Ear temperature monitor and method of temperature measurement

• US 20020035340A1
• Filed: 08/08/2001
• Published: 03/21/2002
• Est. Priority Date: 09/15/2000
• Status: Active Grant

• Current Assignee: Advanced Monitors Corporation
• Original Assignee: Advanced Monitors Corporation
• Inventors: Fraden, Jacob, Ferlito, Richard K.
• Granted Patent: US 6,773,405 B2
• Time in Patent Office: Days
• US Class Current: 600/549
• CPC Class Codes: A01K 29/005 Monitoring or measuring activity, e.g. detecting heat or mating
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/6817 Ear canal
• CPC Class Codes: G01K 1/165 for application in zero heat flux sensors
• CPC Class Codes: G01K 13/022 Suction thermometers
• CPC Class Codes: G01K 13/20 Clinical contact thermometers for use with humans or animals

Abstract

A continuous body core temperature monitor comprises a pliable ear plug that conforms to the shape of an ear canal and incorporates a temperature sensor that is clamped between the plug and the ear canal wall. The external surface of the plug is connected to an external temperature sensor and a heating element that compensate for a heat lost from the ear canal to the environment by maintaining the temperature gradient between the temperature sensor and the heating element close to zero.

Claims

1. A temperature sensing device for monitoring internal temperature of a subject, containing in combination

enclosure for maintaining all components in a mutually stable position;

at least one temperature transducer, thermally attached to said subject for monitoring its surface temperature;

external temperature sensor for measuring temperature of said enclosure;

thermal insulator positioned between temperature transducer and external temperature sensor;

electronic module connected to said temperature transducer and external temperature sensor,

2. A device of claim 1, wherein said enclosure further incorporates a heater which is thermally coupled to said external temperature sensor and electrically coupled to said electronic module.

3. A device of claim 1, wherein said enclosure is comprised of two sections with a first section being a plug and the second section being a disk, wherein said plug is made of a pliable insulating material, incorporating said temperature transducer, while disk is shaped for securing said device on a subject and incorporates said electronic module and external temperature sensor.

4. A device of claim 1, wherein said insulating material has a near-cylindrical shape before insertion into a subject'"'"'s body cavity.

5. A device of claim 1, wherein said insulating material is fabricated in form of a flexible fork that may be compressed before insertion into object'"'"'s cavity and expanded afterwards.

6. A device of claim 1, wherein said thermal insulator is an air gap;

7. A device of claim 1, wherein said thermal insulator is fabricated of compressible foam that may be collapsed and expanded in response to application of external pressure;

8. A device of claim 7, further comprises a sleeve that maintains foam in a compressed state before attaching to said subject.

9. A device of claim 1, wherein said electronic module contains data transmitter for broadcasting responses of said temperature transducer and external temperature sensor.

10. A device of claim 1 further contains an external monitor that is coupled to said electronic module and contains a power supply and signal processor for computation of subject'"'"'s internal body temperature.

12. A method of claim 8 where securing a measuring device involves compression of plug before insertion into a body cavity;

13. A method of claim 8 where computing of subject'"'"'s temperature involves determination of temperature gradient between temperature transducer and heater and a subsequent multiplication of the difference by an experimental constant.

11. A method for continuous monitoring of the internal temperature of a subject, said method comprising the steps of:

securing a measuring device on a subject surface;

measuring subject'"'"'s surface temperature by a temperature transducer;

insulating temperature transducer from a heater that is attached to a measuring device;

measuring temperature of a heater;

generating heat by a heater at a rate that minimizes a temperature gradient between a measuring device and a temperature transducer;

computing subject'"'"'s internal body temperature from signals measured by a temperature transducer and temperature of a heater.

15. A method of claim 14, wherein said transmitting includes transmission of electromagnetic radiation

16. A method of claim 14, wherein said computing involves multiplication of a temperature gradient between temperature transducer and external temperature sensor and subsequent multiplication of said gradient by an experimentally determined constant.

14. A method for continuous monitoring of the internal temperature of a subject, said method comprising the steps of:

securing a measuring device on a surface or inside the subject body cavity;

measuring subject'"'"'s surface temperature by a temperature transducer;

measuring external temperature by an external temperature sensor;

transmitting signals from the external temperature sensor and temperature transducer to a signal processor;

computing subject'"'"'s by a signal processor by using signals received from the external temperature sensor and temperature transducer.

17. A method of securing a transducer inside a body cavity by incorporating said transducer into a compressible plug, comprising steps of:

applying external pressure to said plug so that plug changes its shape toward reducing its outer dimensions;

insertion of a compressed plug into said cavity;

waiting until plug expands and adapts to the shape of said cavity.