JNSE, 10 : 168〜178, 2023

Original Article

Comparing the alarm detectability of electronic axillary thermometer inolder adults aged 70 years or more: buzzer alarm, vibration alarm,or buzzer/vibration alarm
1)

2) 3)

Yuiko Koyano ; Gojiro Nakagami
1)
2)

2)−4)

and Hiromi Sanada

Department of Nursing, The University of Tokyo Hospital

Department of Gerontological Nursing/Wound Care Management, Graduate School of Medicine, The University of Tokyo
3)

Division of Care Innovation, Global Nursing Research Center, Graduate School of Medicine, The University of Tokyo
4)

Ishikawa Prefectural Nursing University

Abstract
This study aimed to compare the detectability of four alarms among two kinds of axillary thermometers in adults aged
≥70 years. In this randomized crossover study, the detectability of four alarms was assessed using within-subject
differences between a reference (A) and a new thermometer with lower frequency and higher volume (B1), vibration (B2),and both functions (B3). The seconds was calculated by subtracting the time buzzer or vibration going off, from the time
participant detected it. Positive detectability was defined as below 5 seconds. Complete data of 47 participants (mean age,
79.7 years) were collected. The numbers (proportions) of participants able to detect the alarm of A, B1, B2, and B3 was 19(40.4%), 31 (65. 9%), 46 (97. 8%), and 46 (97. 8%), respectively. A generalized linear mixed-effects model analysis, alarm
detection was positively associated with alarm type, and age, but not between Mini-Mental State Examination. The odds
ratios (95% confidence interval, P value) of B1, B2, B3, and age were 4.98 (1.15 to 21.51, P = 0.031), 688.92 (23.36 to 20316.95,
P < 0.001), 688.92 (23.36 to 20316.95, P < 0.001), and 0.81(0.67 to 0.99; P = 0.042), respectively. Vibration was the mostimportant variable that allowed for easier detection of alarms in this group, with or without cognitive impairment.
Key words: aging, cognitive impairment, hearing loss

effects of ambient or environmental temperatures in4)5)
older adults . In older adults, using these devices as

Introduction
Accurate measurement of body temperature
among older adult patients with comorbid disorders
has been reported to be necessary for detecting
infection, monitoring inflammatory processes, and1)2)evaluating progress of disease and treatment .
Owing to the coronavirus disease pandemic, the useof non-contact forehead thermometers outside hospitals for infection screening has increased. However,
Nia et al. showed that forehead thermometer readings
3)
had low agreement with the tympanic temperature .
Other studies have indicated that infrared tympanic
thermometers may be inaccurate because of theroutine screening tools for fever may also be difficult
because of decreased finger dexterity resulting fromsymptoms caused by senescence. In addition, an
electronic axillary thermometer with a beep alarm has
been shown to be a highly reliable and valid
alternative to traditional gallium-in-glass thermom6)
eters in older adults . Therefore, an axillary electronic
thermometer may be considered the best way tomeasure fever in older adults because of its ease ofuse, and high reliability.
7)8)
The prevalence of hearing loss increases with age .
European studies have also shown a steady decline in

Corresponding author: Yuiko Koyano
Department of Nursing, The University of Tokyo Hospital
7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
E-mail: yuikokoyano7@gmail.com

Manuscript received: 1 January 2023

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Journal of Nursing Science and Engineering（2023）
9)10)

hearing from the sixth to the ninth decades , whichis the same in Japan. The 10-year incidence rates oftion of all three features. However, whether this new
thermometer with multiple alarm types could im-

hearing impairment in the 60-64- and 70-74-year-old
age groups were 32.5% and 62.5% (age at baseline),
11)
respectively . Although the electronic axillary thermometer, which is easy to use and reliable, isprove the detectability of alarm beeping among adults
aged ≥70 years has yet to be determined.
This study aimed to compare the detectability offour alarm signals among two kinds of axillarythermometers: alarm with high frequency, alarm withhigher volume and lower frequency, that with

commonly used in Japanese older adults, their
reduced ability to hear alarm sounds may also
increase with age. We identified that the prevalence ofvibration, and a mixed alarm with all three features ina reduced ability to hear a beeping alarm signal of
50 dB at frequencies from 2700 to 4000 Hz wasapproximately 70% in older adults aged ≥ 65 years (N12)= 107) . To support appropriate usage of the electronic axillary thermometer in individuals with reduced

older adults aged ≥70 years.

