Keywords

1 Introduction

A society is considered to be aging when the percentage of its population who are 65 or older passes 7%. And when that percentage exceeds 14%, the society is considered to be rapidly aging. When it passes 21%, it is considered a super-aging society. In 2018, our country’s total population was 126,440,000, and the number of people 65 or older was 35.58 million, which corresponds to 28.1% of the total population. Our country is a super-aging society, and the percentage of people 65 or older will continue to rise. It is estimated to peak in 2042. According to the report “Estimated Future Population of Japan” that the National Institute of Population and Social Security Research Center published in April 2017, the country is in a long-term population decline, and as the overall population declines, those who are 65 and older continues to increase, meaning the ratio of elderly to the total population will continue to rise. By 2036, the ratio of the elderly is expected to reach 33.3% and rise to 38.4% by 2065 [1].

The bodies of elderly people experience physical decline due to aging. Even a trivial matter can end up sending an elderly person into a nursing care facility. In 2016, the average life expectancy in Japan, a country of long lifespans, was 80.98 years for men and 87.14 years for women. However, health problems that affect everyday living mean that as of 2016, men could live normally without restrictions for 72.14 years on average, while women could do so for 74.79 years on average [2]. The gap between life expectancy and healthy life expectancy indicates the amount of time someone is living without good health and with limits on their everyday life. For men, the span of living without good health is 8.84 years. For women it is 12.35 years. Of course, the level of ill health varies greatly from person to person, but within that group, the group of people needing care is included.

The rate of aging is on the rise, as is the ratio of elderly to the total population, which brings up the issue of taking care of the elderly. Because it will be necessary to increase the number of facilities that can accommodate elderly people needing care, it will also be necessary to increase the number of people who can work in those facilities. In 2018, the ratio of job openings to job applicants across all types of work was 1.45 times, and the ratio for caregiving-related work was 3.90 times. The ratio for caregiving was about 2.7 times more than the ratio for all jobs, setting a high bar [3]. According to the Survey of Care Workers published for fiscal 2018 by the nonprofit Care Work Foundation, there is a shortage of workers engaged in caregiving services. According to the fiscal 2018 survey, 67.2% of the caregivers said they felt that there was a shortage of workers [4]. In the 2013 survey, 56.5% of workers said they experienced a shortage of workers. In the five years beginning in 2013, the rate of shortage continued to increase. In these circumstances, Japan has been trying to compensate by hiring foreigners, but since the percentage of elderly will continue to rise for quite a while, there will be a lot of obstacles in the effort to find sufficient staffing. The Ministry of Health, Labor, and Welfare has been supporting the development and usage of assistive technology and robotics [5]. The aim is to give autonomy to the care receivers, and to lighten the burden on caregivers.

This research focuses on the preservation of safety for care receivers and the lightening of the burden on caregivers, and reports on the monitoring sensors to observe the elderly in nursing care facilities on behalf of the caregivers. Of the elderly in nursing care facilities, some may take abnormal actions and fall from their bed because of dementia or a decline in physical functions. To keep these elderly people from injuring themselves and getting in accidents, caregivers must keep an eye on them, but because they are serving several care receivers at one time, it is not possible to keep an active watch on every individual. If they look away and something happens, there is a danger that they may not be able to protect the safety of the people in the care facility. This is not something that is out of the ordinary. As we know from the way the caregivers feel the effects of the labor shortage mentioned previously, there is a big burden placed on caregivers working at nursing care facilities. This research looks at the effectiveness of monitoring sensors as a way to lessen the strain on both care receivers and caregivers. Up till now, to prevent residents from falling or to detect abnormal behavior, mat sensors [6], bed sensors [7], infrared sensors [8], clip sensors [9] have been used, but all of them have their strong and weak points. Use of these sensors alone cannot assure the safety of the care receivers. In this survey, the Watch Over Sensor (WOS-114N) by King Tsushin Kogyo Co., Ltd. (referred to as “monitoring sensor” hereinafter) is used. These sensors have been placed in multiple nursing care facilities and used to help caregivers monitor care receivers, to verify their usefulness. In detail, we gathered data from the monitoring sensors used on residents of the nursing-care facility, then analyzed that data both quantitatively and qualitatively. By using the monitoring sensor, it was observed that the caregiver won’t have to focus solely on one care receiver, but would be able to assist another person or do other work. But depending on the way the monitoring sensor was used and the environment in which it was used, it is difficult to say whether some of the sensors were being used correctly. Through this survey, not only the usefulness of the monitoring sensor, but also problem areas and points for improvement became clear. In the near future, monitoring sensors that have fixed those problem areas and improvement points will monitor the safety of the care receivers and lighten the burden on the caregivers.

