Continuous temperature monitor

• US 5,653,239 A
• Filed: 09/07/1995
• Issued: 08/05/1997
• Est. Priority Date: 03/08/1991
• Status: Expired due to Term

• Current Assignee: PNC Bank National Association (The PNC Financial Services Group, Inc.)
• Original Assignee: Exergen Corporation
• Inventors: Ternullo, Janus, Malecki, William W., Pompei, Francesco
• Primary Examiner(s): Tucker, Guy V.
• Application Number:
  US08/524,853
• Time in Patent Office: 698 Days
• Field of Search: 128/736, 128/664, 606/109, 381/68, 381/68.6, 381/68.7, 181/130, 181/135, 181/137, 181/129, 374/128, 374/121, 374/129, 374/132, 374/133, 374/208
• US Class Current: 600/474
• 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 5/0818 Waveguides
• CPC Class Codes: G01J 5/0893 Arrangements to attach devices to a pyrometer, i.e. attaching an optical interface; Spatial relative arrangement of optical elements, e.g. folded beam path G01J5/049 takes precedence
• CPC Class Codes: G01J 5/12 using thermoelectric elements, e.g. thermocouples
• CPC Class Codes: G01J 5/16 Arrangements with respect to the cold junction; Compensating influence of ambient temperature or other variables

Abstract

Temperature of a subject is continuously monitored using a remote sensor assembly mounted in a subject'"'"'s ear canal. The remote assembly connects to a display housing which contains the temperature display and supports electronics for responding to the sensed radiation. In one configuration, the major components of the remote assembly include a radiation detector, a plug structure and a flexible extension. The radiation detector has a thermopile and a first temperature sensor in close thermal contact with a thermopile junction. The flexible extension connects the radiation detector with the plug structure. Because the flexible extension bends to the contours of an ear canal, the remote sensor assembly extends well into a subject'"'"'s ear canal without discomfort. The plug structure is molded to fit securely in the concha region of an ear canal and includes a second temperature sensor which senses the temperature therein. Continuous temperature measurements are determined by combining the sensed temperature for the thermopile and the first and second temperature sensors and converting this combined signal to a temperature indication. In another configuration, the remote sensor assembly has a radiation detector and an ear-piece shaped to fit behind the subject'"'"'s ear. The ear-piece replaces the plug structure for this configuration and provides the same functions. The flexible extension connects the radiation detector and the ear-piece. A hollow adapter shaped to fit in the concha region of an ear is positioned over a portion of the extension. The position of the adapter on the extension may be varied such that the depth of penetration of the radiation detector into the ear canal is adjustable.

Claims

1. An ear canal temperature sensor comprising:

a rigid structure of high thermal conductivity material;

a thermopile having a hot junction and a cold junction and mounted to a film suspended across an opening in the rigid structure of high thermal conductivity material;

a window coupled to the rigid structure adjacent to the opening in the rigid structure;

a temperature sensor for sensing the thermopile cold junction temperature coupled to the rigid structure in close thermal contact with the cold junction of the thermopile;

a first layer of non-thermally conductive material covering the rigid structure;

a coating of electrically conductive paint covering the first layer of non-thermally conductive material; and

a second layer of non-thermally conductive material covering the painted first layer of non-thermally conductive material.

2. A tympanic temperature sensor comprising:

a rigid structure of beryllium oxide having a film suspended across an opening in the rigid structure;

a thermopile having a hot junction and a cold junction and mounted on the film to view a tympanic membrane wherein the thermopile senses radiation emitted from a tympanic membrane and provides a first output signal indicative of the temperature of the tympanic membrane;

a thermocouple mounted on the rigid structure and in close thermal contact with the cold junction of the thermopile wherein the thermocouple provides a second output signal indicative of the temperature of the cold junction of the thermopile;

a window located at one end of the opening in the rigid structure and mounted on the rigid structure;

a first layer of non-thermally conductive material surrounding the rigid structure and providing thermal insulation to the rigid structure;

a coating of silver paint covering the first layer of non-thermally conductive material and providing electrical shielding to the rigid structure; and

a second layer of non-thermally conductive material surrounding the silver painted first layer of non-thermally conductive material and providing additional thermal insulation to the rigid structure.

3. A method for monitoring tympanic temperature comprising:

providing a radiation detector adapted to fit into an ear canal and having a thermopile with a hot junction and a cold junction wherein the thermopile is mounted to view a tympanic membrane, a thermocouple having a hot junction and a cold junction wherein the hot junction of the thermocouple is in close thermal contact with the cold junction of the thermopile, a plug structure from which the radiation detector extends into the ear canal and molded to fit in the concha region of an ear, a second temperature sensor mounted within the plug structure, and a flexible extension connecting the radiation detector to the plug structure;

inserting the radiation detector into the ear canal with the plug structure seated in the concha region of the ear;

sensing the tympanic temperature with the thermopile wherein the thermopile generates a first output signal indicative of the temperature of the tympanic membrane;

sensing the cold junction temperature of the thermopile with the thermocouple wherein the thermocouple generates a second output signal indicative of the temperature differential between the cold junction of the thermopile and the plug structure;

sensing the temperature of the plug structure with the second sensor wherein the second sensor generates a third output signal indicative of the temperature in the plug structure;

combining the first, second and third output signals to produce a total output signal; and

converting the total output signal to a tympanic temperature indication.

