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H C Scholle

Publications and source records attributed to H C Scholle.

14 recordsLinked to original sources
PubMed1992

[Quantitative topographic characterization of the myoelectric activity distribution of the masseter muscle: mapping of spectral EMG parameters].

A new method for quantitative characterization of myoelectrical masseter activity distribution by mapping of spectral EMG-parameters is described. The surface electromyograms of M. masseter were monopolarly recorded (16 channels). On the basis of registered EMG intervals (512 ms) the spectral EMG power of several frequency bands was calculated (Fast Fourier Transformation). The spectral EMG parameters between the 16 electrode positions were estimated by linear interpolation (4-nearest neighbours algorithm). Afterwards the spectral EMG parameters were fitted in a grey-tone or colour scale with 10 intervals. The so obtained EMG activity maps ("EMG-Maps") permit a quantitative-topographic characterization of myoelectrical masseter activity during different functional load procedures. The frequency range which is to consider in masseter surface-EMG investigations encloses frequencies between 15 and 500 Hz. The topography of EMG activation pattern of M. masseter is only described in a comprehensive manner when the electrode array consists of 16 electrodes and more. During defined motor tasks like clenching with controlled forces the reproducibility of EMG-Maps which respect to the topography of EMG activity pattern is very high. The absolute values of spectral EMG power as well as power changes of selected band ranges during clenching correlate to the extent of chewing forces.

Adult↗
PubMed1992

[Mapping spectral EMG parameters of the masseter muscle in normal probands under defined loads].

In 20 healthy volunteers 16-channel surface electromyograms were monopolarly recorded from the right and left masseter muscle during defined functional conditions (force-constant bite, right and left hand side, 196, 333, 530 N chewing force, during a compensation of a load directed from a frontal or a lateral position to the mandible (20, 49, 69 N), during rest position of the mandible). The EMG curves were quantified by the calculation of spectral EMG-parameters (FFT). With respect to the muscle a topographic oriented representation of the myoelectrical activity was realised by a mapping of spectral EMG-parameters. The monopolarly recorded EMG activities significantly differed between the 16 electrode positions (topographic EMG distribution pattern). During the several examination conditions of the masseter muscle different topographic distribution pattern of the myoelectrical activity were found. Moreover, the total EMG power between the muscle functions differed too. The level of the load influenced the spectral EMG power as well as, partly, the topographic EMG distribution pattern.

Adult↗
PubMed1992

[Control of isometric muscle contraction in muscle hypotonia of central origin: EMG mapping analysis].

Electromyographic and mechanographic investigations in patients with muscular hypotonia, which is, for instance, a side-effect after stereotactic treatment of tremor syndromes, permit the presumption that in this sensomotor open-loop situation the decreased muscular resistance to stretching during isometric contraction (initial stiffness) is caused by changes of muscular innervation pattern. Probably, the innervation pattern during tonic activity is changed by a shift of a more tonic motoneurone behaviour to motoneurone activities with predominantly phasic characteristics. In 17 controls and 4 patients with muscular hypotonia caused by stereotactic lesions of VIM area (treatment of tremor syndromes) the EMG of right and left side forearm flexors (especially the activity of the M. biceps brachii) was investigated by a sophisticated, topographically oriented 16-channel-surface-EMG-technique ("EMG-Mapping") during slight isometric contraction. EMG-Maps of forearm flexors (especially of M. biceps brachii) in patients with centrally evoked muscular hypotonia demonstrate that in these open-loop conditions the motor control is changed. For this the reason could be a shift of the activated motor units from a predominantly static to a more phasic functional behaviour. The latest results on muscular activation processes in cats support this presumption.

Adult↗
PubMed1991

[Quantification of artefacts in surface EMG by validating the lower frequency limit in clinico-physiologic studies].

The surface-EMG becomes more and more important because computer assisted analysing systems can be applied. The occurrence of artefacts makes it very difficult to compare several recorded EMG channels with each other. In this study a frequency related quantification of movement artefacts and ECG-related influences on the EMG is carried out to select a suitable lower cut-off frequency for surface-EMG investigations. In 764 monopolar surface-EMG-recordings of the neck and back muscles the solely artefact-caused part of EMG-segments was analysed and quantified by means of modelling methods.

Adult↗
PubMed1991

[Methodologic studies in dynamic EMG mapping based on the Hilbert transformation].