2 Method

2.1 Outline

Monitoring sensors have been placed in many nursing-care facilities, and we had the caregivers use the monitoring sensors on the selected care receivers during the survey period. We saved all the data gathered from the monitoring sensors. After the survey period, we analyzed all the data and sorted the places where the sensors were working correctly and where they were not. Then we considered the places where the monitors were not working correctly.

2.2 Survey Period

The period for our research was for 12 months, from 18/12/2018 through 8/1/2020.

2.3 Recording Procedure

In our research, we used the Watch Over Sensor (WOS-114N) by King Tsushin Kogyo Co., Ltd. and gathered data throughout the survey period.

In our research, sensors were placed in the care receivers’ rooms, so that the actions of those people could be observed in real time. However, these monitoring sensors did not use surveillance cameras. In consideration of the care receivers’ privacy, their actions were recorded in silhouette, and their movements were able to be viewed. In other words, to observe the care receivers’ movements, the monitor showed shadowy figures that made it difficult to identify specific individuals. These silhouette figures looked the same during the day and night through the monitor, which meant there was no restriction on the timing of their usage. Other characteristics are described below (Fig. 1).

Fig. 1.
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Actions are recorded in silhouette.

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The actions of the subject being monitored could be detected and broken down into different categories such as (1) getting up, (2) jutting out, (3) getting out of bed, (4) standing up, and (5) no movement, and an alarm could go off (Fig. 2). Because of this, the caregiver would know that the care receiver may fall out of bed and can rush to the care receiver, helping to protect the care receiver’s safety. The data sent by the monitoring sensor is transmitted over a wireless LAN in the facility and sent to the caregiver’s station or to a tablet or a smartphone. During the monitoring, if an action that sets off an alarm is detected, the alarm will ring, but to make sure whether it is a true emergency, they can check the monitor or the tablet. When the alarm sounds, but when the caregiver checks, he or she sees that it is only the care receiver turning in bed, the caregiver can tend to a higher priority care receiver first (Fig. 3). Also, because all of the data can be stored, the caregiver can look back at the actions of the care receiver that were missed. This will help in grasping the characteristics of each care receiver’s daily life. Our survey used the data saved for this function.

Fig. 2.
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The actions of the subject being monitored could be detected.

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Fig. 3.
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Operation example.

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3 Results and Discussion

3.1 Case Study of Alarms During Observation Period

Figures 4, 5, 6 and 7 indicate video for actual detection of jutting out and getting up. Figure 4 shows the beginning of the video from a monitoring sensor observing a care receiver. The care receiver is lying on the bed without a problem, but the blanket is hanging on the railing, and the alarm went off detecting what it thought to be a jutting out. When the care receiver observes that the blanket is hanging over the railing, Fig. 5 shows the car receiver raising an arm, which sets off the alarm for jutting out again. At the start of the observation, because the blanket is hanging on the railing, the monitoring sensor senses that the height reflects the highest spot, and it automatically adjusts the range of its inspections for jutting out and getting up. Figure 6 shows the caregiver coming to the bedside of the care receiver because the alarm went off. Continuing to Fig. 7, the care receiver has not gotten up, but by grabbing the blanket that looks like it is going to fall, the monitoring sensor detects a getting up action and sounds the alarm. After that, the alarm went off frequently during the night.

Fig. 4.
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Beginning point of observation.

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Fig. 5.
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An arm is raised and “jutting out” is detected.

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Fig. 6.
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The caregiver responds.

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Fig. 7.
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By raising the blanket, “getting up” is detected.

