Journal of rehabilitation R&D最新文献

Recent advances in science have aided research toward the restoration of biped gait in paraplegic patients by means of functional electrical stimulation (FES). In this paper it is shown how FES-restrengthened muscles of paraplegic patients have been used for simple FES-assisted standing. Those experiments subsequently led to biped gait-initializing experiments and to simple forms of biped gait synthesis. The purpose of this paper is to show the feasibility of using FES for standing and for restoring biped gait in many paraplegic patients--to present the past achievements, focus on problems, and highlight directions for future research. The results of gait obtained in three complete spinal cord injured patients (out of a series of 17) are shown, using four to six channels of FES. It is also shown how preserved reflex mechanisms of the transected spinal cord can be incorporated and employed for obtaining improved function while at the same time simplifying the FES hardware. Of the three patients reported on in detail here, two patients have managed to walk in parallel bars while the third patient has mastered independent unassisted walking over shorter distances with the aid of a roller walker. The biomechanical and control problems of this last patient's gait are presented in detail.

The experimental and theoretical procedures used to gather ergonomic data and derive theoretical estimates of stability, effort, and safety in use of a curb-climbing aid for standard manual wheelchairs are presented. The aid, intended for use of paraplegic persons, employs ramps which the user while seated in the chair can deploy and retrieve using attached telescoping rods. Ramps and rods may be carried in a ready-for-use position or stowed away in a bag hung behind the wheelchair backrest. Design, construction and method of use were described in White RN, Szeto AYJ, and Hogan HA: A practical curb-climbing aid for wheelchair-bound paraplegic patients (a progress report) Bull Prosth Res BPR 10-34 17(2):13-19 Fall 1980.

The purpose of this project was to develop instrumentation and protocols in which electrical stimulation is used to induce exercise in paralyzed quadriceps muscles strength and endurance evaluation and conditioning. A computer-controlled electrical stimulation system, using surface electrodes, automatically regulates the bouts of leg extension exercise. Load weights attached just above the ankles can be progressively increased over a number of training sessions in such a manner that a measure of the fitness of the legs can be obtained. With three exercise sessions per week for 9 weeks, the strength and endurance of the quadriceps muscles of two paraplegic and four quadriplegic subjects were gradually and safely increased. During exercise at a means load weight of 5.4 kg, means heart rate did not rise above rest, whereas systolic blood pressure increased about 20 mm Hg, and skin temperature above the active muscles increased about 1.75 degrees C. Such exercise conditioning appears to be safe and may provide important health benefits, including improved fitness of the muscles and bones, better circulation in the paralyzed limbs, and enhanced self-image. Conditioned electrically stimulated paralyzed leg muscles may be used for locomotion in conjunction with special vehicles.

From 1977 through 1980, 251 veterans from the San Francisco Bay Area received permanent lower-extremity prostheses at the two local Veterans Administration hospitals. For a survey, 213 of the 251 were contacted and 179 of them (84%) responded to written or telephone questionnaires concerning their prosthetic problems and complaints and their recommendations regarding prosthetic care. Seventy-four percent of the patients were traumatic amputees and 23 percent were dysvascular amputees. Eighty-six percent of the traumatic amputees said they wore their limbs all day, compared with only 51 percent of the dysvascular group. Seventy-one percent of traumatic and 43 percent of dysvascular amputees engaged in some form of recreational activity. There was a high incidence of complaints of pain in the residual limb: 55 percent among the dysvascular group and 44 percent among the traumatic group. Half of the patients had socket problems. Fifty-four of the 178 patients received a physical examination, a prosthetic evaluation, and a gait analysis. Among this group, 59 percent of the below-knee prostheses and 78 percent of the above-knee prostheses had inadequate socket fitting. Improper shaping of socket margins was the most frequently observed deficiency. Moreover, 41 percent of below-knee and 22 percent of above-knee amputees had mechanical skin irritation or skin breakdown in the examined residual limbs. Faulty suspension and alignment in addition to improper socket fit and construction contributed to this problem. Excessive stiffness of SACH foot heel cushions was the most common prosthetic foot problem and contributed to gait abnormalities.

Functional electrical stimulation has been used to restore some degree of controllable movement to paralyzed muscle. The purpose of this study was to demonstrate the feasibility of using electrically stimulated paralyzed leg muscles to propel a wheelchair-type vehicle. For this, a conventional manual wheelchair was modified by the addition of a drive system which permits forward propulsion by reciprocating movements of the legs. A battery-powered electrical stimulator using surface electrodes over the quadriceps muscles controls locomotive characteristics. This vehicle has been successfully operated by paraplegic and quadriplegic test subjects. Advantages of using paralyzed leg muscles for locomotion may include improvement in locomotive capability, circulation in the lower extremities, cardiovascular and respiratory fitness, strength and size of the exercised muscles and bones, and self-image.

The battery performance of electric wheelchairs was measured under indoor and outdoor conditions, and simulated driving cycles for these two environments were derived from these tests. Driving cycles were used to bench-test deep discharge wet cell and gel cell lead-acid batteries, nickel-cadmium batteries, and experimental nickel-zinc batteries. Results of this study support the conclusion that deep discharge wet cell lead-acid batteries satisfy wheelchair requirements and are the most economical choice. The effect of simulated wheelchair controller pulse width modulation on battery discharge compared to d.c. discharge was found to be negligible. A simple model analogous to Miner's Rule (3) plus results plotted on a Ragone chart of average power versus discharge time were found to correlate the effect of the highly variable actual power requirements of an electric wheelchair. Miner's Rule can predict battery performance for a given driving cycle.