Development and Tuning of a Finite Element Average Human Hand Model: To support research and development of healthcare products for medtech applications

Abstract

The human hand is an essential part in our daily lives and a vital sense in how we feel and interact with the environment around us. However, ergonomic discomfort and pain remains prevalent in workplace and healthcare settings. To tackle these challenges, computer models of anatomical human hands can provide valuable insight into hand structure and object interaction that can support medical product development. This thesis documents the development of an anatomically based finite element (FE) average human hand model designed for applications within research and development for MedTech products. The developed model incorporates derived skin geometry from magnetic resonance imaging (MRI) with open-source skeletal components to match a statistical average hand size. The meshing strategy focuses on a hexahedral model which can aid in future morphing of the geometry. A tetrahedral model was also constructed but only for a comparative study against the hexahedral model. Different constitutive models were investigated for the skin and soft-tissue behaviours, primarily consisting of viscoelastic and hyperelastic material models. Joints were modelled using a kinematic approach, using constraint-based rigid wire connections to enable biofidelic positioning. Parameter tuning was performed with published experimental data that tested the finger pulp compression at selected loading rates of 0.1 and 0.3 mm/s. Simulation results depicted similar mechanical behaviour as experimental tests but an additional dataset would be required to fully validate the model. The study outlines the steps taken along with the models used to construct a feasible anatomical human hand FE model for product interactions. Although the current model has its limitations, a single size and simplified anatomical structure (no muscles, ligaments or tendons modelled), it lays a good foundation for future morphing capabilities and a broad analysis for healthcare product investigation and development.