When a sternum prosthesis is implemented, it must allow the movement of the rib cage. The sternum prosthesis designs that have been developed are completely rigid, this aspect can present discomfort when breathing, as well as fixation problems between the prosthesis and the bone tissue. The aim of this work is to develop a flexible device that allows the movement of the rib cage during breathing. Compliant mechanism design was developed by using the pseudo-rigid body model (PRBM) starting from a 4-bar rigid mechanism. The flexible model was obtained by developing the methodology of replacement from rigid to flexible body. The results show the obtained parameters of the compliant mechanism and the three-dimensional model for subsequent numerical and experimental analysis.

This paper presents a 2 DOF elbow prosthesis design and its control, which includes developing the mechanism, adapting a torsional spring for the flexo-extension movement, and a crown pinion transmission with two torsional springs pronosupination movement. In addition, this prototype has planned an elbow joint control method. The control has been obtained using the kinematic of a pendulum with a torsional spring, where the model comes with a set of dynamic simulations to determine how feasible the proposed mechanism is, and the torque needed for daily activities performance. The results show the physical and kinematic characteristics of the designed system.