Razvoj virtualnega modela človeške roke za ergonomsko oblikovanje izdelkov : doktorska disertacija

slovenian

doktorska dela

2014

Univerza v Mariboru, Fakulteta za strojništvo

A significant part of manual work is still done using hand-tools. Therefore, an ergonomic design of a tool-handle might be crucial for preventing upper-extremity musculoskeletal disorders. Current design methods consider cylindrical handles and provide guidelines for determining optimal diameters to increase performance, comfort and thus minimizing the risk of acute and cumulative traumatic disorders. However, the shape of the handle and the handle's materials have not been investigated in detail yet, which could additionally improve the handles' ergonomics. In order to overcome the limitations of correct shape determination, we have developed an anatomically accurate static virtual human-hand model in its optimal power grasp posture for direct tool-handle modelling based on interdisciplinary methods using medical imaging. To overcome the limitations regarding the correct tool-handle material determination, we have utilized a finite-element method for simulating human fingertip whilst grasping different tool-handle materials. The results have shown that the tool-handle based on the developed virtual human-hand model provides significantly higher contact area and comfort rating compared to the cylindrical handles. With higher contact area and anatomical shape of the handle, extensive deformation of the soft tissue can be avoided, thus preventing excessive load on the hand. Numerical tests have shown that conventional tool-handle materials do not lower the contact pressure. The proposed hyper-elastic foam materials, which take into account the non-linear mechanical behavior of fingertip, can lower the contact pressure significantly whilst maintaining sufficient rate of stability. Results thus support the thesis that correct shape and material determination of a tool-handle can increase the performance and comfort and thus lower the risk of acute and cumulative trauma disorders.

08.08.2023