title: Development of a shear measurement sensor for measuring forces at human-machine interfaces.
abstract: Measuring shear force is crucial for investigating the pathology and treatment of pressure ulcers. In this study, we introduced a bi-axial shear transducer based on strain gauges as a new shear sensor. The sensor consisted of aluminum and polyvinyl chloride plates placed between quadrangular aluminum plates. On the middle plate, two strain gauges were placed orthogonal to one another. The shear sensor (54 mm × 54 mm × 4.1 mm), which was validated by using standard weights, displayed high accuracy and precision (measurement range, -50 to 50 N; sensitivity, 0.3N; linear relationship, R(2)=0.9625; crosstalk error, 0.635% ± 0.031%; equipment variation, 4.183). The shear force on the interface between the human body and a stand-up wheelchair was measured during sitting or standing movements, using two mats (44.8 cm × 44.8 cm per mat) that consisted of 24 shear sensors. Shear forces on the sacrum and ischium were almost five times higher (15.5 N at last posture) than those on other sites (3.5 N on average) during experiments periods. In conclusion, the proposed shear sensor may be reliable and useful for measuring the shear force on human-machine interfaces.
authors.affiliation: Department of Biomedical Engineering and Research Institute for Medical Instruments & Rehabilitation Engineering, Yonsei University, Wonju, Gangwon 220-842, Republic of Korea.
authors.forename: Young Kuen
authors.initials: YK
authors.lastname: Cho
authors.affiliation: Department of Biomedical Engineering and Research Institute for Medical Instruments & Rehabilitation Engineering, Yonsei University, Wonju, Gangwon 220-842, Republic of Korea.
authors.forename: Seong Guk
authors.initials: SG
authors.lastname: Kim
authors.affiliation: Department of Biomedical Engineering and Research Institute for Medical Instruments & Rehabilitation Engineering, Yonsei University, Wonju, Gangwon 220-842, Republic of Korea.
authors.forename: Donghyun
authors.initials: D
authors.lastname: Kim
authors.affiliation: Hyundai Motor Group, Republic of Korea.
authors.forename: Hyung Joo
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Korea Orthopedics & Rehabilitation Engineering Center, Incheon 403-712, Republic of Korea.
authors.forename: Jeicheong
authors.initials: J
authors.lastname: Ryu
authors.affiliation: Department of Mechanical Engineering, Faculty of Mechanical and Aerospace Engineering, College of Engineering, Sejong University, Seoul 143-747, Republic of Korea.
authors.forename: Dohyung
authors.initials: D
authors.lastname: Lim
authors.affiliation: Korea Orthopedics & Rehabilitation Engineering Center, Incheon 403-712, Republic of Korea. Electronic address: cyko@korec.re.kr.
authors.forename: Chang-Yong
authors.initials: CY
authors.lastname: Ko
authors.affiliation: Department of Biomedical Engineering and Research Institute for Medical Instruments & Rehabilitation Engineering, Yonsei University, Wonju, Gangwon 220-842, Republic of Korea. Electronic address: hanskim@yonsei.ac.kr.
authors.forename: Han Sung
authors.initials: HS
authors.lastname: Kim
mesh_terms: D055615:Electrical Equipment and Supplies; D004867:Equipment Design; D006801:Humans; D007512:Ischium / Q000502:physiology; D016014:Linear Models; D011187:Posture / Q000502:physiology; D003668:Pressure Ulcer / Q000503:physiopathology / Q000517:prevention & control*; D015203:Reproducibility of Results; D012447:Sacrum / Q000502:physiology; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D014910:Wheelchairs
keywords: Human–machine interface; Pressure ulcers; Shear force; Shear sensor; Strain gauges