Analysis of Stair-Ascent Activities with Handrail Use in Daily Living Space and Motion Features using RGBD Camera

The geriatric population has increased worldwide over the past few decades. Older adults rarely make a sudden transition from a healthy state to a state requiring nursing care; more often they transition through an intermediate stage called frailty. To assess frailty quantitatively using ambient sensing technology, our group developed a system to automatically and continuously measure and analyze human ascent and descent motions and handrail-use behaviors in homes, using an RGBD camera. This study developed a whole-body motion feature analysis method using principal component analysis (PCA), and analyzed the features of whole-body motions related to handrail use when ascending stairs. Daily stair-ascent motion was measured in two houses, with two participants in their 20s and two in their 50s in the first house, and two in their 70s in the second house. A method for extracting the characteristic motion of ascending stairs while using a handrail was developed using principal component analysis of whole-body skeleton data. The results showed that the third principal component was the characteristic motion of holding the handrail. The developed method makes it possible to evaluate dependence on handrails and clarify the characteristics of movements associated with changes in physical function, through continuous measurement and motion feature extraction techniques for daily stair ascent.