U.S. patent application number 11/379743 was filed with the patent office on 2007-10-25 for infrared thermometer and probe cover thereof.
This patent application is currently assigned to Sherwood Services AG. Invention is credited to Jeffrey E. Price.
Application Number | 20070248141 11/379743 |
Document ID | / |
Family ID | 38437711 |
Filed Date | 2007-10-25 |
United States Patent
Application |
20070248141 |
Kind Code |
A1 |
Price; Jeffrey E. |
October 25, 2007 |
INFRARED THERMOMETER AND PROBE COVER THEREOF
Abstract
An electronic thermometer having an infrared sensor is of a type
suitable for taking temperature in the mouth of a patient. The
thermometer may view body tissue directly or may have a tip that
rapidly heats to equilibrium with the body tissue temperature. The
tip is viewed by the infrared sensor. A probe cover having a
metallized tip for indirectly measuring temperature is also
disclosed.
Inventors: |
Price; Jeffrey E.;
(Wildwood, MO) |
Correspondence
Address: |
TYCO HEALTHCARE - EDWARD S. JARMOLOWICZ
15 HAMPSHIRE STREET
MANSFIELD
MA
02048
US
|
Assignee: |
Sherwood Services AG
Schaffhausen
CH
|
Family ID: |
38437711 |
Appl. No.: |
11/379743 |
Filed: |
April 21, 2006 |
Current U.S.
Class: |
374/131 |
Current CPC
Class: |
G01J 5/02 20130101; G01J
5/021 20130101; G01J 5/0887 20130101; G01J 2005/068 20130101; G01J
5/0025 20130101; G01J 5/0265 20130101; G01J 5/0022 20130101; G01J
5/08 20130101 |
Class at
Publication: |
374/131 |
International
Class: |
G01J 5/00 20060101
G01J005/00 |
Claims
1. An infrared electronic thermometer for measuring temperature of
an object, the thermometer comprising: a display adapted to show
the temperature measured by the thermometer; an elongate probe
shaft having an interior; an infrared sensor mounted on the shaft
and located on the interior of the probe shaft, the infrared sensor
being operatively connected to the display for electronic
communication between the display at the probe wherein the infrared
sensor is capable of sending a signal indicative of the measured
temperature; a probe tip mounted on the probe shaft generally at a
distal end thereof, the probe tip being adapted to rapidly
equilibrate to a temperature corresponding to the temperature of
the object in thermal contact with the probe tip, wherein the
infrared sensor is disposed for measuring infrared radiation from
the probe tip.
2. An infrared electronic thermometer as set forth in claim 1
wherein the probe tip has a generally concavo-convex shape.
3. An infrared electronic thermometer as set forth in claim 2
wherein the probe tip is generally conical in shape.
4. An infrared electronic thermometer as set forth in claim 1
wherein the probe tip is made of metal.
5. An infrared electronic thermometer as set forth in claim 1
wherein the ratio of the length of the probe to the diameter is at
least about 3.
6. An infrared electronic thermometer as set forth in claim 5
wherein the ratio of the length of the probe to the diameter is at
least about 6.
7. An infrared electronic thermometer as set forth in claim 6
wherein the ratio of the length of the probe to the diameter is at
least about 12.
8. An infrared electronic thermometer as set forth in claim 7
wherein the ratio of the length of the probe to the diameter is
about 18.
9. An infrared electronic thermometer as set forth in claim 1 in
combination with a probe cover sized for reception over the probe
shaft to cover the probe shaft.
10. An infrared electronic thermometer as set forth in claim 9
wherein the probe cover comprises a tubular body and film closing
one end of the tubular body, the film being adapted to stretch over
the probe tip at the distal end of the probe shaft.
11. An infrared electronic thermometer as set forth in claim 9
wherein the probe cover has a target region formed of heat
conductive material positioned for viewing by the infrared sensor
when the probe cover is mounted on the probe shaft.
12. An infrared electronic thermometer as set forth in claim 1
further comprising calculating circuitry operatively connected to
the temperature sensor for receiving the temperature indicative
signal, the calculating circuitry being operable to calculate the
temperature and provide an output to the display to show the
calculated temperature.
