Ear temperature monitor and method of temperature measurement

• US 7,306,565 B2
• Filed: 07/08/2004
• Issued: 12/11/2007
• Est. Priority Date: 09/15/2000
• Status: Expired due to Fees

• Current Assignee: Advanced Monitors Corporation
• Original Assignee: Advanced Monitors Corporation
• Inventors: Fraden, Jacob, Ferlito, Richard K.
• Primary Examiner(s): Hindenburg, Max F.
• Assistant Examiner(s): Foreman, Jonathan M
• Application Number:
  US10/887,027
• Publication Number:
  US 20040254497A1
• Time in Patent Office: 1,251 Days
• Field of Search: 600/474, 600/549, 600/379, 374/100, 702/130, 702/131
• 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 method for continuous monitoring of the internal temperature of a subject, comprising:

positioning a first temperature sensor relative to a housing fabricated from metal having high thermal conductivity;

thermally attaching a heater to a second temperature sensor and to the housing, the second temperature sensor being positioned within the housing;

thermally insulating the first temperature sensor from the housing, the heater and the second temperature sensor;

securing the housing on a surface of the subject;

measuring the temperature of the surface using the first temperature sensor;

generating heat with the heater at a rate that minimizes a temperature gradient between the first and second temperature sensors; and

computing an internal temperature of the subject using signals from the first and second temperature sensors.

2. A method for continuous monitoring of the internal temperature of a subject, comprising:

positioning a first temperature sensor relative to a housing fabricated from metal having high thermal conductivity;

attaching a second temperature sensor to the housing;

thermally insulating the first temperature sensor from the housing and from the second temperature sensor;

securing the housing on a surface of the subject;

measuring the temperature of the surface using the first temperature sensor; and

computing an internal temperature of the subject using signals from the first and second temperature sensors.

3. The method of claim 2, where computing the internal temperature further comprises determining a temperature gradient between the first and second temperature sensors and subsequently multiplying the gradient by an experimental constant.

4. A temperature sensing device for monitoring an internal temperature of a subject, comprising:

a housing configured to be in contact with a surface of the subject;

a first temperature sensor thermally insulated from said housing and configured to be thermally attached to the subject for detecting a surface temperature of the subject, wherein said housing is fabricated from metal having high thermal conductivity;

a second temperature sensor thermally coupled to said housing;

a thermal insulator positioned between said first temperature sensor and said second temperature sensor; and

an electronic module electronically connected to said first temperature sensor and said second temperature sensor.

5. The device of claim 4, further comprising a heater thermally coupled to said housing and electrically coupled to said electronic module.

6. The device of claim 4, wherein said thermal insulator further comprises an air gap between said first temperature sensor and said second temperature sensor.

7. The device of claim 4, wherein said electronic module further comprises a data transmitter for broadcasting responses of said first temperature sensor and said second temperature sensor.

8. The device of claim 4 further comprising an external monitor coupled to said electronic module and containing a power supply and signal processor for computation of the internal body temperature of the subject.