Chika Sugimoto

Prototype of pedestrian-to-vehicle communication system for the prevention of pedestrian accidents using both 3G wireless and WLAN communication

For the realization of a safe road traffic environment a wireless communication system which makes an information network between pedestrians and vehicles has been needed. A prototype of pedestrian-to-vehicle communication system was developed by using a cellular phone and a car navigation system equipped with GPS and wireless communication function. By interoperation of 3G wireless network and wireless LAN, it was possible to communicate in a wide area and with little delay time in a local area. The system can exchange the necessary information between pedestrians and vehicles, inform of the location of the ones that have an accident risk, and give an alarm by employing the developed algorithm for estimating the collision risk between each pedestrian and vehicle. The effectiveness of the system was shown by simulation of traffic situations.

Development of a behavior recognition system using wireless wearable information devices

Shoes for measuring foot pressure distribution pattern were developed and the algorithm of action patterns (walking, running, standing, sitting, squatting) recognition was derived. A wearable system which monitors humans movement by a wristwatch-type motion sensor and foot pressure sensing shoes that send data to a wearable PC via Bluetooth and infers context was constructed. The system gives appropriate contents on a glasses mounted display without hindering action, based on work analysis, evaluation of medical treatment, and behavior recognition, for the purpose of work support, medical treatment support, and selective dissemination information service.

Development of Pedestrian-to-Vehicle Communication System Prototype for Pedestrian Safety Using both Wide-Area and Direct Communication

We propose a prototype pedestrian-to-vehicle communication system which uses a cellular phone and wireless communication to improve the safety of pedestrians. One of the effectual measures against pedestrian-to-vehicle accidents is to make each of pedestrians and drivers find the others and recognize the risk from out of sight and with time to spare for avoidance of accidents. A pedestrian-to-vehicle communication system was developed by using a cellular phone and a car navigation system equipped with GPS and wireless communication function. We focused on intersections as a traffic scene to be covered by the system. After data was exchanged via FOMA in a wide area, information could be exchanged between a pedestrian and a vehicle via WLAN 20 m, 100 m away from an intersection to different directions in about 20 ms. And, the system could give an alarm to pedestrians and cars with collision risk.

A Study on HARQ error-controlling scheme for the wireless control of medical equipment

In this paper, we apply HARQ to a wireless feedback control system for realizing high reliable communication. In the wireless control system, since the quantity of state of a control system influences the stability of the system, we propose the new HARQ system which determines a code rate and retransmission judgment according to the quantity of state. As a result, proposal HARQ solved the problem of the overhead by coding and improved control quality compared with HARQ-TypeI.

Interference mitigation method using orthogonal matched filter with modified Hermite pulse for UWB-BAN assuming multi-user and multi-system environment

An ultra wide-band (UWB) communication is used for medical information communication technology (MICT) as a dependable and safe communication technology. On the other hand, there are existing UWB systems that are not used for MICT. Generally these UWB systems use almost the same frequency band. Therefore they interfere to each other. In previous study, multiple access scheme using orthogonal pulse is proposed as a inter user interference free communication scheme. In this paper, we propose a mitigation method for inter-user interference and inter-system interference using combination of orthogonal pulse shape and orthogonal matched filter (OMF). The purposes of our system are; detect all signals of users in same UWB system; and reduce the unknown interference from other UWB system at the same time. The simulation results showed that the proposed system could detect the signals that were transmitted from same UWB system using orthogonal pulse set. Moreover, the proposed system could reduce the interference from unknown UWB system at the same time.

Provision of information support by pedestrian-to-vehicle communication system

We propose a prototype of pedestrian-to-vehicle communication system using both 3G wireless network and wireless LAN for improving pedestrian safety. The system can exchange information between pedestrians and vehicles and give information support to drivers and pedestrians by estimating the collision risk between each pedestrian and vehicle. The effectiveness of information support was verified by a sensory test. The result of an experiment in an intersection where visibility is bad showed that the optimal timing for information provision differs between the pedestrian and the driver and depends largely on the traveling direction of the vehicle and the pedestrian at the intersection.

Vital sign monitoring by using UWB Body Area Networks in hospital and home environments

We investigated advantages and drawbacks of wireless BAN (Body Area Network) systems using UWB (Ultra Wide Band) wireless technology that are expected robustness against interference, low power consumption, and little interference to a body for healthcare. Two types of low and high bands of radio frequency for UWB were examined using various sensors in hospital and home environments. The high band UWB BAN system with TDMA protocol in MAC worked well to prevent interference. The most serious drawbacks was shadowing problem due to a body. We verified most suitable routing to avoid the shadowing problem on the bed.

Context inference techniques for a wearable exercise support system

Computer-aided health care services have become more and more popular. This expansion has provided new means to monitor individuals’ health and to provide efficient and accurate feedback. However, it still remains difficult for people to follow fitness and/or weight loss programs because of some lack of discipline or determination. Indeed, most of these programs enforce a workout often too hard for an individual’s physical and psychological capacities. We envision that wearable computers, an integral part of our every day outfits, can assist us in dealing with such problems. In this paper, we propose the ”e-coaching” wearable computing outfit, aiming at providing interactive coaching services for efficient body regulation. Our e-coaching outfit is equipped with multiple sensors and a small PC. The coaching service processes multiple sensor readings about the user’s body and its environment. From this data, it infers a user’s activity status or context and generates coaching messages to guide the user’s training in realtime. We have implemented the ecoaching system and evaluated its context inference accuracy using resource-limited wireless sensor nodes.

Measures against shadowing problem on a bed using high-band UWB-BAN

We investigated the advantages and drawbacks of wireless body area network (BAN) systems using high-band ultra-wide band (UWB) wireless technology for healthcare. These systems are expected to have robustness against interference, low power consumption, and little interference from a human body. The most serious drawback is the shadowing problem due to a body in a hospital or home care bed. We confirmed by experiments and theoretical analysis that setting a coordinator near the ceiling and another coordinator under the bed is one of the best measures to prevent the shadowing problem. In this study, a shadowing model was used. A helical antenna having high antenna gain in the axial direction was used in the coordinator. In comparison with a biconical antenna, the helical antenna showed better radiation performance and less dependence on the angle direction of the antenna of the sensor node.

Wireless Sensing System for Healthcare Monitoring Thermal Physiological State and Recognizing Behavior

The introduction of ICT in the areas of medicine and welfare has created new systems and services for healthcare and can help promote disease prevention and health maintenance through wirelessly delivered healthcare and ubiquitous medicine. The availability of information about a persons physiological state and daily activity makes it possible to judge their health condition and provide predictive diagnoses and treatment. Therefore, a wireless sensing system for monitoring thermal physiological state in the living environment was developed and its functions were evaluated. The system consists of an ear-worn temperature sensor, two thermo-hygrometers, four skin temperature sensors, and an ECG sensor. The level of data loss in wireless communication was low making it possible to estimate physiological state using more than 10 sensors, even though both the IEEE 802.15.4 radio and the specified low power radio coexist. The system was evaluated for the prevention of indoor heat stroke among the elderly. The thermal physiological state and the location were monitored along with ambient temperature and humidity. We propose a method to detect the activities closely linked with heat stroke prevention and change in physiological state and to give appropriate warnings.