13. An infrared electronic thermometer as set forth in claim 12
wherein the calculating circuitry includes a predictive algorithm
for predicting the temperature of the object before the temperature
indicative signal from the temperature sensor reaches steady
state.
14. An infrared electronic thermometer as set forth in claim 12
wherein the calculating circuitry is calibrated to convert measured
temperature of the probe tip to actual temperature of the
object.
15. A non-tympanic electronic thermometer for measuring temperature
of an object, the thermometer comprising: a display adapted to show
the temperature measured by the thermometer; a probe including an
elongate probe shaft having an interior and a probe tip at a distal
end of the shaft, the probe shaft having a ratio of length to
diameter of at least about 3; an infrared radiation sensor adapted
to receive infrared radiation and to provide a signal indicative of
the temperature of the object, the temperature sensor being in
operative electronic communication with the display for sending the
temperature indicative signal to the display.
16. A non-tympanic electronic thermometer as set forth in claim 15
wherein the length to diameter ratio of the probe shaft is at least
about 6.
17. A non-tympanic electronic thermometer as set forth in claim 16
wherein the length to diameter ratio of the probe shaft is at least
about 12.
18. A non-tympanic electronic thermometer as set forth in claim 17
wherein the length to diameter ratio of the probe shaft is about
18.
19. A non-tympanic electronic thermometer as set forth in claim 15
wherein the temperature sensor is adapted to detect infrared
radiation.
20. A non-tympanic electronic thermometer as set forth in claim 19
wherein the temperature sensor comprises a thermopile.
21. A non-tympanic electronic thermometer as set forth in claim 20
further comprising a waveguide positioned in the probe shaft for
guiding infrared radiation from the distal end of the probe shaft
to the thermopile.
22. A non-tympanic electronic thermometer as set forth in claim 21
wherein the probe tip comprises a lens for directing infrared
radiation into the waveguide.
23. A non-tympanic electronic thermometer as set forth in claim 15
in combination with a probe cover sized for reception over the
probe shaft to cover the probe shaft.
24. A non-tympanic electronic thermometer as set forth in claim 23
wherein the probe cover comprises a tubular body and an end film
mounted on the tubular body and closing one end thereof.
25. A non-tympanic electronic thermometer as set forth in claim 24
wherein the end film has a target region formed of heat conductive
material positioned for viewing by the infrared sensor when the
probe cover is mounted on the probe shaft.
26. A non-tympanic thermometer as set forth in claim 25 wherein the
target region is formed of metal.
27. A non-tympanic thermometer as set forth in claim 25 wherein the
target region occupies less than an entire area of the end
film.
28. A non-tympanic thermometer as set forth in claim 15 further
comprising a calculating unit operatively connected to the
temperature sensor for receiving the temperature indicative signal,
the calculating unit being operable to calculate the temperature
and provide an output to the display to show the calculated
temperature.
29. A non-tympanic thermometer as set forth in claim 28 wherein the
calculating unit includes a predictive algorithm for predicting the
temperature of the object before the temperature indicative signal
from the temperature sensor reaches steady state.
30. A method of indirect measurement of temperature of an object
comprising: placing a probe of an electronic thermometer including
a probe tip in contact with the object; allowing heat transfer from
the object to rapidly heat up the probe tip to an equilibrium
temperature; sensing infrared radiation from the tip with a sensor
sealed in a probe shaft of the probe; generating a signal
corresponding to the temperature of the probe tip detected by the
sensor; communicating the signal from the sensor to a display of
the electronic thermometer; showing the detected temperature on the
display.
31. A method as set forth in claim 30 further comprising sheathing
the probe in a probe cover.
32. A method as set forth in claim 31 wherein sheathing the probe
comprises moving a generally tubular probe cover body over the
probe to a position in which a thermally conductive film at the
distal end of the probe cover is stretched over the probe tip.
33. A method as set forth in claim 30 wherein sensing infrared
radiation comprises directly viewing the probe tip with an infrared
sensor located in the probe.
34. A method as set forth in claim 30 wherein the step of
communicating the signal comprises processing a signal generated by
the sensor and sending a processed signal to the display.
