Radiation clinical thermometer

• US 4,932,789 A
• Filed: 04/10/1989
• Issued: 06/12/1990
• Est. Priority Date: 04/12/1988
• Status: Expired

• Current Assignee: Citizen Watch Co Limited (Citizen Electronics Company Limited)
• Original Assignee: Citizen Watch Co Limited (Citizen Electronics Company Limited)
• Inventors: Yamada, Masato, Egawa, Shunji
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): GUTIERREZ, DIEGO F
• Application Number:
  US07/335,616
• Time in Patent Office: 428 Days
• Field of Search: 374/126, 374/129, 374/121, 374/164, 374/170, 374/128, 374/130, 374/132, 374/133, 374/2, 128/664, 128/736
• US Class Current: 374/126
• CPC Class Codes: G01J 2001/4433 Peak sensing
• CPC Class Codes: G01J 5/02 Constructional details
• CPC Class Codes: G01J 5/026 Control of working procedures of a pyrometer, other than calibration; Bandwidth calculation; Gain control
• CPC Class Codes: G01J 5/0265 Handheld, portable ear thermometers G01J5/049
• CPC Class Codes: G01J 5/04 Casings
• CPC Class Codes: G01J 5/049 Casings for tympanic thermometers
• CPC Class Codes: G01J 5/064 Ambient temperature sensor; Housing temperature sensor; Constructional details thereof
• CPC Class Codes: G01J 5/08 Optical arrangements
• CPC Class Codes: G01J 5/0801 Means for wavelength selection or discrimination
• CPC Class Codes: G01J 5/0818 Waveguides
• CPC Class Codes: G01J 5/0875 Windows; Arrangements for fastening thereof
• CPC Class Codes: G01J 5/16 Arrangements with respect to the cold junction; Compensating influence of ambient temperature or other variables

Abstract

A radiation clinical thermometer includes a probe, a detection signal processing section, a body temperature operating section, and a display unit. A filter correction section for setting a correction value based on the transmission wavelength characteristics of a filter is arranged. The body temperature operating section receives infrared data, temperature-sensitive data, and the correction value from the filter correction section so as to calculate body temperature data.

Claims

1. A radiation clinical thermometer comprising:

a probe including an optical system constituted by focusing means for focusing infrared radiation from an object to be measured and a filter having transmission wavelength characteristics, an infrared sensor for converting infrared radiation energy into an electrical signal, and a temperature-sensitive sensor for measuring a temperature of said infrared sensor and an ambient temperature thereof;

detection signal processing means for receiving electrical signals from said infrared sensor and said temperature-sensitive sensor and outputting the electrical signals as digital infrared data and temperature-sensitive data, respectively;

body temperature operating means for calculating body temperature data; and

a display unit for displaying a body temperature in accordance with the body temperature data, including filter correcting means for setting a correction value based on the transmission wavelength characteristics of said filter, wherein said body temperature operating means receives the infrared data, the temperature-sensitive data, and the correction value from said filter correcting means so as to calculate body temperature data.

2. A thermometer according to claim 1, further comprising sensitivity correction calculating means for receiving the temperature-sensitive data and calculating sensitivity data of said infrared sensor, and wherein said body temperature operating means calculates the body temperature data by receiving the infrared data, the temperature-sensitive data, the correction value from said filter correcting means, and the sensitivity data from said sensitivity correction calculating means.

3. A thermometer according to claim 2, wherein said sensitivity correction calculating means calculates sensitivity data R according to the following equation:

space="preserve" listing-type="equation">R=α

{1+β

(T.sub.0 -T.sub.m)}

where T₀ is sensitivity data of said temperature-sensitive sensor, T_m is a temperature at the time of sensitivity adjustment, α

is a sensitivity at the temperature T_m, and β

is a coefficient of variation of sensitivity.

4. A thermometer according to claim 1, wherein said filter correcting means outputs a symmetrical axis temperature correction value which is used to change a symmetrical axis temperature of a temperature-radiation energy characteristic curve represented by a temperature equation of a higher degree approximated to a temperature-radiation energy characteristic curve based on a Stefan-Boltzmann law.

5. A thermometer according to claim 1, wherein said probe comprises an optical guide for focusing infrared radiation energy, a filter member arranged at one end of said optical guide, an infrared sensor arranged at the other end of said optical guide, and a temperature-sensitive sensor arranged near said infrared sensor, said optical guide, said filter member, said infrared sensor, and said temperature-sensitive sensor being coupled to each other by a metal housing having a high thermal conductivity.

6. A thermometer according to claim 5, wherein said metal housing is an integrally formed housing comprising a cylindrical portion in which said optical guide is inserted and a base portion formed at one end of said cylindrical portion and having a storage recess for housing said infrared sensor and said temperature-sensitive sensor, said optical guide being inserted and fixed in said cylindrical portion, said infrared sensor and said temperature-sensitive sensor being embedded in said storage recess of said base portion with a molding resin.

7. A thermometer according to claim 5, further comprising a second temperature-sensitive sensor for detecting a surface temperature of said optical guide.

8. A thermometer according to claim 7, further comprising said second temperature-sensitive sensor arranged on a surface of said optical guide in tight contact therewith.

9. A thermometer according to claim 7, wherein said detection signal processing section comprises an A/D converter for converting an electrical signal from said second temperature-sensitive sensor into second digital temperature-sensitive data, and said body temperature operating means calculates the body temperature data by using the second temperature-sensitive data as one of input signals.