ability to hear the alarm sound, it is also significant to
identify the factors associated with reduced ability tohear the alarm sound among the known factors for

gastroenterology inpatient unit in a university hospi-

hearing loss. Age was identified to be the mostindependent factor, and the age cut-off point forinability to hear the alarm sound was set to 70 years inthis study. It was also observed that six participants
aged 70 years older with reduced ability to hearbuzzer alarm, without cognitive impairment (5. 6%),
12)
removed the thermometer before buzzer occurrence .
In these six participants, the body temperature could
not be measured because of errors. This is because
older individuals with a reduced ability to hear alarm
beeping could not be identified when the measurement was complete. Therefore, it is possible that older
adults aged ≥70 years may not be able to accurately
measure their own body temperature using electronic
axillary thermometer owing to reduced ability to hear
the alarm sound. For this patient population, electronic axillary thermometer with detectable new alarmfunction is of great importance to measure their own
body temperature.
The largest variation in hearing loss was found at
13)high frequencies and in older ages . Overall, hearing
thresholds increase by 1 dB per year on average inindividuals aged >60 years, depending on age, sex, and14)
initial thresholds . Therefore, higher volume andlower frequency or devising a new alarm type withvibration (no buzzer), may improve the ability todetect thermometer alarm among older adults aged

Methods
1. Study design and participantsThis randomized crossover trial was conducted in atal in Tokyo, Japan, between January and March 2021.
The thermometers used were as follows (Figure 1): a
Terumo Electronic Thermometer-C205 for reference(A) and a Citizen Systems Electronic ThermometerCTEBV720VA with three types of signals: beeping(B1), vibration (B2), and both beeping and vibration(B3). The efficacies of A, B1, B2, and B3 were assessed
for the within-subject differences between the two
types of electronic axillary thermometers with four
different alarms.
The gastroenterology inpatient unit was selected
for this study. Patients in this unit are older every
year, with advances in gastroenterology treatment(mean patient age in this unit in 2020 was 69 years).
The fact that the unit had a good turnover rate of
hospitalized patients made it well suited for theintervention study. The treatments provided in thisunit were as follows: endoscopic resection of thestomach, colon, and esophageal cancer (endoscopic
submucosal dissection); radiofrequency ablation ofliver cancer; stenting plus anticancer chemotherapy
for pancreatic and biliary cancer; endoscopic treatment for biliary and pancreatic stones; and clinical
trials for new drugs for liver cancer, pancreaticcancer, colon cancer, biliary tract cancer, and hepatitis
B and C.
Participants were recruited from new inpatients inthis ward by a primary researcher during the day.
The participants were adults aged ≥70 years. Patients≥70 years. A new electronic axillary thermometer,with three alarm types, has been already developed

who could read and understand Japanese, even if they
had cognitive impairment, history of a noisy job,for older adults. The alarm types included vibration
only, higher volume, lower frequency, and a combina-

hearing impairment due to disease, or accidents inchildhood or adulthood, were included in this study if― 169 ―

Journal of Nursing Science and Engineering（2023）

Figure 1 Samples of electronic axillary thermometer available in this study(A) C205 with a buzzer of 50 dB with dual frequency band at 2700 and 4000 Hz (Terumo
Corporation, Tokyo, Japan).
(B) CTEB720VA with three types of alarms (Citizen Systems Japan Co., Ltd., Tokyo,
Japan): buzzer signal of 60 dB with dual frequency band at 2000 and 4000 Hz
frequencies (B1), vibration (B2), and mixed version with all three features (B3). The
CTEB720VA with a new silicone attachment supports the maintenance of thecorrect position for older adults with age-related sarcopenia.

