EXERGEN
TemporalScanner TM
A kinder, gentler way to take temperature
Reference Manual
Models LXTA/TAT-5000 and TAT-4000
1
Product Map
Product Map
Probe Cone
Probe Lens
ON Button
Automatic turn-off
in 15 seconds
LED Display Screen
Battery Compartment
9-volt battery
Battery Compartment Door
9-Volt Battery
Compartment Door Screw
2
Introduction to Temporal Artery Thermometry
Introduction
Method
The Method
Temporal artery thermometry (TAT) is a completely new method of temperature assessment,
using infrared technology to detect the heat naturally emitting from the skin surface. In addi-
tion, and of key importance, the method incorporates a patented arterial heat balance system
to automatically account for the effects of ambient temperature on the skin.
This method of temperature assessment has been shown to improve results and reduce costs
by non-invasively measuring body temperature with a degree of clinical accuracy unachievable
with any other thermometry method.
Temperatures are more reliable than with other methods. Fevers are identified sooner. Treat-
ment can be initiated sooner. We trust you will find temporal artery thermometry is simply a
better method.
Why the Temporal Ar tery
Why Tem
emporal Artery
The TAT method was developed in response to the clinical requirements for a truly non-inva-
sive, accurate method of thermometry. Oral thermometry is subject to many artifactual errors;
rectal temperature meets with strong resistance from patients, parents, and even many clini-
cians. Ear thermometers, although convenient, are sensitive to technique. Some brands are
known to miss fevers, and its difficult to consider the use of an aural thermometer when 95%
of pediatric visits concern ear infections.
A site for detecting fevers with roots dating back to centuries before Christ, the temporal artery
demonstrated the necessary requirements to meet the stringent demands of clinical medicine
today: it is easily accessible, contains no mucous membranes, and notably, maintains a rela-
tively constant perfusion rate, ensuring the stability of blood flow required for the measure-
ment method.
As a site for temperature measurement, the temporal artery presents many benefits: it poses
no risk of injury for patient or clinician, eliminates any need for disrobing or unbundling, and is
suitable for all ages.
3
Table of Contents
Table of Contents
Page(s)
Product Map 2
Introduction to Temporal Artery Thermometry 3
Familiarize Yourself with the TemporalScanner 5-6
Using the Instrument 7
Using the Instrument on a New Mother 8
Using the Instrument on an Infant 9
Frequently Asked Questions 10-13
Disposable Cover Options 13
Accessories 13
Guidelines for Patient Temperature Assessment
14-15
Comparing with other methods of thermometry
Determining a Fever Threshold 16
Body Sites for Temperature Assessment
17-18
An overview of temperature measuring sites
Reproducibility in Temperature Measurement 19
Forgotten Physiology 20-21
For Kids Only 22
Care and Maintenance of the Instrument 21-25
4
Before Using, Familiarize Yourself with the Instrument
Familiarize yourself with the Instrument
? To Scan Depress the red button. The instrument will continually scan for the highest temperature
Scan:
(peak) as long as the button is depressed.
? Clicking: Each click indicates a rise to a higher temperature, similar to a radar detector.
? To Retain or Lock Reading: The reading will remain on the display as long as the red button is de-
Re Reading:
pressed, and will lock on display for 15 seconds on the LXTA/TAT-5000, or 30 seconds on the TAT-4000
after button is released. If measuring room temperature with the TAT-4000, the temperature will remain
on the display for only 5 seconds.
? To Restart: Depress the button to restart. It is not necessary to wait until the display is clear, the
Restar
estart:
thermometer will immediately begin a new scan each time the button is depressed.
? Pulse Timer: The thermometer has a built-in pulse timer.
LXTA/TAT-5000: To activate, press the red button once and release. The display will
remain on for fifteen seconds.
TAT-4000: To activate, you should touch something >90尊F(32尊C) (skin) , press the
red button once and release. The display will remain on for 30 seconds.
The Scan
One of the most important features of the TAT thermometer is its ability to scan. It is a patented feature of the
instrument. Scanning is critical in obtaining the correct temperature, since there are temperature gradients
present not only inside the body, but across the entire surface of the body.
The object of scanning is to capture the highest temperature, the peak, in the area being scanned. As
long as the button is depressed, the thermometer will be continually sampling and recording the highest
temperature it measures.
Test it first on your hand to get comfortable with the concept.
Depress the red button, and keep it depressed. Scan the probe over the center area of your palm,
keeping the probe about a half an inch off the surface to avoid cooling the skin.
LXTA/TAT-5000: Watch the display as the temperature increases in synchrony with the clicking. When
the numbers on the display stop increasing, the clicking also stops, indicating that the
peak temperature has been reached.
TAT-4000 The display will flash SCAN, and there will be a soft but rapid clicking sound each time the
sensor detects a temperature higher than the one before. When the flashing and
clicking slow to about 1 per second, the peak temperature has been reached.
Any of the above indications can be used to assure the peak temperature has been reached. Notice on
the LXTA/TAT-5000 that the temperature only increases over the initial measurement. Once a peak has
been measured, it is locked on the display , and will not change until a higher temperature has been
measured.
Remove the instrument from your palm, release the button and note the reading on the display.
The reading will be locked on the display for 15 seconds on the LXTA/TAT-5000, and 30 seconds on the TAT-
4000, unless you press the button again before that time. Repeat the above steps and you should get the
same, or very close to the same number, since your hand will usually not appreciably change temperature
very quickly.
5
Practice Holding Your TemporalScanner
Familiarize Yourself with the Instrument
The TemporalScanner is ergonomically designed specifically for
its application. Its best to hold the instrument with your thumb
on the red button, much like you would hold a remote control.
Along with allowing you to easily read the temperature display, you
will automatically be using finger dexterity to gently position the
probe, providing comfort and safety for your patient and consis-
tently accurate temperature readings.
Things To Know Before Taking Temperatures
? Measure only the exposed side. Anything covering the area
to be measured would insulate it and prevent the heat from
dissipating, resulting in falsely high readings. Brush hair aside
if covering the TA, or the area behind the ear.
