Bulletin of prosthetics research最新文献

An experimental protocol for the prescriptive fitting of a wearable master hearing aid was evaluated. The protocol consisted of four stages: (i) acquisition of baseline audiometric data, (ii) fixed test battery using speech-in-noise as the test material, (iii) adaptive adjustments, and (iv) evaluative comparative data. The results showed that systematic improvements in hearing-aid performance were obtained as a result of using the experimental protocol and that the largest improvements were obtained during the fixed-test-battery stage. The protocol in its present form is not clinically practical for most situations.

The foot's response to load during weightbearing is investigated using finite element stress analysis of a two-dimensional model. The analysis predicts the stress states within the plantar aspect tissue during a variety of shoe conditions. Shoe soles with a range of elastic properties are modeled in an attempt to find a shoe sole that minimizes peak stresses within the foot's soft tissue. This presently simplified and idealized model of the foot and shoe during mid-stance demonstrates significant dependency of stress development within the tissue on shoe elastic properties. These results would seem to justify further more detailed and realistic modeling of shoeing mechanics, and systematic efforts to correlate physical measurements and clinical experience with the trends indicated by finite element analyses.

The design of a new three-state myoelectric control system is presented. This controller determines its operating state from the initial rate of increase of the myoelectric signal, and the concept is realized in great measure through digital logic techniques. Proportional control of both active states (same dynamic range) is a unique feature of the controller. A microcomputer was interfaced in a simple way with myoelectric potentials to simulate the three-state controller described and to simulate various other state-determined control methods (some multifunctional). This was found to be a valuable method of evaluating control schemes without building the actual devices.

This article reviews recent progress in our investigations into the wear particles which accumulate in prosthetic and natural diarthrodial joints. Ferrographic analysis of these particles is providing new insight into the manner in which joints undergo wear in situ. It also has the potential to serve as a diagnostic and prognostic technique, with special application to monitoring very early changes in the wear status of joints and distinguishing the various arthritides. Wear particles interact with periarticular cells and tissues, provoking the release of lytic enzymes and eliciting other biochemical changes, which exacerbate the destruction of the joint.

The article describes in detail an arrangement of trough-shaped wheel ramps and telescoping articulating control rods intended to allow a wheelchair-bound paraplegic to quickly ascend and descend single steps or curbs as high as 8 in. Data on testing of the system with trained and untrained able-bodied male and female subjects is reported; very limited testing with paraplegics suggests that their performance may almost equal that of the able-bodied. Advantages claimed include simplicity, light weight (8 lb), and low cost. Required modification of a standard wheelchair is limited to welding a simple bracket to the outer end of each extended main wheel axle. With ramps and control rods mounted ready for prompt use, chair width is increased by a total of 6 in. When the chair is used indoors or no curbs are expected, a paraplegic occupant, unaided, can dismount the ramps and rods and store them in a canvas bag hanging from the seat back. In this configuration the chair is only 1 in wider than its original unmodified width. Further testing with handicapped occupants is intended. Good arm, hand, and lower-back strength and movement, plus good coordination, are user requirements.