they provided written informed consent. Additionally,
eligible participants were required to place thethermometer tip at the axilla by themselves andreport their body temperature to a nurse after it was
beeped. Patients were excluded if they (i) had adepressed level of consciousness due to hepatic coma,
pain, difficulty breathing, or were under sedation; (ii)manifested acute febrile illness or a body temperature≥38. 0℃ at the axilla; or (iii) could not keep thethermometer at the axilla until it beeped due todelirium.
2. Calculation of power and sample size
The difference in the proportion of patients who
were able to detect these alarms for axillarytemperature was assumed to be 40%, derived fromour preliminary study of alarms A and alarm B2. The
sample size that would provide 80% power with a twotailed type I error rate of 0. 05, was calculated toensure the detection of an absolute difference of 40%
between alarms A and alarm B2. The estimatedsample size was 42; therefore, 46 patients wereenrolled, assuming a loss to follow-up of 10%.
3. Data collection
Two types of axillary electronic thermometers
were used. The first was C205, which was used as thereference (Terumo Corporation, Tokyo, Japan). C205
12)
was used in our previous study and is often used inparticipating hospitals. The other was the
CTEB720VA, which was used as the intervention(Citizen Systems Japan Co., Ltd., Tokyo, Japan). These
devices were lightweight and portable. These compact electronic thermometers measure the bodytemperature both actually and predictively. A predictive measurement, which is generally used in clinicalsettings, can measure body temperature in approximately 20‒35 seconds. A predictive measurement
would require less work by each participant compared with actual measurements lasting for 10 min or
more. Therefore, we used predictive measurements.
The thermometers were calibrated for accuracy
according to the manufacturerʼs standards before
measuring body temperature. All temperatures wererecorded at ℃. The room temperature ranged from
20℃ to 26℃.
C205 (A) weighed approximately 13 grams, was 129
mm long and 17.6 mm wide, and had a depth of 12.6
mm. The temperature value is displayed digitally
during temperature taking, with an accuracy of±0.1℃, ranging from 26.7℃ to 43.3℃. A buzzer of 50
dB with dual frequency band at 2700 and 4000 Hz are― 170 ―

Journal of Nursing Science and Engineering（2023）
8)

set to sound alternately when performing predictive
measurement using C205. Different tone generated byboth sides , there would have been a unilateral
hearing loss in the participants. The measurement

each frequency was produced.
The CTEB720VA (B) targets older people, specifically those experiencing physical changes due to age-position of the axilla (left or right) may have an impact
on alarm detectability. Therefore, the participantsʼ
measurement positions were assigned randomly

related sarcopenia, hearing loss at high frequencies,and visual degradation. Thermometer misplacement
at the axilla due to reduced muscle mass or skin folds

using a random number table. All the participants
recorded their body temperature with each alarm fora total of four measurements per participant. There

could frequently lead to significant errors without anurseʼs assistance. To address this problem, a new
silicone attachment to the CTEB720VA was developed. The CTEB720VA with the new silicone

were 24 combinations of measurement orders of theaxillary electronic thermometers with four different
alarms. After informed consent was obtained, theparticipants randomly selected only one combination

attachment was maintained in the correct position
when used by skinny older individuals. This deviceof the measuring order by drawing a lot. A long
washout phase was not required to diminish thehas three alarm types and a wide display for ease ofviewing. One alarm can be selected based on the user
preference: buzzer for 4 s (B1), vibration for 8 s (B2), or
buzzer and vibration for 4 s (B3). Citizen Systems

carryover effect in this study because hearing or
alarm detection could not be affected by the previous
session. We determined the measurement interval
between the devices to be approximately 30 s.

succeeded in bringing lower frequency (2000 Hz) tobuzzer specifications. Buzzer signal for B1 and B3 wasequipped with 60 dB, and dual frequency bands at
2000 Hz and 4000 Hz. Different tones were generated
similar to those by the C205. A vibration noise
approximately of 39 dB was generated as a soundupon rotation of a micro vibration motor within thethermometer. Numbers of seconds of each alarm typewas different. B1 and B3 were set to 4 s in terms ofbattery life. Vibration period (B2) was set to 8 s. Since
the whole external surface of the CTEB720VA wascovered by a silicone attachment, which was a softand flexible material, vibration insulation was generated. That way the silicone attachment could damp