35. A method as set forth in claim 34 wherein the step of
processing the signal includes converting the signal generated by
the sensor according to a predetermined calibration factor from a
temperature of the probe tip to a temperature of the object.
36. A method as set forth in claim 34 wherein processing the signal
comprises employing a predictive algorithm to predict the
temperature of the object prior to the signal from the sensor
achieving a steady state.
37. A probe cover for an infrared electronic thermometer comprising
a generally tubular body having an open end and a closed end, the
body being sized and shaped to receive a probe of the infrared
electronic thermometer into the body through the open end, the body
including a blackbody portion at said closed end of the body, the
blackbody portion being formed of a material that rapidly
equilibrates to a temperature corresponding to the temperature of
an object for viewing by a sensor of the electronic thermometer to
measure the temperature of the object.
38. A probe cover as set forth in claim 37 wherein the material of
the blackbody portion is different than the material of the
remainder of the tubular body.
39. A probe cover as set forth in claim 38 wherein the blackbody
portion material is a metal.
40. A probe cover as set forth in claim 38 further comprising a
film member wherein the blackbody portion is defined by metal
deposited on the film.
41. A probe cover as set forth in claim 40 wherein the blackbody
portion is located in a central region of the film member.
Description
FIELD OF THE INVENTION
[0001] The present invention generally relates to a thermometer and
more specifically to an infrared thermometer that is suitable for
oral body temperature measurement.
BACKGROUND OF THE INVENTION
[0002] Electronic thermometers are widely used in the healthcare
field for measuring a patient's body temperature. Typical
electronic thermometers have the form of a probe with an elongated
shaft. Electronic temperature sensors such as thermistors or other
temperature sensitive elements are contained within the shaft
portion. In one version, the probe includes a cup-shaped aluminum
tip at its distal end. A thermistor is placed in thermal contact
with the aluminum tip inside the probe. When a distal end portion
is placed, for example, in a patient's mouth, the tip is heated up
by the patient's body and the thermistor measures the temperature
of the tip. Additional electronics connected to the electronic
sensor components may be contained within a base unit connected by
wire to the shaft portion or may be contained within a handle of
the shaft portion, for example. Electronic components receive input
from the sensor components to compute the patient's temperature.
The temperature is then typically displayed on a visual output
device such as a seven segment numerical display device. Additional
features of known electronic thermometers include audible
temperature level notification such as a beep or tone alert signal.
A disposable cover or sheath is typically fitted over the shaft
portion and disposed after each use of the thermometer for sanitary
reasons.
[0003] Electronic thermometers have many advantages over
conventional thermometers and have essentially replaced the use of
conventional glass thermometers in the healthcare field. One
advantage of electronic thermometers over their conventional glass
counterparts is the speed at which a temperature reading can be
taken. Several procedures are used to promote a rapid measurement
of the subject's temperature. One technique employed is to use
predictive algorithms as part of thermometer logic to extrapolate
the temperature measurements from the thermistor in contact with
the tip to arrive at a temperature reading in advance of the tip
reaching equilibrium with the body temperature. Another technique
that can be employed simultaneously with a predictive algorithm is
to heat the probe to near the body temperature so that part of the
probe away from the tip does not act as a heat sink, allowing the
tip to reach a temperature close to the body temperature more
rapidly. Heating can be accomplished by a thermistor placed in
contact with the probe. Another thermistor may be placed in contact
with the probe to measure the amount the resistor is heating the
probe, which is used to control the heating. It is also known to
use an isolator to reduce heat loss from the tip to other parts of
the probe.
[0004] It would be desirable to improve further upon the
conventional electronic thermometer. In particular, the electronic
thermometer is challenging to assemble because of the various small
components that must be placed in the probe. Moreover, although the
electronic thermometer quickly provides a body temperature
measurement, particularly as compared to conventional glass
thermometers, additional speed would be desirable. Moreover in
order to obtain the temperature quickly, the probe is heated, which
causes a power drain on the batteries. Still further, rapid
temperature measurement also relies upon the use of predictive
algorithms that add to the complexity of the thermometer.
