Micro-Doppler Radar Measurement of Sit-to-Stand-to-Sit Movement for Evaluation of High-level Instrumental Activities of Daily Living

This study shows a significant relationship between the kinematic parameters of the sit-to-stand-to-sit movements (STSTS) sensed with a Micro-Doppler radar (MDR) and the scale of High-level Instrumental Activities of Daily Living (HL-IADLs) defined as an ability to perform modern daily activities independently. HL-IADLs are useful in evaluating the degree of disability in daily life; hence, this study aims to develop an MDR system that would enable HL-IADL impairment to be unconstrainedly monitored on a daily basis. The study participants were 65–74 years old. Their motion parameters (e.g., velocity and acceleration) in natural STSTS were extracted via a single 24-GHz MDR installed on the ceiling. Their HL-IADL scales were evaluated using a questionnaire-based scale, called the Japan Science and Technology Agency Index of Competence (JST-IC). The relationship between the JST-IC and the extracted STSTS kinematic parameters was then statistically analyzed. The results reveal that the extracted parameters were associated with the JST-IC score, suggesting the possibility of the HL-IADL impairment detection based on the MDR monitoring.