Masato Takanokura

Optimal handgrip height of four-wheeled walker on various road conditions to reduce muscular load for elderly users with steady walking

A four-wheeled walker is a valuable tool for assisting elderly persons with walking. The handgrip height is one of the most important factor determining the usefulness of the walker. However, the optimal handgrip height for elderly users has not been considered from a biomechanical viewpoint. In this study, the handgrip height was optimized by a two-dimensional mechanical model to reduce muscular loads in the lower body as well as in the upper body with various road conditions during steady walking. A critical height of the handgrip existed at 48% of the body height for the user regardless of gender and body dimension. A lower handgrip relieved muscular load for stooping users with a lower standing height. The stooping user pushed the handgrip strongly in the perpendicular direction by leaning the upper body on the walker. However, upright users with a higher standing height should use a four-wheeled walker with a higher handgrip for maintaining his or her upright posture. For downhill movement, the optimal handgrip height depended on the slope angle and the friction coefficient between the road and the wheels of the walker. On a low-friction downhill such as asphalt with a steeper slope angle, the user was required to maintain an erect trunk with a higher handgrip and to press on the handgrip strongly in the perpendicular direction. Movement on a low-friction road was easier for users on a flat road and an uphill road, but it compelled distinct effort from users when moving downhill.

Theoretical optimization of usage of four-wheeled walker and body posture of elderly users for comfortable steady walking

Usage of a four-wheeled walker and body posture of elderly users is optimized by a two-dimensional statics model for comfortable steady walking. Analytical results suggest that fundamentals of body posture for comfortable walking should be as upright as possible. However, usage of the walker varies with exercise capabilities of elderly users. Users with high capabilities should use a higher handgrip for maintaining upright posture. Stooping users with low capabilities should use a lower handgrip, should maintain an erect trunk as much as possible, and should push the handgrip downward by leaning their upper body on the walker.

Systems Approach for Preventing Falls in Hospitals and Nursing Homes Using Sensing Devices Surrounding the Patient’s Bed

Falls are critical accidents occurring in hospitals and nursing homes. They can reduce the quality of life of care-receivers (patients and elderly persons) and deteriorate the professional duties of care-givers (nurses and care workers). As the initial approach to preventing such falls, micro-electro-mechanical systems (MEMS) have been applied around the care-receiver’s bed. For the present study, a system was developed using a tool kit with an AVR microprocessor (Arduino Uno), seven force-sensing resistors, and two human-detection sensors. This system can detect and predict dangerous motions that may lead to a fall. A predicted motion is notified visually and aurally to care-givers and/or care-receivers. The developed system is a technical product, and thus an organizational measurement is also required for preventing falls. As the second approach, the nursing process of care-givers was visualized using process modeling. Two diagrams, process content and state transition diagrams, were generated from daily nursing logs taken at night in both a hospital and a long-term care facility. Although a process content diagram can be used to visualize the nursing process of care-givers, a fall is a non-process type accident. A state transition diagram can thus express the nursing process in a care-receiver centered manner. Whereas care-givers take care of care-receivers early in the night, non-process type accidents may occur after this early period until the following morning. The developed sensing-device based system is useful after the early period of care at night for the prevention of falls.