Browsing by Subject "arm prosthesis"

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    A SEVEN-DEGREE-OF-FREEDOM ARM WITH UNIQUE SHOULDER FUNCTION
    (2005) Williams, T. Walley III
    The most advanced powered prosthetic arm in 2005 is the experimental seven-degree-of-freedom (DOF) arm prepared for a bilateral shoulder disarticulation patient at the Rehabilitation Institute of Chicago. The major components are an LTI Boston Digital Arm supplying the elbow drive and control electronics, a hand with wrist flexion-extension from China, a Bock wrist rotator, a humeral rotator from Northwestern University (NWU), a shoulder flex-extension module from TouchEMAS in the UK, an LTI Locking Shoulder Joint, and an LTI VariGrip III Controller
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    BIOMECHANICAL ANALYSIS IN ARM PROSTHETICS 􀂱 OBJECTIFYING OF FUNCTIONAL ADVANTAGES OFFERED BY WRIST FLEXION
    (2008) Bertels, Thomas; Fiedler, Kerstin; Schmalz, Thomas
    By means of flexion wrists the functionality of prosthetic fittings for upper extremities can be improved significantly. Objects can be manipulated more favourably. Furthermore an optimized gripping position allows an improved body posture. Reaching objects or other dynamic processes are essential in amputee􀂶s ADL􀂶s. The path of motions influences the whole extremity in a physiological manner. Biomechanical measuring results demonstrate the advantages in movement by individual hand positioning. Measurements were conducted by means of an optoelectronic camera system for recording motion kinematics (VICON 460, VICONPEAK Oxford, GB). The subjects were fitted with myoelectric arm prostheses and performed predefined motion tests. Position of flexion angle and hand rotation varied systematically. Depending on the posture of the hand the optimization of certain motion patterns could be proved. Repeating action is supported and can be performed more persistently. Some activities confirmed the significance of optimized interaction between wrist rotation and flexion.
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    ELECTROMECHANICAL ANALYSIS OF A COMPLETE ARM PROSTHESIS (EMAS)
    (2005) Hill, Stewart Scotland; Binnie, T.D.; Gow, D. J.
    A characterisation of a complete arm prosthesis is necessary to develop effective control. This is a description of the use of Lagrange methodology to describe the system and to optimise for motion control. The Lagrange equations of motion are derived from the Newtonian equations of motion. Lagrange analysis describes the system in terms of Kinetic (T) and Potential energies (V). The Kinetic energy (T) is found through a generalised co-ordinate system, where T is a function of the co-ordinates and time derivates. In the non-conservative prosthetic arm, potential energy (V) is found from the generalised forces. These descriptions encompass both electrical and mechanical energies, which are then used to provide the optimum control settings. This analysis method allows multiple terminal analysis points to be combined, allowing an electrical network with losses, and a mechanical network with losses, combined by a coupling network. Thus the analysis allows for n mechanical and electrical terminals in the network. This network approach lends itself to a complete prosthetic arms system, where terminals in the network can range from individual fingers to shoulder joints.