A Doppler-Tolerant Ultrasonic Multiple Access Localization System for Human Gait Analysis.
Ranging based on ultrasonic sensors can be used for tracking wearable mobile nodes accurately for a long duration and can be a cost-effective method for human movement analysis in rehabilitation clinics. In this paper, we present a Doppler-tolerant ultrasonic multiple access localization system to analyze gait parameters in human subjects. We employ multiple access methods using linear chirp wave-forms and narrow-band piezoelectric transducers. A Doppler shift compensation Technique is also incorporated without compromising on the tracking accuracy. The system developed was used for tracking the trajectory of both lower limbs of five healthy adults during a treadmill walk. An optical motion capture system was used as the reference to compare the performance. The average Root Mean Square Error values between the 3D coordinates estimated from the proposed system and the reference system while tracking both lower limbs during treadmill walk experiment by 5 subjects were found to be 16.75, 14.68 and 20.20 mm respectively along X, Y and Z-directions. Errors in the estimation of spatial and temporal parameters from the proposed system were also quantified. These promising results show that narrowband ultrasonic sensors can be utilized to accurately track more than one mobile node for human gait analysis.
['Ashhar|Karalikkadan|K|0000-0001-8799-5060', 'Khyam|Mohammad Omar|MO|', 'Soh|Cheong Boon|CB|', 'Kong|Keng He|KH|']
D000328:Adult D005260:Female D005684:Gait D006801:Humans D007866:Leg D008297:Male D014159:Transducers D014465:Ultrasonics D000076251:Wearable Electronic Devices
gait analysis doppler shift compensation channel multiple access motion tracking ultrasonic localization