? Slide the thermometer straight across the forehead (midline),
and not down the side of the face. Midline over the TA area,
the TA is less than 2mm below skin surface, whereas as the
TA winds down the side of the face it is further from the skin
surface. Although anatomically correct, sliding downwards
could result in falsely low readings.
? It is preferable to hold the instrument sideways, as illustrated
in Figure 2. Approaching your patient with the instrument
straight up and down could be somewhat intimidating.
? When making the measurement behind the ear as in Figure
3, tuck the thermometer under the ear lobe in the soft coni-
cal depression on the neck just below the mastoid. This is
the place where a dab of perfume is typically applied.
Using on an Infant
? An infant is apt to be presented bundled, with blankets and
clothing covering the neck area. Fortunately, the perfusion
rate is normally strong for infants, and unless visibly dia-
phoretic, one measurement at the TA is typically all that is
required.
Should you feel that the temperature is too low, push aside
any clothing or blankets covering the neck area for ~30
seconds or so and repeat the measurement behind the ear.
6
Using the TemporalScanner
Basics of Using the TemporalScanner
aw cov
Brush hair away if covering ear
exposed
Measure only the exposed side
cov
Brush hair aside if covering the
TA area
1 . With probe flush on the cen- 3. Lift probe from forehead
ter of forehead, depress red and touch on the neck just
button, keep depressed? behind the ear lobe.
4. Release the button, read,
2. Slowly slide probe midline
Slowly
and record temperature.
across forehead to the hair line,
not down side of face.
Alternate sites when TA or BE are unavailable:
Alternat sites
ernate TA unav
? Femoral artery: slowly slide the probe across groin
artery
? Lateral thoracic ar tery: slowly scan side-to-side in the
Lateral artery
area midway between the axilla and the nipple
? Axilla insert probe in apex of axilla for 2-3 seconds
Axilla:
888-838-9073
Questions? Please call us at 888-838-9073 or 800-422-3006.
7
Using the TemporalScanner on a New Mother
Using the TemporalScanner on a New Mother
exposed
Measure exposed skin
?
Keep the red button
button
?
throughout
depressed throughout
measurement
(Brush bangs aside if present)
probe center forehead, button
1. With probe flush on center of forehead, depress red button
Slowly probe across forehead into
2. Slowly slide probe across the forehead into the hair line
Lift probe from forehead
3. Lif t probe from forehead
aw cov
(Brush hair away if covering ear)
probe to
4. Touch probe to neck just behind the ear lobe
button, record tem
emperature
5. Release button, read, and record temperature
? Temperature will remain on display for 15 seconds after the
red button is released.
? Sequence can be restarted at any time without waiting for
display to clear.
888-838-9073
Questions? Please call us at 888-838-9073 or 800-422-3006.
8
Temping Baby in Bassinette, Open Crib, or with Mom
Using the TemporalScanner on an Infant
Instrument should be in same environment as the baby.
?
Measurement site must be exposed.
?
One measurement, preferably at the TA, is all that is required.
?
Preferred site is the temporal Temporal artery area is
artery area. In this case, the only option in this
behind the ear could be an case, as the neck area is
alternate site, as both are not exposed.
exposed.
Temperature at the Temporal Ar ter y Area
emperature Tem
emporal Artery Prefer
red
Site
touch probe to center forehead.
1) Gently touch probe to center of forehead.
? button keep
Depress red button and keep depressed .
probe ov TA into
2) Slide probe over the TA area into hairline.
? conv from to ards center
If more convenient, slide from hairline towards center
of forehead.
forehead.
Release button, remove from head, and record.
Release button, remov from record.
3)
Temperature Behind the Ear
emperature
probe ear.
1) Gently nestle probe on neck behind the ear.
Altern
ate
? button keep
Depress red button and keep depressed. Site
numbers stop.
2) Maintain skin contact until numbers stop.
Release button, remove from head, and record.
Release button, remov from record.
3)
888-838-9073
Questions? Please call us at 888-838-9073 or 800-422-3006.
9
Frequently Asked Questions
Frequently Asked Questions
What is the TemporalScanner?
The TemporalScanner is an infrared thermometer designed for accurate, completely non-
invasive temperature assessment by scanning the temporal artery (TA). It is breakthrough
technology.
How does it work?
Temperature is measured by gently stroking the TemporalScanner across the forehead,
and includes a momentary touch of the probe to the neck area behind the ear lobe, to
account for any cooling of the forehead as a result of diaphoresis. The patented arterial
heat balance technology (AHB?) automatically measures the temperature of the skin sur-
face over the artery and the ambient temperature. It samples and calculates these paired
readings some 1000 times a second to control for the effect of ambient temperature on
the skin, ultimately recording the highest temperature measured (peak) during the course
of the measurement. The TemporalScanner emits nothing - it only senses the natural
thermal radiation emitted from the skin.
How accurate is it?
It has been clinically proven in premier university hospitals to be more accurate than ear
thermometry, and better tolerated than rectal thermometry. It is a superior method for
patient and clinician alike.
What if the TA area has been traumatized by burns or lacerations, or
is completely covered with dressings?
With head trauma, surgical or accidental, the temperature can be obtained from the
alternate site behind the ear lobe. As with diaphoresis, the perfusion will be high in the
presence of head trauma.
Why measure behind the ear lobe?
Sweat causes evaporative cooling of the skin on the forehead and introduces the possibil-
ity of a false low temperature. Fortunately for the method, during diaphoresis the area on
the head behind the ear lobe will always exhibit the high blood flow necessary for the
arterial measurement.
10
Why not use only the area behind the ear lobe?
Frequently Asked Questions
Since the arterial branch is deeper behind the ear lobe than at the temple, under normal
conditions it is less accurate because of its variability. But under diaphoretic conditions, the
blood flow behind the ear lobe is as high as at the TA, making it as accurate as the TA, but
only during diaphoresis or with head trauma as previously mentioned.
What are the benefits of using temporal artery thermometry?