10. A thermometer according to claim 9, further comprising a temperature difference detector for receiving the temperature-sensitive data from said temperature-sensitive sensor arranged at said base protion of said probe and the second temperature-sensitive data from said second temperature-sensitive sensor, and wherein said temperature difference detector outputs a detection signal when a temperature difference is determined to be smaller than a predetermined measurement limit temperature difference.

11. A thermometer according to claim 10, wherein said display unit comprises a measurement permission mark adapted to be illuminated by the detection signal output from said temperature difference detector.

12. A radiation clinical thermometer comprising:

a probe including an optical means for focusing infrared radiation from an object to be measured, an infrared sensor for converting infrared radiation energy into an electrical signal, and a temperature-sensitive sensor for measuring a temperature of said infrared sensor and an ambient temperature thereof;

detection signal processing means for receiving electrical signals from said infrared sensor and said temperature-sensitive sensor and outputting the electrical signals as digital infrared data and temperature-sensitive data, respectively;

body temperature operating means for calculating body temperature data, and

a display unit for displaying a body temperature in accordance with the body temperature data, characterized by

a zero detector for receiving the infrared data output from said detection signal processing means and determining presence/absence of the infrared data, wherein said zero detector outputs a detection signal when the infrared data is determined to be zero or a small value.

13. A thermometer according to claim 12, further comprising a storage case for storing said radiation clinical thermometer and a reflecting plate arranged in said storage case at a position corresponding to a probe end of said radiation clinical thermometer stored in said storage case.

14. A thermometer according to claim 13, wherein said display unit comprises a measurement permission mark adapted to be illuminated by the detection signal output from said zero detector.

15. A radiation clinical thermometer comprising:

a probe including an optical means for focusing infrared radiation from an object to be measured, an infrared sensor for converting infrared radiation energy into an electrical signal, and a temperature-sensitive sensor for measuring a temperature of said infrared sensor and an ambient temperature thereof;

detection signal processing means for receiving electrical signals from said infrared sensor and said temperature-sensitive sensor and outputting the electrical signals as digital infrared data and temperature-sensitive data, respectively;

body temperature operating means for calculating body temperature data; and

a display unit for displaying a body temperature in accordance with the body temperature data, wherein said detection signal processing means includes a peak holding circuit for holding a peak value of the electrical signal from said infrared sensor as analog data and an A/D converter for converting a peak value voltage held in said peak holding circuit into digital infrared data, and said body temperature operating means calculates the body temperature data by using the infrared data converted from the peak value voltage; and

wherein said probe including a filter having transmission wavelength characteristics and wherein said display unit includes filter correcting means for setting a correction value based on the transmission wavelength characteristics of said filter, wherein said body temperature operating means receives the infrared data, the temperature-sensitive data, and the correction value from said filter correcting means so as to calculate body temperature data.

16. A thermometer according to claim 15 wherein said filter correcting means outputs a symmetrical axis temperature correction value which is used to change a symmetrical access temperature of a temperature-radiation energy characteristic curve represented by a temperature equation of a higher degree approximated to a temperature-radiation energy characteristic curve based on a Stefan-Boltzmann law.

17. A thermometer according to claim 15 wherein said probe includes a filter having transmission wavelength characteristics and wherein said display unit includes filter correcting means for setting a correction value based on the transmission wavelength characteristics of said filter and further comprising sensitivity correction calculating means for receiving the temperature-sensitive data and calculating sensitive data of said infra-red sensor and wherein said body temperature operating means calculates the body temperature data by receiving the infra-red data, the temperature-sensitive data, the correction value from said filter correcting means, and the sensitivity data from said sensitivity correction calculating means.

18. A thermometer according to claim 17, wherein said sensitivity correction calculating means calculates sensitivity data R according to the following equation:

space="preserve" listing-type="equation">R=α

{1+β

(T.sub.0 -T.sub.m)}

where T₀ is sensitivity data of said temperature-sensitive senor, T_m is the temperature at the time of sensitivity adjustment, α

is a sensitivity at the temperature T_m, and β

is a coefficient of variation of sensitivity.

19. A thermometer according to claim 15, wherein said optical means comprises an optical guide, a filter member arranged at one end of said optical guide, said infrared sensor arranged at the other end of said optical guide, and a temperature-sensitive sensor arranged near said infrared sensor, said optical guide, said filter member, said infrared sensor, and said temperature-sensitive sensor being coupled to each other by a metal housing having a high thermal conductivity.

20. A thermometer according to claim 19, wherein said metal housing is an integrally formed housing comprising a cylindrical portion in which said optical guide is inserted and a base portion formed at one end of said cylindrical portion and having a storage recess for housing said infrared sensor and said temperature-sensitive sensor, said optical guide being inserted and fixed in said cylindrical portion, said infrared sensor and said temperature-sensitive sensor being embedded in said storage recess of said base portion with a molding resin.

21. A thermometer according to claim 15, wherein said display unit includes a zero detector for receiving the infrared data output from said detection signal processing means and determining presence/absence of the infrared data, wherein said zero detector outputs a detection signal when the infrared data is determined to a zero or a small value.

22. A thermometer according to claim 15, further comprising a storage case for storing said radiation clinical thermometer and a reflecting plate arranged in said storage case at a position corresponding to a probe end of said radiation clinical thermometer stored in said storage case.

23. A thermometer according to claim 22, wherein said display unit comprises a zero detector and a measurement permission mark adapted to be illuminated by detection signal output from said zero detector.