SUMMARY OF THE INVENTION
[0005] In one aspect of the present invention, an infrared
electronic thermometer for measuring temperature of an object
generally comprises a display adapted to show the temperature
measured by the thermometer and an elongate probe shaft having an
interior. An infrared sensor mounted on the shaft and located on
the interior of the probe shaft is operatively connected to the
display for electronic communication between the display and the
probe. The infrared sensor is capable of sending a signal
indicative of the measured temperature. A probe tip mounted on the
probe shaft generally at a distal end thereof is adapted to rapidly
equilibrate to a temperature corresponding to the temperature of
the object in thermal contact with the probe tip. The infrared
sensor is disposed for measuring infrared radiation from the probe
tip.
[0006] In another aspect of the present invention, a non-tympanic
electronic thermometer for measuring temperature of an object
generally comprises a display adapted to show the temperature
measured by the thermometer. A probe includes an elongate probe
shaft having an interior and a probe tip at a distal end of the
shaft. The probe shaft has a ratio of length to diameter of at
least about 3. An infrared radiation sensor is adapted to receive
infrared radiation and to provide a signal indicative of the
temperature of the object. The temperature sensor being in
operative electronic communication with the display for sending the
temperature indicative signal to the display.
[0007] In yet another aspect of the present invention, a method of
indirect measurement of temperature of an object generally
comprises placing a probe of an electronic thermometer including a
probe tip in contact with the object. Heat transfer from the object
to the probe tip to rapidly heat up the probe tip to an equilibrium
temperature is allowed and infrared radiation from the tip is
sensed with a sensor sealed in a probe shaft of the probe. A signal
corresponding to the temperature of the probe tip detected by the
sensor is generated. The signal is communicated the sensor to a
display of the electronic thermometer. The detected temperature is
shown on the display.
[0008] In still another aspect of the present invention, a probe
cover for an infrared electronic thermometer generally comprises a
generally tubular body having an open end and a closed end. The
body is sized and shaped to receive a probe of the infrared
electronic thermometer into the body through the open end. The body
includes a blackbody portion at said closed end of the body. The
blackbody portion is formed of a material that rapidly equilibrates
to a temperature corresponding to the temperature of an object for
viewing by a sensor of the electronic thermometer to measure the
temperature of the object.
[0009] Other objects and features will be in part apparent and in
part pointed out hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective of an infrared electronic
thermometer;
[0011] FIG. 1A is a diagrammatic representation of the
thermometer;
[0012] FIG. 2 is a perspective of a probe of the thermometer;
[0013] FIG. 2A is a schematic perspective showing the probe as
received in a patient's mouth;
[0014] FIG. 3 is a schematic, fragmentary elevation of internal
components of the probe showing a configuration of a first
embodiment;
[0015] FIG. 4 is a schematic, fragmentary elevation of a probe of a
second embodiment;
[0016] FIG. 5 is a perspective of a probe cover;
[0017] FIG. 6 is an enlarged, fragmentary elevation similar to FIG.
4 but showing the probe cover on the probe;
[0018] FIG. 7 is an enlarged, fragmentary elevation similar to FIG.
4 but showing a probe and probe cover of a third embodiment,
and
[0019] FIG. 8 is a schematic, fragmentary elevation of internal
components of the probe showing a configuration of a fourth
embodiment.
[0020] Corresponding reference characters indicate corresponding
parts throughout the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Referring now to the drawings, and in particular to FIGS. 1
and 2, an electronic thermometer constructed according to the
principles of the present invention is indicated generally at 1.
The electronic thermometer comprises a temperature calculating
unit, indicated generally at 3, that is sized and shaped to be held
comfortably in the hand H. The calculating unit 3 (broadly, "a base
unit") is connected by a helical cord 5 to a probe 7 (the reference
numerals indicating their subjects generally). It will be
appreciated that calculation electronics could be incorporated into
the probe so that a separate base unit and connection cord could be
omitted. The probe 7 is constructed for contacting the subject
(e.g., a patient) and sending signals to the calculating unit 3
representative of the temperature. The calculating unit 3 receives
the signals from the probe 7 and uses them to calculate the
temperature. Suitable circuitry, such as a programmable
microcontroller 8, for performing these calculations is contained
within a housing 9 of the calculating unit 3. The circuitry makes
the calculated temperature appear on a LCD display 11 on the front
of the housing 9. The microcontroller 8 in the calculating unit 3
can be calibrated to convert the temperature signal from the probe
7 to the temperature of the object being measured. In the
illustrated embodiment, a direct temperature measurement is made.