Besides the inherent accuracy of the method, TAT presents no risk of injury for patient or
clinician, eliminates the need for disrobing or unbundling, and is suitable for all ages.
What is arterial temperature?
Arterial temperature is the same temperature as the blood flowing from the heart via the
pulmonary artery. It is the best determinate of body temperature and is unaffected by the
artifactual errors and time delays present with oral and rectal methods.
How does the TemporalScanner compare to our old method?
Arterial temperature is close to rectal temperature, approximately 0.8属F (0.4尊C) higher than
oral temps. Expect larger differences at times, however, as the dynamics of thermoregula-
tion favor the temporal artery method.
High readings?
Temperatures measured with the TemporalScanner may be higher than your current method,
especially if you are used to oral or axillary temps. Oral and axillary temperatures can be
misleadingly lowered due to patient activity such as mouth breathing, drinking, tachypnea,
coughing, talking, etc., and periods of vasoconstriction during the fever process. Any or all of
these conditions may even mask fevers that the TemporalScanner will detect.
Low readings?
A patients temperature measured with the TemporalScanner is normally never appreciably
lower than oral temperature. Lower temperatures are usually from scanning too fast, not
keeping the button depressed, a dirty lens, or a sweaty forehead.
What else should I know?
False high readings:
? Measure only skin that is exposed to the environment. Any covering, hair, hat, bandages,
etc., will prevent the heat from dissipating, causing the reading to be falsely high.
11
False low readings:
Frequently Asked Questions
Multiple readings can cool the skin, so if you take another
?
measurement immediately, expect a slightly lower reading.
Slide the thermometer straight across the forehead, not
?
down the side of the face where the TA could be embed-
ded under cartilage or fat.
Keep the probe flush on the skin, as in the picture on the
?
right. If angled, you will be measuring ambient air as well
as the TA area.
Memorable solutions?
Measure only the side exposed to the environment. The TemporalScanner as-
?
sumes the skin it measures has equilibrated to ambient, so a down or covered side
could be falsely high as heat is trapped and the skin is unable to equilibrate.
If the up side is not the side closest to you, try scanning from the hairline towards
?
the center of the forehead.
Scan slowly across the TA area; if you scan too quickly you can miss the peak.
?
Conditions that could affect a reading ...and their solutions
?
?
? Bandages or pressure dressings covering the
?
? If accessible and dry, measure on
?
forehead
?
the area behind the ear lobe only.
?
? Forehead abrasions, burns, or sweat
?
?
? Consider using the alternate sites:
?
? Agitated or combative patient
?
femoral artery, lateral thoracic, or
?
? Patients forehead in direct draft from vent axillary areas.
?
?
or fan
?
?
?
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
?
?
?
? Thermometer in different ambient tempera- ? The TemporalScanner should be kept
?
?
ture than patient, i.e. window ledge directly in the same ambient temperature as
?
exposed to hot sun or cold weather, or in your patient. Each 10属 difference in
?
?
direct line of air conditioning or fan ambient can cause a 1属 error in the
?
?
reading.
?
12
What should I know about the instrument
Frequently Asked Questions
LXTA/TAT-5000 can be used with either Probe lens should be shiny clean. If not,
? ?
disposable probe cover, cap, or sheath. wipe with an alcohol prep or Q-tip
Can be used without disposables if dipped in alcohol. Occasionally follow
with a damp wipe of water to remove
terminally cleaned between patients.
any alcohol residue buildup.
TAT-4000 requires disposables.
?
A low or high reading outside body
?
temperature range is indicative of the
Can be cleaned with any hospital ap-
?
instruments failsafe mode, signifying a
proved disinfectant, alcohol, and even
mechanical failure.
bleach solutions.
Single beeping indicates ambient or
?
Double beeping indicates a low battery.
? target temperature outside limits.
Replace with either a 9-volt alkaline or
9-volt lithium battery. Can be used in either 尊C or 尊F.
?
Cov
Disposable Cover Options
Illustrated: LXTA/T
A/TA
(Model Illustrated: LXTA/TAT-5000)
Probe Wrap Probe Cap Full Sheath
Cov Cov Probe Wrap Probe
No Cover No Cover
Terminal Disinfectant Covers Entire Covers Entire Covers Entire
Cleaning at Wipe Between Probe Probe Instrument
Patient Patients
TA
Model TAT-4000 Options
LXTA/T
A/TA
Model LXTA/TAT-5000 All Options
Accessories (Model Illustrated: TAT-4000)
1. Combination Unit
Part No. 134200
2. Instument Holder
(shown with security cable)
Part No. 134201
3. Cap Dispenser
Part No.134202
4. Disposable Caps
Part No. 134203
5. Security Cable
Part No. 124307
13
Guidelines for Patient Temperature Assessment
Guidelines for Patient Temperature Assessment
Comparing with Other Methods of Thermometry: Expect the Differences
Unless you are using PA catheters or Exergen aural thermometers with AHB for temperature as-
sessment, expect to see differences compared to your current thermometers. Arterial tempera-
ture measurement leads all other methods in identifying fever or defervescence, and is unaffected
by patient activity. Accordingly, it will be sometimes be differentbut correct.
The following chart presents the range of normal temperatures at the common temperature
measurement sites under normal resting conditions.
Arterial
97.4 -100.1属F
(36.3 - 37.8属C)
Oronasal Oral
96.6 - 99.0尊F 96.6 - 99.5尊F
(35.9 - 37.2尊C) (35.9 - 37.5属C)
Axillary Esophageal
95.5 - 98.8属F 98.4 -100.0尊F
(35.3 - 37.1属C) (36.9 - 37.8属C)
Rectal
97.7 - 100.3尊F
(36.5 - 37.9属C)
Normal Body Temperature (BT)
Normal BT is not a single temperature but a range of temperatures influenced by age,
time of day, and the measurement site.
General Rule of Thumb
On a stable, resting patient, rectal temperature is ~2属F (1属C) higher than axillary and
~1属F (0.5属C ) higher than oral temperature.1
On a stable, resting patient, arterial temperature ~ rectal temperature.