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Because of detection of jutting out or getting up, the alarm is sounded, and the caregiver can go to the care receiver before she falls out of bed or makes some abnormal movement. Even if a caregiver is looking after several care receivers at the same time, this allows for the care receiver to remain safe. That is one thing that can be said by these series of images. This is the intended usage of the monitoring sensor, but on the other hand, at the start of the observation, the alarm going off unnecessarily may cause problems later for the caregiver. In Fig. 4 at the start of the observation, the care receiver is not engaging in any abnormal actions. But the fact that the alarm continues to go off, but the caregiver does not change its settings shows that in Fig. 5, just by raising an arm, the alarm is set off again. The fact that a care receiver lying on the bed raises an arm is not a particularly dangerous action, but when the alarm goes off, the caregiver has to go to the bedside. The fact that the action is not dangerous, but the alarm still goes off means the caregiver will gradually get used to the situation. The fear is that the caregiver will not come to the bedside. Depending on the condition of the care receiver, it may be necessary to have settings indicating when a person raises their arm. However, as shown in this series of images, it may be necessary for a caregiver to adjust the settings on the alarm to protect the care receiver’s safety. That does not happen in this video. It could be because the caregiver does not know how to adjust the settings or that she does not realize that there is a way to adjust the alarm settings on the monitoring sensor. It is necessary to find a method for the caregiver, who does not have spare time to read the manual during work, to quickly and easily understand how to use the sensor.

3.2 Case Study of When Alarm Goes off Unnecessarily Because of the Care Receiver’s Movement

In Fig. 8, the observed care receiver does not move, yet “getting up” is detected and the alarm sounds. In the upper left of the Fig. 8 image, there’s some interference from a black lump. The monitoring sensor has detected this as the care receiver getting up. The origin of this interference could not be confirmed, but it could be sunlight coming in from the window. In Fig. 9, the care receiver is not in bed, and yet a “getting up” action is detected. This is similar to Fig. 8 in that it looks like the sunlight shining in the window set off the alarm. Looking at the data of this example, we came to understand that as the sunlight shines in at an angle, hitting the window that is being filmed for a short time, creating occasional interference. Even though when confirming the image, it is clear that no one is on the bed, the interference continues to set off the alarm from time to time day and night. The signal to shut off the alarm cannot be found in the data. It’s plausible to think that as the alarm continues to go off, it will be neglected or that the alarm will be set so that it cannot be heard. It can be assumed from here that usage of the monitoring sensor could cause an accident. There were also images that were set off as “standing” or “getting up” when a car headlight shone through the window at night. The weak point of the monitoring sensor is that it registers false positives based on rays of light, which means the person installing the monitor must take this into consideration when finding the proper environment to install it. For example, blackout curtains could be used to shut out the interference.

Fig. 8.
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Interference in the image sets off a “getting up” detection.

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Fig. 9.
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Interference in the image sets off a “standing up” detection.

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3.3 Example of Alarm Sounding for Someone Other Than the Care Receiver

Data acquired from the facility in Fig. 10 shows a translucent partition next to the care receiver’s bedside to divide up the room into sections. Looking at Fig. 10, we see the caregiver’s reflection in the upper left of the image on the other side of the partition. The care receiver is lying on the bed without any issues, but the monitoring sensor picks up the image of the caregiver and registers a “getting out of bed” detection. This is not a false positive of the monitoring sensor, but a problem of the environment in which the sensor is set. To eliminate the false positive, the monitoring sensor should be installed as aforementioned explanations on how to avoid environments such as in examples Sects. 3.2 or 3.3.

Fig. 10.
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Caregiver’s reflection sets off a “getting out of bed” detection.

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3.4 Case Study of Caregiver not Being Sent While Alarm Rings

In the image from Fig. 11, at 4 h 16 min and 40 s, the care receiver gets up in bed and makes a gesture as if searching for footwear on the floor. The monitoring sensor detects a “jutting out” and sounds the alarm, but the caregiver does not visit. Eighteen minutes pass in the images when, at 4 h 34 min and 25 s, the monitoring sensor detects a “getting out of bed” motion and sounds the alarm (Fig. 12). Immediately after that, the caregiver arrives. The reason for the caregiver not coming for a long time despite the alarm sounding is that the caregiver can check the terminal he is caring during work and see why the alarm is sounding. The caregiver can check the smartphone during work to monitor the care receiver. For example, while tending to another care receiver, the alarm goes off and the caregiver can see the images of that care receiver and can make a judgment about the priority of serving the different care receivers. When the caregiver confirmed the images in Fig. 11, the decision was made that it was not an emergency. But after that, when confirming the images of Fig. 12, seeing that it was necessary to rush to the care receiver’s bedside, so that she would not fall out of bed, the caregiver was able to act. This is especially useful for caregivers working the night shift who are likely to be shorthanded. It limits the wasted movements of the caregiver and connects to increased safety for the care receiver.

