Yukitoshi Kashimoto

Beacon-based multi-person activity monitoring system for day care center

Recently, as elderly people population grows, the burden on caretakers are getting larger. In day care center, caretakers are taking care records aiming to improve care receivers Quality of Life (QoL). However, in the present situation, it is difficult for caretakers to record care receivers activity in detail because each care worker needs to take care of several care receivers at the same time and it is a large burden. To reduce the burden of caretakers, many elderly monitoring systems have been proposed so far, but most of them are not effective in the sense that they force care receivers to use dedicated device such as smart phone and/or particular applications that are obtrusive and cumbersome for care receivers. In this paper, we propose a novel elderly monitoring system which can monitor movements/activity of multiple care receivers at the same time by estimating existence area of each of the care receivers, without burdening them. Our proposed system estimates multiple care receivers existence area only using RSSI (Received Signal Strength Indication) of BLE (Bluetooth Low Energy). The feature of our proposed system is that it takes Movable-Beacon and Fixed Scanner style. We have validated the proposed system and confirmed that we can estimate multi-persons existence area at high accuracy using only BLE devices.

Low-cost and Device-free Activity Recognition System with Energy Harvesting PIR and Door Sensors

Progress of IoT and ubiquitous computing technologies has strong anticipation to realize smart services in households such as efficient energy-saving appliance control and elderly monitoring. In order to put those applications into practice, high-accuracy and low-cost in-home living activity recognition is essential. Many researches have tackled living activity recognition so far, but the following problems remain: (i)privacy exposure due to utilization of cameras and microphones; (ii) high deployment and maintenance costs due to many sensors used; (iii) burden to force the user to carry the device and (iv) wire installation to supply power and communication between sensor node and server; (v) few recognizable activities; (vi) low recognition accuracy. In this paper, we propose an in-home living activity recognition method to solve all the problems. To solve the problems (i)--(iv), our method utilizes only energy harvesting PIR and door sensors with a home server for data collection and processing. The energy harvesting sensor has a solar cell to drive the sensor and wireless communication modules. To solve the problems (v) and (vi), we have tackled the following challenges: (a) determining appropriate features for training samples; and (b) determining the best machine learning algorithm to achieve high recognition accuracy; (c) complementing the dead zone of PIR sensor semipermanently. We have conducted experiments with the sensor by five subjects living in a home for 2-3 days each. As a result, the proposed method has achieved F-measure: 62.8% on average.

Saving energy in smart homes with minimal comfort level reduction

In this paper, we propose an energy-saving device control method with the minimal reduction of users comfort level. Given the past histories of devices states and the target energy-saving ratio, our method first assigns each device the weight proportional to the comfort level deterioration when reducing energy supply to the device by a unit of energy and reduces more energy supply from less weighted devices, in order to achieve the target-energy-saving ratio. Moreover, we propose a method for constructing power consumption models of devices based on measurements of actual power consumption of real devices and a method for constructing comfort level functions of users based on the questionnaires. Through simulations, we confirmed that the proposed method achieves the target energy saving ratio with small comfort level reduction.

Elderly person monitoring in day care center using Bluetooth Low Energy

Recently, as elderly people population grows, the burden on caretakers are getting larger. In day care center, caretakers are taking care records aiming to improve care receivers Quality of Life. However, in the present situation, its difficult for caretakers to record care receivers activity in detail because each care worker needs to take care of several care receivers at the same time and it is a large burden. To reduce the burden of caretakers, many elderly monitoring systems have been proposed so far, but most of them are not effective in the sense that they force care receivers to use dedicated device such as smart phone and/or particular applications that are obtrusive and cumbersome for care receivers. In this paper, we propose a novel elderly monitoring system which can monitor movements/activity of multiple care receivers at the same time by estimating existence area of each of the care receivers, without burdening them. Our proposed system estimates multiple care receivers existence area only using RSSI of BLE (Bluetooth Low Energy). The feature of our proposed system is that it takes Movable-Beacon and Fixed Scanner style. We have validated the proposed system and confirmed that we can estimate multi-persons existence area at high accuracy using only BLE devices.

Twinkle Megane: Near-Eye LED Indicators on Glasses for Simple and Smart Navigation in Daily Life

We present an eyeglass-type wearable device that has light emitting diode (LED) indicators on the frame of it. The device produces lighting patterns of 14 RGB LEDs near user’s eyes as guiding information. Since installed LEDs on the frame of glasses are light and saving power, it is feasible to develop it for daily use. On the other hand, it cannot provide rich information such as text or images. In this study, we aim to realize a remote assistive system that provides assistive commands by lighting patterns of the eyeglass-type device from remote sites. Especially, we consider elderlies who are suffering from mild cognitive impairment as users. They would be one of potential user groups since the device does not block their sights by text or images and it can be worn in daily life without the additional sense of restraint. This paper explains our conceptual assistive system structure, a prototype eyeglass-type device with near-eye LED indicators and usability experimentation in simple navigational tasks.

