A method for custom-contoured cushion design using interface pressure measurements.

The interface pressure distributions between flat foam cushions and the buttocks of seated test subjects were compared to custom-contoured cushion surface shapes generated with a seated-buttock contour gauge. Our hypothesis was that pressure measurements could be used to generate a contour equivalent to that obtained with a force-deflection contour gauge. The study was performed in a university medical center using spinal cord injured (SCI) (12) and elderly (30) test subjects. Interface pressure was measured using a pressure mapping pad. Contour shape was measured using an electronic force-deflection contour gauge. Pressure and contour information were reduced prior to analysis using singular value decomposition. Polynomial regressions were performed on the values in the first singular vectors of the corresponding pressure and contour decompositions. Relationships best described by cubic polynomials were detected between pressure and contour shape suggesting that interface pressure predicts optimal contour shape.

[1]  E. I. Odell,et al.  Deformations and Stresses in Soft Body Tissues of a Sitting Person , 1978 .

[2]  C E Brubaker,et al.  Reduction of sitting pressures with custom contoured cushions. , 1990, Journal of rehabilitation research and development.

[3]  G V Cochran,et al.  Development of test methods for evaluation of wheelchair cushions. , 1980, Bulletin of prosthetics research.

[4]  D M Brienza,et al.  Seat cushion design for elderly wheelchair users based on minimization of soft tissue deformation using stiffness and pressure measurements. , 1996, IEEE transactions on rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society.

[5]  C E Brubaker,et al.  Computer design and fabrication of custom-contoured seating. , 1991, Medical design and material.

[6]  S. P. Levine,et al.  Electric muscle stimulation for pressure sore prevention: tissue shape variation. , 1990, Archives of physical medicine and rehabilitation.

[7]  N Yamazaki.  Analysis of sitting comfortability of driver's seat by contact shape. , 1992, Ergonomics.

[8]  Ralph Roskies,et al.  Fourier Descriptors for Plane Closed Curves , 1972, IEEE Transactions on Computers.

[9]  M Ferguson-Pell,et al.  Prototype development and comparative evaluation of wheelchair pressure mapping system. , 1993, Assistive technology : the official journal of RESNA.

[10]  Peihua Gu,et al.  Localization and comparison of two free-form surfaces , 1996, Comput. Aided Des..

[11]  Hirosuke Nakaya,et al.  A Development of Statistical Human Back Contour Model for Backrest Comfort Evaluation , 1993 .

[12]  Gene H. Golub,et al.  Matrix computations , 1983 .