Validation of 24-Hour Ambulatory Gait Assessment in Parkinson's Disease With Simultaneous Video Observation
By Moore, Steven T.; Dilda, Valentina; Hakim, Bandar; MacDougall, Hamish G.; BioMedical Engineering OnLine, Volume 10, Number 82Publication Date: September 21, 2011
Study assessed the accuracy of a gait monitor that uses acceleration and angular velocity sensors to calculate stride length and identify freezing of gait in patients with Parkinson’s disease (PD). The prototype gait monitor is described as a small battery powered device whose components include a dual axis gyroscope, a triaxial accelerometer, an A/D converter sampling linear and angular leg movements saved as digital data on a flash memory card, and a microcontroller programmed to communicate with PC software and manage data logging. Study participants were 1 male and 2 female PD patients with a mean age of 73 years. A sleep laboratory was adapted to perform continuous video monitoring of participants. Monitoring of the sleep lab, a hallway, kitchen, and conference room was performed using a 4 camera security system and recorded to hard disk. Participants wore the gait monitor on the left shank just above the ankle for a 24 hour period beginning around 5 in the evening. Accuracy of stride length measures was assessed at the beginning and end of the trial. Two independent observers rated the video logs to identify when participants were walking or lying down. The mean error in stride length at the start of recording was 0.05 meters and at the conclusion of the 24 hour epoch was 0.06 meters. There was full agreement between observer coding of the video logs and the output from the gait monitor software. The accuracy of ambulatory stride length measurement was maintained over the 24 hour period, and there was 100 percent agreement between the autonomous detection of locomotion by the gait monitor and video observation.
Published by: BioMed Central Ltd (Website:http://www.biomedcentral.com)
Link to text: http://www.biomedical-engineering-online.com/content/10/1/82/abstract
