L. Leija

Upper limb prostheses for amputations above elbow: A review

In this article, it will be described the state of the art of upper limb prosthesis and several types of them. The prosthesis evolution had allowed people who lost an extremity to win back their normal life and live it with fewer limitations. Designing a myoelectric prosthetic arm that interacts with the amputee requires the integration of countless disciplines. Traditional commercial prosthesis has at least three degrees of freedom: open and close the hook, bend and straighten the elbow and rotate the wrist; but the human arm has 22 degrees of freedom. Thus, it is important to realize that the prosthetics have a long way to go. Furthermore, the higher the amputation level, the greater the demands on the fitting technique. Each prosthesis has different characteristics, advantages and drawbacks. Finally, four different kind of prosthesis will be presented: the Boston Elbow, the Utah Arm, the Kuikens Prosthesis within DARPAs Project and the prosthesis under development in our laboratory.

Tracking training evolution: Patient with upper limb amputation above the elbow

This article describes a patient training evolution to achieve myoelectric control in the remnant limb. The methodology is divided in two main stages: (i) the training procedure, where the patient is submitted to a protocol for educating the muscles of the remnant limb, and (ii) myoelectric signal acquisition and analysis, in order to measure the patient evolution to reach different contraction levels along the training sessions. After three training stages, the results suggest that the patient gradually achieved strength control over the muscles of the remnant limb.

Using ‘stall detection’ as an auxiliary mechanism for sensing obstacles and hand grasping in arm prosthesis

This paper proposes a novel method for sensing obstacles and hand grasping activities in electromechanical arm prosthesis. The described method is based on indirectly sensing ‘Stall’ condition in prosthesis actuators through hall-effect sensors already embedded on its dc motors, thus not requiring external sensors. To test the proposed methodology, an electromechanical arm prosthesis of 3 degrees of freedom (DOF), plus ‘open-close’ of hand, which is being developed at CINVESTAV Mexico, was used. At the end of this paper, experimental measurements performed on the tested prosthesis, using and non using ‘Stall Detection’, are shown. We demonstrated that methodology can be used successfully for “sensing obstacles”, but it cannot be used alone for “hand grasping”. In any case, this technique demonstrated to be a good method to simplify and strengthen control of prosthesis

Movement measurement of isolated skeletal muscle using imaging microscopy

An imaging-microscopy methodology to measure contraction movement in chemically stimulated crustacean skeletal muscle, whose movement speed is about 0.02 mm/s is presented. For this, a CCD camera coupled to a microscope and a high speed digital image acquisition system, allowing us to capture 960 images per second are used. The images are digitally processed in a PC and displayed in a video monitor. A maximal field of 0.198 X 0.198 mm2 and a spatial resolution of 3.5 micrometers are obtained.

Man/machine communication by IR tracking detection

An interactive system for disableds is shown. The interactive system uses the head position as communication mean. The systems uses an IR light source to have the relative or absolute position over the work frame. In the work frame an interactive software was made in the Windows platform to active and modify appliances.

Videoconferencing automatic pointer through image processing

An autofocus and supervisory positioning system for video- conferencing is showed. The system developed is based in diameter circle detection made by IR pointers. The IR tracks are used after they have been processed as feedforward signals.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.