For each participant, body temperature and information on known correlations with hearing sensitivity were recorded by the primary researcher. As
vibration alarm (B2), the primary researcher was able
to detect a rotational noise of vibration with 39 dB at
30 cm from participantʼs axilla. This sound pressure
was enough to hear in silent position, like a patientroom or library. Therefore, every recording was set tokeep an appropriate distance (approximately 30 cm)
between the primary researcher and the participantʼsaxilla. If participant wore thick clothing, like asweater, this sound was not clear. Therefore, they
were only in their underclothes and wearing hospital
pyjamas, no sweater or layers of clothing. To ensure

the vibration by thermometer. Therefore, more time
was needed to detect vibration at the axilla. A small
hole was made at the back side of thermometer andsilicone attachment, all sounds coming from there.

accurate results, the participants were instructed to
dry their axillary region using a towel, turn off the
television, and remove their hearing aids before
temperature measurement. With the participants

CTEB720VA weighs approximately 25. 5 grams(approximately 35 grams with a silicone attachment)
and was 126. 5 mm long and 31. 5 mm wide, with asitting on their beds, an electronic thermometer wasplaced at the center of the axilla (left or right). The
instructions given by the primary researcher to each

depth of 15 mm deep. In this study, the CTEB720VA
had no functional customization, by which this
instrument on board was unchangeable. The tempera-

participant were as follows: after thermometer tip
placement (starting body temperature measurement),
please tell me when you hear a beeping sound or feel ature value is displayed digitally during temperature
taking and ranges from 32. 0℃ to 42. 0℃, with anaccuracy of ±0.1℃.

vibration. If you do not hear a buzzer sound or feelvibration, please hold the thermometer in the axilla
until the primary researcher gives you further

4. Procedure with randomization and blinding
Although age-related hearing loss was consideredbeing a gradual deterioration equally occurring on

instructions. Blinding was only possible for theparticipants with thermometers B1, B2, and B3
because the thermometers were exactly the same

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Journal of Nursing Science and Engineering（2023）

Figure 2 The time of the buzzer or vibration (a), the time of theparticipantʼs detection of the buzzer or vibration (b), and the cut-off
point (45 s). Positive and negative detectability were defined as (b or45) - a <5, and (b or 45) - a ≥5, respectively.

product; therefore, they were identical in shape andcolor. However, blinding was not possible for theusing the IBM SPSS Statistics version 24 (IBM
Corporation, Armonk, NY, USA). The statisticalresearcher who measured the period from thethermometer tip placement to the participantsʼ selfreports of alarm detection using a stopwatch.
5. Evaluation of the alarm detectability (hearing the
beeping signal or feeling the vibration)
The period from the thermometer tip placement(starting body temperature measurement) to thealarm signal (buzzer and vibration) differed between
the two devices, from 30 to 38 s and from 20 to 35 s for
C205 and CTEB720VA, respectively. Forty-fiveseconds was the cutoff point if a participant did not
notice the ringing alarm due to impaired hearing. The
primary researcher measured the period from thethermometer tip placement to participantsʼ selfreport “I hear a buzzer sound, or feel a vibration.” Thesignificance level was set at P<.05.
A generalized linear mixed-effects model was used
to identify the factors associated with alarm detectability, including the association among alarm type, age,and cognitive impairment. Age and cognitive impairment, which was shown to be associated with hearing
15)16)
loss . Cognitive impairment was defined as a Mini17)18)
Mental State Examination (MMSE) score <23 .
Regarding to alarm type, alarm A was used as
reference for B1, B2, and B3. Patient ID was used as
the random effect. The odds ratios and 95% confidence intervals (95% CIs) of these variables were
estimated using the model. In the case of odds ratio
greater than 1, alarm detectability of B1, B2, B3, orage, was higher rather than reference, and was higher
with advancing age, respectively.
7. Ethical considerations

