title: Performance Assessment of a Humidity Measurement System and Its Use to Evaluate Moisture Characteristics of Wheelchair Cushions at the User-Seat Interface.
abstract: 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.
authors.affiliation: The Higher Educational Key Laboratory for Measuring & Control Technology and Instrumentations of Heilongjiang Province, Harbin University of Science and Technology, Harbin 150080, China. zhuofu_liu@hrbust.edu.cn.
authors.forename: Zhuofu
authors.initials: Z
authors.lastname: Liu
authors.affiliation: The Higher Educational Key Laboratory for Measuring & Control Technology and Instrumentations of Heilongjiang Province, Harbin University of Science and Technology, Harbin 150080, China. mm7723@163.com.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Cheng
authors.affiliation: The Higher Educational Key Laboratory for Measuring & Control Technology and Instrumentations of Heilongjiang Province, Harbin University of Science and Technology, Harbin 150080, China. 13936198757@163.com.
authors.forename: Zhongming
authors.initials: Z
authors.lastname: Luo
authors.affiliation: Murdoch University Chiropractic Clinic, Murdoch University, Murdoch 6150, Australia. v.cascioli@murdoch.edu.au.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Cascioli
authors.affiliation: Welsh Institute of Chiropractic, University of South Wales, Treforest, Pontypridd CF37 1DL, UK. aiheusch@uwclub.net.
authors.forename: Andrew I
authors.initials: AI
authors.lastname: Heusch
authors.affiliation: Welsh Institute of Chiropractic, University of South Wales, Treforest, Pontypridd CF37 1DL, UK. nadianair@yahoo.co.uk.
authors.forename: Nadia R
authors.initials: NR
authors.lastname: Nair
authors.affiliation: Faculty of Life Science and Education, University of South Wales, Treforest, Pontypridd CF37 1DL, UK. peter.mccarthy@southwales.ac.uk.
authors.forename: Peter W
authors.initials: PW
authors.lastname: McCarthy
mesh_terms: D006813:Humidity; D055617:Micro-Electrical-Mechanical Systems; D011312:Pressure; D003668:Pressure Ulcer; D014910:Wheelchairs
keywords: cushion; humidity measurement; sensor position; wheelchair