研究課題名（英文）Development of a reminder system with multisensory stimulation to support thedaily living of elderly individuals with cognitive impairment

Research Center for Advanced Science and Technology,
The University of Tokyo, Project professor, Toshiaki TANAKA

全体要旨（英文）This study aimed to develop a reminder system using multisensory (visual,somatosensory, and auditory) stimulation to assist individuals with unilateral spatial
neglect (USN) or dementia to operate an ambulatory support device, especially awheelchair, as both conditions adversely affect activities of daily living, and ambulationin particular.
For individuals with USN, the HMD system was utilized to provide additional
visual information. The system has reminder modes of arrows, shrinkage, and edge
enhancement to alert them. For individuals with dementia, the system also uses a lightemitting diode (LED) to assist their wheelchair operation. Reminders can also beprovided in the form of textual information through the HMD or a small television.
Voice is used as auditory stimulation to direct wheelchair operation, such as braking.
Moreover, somatosensory stimulation in the form of vibration is used to warn the seatedwheelchair operator about a potential risk of overturning if the system detects a large
shift in the center of gravity to the front, back, left, or right.
The new system has two specific functions: (a) directing correct operation of
an automatic wheelchair and (b) warning the operator about incorrect operation andpotential overturning. The current prototype is equipped with sensors (for thedetection of mechanical motion) mounted on the right (1) and left (2) brakes and theright (3) and left (4) footrests to monitor operation of the ambulatory device, andanother sensor on the seat (5) to detect standing motion. In addition, the brakes andfootrests are mounted with an LED to provide a visual reminder of the next step, toprevent incorrect operation. For individuals with dementia who have difficulty
recognizing the situation from visual cues only, a speaker with an audio visual display
function has been mounted to enhance the warning capability of the system. We havealso developed a system with a transparent HMD to provide supplement visual
information when performing a dynamic movement (gait, wheelchair operation, etc.).
The main computer accurately sends out light signals, displays on the HMD device, andpresents audio messages as a reminder to use the brakes and footrests. When thewheelchair operator is using the brakes and footrests in the correct manner, the system
simply prompts the next step. The system also has a function that emits light flashes
and voice messages for risk avoidance when the operator mistakenly uses the brakes orstands up with the footrests still lowered. A vibratory stimulation warning system wasalso built in so the operator is warned if the risk increases of tipping over.
The study was to analyze the effectiveness of new reminder system for patientswith clinical symptoms of unilateral spatial neglect or dementia. Wheelchair operation
was videotaped to analyze their movements and postural changes. A data logger withan on/off switch was also used to record various wheelchair operations (braking, using
the footrests, and postural changes from sitting to standing position) to compare theinfluence of light, audio, HMD, and vibratory signals on the correction of incorrect
wheelchair operations. In addition to the light, audio, and HMD (text and voice)signals, a vibrating seatbelt was investigated to determine its contribution as a warning
system in stopping a wrong motion at the time of incorrect braking and initiating acorrect one. The results indicated that visual or audio stimuli could reduce the numberof operation errors. We plan to develop a reminder system that can be tailored to theneeds of individuals with a variety of difficulties operating a wheelchair.