Expect the Differences
Arterial temperature measurement (PA Catheter, TA Thermometry) leads all other
methods in identifying fever or defervescence, unaffected by activities of daily living. It
will sometimes be different from your present methods ? but accurate.
14
Guidelines for Patient Temperature Assessment
Guidelines for Patient Temperature Assessment
1 . Fever Definition: Clinically, fever is defined as a BT =1.8属F (1属C) above the mean standard
Definition:
deviation at the site of recording.2 A single oral temperature of 101属F (38.3属C ) in the absence
of obvious environmental causes is usually considered fever. An oral temperature of 100.4属F
(38.0属C ) over at least 1 hour indicates a fever state.3
2. Oral Temperature Risks: Oral temperature can be clinically misleading, and many febrile pa-
Tem
emperature
tients can have a normal? temperature, even when tachypnea was unobserved.4
3. Rectal Temperature Risks: Rectal temperature should only be considered as a good approxi-
Tem
emperature
mation of core temperature when the patients thermal balance is stable. When monitored
during or after surgery, rectal temperature measurement is not suitable, and the possible delay
in diagnosis of a thermal abnormality could lead to an irreversible crisis.5
4. Axillary Temperature Risks: Axillary temperature is contraindicated in critically ill adults, and
Axillary Tem
emperature
its use in the general patient population should be discouraged due to its unreliable correlation
with core temperature and its poor reproducibility.6
5. Temporal Ar tery Temperature (TAT) Values: On a stable resting patient, TAT is ~0.8属F ( 0.4属C)
emporal Artery Tememperature (TA Values:
higher than an optimum oral temperature, and close to a rectal temperature.7 However, during
febrile episodes, the difference can be much higher, mainly because of the artifacts of oral and
rectal sites.
Note: If your temporal artery thermometer is marked ArterialOral, it is programmed to compute the normal
average cooling effect at the mouth, and automatically reduces the higher arterial temperature by that amount.
This allows existing protocols based on oral temperature to be maintained, and results in a reading consistent
with the mean normal oral temperature of 98.6尊F (37尊C) .
6. Comparison Between Sites: Review of published literature reveals mean differences between
Comparison Betw tween Sites:
non-TA sites of 0.4属 to 3.1属F (0.2属 to 1.7属C) with actual differences of up to 6.5属F (3.6属C )
routinely reported, especially in febrile patients.8
References:
Kuzucu EY. Measurement of temperature. Int Anesthesiol Clin, 3(3):435-49, May, 1965
1
El-Radhi AS, Carroll JE. Fever in Paediatric Practice, Ch 2, pp 15-49, Oxford Blackwell Scientific Publications,
2
1994
Hughes WT et al. 1997 Guidelines for the use of antimicrobial agents in neutropenic patients with unexplained
3
fever. Infectious Diseases Society of America (IDSA)
Tandberg D et al. Effect of tachypnea on the estimation of body temperature by an oral thermometer. NE J Med,
4
308, 945-46,1983
OGrady NP, Barie PS, Bartlett JG, et al. Practice guidelines for evaluating new fever in critically ill adult patients.
5
Task Force of the Society of Critical Care Medicine and the Infectious Diseases Society of America. Clin Infect Dis
1998 May: 26(5):1042-59
Houdas Y, et al. Human body temperature. Ch 5, p89 Plenum Press, 1982, USA, UK
6
Exergen Corporation. Manufacturers data on file.
7
Review of subject material peer-reviewed journals.
8
15
Determining a Fever Threshold for Temporal Artery Thermometry
Determining a Fever Threshold
Defining Fe
Threshold Defining Fever
? A threshold for defining fever is the temperature above which false positives due to
normal variations in temperature, including range of normal mean + circadian effects +
other effects (metabolic, ovulation, etc.) are unlikely.
for Fe Wor
ork
Threshold for Fever Workup
? Not all fevers require a fever workup. A fever workup is an early management tool in
assessment of the likelihood of septicemia or bacteremia, and initiated whenever an
infectious source is suspected. The level of temperature triggering such an investigatory
workup is sufficiently high to avoid false positives resulting in unnecessary discomfort
and expense for the patient, but low enough for early identification and intervention.
Primar y Points
Primary Points
? Temperatures measured with temporal artery thermometry may be higher than normally
seen with other clinical methods, and therefore require an adjustment in both protocol
and perception.
? No one value can apply to every temperature measurement site. Note this old rule of
thumb: Rectal temperature is ~1属F higher than oral temperature and ~2属F higher than
axillary temperature.
? Recommended threshold for fever workup using arterial temperature assessment is a
single temperature >101.8属F or a temperature >101.2属F sustained for more than 1
hour.
? Adjustment of ~ 1属F is necessary to raise the temperature level normally mandated for
fever workups to prevent false positives, unnecessary cultures and blood tests, etc.
Physician Recommended Guidelines for Fever Workup孫
Physician Recommended for Fe Wor
ork
Core & Oral & Temporal Artery in
Temperature Site Axillary
Temporal Artery Oral Calibration
Single value >101.8 Single value >101
Fever Workup
Sustained values (>1h) Sustained values (>1h) Single value >99
Recommendation
>101.2 >100.4
孫Source on file at Exergen Corporation
16
Body Sites for Temperature Assessment
Body Sites for Temperature Assessment
Overview
ervie Tem
emperature Sites
An Overview of Temperature Measuring Sites
Tem
emperature
Oral Temperature
Oral temperature measurement is by far the most common clinical method in use today, and is respon-
sible for masking the greatest number of fevers. Oral temperature can be misleadingly lowered by patient
activity such as tachypnea, coughing, moaning, drinking, eating, mouthbreathing, snoring, talking, etc.
Alarmingly, another cause of low oral temperatures is the fever itself. For each 0.6属C (1属F) temperature
elevation, the pulse rate usually increases approximately 10 beats per minute, there is a 7% increase in
oxygen consumption, and the respiratory rate increases approximately 2 cycles per minute. The resulting
increase in respiration can further lower oral temperature
4
sufficiently to mask a fever.
