficients associated therewith; and

the first first-order differential equation (A) comprises a first derivative of each of the sampled sensed temperatures; and

the second first-order differential equation (B) comprises a first derivative of the compensated temperature;

whereby the electronic thermometer calculates a second order prediction of the temperature of the human body based on the compensated temperature before the sensor has reached the temperature of the human body.

2. The electronic thermometer of claim 1, wherein an initial temperature sensed by the sensor comprises room temperature.

3. The electronic thermometer of claim 1, wherein the compensation coefficient is 0.9 to 1.1 in the mouth of the human body.

4. The electronic thermometer of claim 1, wherein the compensation coefficient is 0.7 to 0.9 in the armpit of the human body.

5. The electronic thermometer of claim 1, wherein the compensation coefficient is 0.6 to 0.8 in the anus of the human body.

6. In an electronic thermometer having a probe, a sensor for sensing temperatures, and a processor, a method for calculating the temperature of a human body comprising the steps of:

a) obtaining a plurality of temperatures from the human body;

b) performing a first calculation on the temperatures to obtain an initial prediction of the temperature of the human body;

c) in a first first-order differential equation (A), applying a compensation coefficient selected from a plurality of different compensation coefficients, based on a rate of change of the plurality of temperatures, different parts of the human body having different compensation coefficients associated therewith;

d) generating a compensated temperature based on a combination of the initial prediction of the temperature of the human body and the compensated coefficient; and

e) in a second first-order differential equation (B), calculating a stabilized prediction of the temperature of the human body based on the compensated temperature before the sensor has reached the temperature of the human body.

7. The method of claim 6, wherein the temperatures sensed by the sensor comprise an initial temperature.

8. The method of claim 7, wherein the initial temperature is room temperature.

9. The method of claim 6, wherein the temperatures obtained in the step a) are equally spaced in time from each other.

10. The method of claim 6, wherein the compensation coefficient is a slope of the first-order differential equation.