Estimating Ease of Single-Fingered Operations of Hand-Held Appliances With Digital Hand

Ergonomic-conscious design of hand-held information appliances greatly strengthens their competitiveness. However, current ergonomic assessments are carried out in the form of “real” user-tests which need many human subjects and expensive physical mockups, and only subjective evaluations are obtained. To solve these problems, in this paper, the Digital Hand where the 3D bone structure, surface skin geometry of the human hand are imitated was developed for quantitatively estimating the ease of single-fingered operations of hand-held appliances. The ease is estimated based on the reachability of a finger tip to several specified operation target points, and on the finger joint angle margin which reflects the mobile range of motions of all operating fingers’ joints. An effective correlation was found between the estimation measures and the subjective comfort ratings in the fingered operations of a SLR camera.