TEMPERATURE DIFFERENCE (属C)
3
Figure 1 is of interest as it illustrates fever masking even N = 310
when clinicians had eliminated all obvious mouthbreathers r = .490
P<0.001
from the study. This emergency room study presents the 2
temperature difference (rectal minus oral) in 310 patients
with a wide range of respiratory rates. The straight line of
1
best fit is shown. The stippled area demonstrates the tra- di-
tional normal difference between rectal and oral tempera-
0
ture (0.3属- 0.65属C). The investigators concluded, that
many patients with tachypnea would have oral tempera-
10 20 30 40 50
tures in the normal range despite the presence of clinical
RESPIRATORY RATE (MIN-1)
fever, seriously misleading the clinician.
Figure 1 Temperature Difference (Rectal
minus Oral) in 310 Patients with a Wide
Rectal Temperature
Tem
emperature Range of Respiratory Rates. The straight line
Generally, rectal temperature is considered an indicator of best fit is shown. The stippled area
of deep tissue and critical tissue temperatures, but long- demonstrates the traditional normal? differ-
ence between rectal and oral temperature (0.3
standing data demonstrate that rectal temperature can
to 0.65属C).
be a lagging and unsatisfactory index. Fifty years ago,
Eichna et al reported differences between intracardiac,
intravascular and rectal temperatures on afebrile patients to be so insignificant that for all practical pur-
poses, the temperatures may be considered to be the same. Certainly rectal temperature is far less inva-
sive than a pulmonary artery catheter, however, in the same study, data on febrile patients support size-
able differences.
Other comparisons between rectal, esophageal and aortic temperatures undertaken on hypothermic pa-
tients by different researchers also confirm similar differences. Subsequent but equally comprehensive
comparisons on healthy volunteers further confirmed not only temperature differences, but also quanti-
fied significant lags in rectal temperature vs. hypothalamic temperature by times of order one hour. This is
of interest since the blood as it enters and affects the critical tissue in the hypothalamus should have
considerable significance in thermal homeostasis. However, this early data on hypothalamic temperature
was measured by a thermocouple inserted against (and often times perforating) the tympanic membrane.
With significant improvements in the methodology, more recent clinical observations show that the time
constant of rectal temperature in critically ill patients may be considerably longer, and in some cases as
much as a day.
17
Under certain conditions, rectal temperature is even contraindicated; for example, severe arterial insuffi-
Body Sites for Temperature Assessment
ciency in one or both legs might be associated with falsely low readings, or in conditions affecting periph-
eral blood flow such as cardiogenic shock. More common contraindications include neutropenia, severe
hemorrhoids, and recent anorectal surgery. A less common but serious complication of rectal temperature
measurement is perforation of the rectum, which has even occurred in the absence of predisposing rectal
pathology.
Rectal temperature measurement is not well tolerated by either the patient or the caregivers, and is un-
comfortable and embarrassing. Rectal temperature is subject to inaccuracies of placement, environment,
and time of insertion. Although it is well established that a rectal temperature requires two to five minutes
or more to reach optimum measurement with a glass mercury thermometer, in practice many are with-
drawn in just one minute, a technique responsible for misleadingly low readings.
In fact, it is difficult to attribute any thermal significance at all to the rectal area. It is not known to contain
any thermoreceptive elements and its geographical location distances it from both the CNS and the cross-
roads of circulation at the heart, which are the vital informational elements.
Tympanic Membrane and Ear Temperature
ympanic Tem
emperature
A temperature site of more recent onset is the ear. It is a compelling site, accessible, free from bodily
fluids, and not easily influenced by patient activity. This temperature is measured using infrared technol-
ogy, and there are three types of infrared thermometers: tympanic, ear, and arterial heat balance. It has,
however, become common practice to refer to any thermometer making the measurement at the ear as a
tympanic thermometer. Although the terms tympanic and ear may be used interchangeably, they actually
describe quite different measurements.
True Tympanic Membrane Temperature
Tym
ympanic Tem
emperature
The tympanic membrane is deep inside the skull, and is not subject to the artifactual errors that can affect
oral, rectal, axillary and ear temperatures. True tympanic thermometers provide an uncorrected, direct
reading of the temperature of the tympanic membrane, and are preferred for continual measurement
during certain surgical procedures, and for use in extreme conditions such as military use, research, and
sporting events.
There are two types of instrument used to make the measurement. One is a long thin thermocouple probe,
usually fitted with cotton at the end, that must come in contact with the tympanic membrane. There is
much historical data on the efficacy of tympanic thermometry using contact thermocouples, stemming
originally from work done over thirty years ago. However, this method never gained wide acceptance due to
the risk of injury to the delicate membrane. The other type of instrument is the Exergen Ototemp 3000SD,
which scans the tympanic membrane without contact.
Tem
emperature
Ear Temperature
Ear thermometry is a method of measuring the temperature of the external portion of the ear canal. For
routine clinical use, ear thermometry has been preferred as a simpler, faster, and more convenient alterna-
tive to true tympanic thermometry. The absolute temperature of the outer ear, however, is lower, and more
variable than tympanic membrane temperature. It is subject to a cooling effect resulting from the body
heat being radiated to the environment, and a heat balance method is required in order to produce the
requisite accuracy. When combined with an arterial heat balance method, ear thermometry provides a
highly accurate indication of body temperature, but those ear thermometers without it have high rates of
missed fevers.
18
Reproducibility in Temperature Measurement
Reproducibility of Readings
Multiple temperature readings in the same area, mouth, rectum, axilla, ear or temporal artery, make for
variability with each separate measurement. This can be confusing for clinicians, since they expect the
same number with each measurement. The non-reproducibility of the readings, however, is not a func-
tion of the devices, but simply a function of physiology. The human body is a myriad of small gradients,
and variability of readings will occur on every method of temperature measurement. In addition, ther-
mometers are at room temperature, nearly 30属F (17属C) cooler than the tissue being measured. That
said, it is then easily recognized how time of insertion, probe placement, and tissue cool down all affect
reproducibility of temperature readings, no matter what device is employed.
