title: A continuous patient activity monitor: validation and relation to disability.
abstract: The measurement of patient activity over prolonged periods has been attempted with accelerometer-based devices, but these summate total acceleration and deceleration over time periods, are difficult to relate to recognizable activities and are influenced by passive movement. We describe the development of a portable monitor of ambulation. This logs posture (sitting, standing and lying) and number and vigour of steps in real time over prolonged periods, usually 24 h. This is based on a system of position sensors and an accelerometer which is sampled when the subject is standing. Data are processed through an interface and stored on a Psion Series 3 'palm top' computer. The system has been validated against observation, and the relationship of activity to disability in rheumatoid arthritis explored.
authors.affiliation: Musculoskeletal Department, Freeman Hospital, High Heaton, Newcastle-upon-Tyne, UK.
authors.forename: D J
authors.initials: DJ
authors.lastname: Walker
authors.forename: P S
authors.initials: PS
authors.lastname: Heslop
authors.forename: C J
authors.initials: CJ
authors.lastname: Plummer
authors.forename: T
authors.initials: T
authors.lastname: Essex
authors.forename: S
authors.initials: S
authors.lastname: Chandler
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000503:physiopathology*; D002648:Child; D006233:Persons with Disabilities; D004734:Energy Metabolism; D006801:Humans; D008124:Locomotion; D018670:Monitoring, Ambulatory / Q000295:instrumentation* / Q000379:methods*; D015588:Observer Variation; D011187:Posture; D012016:Reference Values; D015203:Reproducibility of Results; D013177:Sports; D014741:Video Recording; D016138:Walking