time measured was as follows (Figure 2): the time of
the buzzer or vibration going off (a), the time theparticipant heard the buzzer or felt the vibration (b),and the cutoff point was 45 s. By subtracting (a) from(b) or 45, the detectability in this study was defined asfollows: <5 s, participants were determined to be able
to detect the alarm (positive detectability), and ≥5 s,
the alarm was considered to have not been properly
detected (negative detectability). If participants could
detect the vibration over 5 s after vibration alarmThis study protocol was approved by the EthicalCommittee of the Graduate School of Medicine, The
University of Tokyo, Tokyo, Japan (study number
2020107N1). Written informed consent to participate
in the study was obtained from all participants. The
study was conducted in accordance with the STROBE
statement and ethical guidelines of the Declaration of
Helsinki.

starting, it denoted negative detectability.
6. Statistical analysis

Results

Descriptive data are expressed as mean±standard
deviation (SD) for continuous variables or as n (%) for
categorical variables. The proportion of alarm detection for each alarm version was calculated as follows:

During the 3-month study period, 182 patients aged
≥70 years were hospitalized in a gastroenterology
inpatient unit. Approximately 84 patients left the(number of participants detecting an alarm/all participants) ×100. All statistical analyses were performed

patients, sixty patients agreed to participate in the
study. We excluded 13 patients due to insufficient

hospital before enrolling as participants. Of 98― 172 ―

Journal of Nursing Science and Engineering（2023）

Table 1of hearing was 18 (38.3%), and use of hearing aids wasCharacteristics of participants

Characteristic
Age (years)

79.72 (5.26)

Sex (male)31 (66.0)

Body mass index

23.04 (3.87)

Scores < 18.5

4 (8.5)Mini-Mental State Examination

MMSE scores >24 and <23 was 24 (58. 5%) and 17(41.5%), respectively. Six participants refused tocomplete the MMSE.
The average value and SD in measurements

24.04 (4.13)

Scores > 24

24 (58.5)

Scores < 23 (cognitive impairment)

17 (41.5)

History of smoking

three (6.4%). The average value and SD for the MMSE
were 24.04 (4.13), and the number of participants with

N=47

subtracted a from b of the four alarms were 6±4.03(A), 5. 42±6. 83 (B1), 1. 29±1. 44 (B2), and 1. 10±2. 39(B3), respectively. Plots of the participants with andwithout the ability to detect each alarm as an outcome
are shown in Figure 3. Each number of participants,
and proportion below the dotted line (5 seconds),

25 (53.2)

Barthel index

18.93 (3.39)

Number of pharmacies

5.93 (3.32)

Diabetes mellitus

19 (40.4)

Hypertension

25 (53.2)

which was being able to detect the alarm, was 19 (A:40. 4%), 31 (B1: 65. 9%), 46 (B2: 97. 8%), and 46 (B3:

Measurement position at axilla
Right

24

Left

23

Information related to hearing loss
Hearing impairment

10 (21.3)

History of noisy job

6 (12.8)

Subjective hard of hearing

18 (38.3)

Right

9

Left

9

Use of hearing aid

3 (6.4)

Platinum antitumor agent

1 (2.1)

Values are mean (standard deviation) or number ofparticipants (%).

data (n = 2), withdrawal before performing statisticalanalysis (n = 2), and catching infections, including
coronavirus or deterioration in condition before

97.8%), respectively. Regarding the participants withcognitive impairment (MMSE scores <23, n=17), thenumber of participants and proportion, being able todetect the alarm, was 3 (A: 17.6%), 10 (B1: 58.8%), 17(B2: 100%), and 16 (B3: 94%), respectively. The mean
body temperature was 36.3℃ (SD 0.37) for B1, 36.41℃(SD 0.44) for B2, and 36.39℃ (SD 0.37) for B3.
As shown in Table 2, generalized linear mixedeffects model analysis using the adjusted model, alarm
detection was positively associated with alarm type,and age (odds ratios 0.81, 95% confidence interval 0.67
to 0.99; P = 0.042), but not between MMSE (odds ratios
0. 2, 95% confidence interval 0. 02 to 1. 49; P = 0.118).
The odds ratios (95% confidence interval, P value) of
B1, B2, and B3 in the adjusted model were 4.98 (1.15 to
21.51, P = 0.031), 688.92 (23.36 to 20316.95, P < 0.001),
and 688.92 (23.36 to 20316.95, P < 0.001), respectively.