Floor vibration type estimation with piezo sensor toward indoor positioning system

These days, smart home applications such as a concierge service for residents, home appliance control and so on are attracting attention. In order to realize these applications, we strongly believe that we need an indoor positioning system which fulfills the following requirements: Req 1: high accuracy; Req 2: low installation cost; Req 3: small burden on the user; Req 4: low privacy invasion. There are several studies which work on the indoor positioning system. However, these previous works do not accomplish the requirements. In this paper, we present a piezo sensor-based indoor positioning system which estimates the position of the user by utilizing a piezo component attached on the floor. To realize the proposed positioning system, we have tackled two challenges. First challenge is the development of an indoor positioning technique. We cannot utilize TDoA technique that is used to estimate the distance from the target, since the calculation of vibration velocity is difficult. To cope with this challenge, we have developed a new technique which estimates the position of the user from floor vibrations caused by their actions. Second challenge is the selection of the feature vector to estimate the vibration type accurately. We have selected MFCC, FFT, and Envelope shape features from preliminary experiments. We have implemented the proposed system in our smart home testbed. We have evaluated the performance of the vibration type estimation technique. As a result, we have confirmed that our technique estimates the type with F-measure: 93.9%.

Sensing Activities and Locations of Senior Citizens toward Automatic Daycare Report Generation

Recently, as elderly people population grows, the burdens on caretakers are getting larger. In daycare centers, caretakers make a daycare report aiming to improve the senior citizens Quality of Life. However, in the present situation, it is difficult for caretakers to record the senior citizens activity in detail, since each caretaker needs to take care of several senior citizens at the same time. To reduce the burden of caretakers, many elderly monitoring systems have been proposed so far, but most of them are not effective in the sense that they force the senior citizen to use dedicated devices such as smart phone and/or particular applications that are obtrusive and cumbersome for care receivers. In this paper, we propose a semi-automatic care-taking report generation system which can monitor movements/activity of senior citizens in daycare centers. Our proposed system estimates multiple locations (areas) where senior citizens are located with the BLE beacon, by utilizing RSSI of the Bluetooth radio wave. Also, the accelerometer implemented in the tag estimates the activity of the elderly. The information of the estimated area and activity is stored in a server with time stamp. The server generates the daycare report based on it. In order to evaluate the proposed system, we have deployed our system in a daycare center: Ikoi-no-ie 26. Evaluation result in Ikoi-no-ie 26 showed that our system estimated the subjects present area with F-measure: 80.6% and activity with F-measure: 73.8% and generated the daycare report.

Twinkle Megane: Evaluation of Near-Eye LED Indicators on Glasses for Simple and Smart Navigation in Daily Life

We present an eyeglass-type wearable device that has light emitting diode (LED) indicators on the frame. The device produces lighting patterns of 14 RGB LEDs near user’s eyes as guiding information. Since installed LEDs are light and saving power, it is feasible to develop it for daily use. On the other hand, it cannot provide rich information such as text or images. In this study, we aim to realize a remote assistive system that provides assistive commands by visual cues from remote sites. Especially, we consider elderlies who are suffering from mild cognitive impairment as users. They would be one of potential user groups since the device does not block their sights by text or images and it can be worn in daily life without the additional sense of restraint. This paper explains our conceptual assistive system structure, a prototype eyeglass-type device with near-eye LED indicators and usability experimentation in simple detecting and walking navigational tasks. Received on 21 November 2016; accepted on 05 September 2017; published on 07 September 2017

Implementation and evaluation of daycare report generation system based on BLE tag

Recently, as elderly people population grows, the burdens on caretakers are getting larger. In daycare center, caretakers make a daycare report aiming to improve the senior citizens Quality of Life. However, in the aged society, it is difficult for caretakers to record the senior citizens activity in detail, since each caretaker needs to take care of several senior citizens at the same time. In this paper, we propose a semi-automatic day-care report generation system. Our proposed system estimates the present area and activity of the senior citizen by utilizing the accelerometer-implemented-BLE-beacon tags and generate the daycare report. Based on the generated report, the caretaker works effectively. Evaluation result in a daycare center showed that our system estimated the subjects present area with F-measure: 80.6% and activity with F-measure: 73.8% and automatically generated the daycare report.

Twinkle megane: Near-eye LED indicators on glasses in tele-guidance for elderly

The development of wearable technologies has generated significant interest in the last decades. Considering global social issues such as aged society besides the technologies, senior citizens suffering from memory loss would be one of potential user groups. Since the use of eyeglasses among the elderly is quite common, we have constructed a navigation interface on eyeglasses by implanting a set of light emitting diode indicators on the frame of the glasses. We aim to realize eyeglasses-based navigation system that provides the elderly with the visual cues and could be interpreted intuitively as navigational commands. Furthermore, we believe that our system would improve the independent mobility of the elderly. This paper explains our first prototype glasses with near-eye LED indicators, incremental experimentation, and the preliminary results that are used to optimize the visual cues for real navigational tasks. The system was evaluated in simulated navigational tasks by the elderly participants suffering from dementia. We assessed our system by he experimentation and living lab methodology with data-driven approach.