However, it will be understood that the microcontroller 8 could
include predictive software to provide a temperature reading for
exhibition on the display 11 prior to the temperature signal output
from the probe 7 to the microcontroller becoming steady state.
Other information desirably can appear on the display 11, as will
be appreciated by those of ordinary skill in the art. A panel 11A
of buttons for operating the thermometer 1 is located just above
the display 11.
[0022] The housing 9 includes a compartment (not shown) generally
at the rear of the housing that can receive a distal portion of the
probe 7 into the housing for holding the probe and isolating the
distal portion from the environment when not in use. FIG. 1
illustrates the probe 7 being pulled by the other hand H1 from the
compartment in preparation for use. The housing 9 also has a
receptacle 13 that receives a suitable container such as a carton C
of probe covers 12 (see, FIG. 2). In use, the top of the carton C
is removed, exposing open ends of the probe covers. The distal
portion of the probe 7 can be inserted into the open end of the
carton C and one of the probe covers 12 can be releasably secured
in an annular recess 14. Pushers 15 are located at the junction of
a handle 17 of the probe 7 with a probe shaft 19. The probe shaft
is protected from contamination by the cover 12 when the distal
portion of the probe shaft 19 is inserted, for example, into a
patient's mouth (FIG. 2A). In order to be used for insertion into
the mouth or other larger cavity (e.g., the rectum), the probe
shaft 19 is relatively long and thin. For example in one
embodiment, the ratio of the length of the probe shaft to its
diameter is at least about three, in another embodiment, the ratio
is at least about six, in a yet another embodiment, the ratio is at
least about twelve, and in still another embodiment the ratio is
about eighteen. The length of the probe shaft is measured from
where it exits the probe handle 17 above the recess 14 to its
distal end from which the metal tip 29 projects. The diameter of
the probe shaft 19 is generally constant along its length, but an
average or median diameter might be used to calculate the ratio of
length to diameter of a non-constant diameter probe shaft. A button
21 on the probe handle 17 can be depressed to cause the pushers 15
to move forward for releasing the probe cover 12 from the probe
shaft 19. Subsequent to use, the probe cover 12 is discarded. Other
ways of capturing and releasing probe covers may be used without
departing from the scope of the present invention.
[0023] One aspect of the present invention is directed to a
temperature sensing arrangement that senses infrared radiation to
acquire the body temperature (FIG. 2A). Although the preferred
embodiments of the present invention are for acquisition of body
temperature, it will be understood that the principles of the
present invention may be applied to measure the temperature of an
"object," be it a living being or otherwise. Moreover, the object
being measured may be solid, liquid or gas. In a first embodiment
illustrated in FIG. 3, the internal components of the probe 7
include a temperature sensor 25, a waveguide 27 and a conical metal
tip 29 (the reference numerals indicating their subjects
generally). In the illustrated embodiments, the tip 29 is made of
aluminum, but other materials (including non-metals) may be used
within the scope of the present invention. These components are
supported by the probe shaft 19 (not shown in FIG. 3). The metal
tip 29 is mounted on a distal end of the probe shaft 19 and is
heated up by contact with tissue in the mouth. The metal tip 29 has
a high thermal conductivity, low heat capacity and low mass, and a
shape selected to warm rapidly to the temperature of the body
tissue in thermal contact with the tip. The conical shape of the
tip 29 improves its emissivity and reduces reflection of infrared
radiation. Infrared radiation emitted from the heated metal tip 29
is received into the waveguide 27 that has a reflective material
(e.g., a layer of gold) on its interior. The waveguide 27 transmits
the infrared radiation with minimal losses along its length to a
proximal end where it impinges upon the temperature sensor 25. The
temperature sensor comprises a thermoelectric effect sensor in the
form of a thermopile 31 positioned adjacent to the proximal end of
the waveguide 27. It will be understood that other thermoelectric
effect sensors (not shown), such as pyroelectric sensors,
microbolometers or other sensors that do not employ the
thermoelectric effect may be used without departing from the scope
of the present invention.