Fig. 11.
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A dangerous movement results in “jutting out” detection.

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Fig. 12.
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A dangerous movement results in “getting out of bed” detection.

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3.5 Case Study of Caregiver Adjusting the Monitoring Sensor

Figure 13 is the image immediately after observation begins. The image shows the care receiver on the bed with her knees pointing up. Because nothing is detected, the alarm is not going off. However, about 7 s after the observation the images are temporarily suspended. After that, the caregiver comes to the care receiver’s bedside and adjusts the care receiver’s posture by extending the legs, as seen in Fig. 14. In this example, the caregiver understands that the monitoring sensor needs to be adjusted. Probably, the caregiver checked the images on the smartphone, noticed that the care receiver’s knees were extending into the area where a jutting out should be detected, quickly stopped watching and adjusted the care receiver. At the beginning of the observation, the care receiver had her knees up, and the high point of the knees was seen as the baseline, so that the monitoring sensor adjusted accordingly to detect jutting out, getting up, and getting out of bed actions. If the sensor detected the knees in Fig. 13 as the baseline, even if the care receiver tried to get up, it is possible that the alarm for getting up would not go off. This makes it more difficult to keep the care receiver safe. In this example, after adjusting the care receiver’s posture, it would be ideal to restart the observation through the monitoring sensor.

Fig. 13.
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Knees are up when the observation begins.

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Fig. 14.
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Caregiver makes adjustments.

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3.6 Case Study of Alarm Going off for a Long Time

Figure 15 continues images from example Sect. 3.5. The height of the care receiver’s knees is adjusted, and the monitor is reset, but the monitoring sensor detects a jutting out action when the blanket droops along the side of the bed. It is clear from the data that the alarm goes off from this point for a long time. But since no adjustments are made, the care receiver is seen through the smartphone as not being in danger, the continuous alarm is annoying, and it may have been set to no longer go off.

Fig. 15.
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Blanket’s position results in “jutting out” detection.

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4 Conclusion

To ensure the safety of care receivers in a nursing-care facility and lighten the burden on caregivers, monitoring sensors are used to verify their usefulness. In some places, the proper use of the monitoring sensors is achievable, but it is clear that for various reasons, unexpected problems arise.

For the monitoring sensors to be used beneficially, it is necessary to explain to the caregiver the proper way to use them. To use the monitoring sensors to observe care receivers, first the range of detection of the monitoring sensors must be set, but there are caregivers who use the sensors without knowing about this function. The proper way to use the monitoring sensors is written in the manual, but the very busy caregivers don’t have the time to carefully read the manual while on the job. To solve this problem, the explanations shouldn’t be on paper. Instead, a device is needed to correct wrong usage while the sensors are being used.

To use the monitoring sensor functions correctly, it’s necessary to prepare ahead of time in an environment that limits interference. This survey indicates that sunlight and car headlights can cause such interference. This is an unexpected situation involving the development of the monitoring sensor, and some improvement is required. Of course, it is important to alert users as to the proper environment in which to use the sensors, but when interference appears in unsuitable environments, the alarm is set off by things other than the care receiver’s actions, a function that can filter out the interference should be considered.

This survey found those problems and points for improvement, but also found in the data that proper use of the monitoring sensors connects to the safety of care receivers and the lightening of the burden on caregivers. There is also the thought that to increase the safety of the care receivers, a surveillance camera may be useful. But that infringes on the privacy of the people being observed. The monitoring sensors studied in this survey do not infringe on privacy and also have the advantage of delivering the same quality images both day and night. To take advantage of that strength, improving many of the problems indicated in this survey should allow for better usage of these monitoring sensors.