Measurement of stand-sit and sit-stand transitions using a miniature gyroscope and its application in fall risk evaluation in the elderly

• Published in: IEEE transactions on biomedical engineering Vol. 49; no. 8; pp. 843 - 851
• Main Authors: Najafi, B., Aminian, K., Loew, F., Blanc, Y., Robert, P.A.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.08.2002; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Accidental Falls - prevention & control; Age Factors; Aged - physiology; Algorithms; Biological and medical sciences; Biomechanical Phenomena; Discrete wavelet transforms; Equipment Design; Female; Gyroscopes; Hospitals; Humans; Laboratories; Legged locomotion; Male; Measurement standards; Medical sciences; Metrology; Models, Biological; Movement - physiology; Older people; Physical and Rehabilitation Medicine - instrumentation; Posture - physiology; Risk Assessment - methods; Risk Factors; Senior citizens; Sensitivity and Specificity; Signal Processing, Computer-Assisted; Standard deviation; Time measurement; Transducers; Wavelet transforms
• ISSN: 0018-9294; 1558-2531
• DOI: 10.1109/TBME.2002.800763

A new method of evaluating the characteristics of postural transition (PT) and their correlation with falling risk in elderly people is described. The time of sit-to-stand and stand-to-sit transitions and their duration were measured using a miniature gyroscope attached to the chest and a portable recorder placed on the waist. Based on a simple model and the discrete wavelet transform, three parameters related to the PT were measured, namely, the average and standard deviation of transition duration and the occurrence of abnormal successive transitions (number of attempts to have a successful transition). The comparison between two groups of elderly subjects (with high and low fall-risk) showed that the computed parameters were significantly correlated with the falling risk as determined by the record of falls during the previous year, balance and gait disorders (Tinetti score), visual disorders, and cognitive and depressive disorders (p < 0.01). In this study, the wavelet transform has provided a powerful technique for enhancing the pattern of PT, which was mainly concentrated into the frequency range of 0.04-0.68 Hz. The system is especially adapted for long-term ambulatory monitoring of elderly people.