Category: Technology (e.g. robotics, assistive technology, mHealth); Measurement
To quantitatively reveal the correlation between contact pressure of customised hand orthoses and subjective sensation of pressure in terms of comfort.
Correlative analysis between (1)contact pressure at thumb metacarpophalangeal joint (MCP), thumb carpometacarpal joint (CMC), radial styloid (RS) and ulnar styloid (US) of subjects wearing customised hand orthoses; (2)subjective feedback regarding comfort (blinded experiment).
Xuzhou Central Hospital, China
Participants (or Animals, Specimens, Cadavers) :
3 healthy adults (age 27, 22, 30)
Main Outcome Measure(s) :
Pressure measurement using self-designed sensors, designated for hand orthotic pressure; Subjective data given by subjects, which was transcribed into discomfort scores (1-5, lower means more comfortable).
Across three subjects, the highest average pressure (AP) is 33.26kPa at US, standard deviation (SD) 7.1, and its average total discomfort score (TDS) 13.67 (SD=0.58) is the highest as well. The lowest AP is 14.3kPa (SD=0.92) at RS, but the TDS (11, SD=1.73) is moderate with highest TDS/AP ratio 0.77. The lowest TDS (9.33, SD=1.53) is at CMC, but its AP (26.42kPa, SD=7.19) is higher than RS with lowest TDS/AP ratio 0.35. The error variance of linear regression between AP and TDS of Subject 1 is the lowest (13.16) with highest R-squared value (R=79.86%) and Pearson coefficient (r=0.89). Subject 2 has the lowest R=0.68% and r=-0.08.
This study has shown a non-linear correlation between contact pressure of hand orthoses and subjective sensation regarding comfort, which means lower pressure may correspond to higher discomfort and vice versa. Subject 1 has the highest sensitivity to pressure. Subject 2 has the lowest. RS may have higher sensitivity than other three measuring points. Further study will explore the correlation specifically and develop an estimation method to assist orthoses fabrication.
Xinyang Tan– PhD candidate, Imperial College London, London, England
Jiangang Cao– Head of Rehabilitation Engineering Department, Xuzhou Central Hospital, Xuzhou, Jiangsu
Thrishantha Nanayakkara– Reader in Design Engineering and Robotics, Imperial College London, LONDON, England
Wei Chen– Director of Rehabilitation Department, Xuzhou Central Hospital, Xuzhou, Jiangsu