Temperature:
emperature
Oral Temperature
By far, the most common method of temperature measure-
ment is sublingual measurements. Placement of the probe
under the tongue, however, can result in substantial
differences caused by just a slight repositioning of the
probe. The standard heat chart commonly used by manu-
facturers of electronic thermometers on the right illustrates
a difference of nearly 2属F (1属C) depending on exactly what
area is being touched by the probe.
Differences from repeated oral temperatures can vary even
further, as they can superimpose artifactual errors over the
thermal gradients. Patient activities also affect the reading,
these varying by individual and activity. In fact, one large
manufacturer cautions waiting at least 15 minutes after
ingesting hot or cold food or drink, after exposure to
extremely hot or cold weather, and after smoking.
Tem
emperature
Ear Temperature
The journals abound with citations addressing the lack of reproducibility of ear thermometers. In fact,
some manufactureres instruct the user to take three separate temperature measurements, and to select
the highest of the three. While much of this has to do with the device, physiology also plays a large part.
In such a small area, the difference of 30属F (17属C) between the room temperature probe and the
temperature of the ear being measured results in a noticeable tissue cool down. Geriatric patients
typically have a lower rate of perfusion than a younger individual, and it can take several minutes for the
ear to equilibrate following the use of an ear thermometer.
Rectal Temperature
Tem
emperature
Time and placement are critical for rectal temperature measurement. It has long been recommended
that the measurement be taken for at least five minutes or more for accuracy. The measurement is also
dependent on the depth of insertion, and just a few centimeters can result in a noticeable difference.
Temporal Ar ter y Temperature
emporal Artery Tem emperature
Because of the expanse of area being measured, and the normally strong perfusion of the artery in
particular, temporal artery temperatures are at least as reproducible as any other method. Of interest,
the temporal artery area will equilibrate in the shortest period of time compared to any other site. For
absolute accuracy, however, it is recommended to wait 30-60 seconds before repeating a temperature on
the same side, although, depending on the individual, the time involved can be much shorter. The
limitation in time is almost entirely the behind-the-ear measurement, as the perfusion rate per tissue
mass is not quite as high as the temporal artery. Since the method employs the area behind-the-ear with
every measurement, this area is the time limitation.
19
Your Temperature
Forgotten Physiology
Normal Temperature
112尊-114尊
Normal human temperature is the temperature rises, the to bur
urn
Cells begin to burn up
around 98.6 degrees. But did bodys chemical actions speed
you know that only 8% of the up so that damaged tissues can
people in the world have a be repaired more quickly. Also,
normal temperature of exactly virus or bacteria invaders dont
106尊
98.6? survive well at high tempera-
Dangerous fever
angero fevever
tures. Perhaps fever is the
A temperature that is normal
bodys attempt to cook them 103尊-104尊
for you may even be a whole
into submission. ard exercise
Hard exercise
degree or so above or below
101尊
normal.? It is good to know
Chills Excit ement
Excitement
what is normal for you. Try
You have a high temperature Some active kids
active
98尊-100尊
taking your temperature at
and cold skin. You are hot No rmal
N mal?
different times, like in the
inside, but still you shiver.
morning, after a cold shower, or
Chills are your bodys way of
after a five-mile hike. 96尊-97尊
creating a fever. The muscle
Cold weather or
Cold or
action from shivering produces
Fever Early mor
Ear ly morning
heat, which raises your tem-
Fever is when your bodys perature in an effort to fight
temperature control is set off infection. When the crisis
above normal. Fever is a sign is over, your temperature is set 86尊
that your body is fighting off back to normal, the skin warms, Lower limit of s urvival
surviv
urvival
an infection. It is thought that and you sweat.
fever does two things. When
Hot Blood or Cold Blood?
A frog in a 70 degree pond is a bodies keep them at an even Cold blooded creatures have no
70 degree frog. A frog in a 40 temperature by carefully internal temperature control.
degree pond is a 40 degree controlling the rate of burning Their rate of metabolism is
frog, and is moving very slowly, determined by their environ-
in their cells.
if at all. ment. When the outside
temperature drops way down, all
A kid in a 70 degree pond is a their body processes slow way
98 degree kid. A kid in a 40 down.
degree pond is still a 98 degree
Frogs are cold blooded,
kid, although you can bet hes Humans and all mammals are
meaning that their
swimming as fast as he can to souped-up hot-blooded beings.
temperature changes
get out. Their metabolisms are speedy,
depending on
but are kept at an even keel.
where
One difference between kids So no matter what the tem-
they
and frogs is the difference perature is outside, the climate
are.
between warm-blooded and on the inside is ever warm and
cold-blooded beings. People ready for action.1
have automatic climate control
inside their bodies. Their
Exerpts from Blood and Guts: A Working Guide to Your Own Insides, Allison L, Katz D. , Little, Brown and Company, Boston, New York, Toronto, London
1
20
Perspiration
Forgotten Physiology
The TemporalScanner relies on the skin over the temporal artery to help provide an accurate body
temperature. In fact, it is measuring the inside by measuring the outside. Your skin is a sensor,
controlling body temperature in two ways: radiation and evaporation. Since most of us dont think about
our skin as a sensor, this might be a good time to discuss a little physiology.
We live our entire lives with a body temperature that changes only a few degrees. This is thanks to a
very sophisticated climate control, of which the skin is a very important part. Sweating, goose bumps,
and heat loss from the skin all help maintain our normal temperature, keeping us comfortable.
When your internal temperature rises, your brain signals your blood to increase circulation to the skin.
In this way, the bodys internal heat is carried to the surface by the blood, where it is lost by radia-
tion.
If this is not sufficient, your sweat glands sprint into action, and perspiration is released through the
pores. This liquid evaporates on your skin and you cool right down. When your temperature drops, your
brain signals that heat must now be saved. Less blood circulates to the skin, and sweating stops.
Since there is a lot of cooling going on when you are sweating, both inside and out, it is a good idea to
wait till your forehead is dry before taking your temperature with the TemporalScanner. If your
forehead is sweaty, the reading will be low. Drying your forehead could shorten the wait, but there is
another place to measure an accurate temperature when perspiring. It is in the little soft depression
just behind the ear lobe, the place where young ladies are usually taught to apply perfume.