[0024] The thermopile 31 emits a voltage corresponding to the
temperature of the "hot junction" relative to the "cold junctions".
It includes a plurality of individual thermocouples (not shown)
connected in series. Each thermocouple has a cold junction and a
hot junction. See, U.S. Pat. No. 4,722,612 of Junkert et al. issued
Feb. 2, 1988. The hot junction is typically formed by a small
blackbody ("a target area") onto which the infrared radiation is
directed. The blackbody rapidly heats to a temperature
corresponding to the temperature of the object radiating the
infrared radiation. The thermopile 31 generates an analog output
signal (voltage) representative of the amount of infrared radiation
that impinges thereon. The illustrated embodiment of the present
invention is designed to sense infrared radiation emitted by the
metal tip 29, which is related to the temperature of the biological
surface tissue in the mouth of a human body. It is to be understood
that a thermometer incorporating the principles of the present
invention could be used to measure the temperature of tissue at
other locations on the body (e.g., in the rectum, axilla, etc.)
within the scope of the present invention.
[0025] The temperature sensor 25 further includes a second sensor
secured to the thermopile 31 in a suitable manner or incorporated
into the thermopile. The second sensor generates an analog output
signal (resistance) representative of the temperature of the
thermopile 31. One sensor suitable for this purpose is a thermistor
33. The second sensor or thermistor 33 is sometimes referred to as
the ambient sensor because it effectively measures the ambient
temperature of the room in which the thermometer 1 is being used,
and thus the temperature of the thermopile 31. In the illustrated
embodiment, it is necessary to know the temperature of the
thermopile 31 in determining the actual body temperature from its
output signals. The temperature sensor 25 is preferably sealed
within the probe shaft 19. The probe cover 12 is received over the
metal tip 29 and probe shaft 19 in use of the thermometer. The
probe cover 12 fits over the distal end of the probe 7 and is
releasably held on the probe shaft 19 by the annular recess 14. The
probe cover 12 is described in more detail hereinafter with respect
to a second embodiment of the thermometer.
[0026] A tubular waveguide 27 is placed in proximity with the
viewing aperture of the thermopile 31. It is preferable that the
waveguide 27 be brass or copper with the inside diameter plated
with gold to achieve the highest possible reflectivity in the
infrared region of the spectrum, i.e. a wavelength of 8-12
microns.
[0027] Referring now to FIG. 4, a probe of a second embodiment
(indicated generally at 107) is shown to comprise a probe shaft 119
and a metal tip 129 mounted in a distal end of the probe shaft
(only a fragmentary portion of which is shown). Parts of the probe
107 corresponding to those of the probe 7 of the first embodiment
are given the same reference numeral, plus "100". Unlike the probe
7 of the first embodiment, there is no waveguide 27, and a
temperature sensor 125 is mounted by a collar 126 within the probe
shaft 119 near the distal end of the probe shaft. Thus, infrared
radiation emitted from the metal tip 129 is seen directly by a
thermopile (not shown) of the temperature sensor 125 and is not
transmitted by any intervening structure (e.g., a waveguide) to the
temperature sensor. The cone-shaped field of vision FV of the
thermopile is illustrated in FIG. 4, and is equal to the width of
the base of the metal tip 129 where the field of vision intersects
the base of the metal tip. In order to isolate sensor 125 from heat
in the oral cavity, the sensor is placed as far away from the
distal end of the probe 107 as possible. In that case, sensor 125
would have a narrow field of vision so that it sees only the tip
129. Thus, the thermopile is able to see the entire metal tip 129.
An example of suitable arrangement of the temperature sensor 125
near the distal end of a probe in the tympanic thermometer context
is shown in co-assigned U.S. patent application Ser. No.
10/480,428, filed Dec. 10, 2003, the disclosure of which is
incorporated herein by reference. A similar arrangement may be used
here. Wires 128 from the temperature sensor 125 extend through the
probe shaft 119 to its handle (not shown). A flex circuit (not
shown) or other suitable electrical connection structure may be
used.
