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Biomedical subjects

D Graupe

Publications and source records attributed to D Graupe.

24 records · Page 2Linked to original sources
PubMed1985

Activation of paraplegic patients by functional electrical stimulation: training and biomechanical evaluation.

A training method for the activation of the lower limb muscles of paraplegics by functional electrical stimulation (FES) for standing and walking is described. It consists of a daily program which does not interfere with the normal routine of the patient. The treatment of four patients, paralysed form 7 to 30 years, is described. In these patients, a good standing position was achieved by stimulating the quadriceps, sometimes supplemented by the gluteus maximus or medius muscles. Gait was obtained by activation of the flexion reflex in a single stimulation and by tilting the trunk. Difficulties during gait were encountered due to the strong adduction of the legs. No mechanical support was required for locking of the lower limb joints. However, to maintain the equilibrium of the body, external support such as parallel bars, walker or Canadian crutches were used. During treatment gait improved due to reduction of spasticity and better stability of the body. Biomechanical measurements of weight bearing on the legs indicated values ranging between 41 to 65% of the body weight. During gait, a steady improvement of velocity was noted, with a parallel decrease in stance and stride times.

Activities of Daily Living↗
PubMed1982

Multifunctional prosthesis and orthosis control via microcomputer identification of temporal pattern differences in single-site myoelectric signals.

The paper discusses results of on-line tests on amputees and hemiplegics of multifunctional prostheses and orthoses control by identifying the parameters of single-site temporal EMG signal signatures. The results relate to tests on above-elbow amputees, on shoulder-disarticulation amputees (including a congenital disarticulation amputee) and on hemiplegics, varying from 5 to 50 years of age. The system employed is based on an 8-bit Intel 8080 microprocessor, when computation is in double precision, to obtain an effective 16-bit work-length. The system employs a sequential least-squares algorithm to identify a 4-parameter auto-regressive time-series model of the EMG signal, and a Bayesian rule discrimination algorithm.

Adolescent↗
PubMed1980

Speech recognition and control system for the severely disabled.

The availability of microprocessors opens many applications for speech recognition systems where constraints on price, weight, volume and power consumption are imposed, such as in the case of a voice control system for the severely disabled. A microprocessor based speech recognition system for the voice control of wheelchair, touch-tone phone, typewriter and environmental control unit, is described. The finite word length, fixed point arithmetics and relatively slow execution time of the microprocessor introduce several difficulties in the implementation of the recognition process. Algorithms for feature extraction (mainly the autoregressive, or linear prediction coefficients), classification and training are presented. The hierarchical memory organization is discussed. Results with the ten digit set, used to activate a touch-tone phone, are given. With this set the system exhibits less than one percent substitutions and eleven percent rejections.

Computers↗
PubMed1977

A multifunctional prosthesis control system based on time series identification of EMG signals using microprocessors.

This paper describes a real-time system for separation among several limb functions, in order to provide multifunctional control of an upper-limb prosthesis for above-elbow amputees. The system employs microprocessor hardware and is based on identification of voluntary myoelectric signals resulting from isometric contractions of the musculature of the residual limb, and on subsequent discrimination of these signals for control of the several degrees of motion of the prosthesis. The system requires only one to two electrode sites. (Contrary to the usual placement of electrode pairs directly over specific muscle bellies, to eliminate crosstalk, we prefer to place our electrode pair between muscles so as to acquire the different weakly-correlated signals associated with each of several different voluntary functions). The system satisfies the various practical constraints of weight, volume, and speed, as arise in practical prostheses. Preliminary amputee tests on the system have resulted in an 85 percent success rate using 8-bit double-precision micro-computer hardware.

Adult↗