starting the research (n = 9). Therefore, complete data

Discussion

were obtained from 47 participants (31 male, 16
female) with a mean±SD age of 79.7±5.26 years. The
type of patient room was divided into three types,
single room (n = 6), a room for two patients (n = 15),
and a room for four patients (n = 36). The clinicalThis clinical study represents the first effort toidentify the type of electronic axillary thermometer
alarm (higher volume and lower frequency, vibration,or all three features) that can be an independent factor

characteristics of the 47 participants were as follows:esophageal cancer (n = 4, 8.5%), stomach cancer (n = 4,

for detecting the thermometerʼs alarm signal inpatients aged ≥70 years, regardless of cognitive

8.5%), pancreatic cancer (n = 6, 12.8%), liver cancer (n= 9, 19.1%), biliary tract cancer (n = 2, 4.3%), colorectal
cancer, and lateral spreading tumor (n = 13, 27. 7%),cholangitis (n = 5, 10. 6%), and others (n = 4, 8. 5%).

impairment. Figure 3 shows that almost all participants using alarm B2 and B3 were below the dottedline (5 seconds), which indicated positive detectability.
Although one participant could not detect theTable 1 presents the demographic data of theparticipants. The number of patients with hearing

vibration or another patient could not detect thesignal when all three features were used, this was well

impairment due to disease or accident was 10 (21.3%),
history of a noisy job was six (12.8%), subjective hardwithin tolerance. For verifying associations between
alarm detectability and alarm types in a generalized― 173 ―

Journal of Nursing Science and Engineering（2023）

Figure 3 Age-categorized distribution data of participantsʼ ability to detect the alarm
X-axis indicates age, and Y-axis indicates the values after a is subtracted from b.
Participants below the dotted line (< 5 s) were determined to be able to detect the alarm, as
positive detectability. Participants over the dotted line (≥ 5 s) were determined to not havedetected the alarm, as negative detectability. The number of participants (proportion)
below the dotted line was 19 for A (40.4%), 31 for B1 (65.9%), 46 for B2 (97.8%), and 46 for B3(97.8%).

linear mixed-effects model, alarm types had significant association with alarm detectability. The odds
ratios of alarm detectability B2, and B3 were highest.
According to these results, it is thought that alarm

possibility that the change in frequency and volume
contributed to an increasing number of participants
being able to detect the buzzer alarm. To date, noresearch has compared the alarm detectability ofdetectability of B2, and B3 was higher rather than A,
and B1 in older adults aged ≥70 years. Thereby, theaxillary thermometers with different alarm types.
Owing to the lack of published research regarding thebest alarm types of axillary thermometer for in older
adults aged ≥70 years with or without cognitive
impairment were vibration and the mixed version.
The proportion of participants aged ≥70 years who

detectability of alarm beeping, there is a paucity ofdata against which to benchmark the findings of thisstudy. Referring to the ISO 7029 standards in men and19)
women , older adults aged ≥70 years could hear asound of 60 dB at frequencies from 2000 to 4000 Hz.

could detect the buzzer alarm with high frequency (A)and those with higher volume and lower frequency(B1) was only 40.4% and 65.9%, respectively. We did
not determine which function, bigger volume or lower
frequency, did contribute to good alarm detectabilityof B1, as separate verification of each function has notbeen conducted. However, the odds ratio of B1 (4.98)
was higher than C205 in Table 2, this suggests the

The average pure-tone audiogram in different age
groups in Japanese (ranging from 20 to 84 years withan increment of 5 years) showed that the averagehearing threshold in both men and women aged 70‒74
20)
years was 40 dB at 4000 Hz . However, even if
frequency and volume were improved in this age
group, approximately 35% of the participants had no― 174 ―