During perspiration, taking a temperature with the TemporalScanner in the area behind the ear lobe
has been proven to be as accurate as a temperature taken at the temporal artery area when it is not
wet. Since we sweat first on the forehead, then on the hands and feet, the chances of the area
behind the ear lobe remaining dry for the measurement are excellent. And since we already have
increased circulation to the skin during perspiration, this area will have the high blood flow necessary
for the measurement.
Another instance when a high rate of blood flow on the neck can be assured is following head trauma,
either surgical or accidental. At such times the neck area behind the ear lobe can be used as a primary
site if the forehead is not available.
If perspiration or head trauma is not present, the area on the neck behind the ear lobe may not have
sufficient blood flow to be reliable, and should not be used as the primary measurement site.
21
For Kids Only
Your ears. Now were down to ears. And please
Did you know you always have a temperature?
pardon us, ears beat
Bet you thought you only had a temperature
rears. But having your
when you were sick. Absolutely everything
has a temperature, even icicles. Brrrrrr! ear pulled sure isnt
fun, and when you have
When you dont feel well, your mom or a nurse
an ear infection, it
might say lets see if you have a tempera-
even hurts. Tempera-
ture,? but what they really mean is lets see if your tempera-
ture taken in your ear
ture is different from normal.?
should be higher than
So, when you have your temperature taken, dont be fooled. in your mouth, but not
Your mom and your doctor already know you have a tempera- as high as in your rear.
ture, and are just getting an idea of how things are going
Your heart. If we were to pick the
inside your body.
best place to measure temperature it
would be in the center of your
Places to measure
heart. But thats pretty danger-
your temperature
ous, and surely not be something
Your bum. Babies and you would think was fun.
little kids get their Arrrrghhh! In case youd like to
temperature taken is in know, though, temperature in your heart is around
their bum. Poor little 99.4属F.
kids, how embarrassing!
The temperature taken in
Your temporal arter-
your bum is the hottest of
ies. There is a special
all the places to take
place on your head where
temperature. Its around 99.6属F most of the time.
we can measure the same
temperature as the blood
Your armpit. When kids get
in the middle of your
a little bit older, they might
heart. This is because
have their temp taken under
blood is pumped directly
the arm instead of the bum.
from your heart to your
This is better, but you have to
head through little tubes
keep the thermometer in your
called arteries that carry
armpit with your arm tight
blood up the sides of your neck, up the side of your
against your chest for a long
face just under your skin, and stop at at a place on your
time. Its hard to keep it from
forehead called your temple. Guess what theyre
falling out and breaking,
called? Wow! Isnt this the same place your mom
especially if you fly! I wonder
touches with her hand when you dont feel good?
if flying causes the armpit temperature to be the lowest in
your body. Its around 97.6属F most of the time.
Did you know that the forehead has been used to
detect fevers as far back in time as anyone can
Your mouth. Now, if youre
remember, over 2000 years? Theres a new technol-
reading this, youre probably a big
ogy that scans the same place your mom touches, and
kid and so you would most likely
its almost as gentle. Its an infrared thermometer
have your temperature taken in
called the TemporalScanner. It measures your
your mouth. Not too bad, but
temperature with a quick and gentle scan across your
everyone knows you can trick your
forehead. Most of the time, temperature here is
mom or your doctor into thinking
around 99.4属F, same as your heart. Nothing goes in
youre sick by doing stuff with
your mouth, your ear, or your rear, and in just a
that thermometer. Bet you
second or two, done!
already know of ways to do that!
Most of the time, a temperature in your mouth is about
Now, where is the best place to take
98.6属F. Well, sort of...
your temperature?
22
Care and Maintenance
Care and Maintenance
? Battery: A standard alkaline 9V battery pro-
Batter
ery
vides approximately 5,000 readings.
To replace, loosen the single screw at the
bottom of the instrument and remove the cover.
Disconnect the old battery and replace with a
new one in the same location. Replace the
cover, push down to snap shut, and tighten the
screw. Use only high quality alkaline batteries
or equivalent.
? Handling: The TemporalScanner is designed
and built to industrial durability standards in
order to provide long and trouble-free service. However, it is also a high precision optical instrument,
and should be accorded the same degree of care in handling as you would provide other precision
optical instruments, such as cameras or otoscopes.
? Cleaning The TemporalScanner can be wiped down with any hospital approved disinfectant, includ-
Cleaning:
ing bleach, and can even be gas or plasma sterilized. With normal use, the only maintenance
required is to keep the lens on the end of the probe clean. It is made of a special mirror-like, infra-
red-transmitting material. However, dirt, greasy films or moisture on the lens will interfere with the
passage of infrared heat and affect the accuracy of the instrument. If necessary, clean the lens with
a cotton swab dipped in alcohol. Periodic cleaning is a good practice.
? Sterilization: The industrial grade housing and design of the electronic components allow for safe
Sterilization:
gas or plasma sterilization, and for disinfecting with any accepted solution, even bleach. The probe
can even be immersed in cleansing solution because it is hermetically sealed.
? Calibration Factory calibration data is installed via a computer to the TemporalScanners micropro-
Calibration:
cessor. The instrument automatically self-calibrates each time it is turned on using this data, and will
never require recalibration. If readings are not correct, the instrument should be returned for repair.
23
Instructions for Fahrenheit or Celsius Conversion
Care and Maintenance
The TemporalScanner can be used in either 属F or 属C. To convert from one scale to the other, the only tool necessary
is a paper clip or the tip of a small screwdriver.
For 属F/属C Conversion
Conversion
sion:
? Loosen single screw on bottom of case and remove battery cover.
? Lift battery out of the way.
TAT-4000
? Locate the little switch to the right of the battery as indicated in the
drawing, and with the tip of the paper clip or screwdriver, slide up or
down to the opposite position. TAT-4000
? Remove the paper clip or screwdriver.
