A New Design Concept and Method Based on Ergonomics and Kansei Engineering and So On

Kansei Engineering was born from Ergonomics and Kansei Engineering is extending to Kansei Ergonomics for products matching every people's demands. General evaluation procedure of Kansei engineering is applied to determining the design details of the toilet seat. At first, Kansei evaluation was carried out with kansei words on several prototypes of toilet seats. The subjects filled the Kansei questionnaire during sitting on the seats. Finally, relations between design details of the toilet seat (opal hole size, seat width, entire 3D shape and profile shape) and the Kansei evaluations were analyzed with PLS (Partial Least Square), regression analysis. Complete 3D design was determined from these analysis results: 1) Back yard should be a little wider compared with the ordinal toilets. 2) The toilet seat should be wider in the middle area than the ordinal ones. 3) The frontal area of seat should be fit to three-dimensional shape of human body which will be soft touch and soft support to thigh. At the final stage of the development, we measured hip pressure with an electronic pressure measurement device. By comparing the measurement of ordinary seat and this new designed seat, we confirmed that the pressure pattern on the new sheet has natural and comfortable pattern like sitting on a chair. Pressure was widely distributed and its center moved towards thigh under pelvis. The new toilet was named "TRES" and it had a good sales quickly after going into the market in 2004