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Table 2 Generalized linear mixed-effects model for the factors associated with detecting the alarm
Crude model
Variables

OR(95% CI)

Adjusted model
p-valueOR(95% CI)

p-value

Alarm B-1

7.18

(1.73-29.78)

0.007

4.98

(1.15-21.51)

0.031

Alarm B-2

811.78(30.43-21655.50)< 0.001

688.92(23.36-20316.95)< 0.001

Alarm B-3

811.78(30.43-21655.50)< 0.001

688.92(23.36-20316.95)< 0.001Age

0.92(0.86-0.98)

0.015

0.81

(0.67-0.99)

0.042

MMSE

0.46

(0.21-1.03)

0.062

0.2

(0.02-1.49)

0.118

CI, confidence interval, OR, odds ratio
MMSE, Mini-Mental State Examination

ability to detect the buzzer signal (B1). Alarm
detectability was less affected by the laterality of themeasurement position when the measurement position at the axilla was randomly assigned for equality
on the left or right. The number of participants withsubjective hearing difficulties was the same for theright and left sides. Therefore, the negative factor ofbuzzer detectability was not due to the laterality ofthe measurement position (right or left), but the closed
environment within the axilla.
Aging has long been associated with a decline insensory function, which is a critical component of the21)
health and quality of life of older adults . Individual
sensory impairments are common. The prevalence ofhearing loss (33%) and vision impairment (18%) is high22)23)
among older adults aged ≥70 years . Impairment of
the sense of touch has been found in adults as young24)
as 55 years . However, in our study, almost all older
adults could detect the vibration at the axilla due toeffects of the silicone attachment. Thermometer
misplacement at the axilla due to reduced muscle
mass or skin folds associated with age-related
sarcopenia did not enable these patients to measure
their body temperature, as the thermometer tip andprobe could be in less contact with the skin at theaxilla. Thus, a new silicone attachment to the CTEB
720VA was developed to enable contact with the skin.
On the other hand, a silicone attachment withviscoelasticity also had a negative side regarding
vibration absorption of alarm signal. However, almost
all older adults could detect the vibration alarm at theaxilla for a few seconds (average, 1. 29). There is apossibility that the surface area of the thermometerprobe would be created more than expected due tosilicone attachment, and larger propagation of vibration contributed to enable good detection of vibration

alarm.
Age was also positively associated with alarm
detection, and the odds ratio (0. 81) was less than 1.
This indicates that alarm detectability was lower withadvancing age. As the prevalence of hearing loss in7)8)
older adults increases with age , it is quite possiblethat older adults, whose alarm detectability is
negative, increase with aging. However, almost all
participants using alarm B2 and B3 were positive
detectability, regardless of age. As shown to Figure 3,
possible causes include that the numbers of participants, who were able to detect alarm A and B1,
decrease with aging.
Vibration is an important feature of thermometer
alarms that allows for easier detection of alarm signals
in adults aged ≥70 years with or without cognitive
impairment. All participants with cognitive impairment had detected vibration alarms, and the odds
ratios of vibration and mixed-version alarms werehighest in adults aged ≥70 years in this study,
regardless of cognitive impairment. The proportion ofparticipants who could detect the buzzer alarm withhigher volume and lower frequency (B1), or mixedversion (B3) was 65. 9%, and 98%, respectively. Just
including vibration in buzzer alarm, the proportion ofparticipants who could detect the alarm increased
over thirty percent. Using the vibration alarms of the
CTEB720VA, older adults with cognitive impairment
were able to measure their own body temperature if
they received assistance in maintaining the temperature probe in an accurate position. In addition, we
recommend using different positions for each alarm.
The CTEB720VA was used for additional resounding
and vibrations. Clinical nurses also could hear thevibration alarm, even if they were close to patient
during body temperature measurement by the― 175 ―

Journal of Nursing Science and Engineering（2023）

CTEB720VA. However, the clinical nurse often
missed hearing vibration alarm due to loud environ-deepest gratitude to CITIZEN SYSTEMS Japan Co.,
Ltd. for providing detailed information on the alarm

ment in patient room or having conversation withpatients. The use of a mixed thermometer may be
optimal for healthcare professionals. In addition, thesystem for the CTEB720VA and disclosing confidential information on the thermometer alarms.

use of a thermometer with vibrations may be optimalfor self-management in community-dwelling older
adults.