LXTA/TAT-5000
? To return to the original setting, repeat the process.
LXTA/TAT-5000:
LXTA/T
A/TA
? Make sure the display is blank.
? Insert the tip of the paper clip or screwdriver into the slot shown on the drawing, directly below and to the left
of the battery, and push in to activate.
? While pressing the little switch, slide your finger around the other side of the instrument and turn the instru-
ment on by pressing the red button.
? To return to the original setting, repeat the process.
DISPLAY DIAGNOSTICS CHART
ISPLAY DIAGNOSTICS CHAR
IAGNOS HART
The following chart summarizes the fault conditions, and the associated indications.
Di LX
C o nd itio n Displa y So u n d LX T A / TA T -5 0 0 0 T A T -4 0 0 0
High Target HI 1 beep/second >110 属F (43 属C) >110 属F (43 属C)
Low Target LO 1 beep/second <60 属F (16 属C) <61 属F (16 属C)
High Am bient HI A 1 beep/second >110 属F (43 属C) >104 属F (40 属C)
Low Am bient LO A 1 beep/second <60 属F (16 属C) <60 属F (16 属C)
Low Battery N/A 2 beeps/second bAtt
Dead Battery ???? 2 beeps/second ????
Restart. Return to Exergen for repair if error message persists.
Processing Error E-## or Err
24
? Specifications LXTA/TAT-5000 TAT-4000
Care and Maintenance
Accuracy 賊 0.2 F or 0.1 C 賊 0.2 F or 0.1 C
Temperature Range 60 to 110 F (16 to 43 C) 61 to 110 F (16 to 43 C)
Arterial Heat Balance Range
94 to 110 F (34.5 to 43 C) 94 to 110 F (34.5 to 43 C)
for Body Temperature*
Operating Environment 60 to 110 F (16 to 43 C) 60 to 104 F (16 to 40 C)
Resolution 0.1 F or C 0.1 F or C
Response Time ~ 0.1 seconds ~ 0.04 seconds
Battery Life ~5,000 readings ~5,000 readings
Time Displayed on Screen 15 seconds 30 seconds
2" x 8" x 1.25" 2" x 8" x 1.25"
Size
(5 cm x 20 cm x 3 cm) (5 cm x 20 cm x 3 cm)
Weight 8.3 oz (235 gm) 7.0 oz (199 gm)
Display Type and Size Large bright LED's Large bright LED's
? Industrial duty impact resistant ? Industrial duty impact resistant
casing casing
Construction Method ? Hermetically sealed sensing ? Hermetically sealed sensing
system system
? Stainless steel probe ? Aluminum probe
Lifetime Lifetime
Warranty
*Automatically applied when termperature is within normal body temperature range, otherwise reads
surface temperature.
Calibration Verification Procedure
All Exergen infrared thermometers are designed to permanently maintain their accuracy, and normally
recalibration is not required unless the thermometer has been physically damaged or experiences
component failure. In the unlikely event that recalibration may be required, the thermometer must be
returned to Exergen for the procedure.
However, calibration can be verified in the lab or clinical units quite easily using a device known as a
portable blackbody. A portable blackbody is a reference heat generator (see below), which is a self-
contained device providing a stable reference target temperature in the clinical temperature range.
The device can be used to verify the calibration of any Exergen thermometer in question, or for quality
checks done on a routine basis. The verifier operates with either a 9-volt power supply plugged directly
into any 120 vac wall receptacle, allowing extended use in the laboratory, or a 9-volt battery for
portable use on the nursing floors.
There are two ways to use the portable blackbody to verify the calibration accuracy of the thermometer
in question, either (1) with a certified master reference infrared thermometer, or (2) by using two
identical thermometers as a reference against the one in question.
25
Using the Portable Blackbody
Care and Maintenance
1. Turn on the verifier device, using either a 9-volt battery or the power supply. Make sure the
red LED is illuminated.
2. Allow device ~5 minutes for warm-up and stabilization time.
3. Allow certified master or the two reference thermometers and the instrument to be tested
to acclimate in the same ambient temperature for at least 10 minutes.
4. For all instruments, make sure the lens at the tip of the probe is clean. To clean, use an
alcohol prep or a swab dipped in alcohol, followed by a damp wipe with water to remove
any residue.
5. Alternately insert the reference instrument(s) and the instrument being verified into the
aperture opening, comparing the readings.
Por table Blackbody
ortable
Verif
erifier
Calibration Verifier
2
3 1. Power On LED
1
2. Blackbody Aperture
3. ON/OFF Switch
4 4. Battery Compartment
5 5. Power Supply Jack
Certif
tified Master Refer-
efer
Using a Cer tified Master Refer-
ence Thermometer in a Por table
Thermomet Por
ortable
to Verify
Blackbody to Verify Calibration
26
? Accuracy Limits: Comparison between the reference instrument(s) and the instrument being verified
Care and Maintenance
should be within 賊0.4尊F (0.2尊C) for acceptable limits. If not, repeat the process. In the event they
still differ by more than the acceptable limits, call Exergen for repair or replacement of the failed
instrument.
Verifier Specifications:
erifier Specifications:
Power Source 9-volt battery, or 9-volt power supply
Battery Life Approximately 1 hour continuous use
Red LED shuts off when battery voltage drops below ~5
Low Voltage Indicator
volts
Temperature Range 97-104 属F (36-40 属C)
Wipe down with alcohol or any hospital approved
Cleaning
disinfectant. Do not immerse.
Repair
If repair is required:
? Contact Exergen at (617) 923-9900 for a Return Materials Authoriza-
tion (RMA) Number.
? Mark the RMA number on the outside of your package and packing
slips.
? Include a description of the fault if possible.
? Send the instrument freight/postage prepaid to:
Exergen Corporation
51 Water Street
Watertown, MA 02472
? The instrument will be returned freight/postage prepaid.
27
EXERGEN
Straight From the Heart属
? 51 WATER STREET ? WATERTOWN, MA ? 02472 ? PH 617.923.9900
EXERGEN CORPORATION
www.exergen.com
28
p/n 818528 r1
|