4. A method for monitoring tympanic temperature as claimed in claim 3 wherein the plug structure comprises electronics for combining the first and second output signals to produce a total output signal.

5. A method for monitoring tympanic temperature as claimed in claim 4 further comprising:

providing electronics located in the plug structure and a remote housing for receiving the total output signal and the third output signal and having a display mounted in the remote housing;

combining the total output signal and the third output signal to produce a combined output signal and converting the combined output signal into a tympanic temperature in the remote housing; and

displaying the tympanic temperature on the display.

6. An ear canal temperature monitor comprising:

a radiation detector mounted to view a tympanic membrane;

an adapter shaped to fit in the concha region of an ear;

an ear-piece shaped to fit behind the ear; and

an extension at least 8 mm in length connecting the radiation detector with the ear-piece;

wherein the adapter is positioned along the extension such that separation between the adapter and the radiation detector is adjustable.

7. An ear canal temperature monitor as claimed in claim 6 wherein the extension is a flexible member which deflects upon insertion to the ear canal to conform to the contours therein.

8. An ear canal temperature monitor as claimed in claim 6 wherein range of separation between the adapter and the radiation detector is from eight to nineteen millimeters.

9. An ear canal temperature monitor as claimed in claim 8 wherein the radiation detector comprises:

a rigid structure of high thermal conductivity material;

a thermopile mounted to a film suspended across an opening in the rigid structure of high thermal conductivity material;

a window mounted on the rigid structure over one end of the opening in the rigid structure; and

a temperature sensor for sensing the cold junction temperature of the thermopile mounted on the rigid structure in close thermal contact with a junction of the thermopile.

10. An ear canal temperature monitor as claimed in claim 6 further comprising a removable plastic sheet stretched over the radiation detector, the extension and the adapter.

11. An ear canal temperature monitor comprising:

a radiation detector which comprises a thermopile with a hot junction and a cold junction wherein the thermopile senses the radiation emitted by a tympanic membrane and provides a first output signal indicative of the temperature of the tympanic membrane and a first temperature sensor which senses the temperature of the cold junction of the thermopile and provides a second output signal indicative thereof;

an adapter shaped to fit in the concha region of an ear;

an ear-piece shaped to fit behind the ear and which comprises electronics for combining the first and second output signals and a second temperature sensor for providing a third output signal indicative of the temperature within the ear-piece;

a flexible extension which conforms to the contours of the ear canal and which fits through the hollow adapter to connect the radiation detector with the ear-piece, wherein the adapter is positioned along the flexible extension such that separation between the adapter and the radiation detector is adjustable with a maximum separation of nineteen millimeters; and

a remote housing unit which comprises additional electronics for combining the first, second and third output signals to produce an ear canal temperature indication.

12. A method for monitoring ear canal temperature comprising:

providing a radiation detector mounted to view a target, a plug structure shaped to fit in the concha region of an ear, an ear-piece having electronics and shaped to fit behind the ear, and a flexible extension which fits through the plug structure and connects the radiation detector and the ear-piece;

inserting the radiation detector into an ear canal wherein the radiation detector views the tympanic membrane, the flexible extension conforming to the contours of the ear canal and the ear-piece fitting behind the ear to prevent the remote assembly from backing out of the ear canal;

sensing the radiation in the ear canal emitted by the tympanic membrane with the radiation detector; and

converting the sensed radiation to ear canal temperature.

13. A method for monitoring ear canal temperature as claimed in claim 12 further comprising adjusting the position of the plug structure on the extension to provide a distance of separation of less than nineteen millimeters between the plug structure and the radiation detector.

14. A method for monitoring the rate of change of ear canal temperature comprising:

providing a radiation detector mounted to view a target, a plug structure shaped to fit in the concha region of an ear, an ear-piece having electronics and shaped to fit behind the ear, and an extension connecting the radiation detector and the ear-piece;

inserting the radiation detector into an ear canal wherein the radiation detector views the tympanic membrane, the extension being shaped to conform to the contours of the ear canal and the ear-piece fitting behind the ear to prevent the remote assembly from backing out of the ear canal;

sensing the radiation in the ear canal emitted by the tympanic membrane with the radiation detector; and

converting the sensed radiation to a rate of change of ear canal temperature.

15. A method for monitoring the rate of change of ear canal temperature as claimed in claim 14 further comprising adjusting the position of the plug structure on the extension to provide a distance of separation of less than nineteen millimeters between the plug structure and the radiation detector.