Conflict of Interest
All authors and persons involved in the projectgroup confirm that they have no financial or other

One important limitation of this study is that
community-dwelling older adults who most likely
required temperature measurements were not included. This study was conducted in the inpatient unit

interests concerning the manufacturers or vendors.

of a university hospital. Older adults with fever or
acute illnesses were excluded from this study.

1) Fulbrook P. Core body temperature measurement: A

Therefore, the results may not have been generalizable to all older adults, particularly those who most
likely need temperature measurement, such as thoseliving in the community and those with persistentpulmonary artery blood temperature. Intensive Crit

high fever >38.0℃. In addition, we could not show arelationship between an environmental noise ofpatient room, and alarm detectability. The primaryresearcher subjectively confirmed that noise level ofeach patient room has not been changed whenparticipants measured their body temperatures forfour times by two electronic axillary thermometers.

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Conclusions

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Acknowledgments

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原著

70 歳以上高齢者における腋窩電子体温計のアラーム検知の比較：
ブザーアラーム，振動アラーム，ブザー / 振動アラーム
/）

0）1）

小谷野結衣子 ・仲上豪二朗

・真 田 弘 美

0）−2）

/）

東京大学医学部附属病院看護部

0）1）

東京大学大学院医学系研究科老年看護学/創傷看護学分野

東京大学大学院医学系研究科附属グローバルナーシングリサーチセンターケアイノベーション創生部門
2）

石川県立看護大学要

旨

目的は 70 歳以上の高齢者を対象に腋窩体温計0種に備わった2つのアラームの検知結果を比較することである．デザインはランダム化クロスオーバー試験で全参加者が2アラームで体温を測定した（高音域ブザーＡはリファレンス，音量大で低音域ブザー B1，振動 B2，振動とブザー B3）．参加者がアラームを検知した秒数からアラームが鳴った秒数を差し引き，アラーム検知可を3秒未満と定義した．参加者 47 名の平均年齢は 79.7 歳，アラームを検知できた人数（％）
はＡが 19 人（40.4），B1 が 31 人（65.9），B2 が 46 人（97.8），B3 は 46 人（97.8）であった．アラームタイプと年齢がアラームの検知に有意に関連しており，ミニメンタルステート検査に関連はなかった．各オッズ比は B1 が 4.98，B2 が688.92，B3 が 688.92，年齢が 0.81 であった．振動は認知機能低下にかかわらず 70 歳以上のアラームの検知に重要であることが分かった．

キーワード：加齢，認知機能低下，難聴
キーメッセージ
ઃ．今回の研究は看護・介護のどのような問題をテーマにしているのか？
研究を行うきっかけとなったことはどのようなことか？
・高齢者にとって腋窩体温計のブザーアラームのように高音域の電子機器音は聞き取りづらい．
・ブザーアラーム聞き取り調査を実施すると（対象者 107 人の平均年齢：70.9 歳），対象者 58 人（54.2％）がア
ラームを聞き取れていなかった．
・今回は 70 歳以上の高齢者を対象に，振動・低音域ブザーといった新しいアラームを有する腋窩体温計を用いて，どのアラームが最も聞き取れるか評価した．
઄．この研究成果が看護・介護にどのように貢献できるのか？あるいは，将来的に貢献できることは何か？
70 歳以上の高齢者は振動アラーム付き腋窩体温計を使用すれば振動を検知できるため，病院または自宅でサポートがなくても正確に体温管理ができる可能性がある．
અ．今後どのような技術が必要になるのか？
非接触型体温計は数秒で体温測定ができるためコロナ禍で市場が拡大した．腋窩体温計（測定に 30〜35 秒を要す
る）の汎用性を維持するためには，測定時間の短縮化が課題である．

― 178 ―