Performance Assessment of a Humidity Measurement System and Its Use to Evaluate Moisture Characteristics of Wheelchair Cushions at the User–Seat Interface

Sensors

Nadia R. Nair¹  Haifeng Cheng¹  Vincenzo Cascioli¹  Peter W. McCarthy²  Andrew I. Heusch³  Zhuofu Liu³  Zhongming Luo³ 

[1] Control Technology and Instrumentations of Heilongjiang Province, Harbin University of Science and Technology, Harbin 150080, China;Murdoch University Chiropractic Clinic, Murdoch University, Murdoch 6150, Australia;;The Higher Educational Key Laboratory for Measuring &

关键词: humidity measurement;    cushion;    wheelchair;    sensor position;   

DOI  :  10.3390/s17040775

来源: DOAJ

【 摘 要 】

Little is known about the changes in moisture that occur at the body–seat interface during sitting. However, as increased moisture can add to the risk of skin damage, we have developed an array of MEMS (Micro-Electro-Mechanical System) humidity sensors to measure at this interface. Sensors were first evaluated against traceable standards, followed by use in a cross-over field test (n = 11; 20 min duration) using different wheelchair cushions (foam and gel). Relative humidity (RH) was measured at the left mid-thigh, right mid-thigh and coccyx. Sensors were shown to be unaffected by loading and showed highly reliable responses to measured changes in humidity, varying little from the traceable standard (<5%). Field-test data, smoothed through a moving average filter, revealed significant differences between the three chosen locations and between the gel and foam cushions. Maximum RH was attained in less than five minutes regardless of cushion material (foam or gel). Importantly, RH does not appear to distribute uniformly over the body–seat interface; suggesting multiple sensor positions would appear essential for effectively monitoring moisture in this interface. Material properties of the cushions appear to have a significant effect on RH characteristics (profile) at the body–seat interface, but not necessarily the time to peak moisture.

【 授权许可】

Unknown