[0028] Referring now also to FIGS. 5 and 6, a probe cover generally
indicated at 112 for covering the probe shaft 119 in use to prevent
contamination and reduction or loss of operability (e.g., by
saliva) upon insertion into the mouth. The probe cover 112 includes
a tubular body 116 of and a stretchable film 118 closing one end of
the tubular body. The film 118 can be constructed, for example,
from a lower density plastic (e.g., low density polyethylene
(LDPE)), while the body 116 is constructed from a higher density
plastic (e.g., high density polyethylene (HDPE)). As shown in FIG.
5 prior to placement on the probe shaft 119, the film 118 extends
generally perpendicularly across the end of the tubular body. When
applied over the probe shaft 119, the film 118 engages and is
stretched over the metal tip 129 of the probe shaft. Thus, the film
118 closely conforms to the shape of the exterior surface of the
metal tip 129 when the probe cover 112 is mounted on the probe
shaft 119. Thus, conductive heat transfer from the body tissue
through the film 118 to the metal tip 129 is facilitated.
[0029] A third embodiment of the probe 207 is shown in FIG. 7 to
comprise a probe shaft 219 and a temperature sensor 225 mounted
near the distal end of the probe shaft similar to the embodiment of
FIGS. 4-6. Parts of the probe 207 corresponding to those of the
probe 107 will be given the same reference numeral, plus "100". In
the third embodiment, the metal tip 125 is omitted. Instead, the
probe shaft 219 has a transparent window 220 closing off its distal
end. For purposes of the present invention, the window 220 need
only be transparent to infrared radiation. In other respects, the
construction of the probe 207 can be the same as the probe 107 of
the second embodiment.
[0030] A probe cover 212 of the third embodiment includes a tubular
body 216 and film 218 closing the distal end of the body. The
tubular body 216 has spacers 221 (two of which are shown) on its
interior that engage and space the tubular body from the probe
shaft 219. The spacers 221 may have other configurations, different
in number or may be omitted without departing from the scope of the
present invention. When fully seated on the probe 207, the probe
cover film 218 (unlike the first two embodiments) does not engage
the end of the probe shaft 219, but is spaced axially from the end
of the probe shaft. A central region 222 of the film has metal
deposited on it. It is to be understood that the metal deposit need
not be located in or confined to a central region. For example, the
entire film may be metallized. The metal central region 222
replaces the metal tip 29, 129 of the prior two embodiments. The
field of vision of the thermopile (not shown) of the temperature
sensor 225 encompasses the central region 222. The central region
can be formed by other materials having high thermal conductivity,
low heat capacity and low mass.
[0031] Components of a probe of a fourth embodiment are show in
FIG. 8 to comprise a temperature sensor 325, a waveguide 327 and a
lens 328. The probe of the fourth embodiment generally corresponds
to the probe 7 of the first embodiment in that both have a
waveguide (27 and 327). Parts of the probe of the fourth embodiment
corresponding to parts of the probe 7 of the first embodiment will
be given the same reference numerals, plus "300". In the fourth
embodiment, infrared radiation from body tissue (e.g., tissue
inside the mouth) is focused by the lens into the waveguide 327.
The waveguide conducts the infrared radiation to the temperature
sensor 325 in substantially the same way as the waveguide 27 of the
first embodiment. Thus in the fourth embodiment the temperature
sensor 325 directly views the body tissue, not any intermediate
structure such as a metal tip.
[0032] When introducing elements of the present invention or the
preferred embodiments(s) thereof, the articles "a", "an", "the" and
"said" are intended to mean that there are one or more of the
elements. The terms "comprising", "including" and "having" are
intended to be inclusive and mean that there may be additional
elements other than the listed elements.
[0033] In view of the above, it will be seen that the several
objects of the invention are achieved and other advantageous
results attained.
[0034] As various changes could be made in the above thermometers
and methods of their use without departing from the scope of the
invention, it is intended that all matter contained in the above
description and shown in the accompanying drawings shall be
interpreted as illustrative and not in a limiting sense.
* * * * *