On the basis of Discrete Hilbert Transformation spectral parameters for dynamic EMG analysis can be introduced. Within analysis intervals which are used in the same manner as in spectral analysis, the momentary power of EMG frequency bands can be computed as time series of the same interval duration. A close connection exists between momentary power and the current phenomenology of power spectral analysis because the momentary power of a defined frequency band can be seen as the exact dynamic equivalent of the corresponding mean power value deduced from the power spectrum. A multichannel EMG recording (greater than or equal to 16 channels) makes the representation of the topographical distribution of the spectral parameter by a coloured map possible. Additionally, the momentary power can be used to calculate map sequences. In this way, changes of EMG activity can be quantified by map sequences of an arbitrary time resolution. By calculation of momentary frequency via DHT an artefact detection scheme for ECG interference can be suggested. A completion of this methodology can be carried out by applications of adaptive filtration procedures. Using this concept of EMG processing, a new and common methodical basis of EMG power spectral analysis can be introduced.

Brain Mapping↗
PubMed1990

[EEG and evoked potential mapping].

By spectral EEG-mapping and EP-mapping, especially the topologic dimension of electrical brain activity can be evaluated for clinical use. On the other hand, this method allows the highest solution from all functional imaging procedures within the time dimension of brain activity. On the other hand, the ability of topological solution is limited. But the latter is probably better than hitherto assumed and surprisingly well at least regarding neonates. However, several methodological prerequisites described here must be fulfilled. From the pathophysiological point of view, the limits must be considered besides the diagnostic possibilities. Meanwhile, spectral EEG-mapping and EP-mapping are diagnostically used in all main fields of traditional EEG-analysis, like seizures and in the preadiagnostics of tumors a.o. Also in the diagnostics of cerebrovascular disease including transient ischemic attacks, the EEG-mapping and/or EP-mapping are useful within the total diagnostics. There is a similar situation in the diagnostics of degenerative brain disorders. But the significance of frequently described changes inpsychoses, partly also neuroses and other functional disorders is not clear. Altogether, this non-invasive, economically most favourable method for the functional imaging procedures in brain diagnostics is promising to extent the routine diagnostics also to a more precise manner.

Brain↗
PubMed1990

Electrophysiological characterization of central sensory and motor pathway function in patients with moderate hemiparesis. I. Methodical approach.

The central sensory and motor pathway function in healthy persons and patients with several neurological disorders was selectively characterized by evaluation of latencies of short (R1) and long (R2) latency EMG responses as well as simultaneously recorded somatosensory potentials (N19, N26) evoked by electrical stimulation of N.medianus and N.peroneus. On the basis of these latencies the peripheral and central sensory/motor conduction times were calculated. By using this investigation procedure a selective quantification of central pathway functions is possible.

Adolescent↗
PubMed1990

Electrophysiological characterization of central sensory and motor pathway function in patients with moderate hemiparesis. II. Clinical results.

The central sensory and motor pathway function in patients with moderate hemiparesis and in healthy persons was selectively characterized by evaluation of latencies of short (R1) and long (R2) latency EMG responses as well as simultaneously recorded sensorimotor potentials (N19, N26) evoked by electrical stimulation of median and peroneal nerve (additionally, calculation of peripheral and central sensory/motor conduction times). This investigation procedure permits a noninvasive quantification of disturbed central sensory and motor pathway function in hemiparetic patients. The results found are in agreement to clinical, CT and other examination findings.

Adolescent↗
PubMed1989

[Model studies of muscle postural control in children with spastic hemiparesis: pathophysiologic and clinical relevance].

By means of a biocybernetic method the transfer behaviour of postural motor control system was characterized in children with spastic hemiparesis and matched healthy subjects. There were significant differences between the initial reactions of the postural motor systems of both examination groups to pseudorandom torque sequences (fig. 3, tab. 1). Considering these results we created a postural motor control model for both examinations groups (model see fig. 2). From this model it is possible to estimate separately the biomechanical effect of augmented segmental reflex activity and muscle-inherent dysfunctions in patients with spastic syndrome (fig. 4). The determination of these disturbed functions enables us to give instructions on a focused treatment of spastic syndrome according to the dominant dysfunction quantified.

Brain Damage, Chronic↗
PubMed1988

A method for the biocybernetic physiological investigation of postural motor control and its disorders in children.

On a biocybernetic basis, a method for the investigation of human postural motor control with optimal multifrequent binary test-signals is described. The examinations presented demonstrate that a comprehensive and quantitative characterization of normal postural motor control and its disorders is possible by means of this method in children. The examination time is short, the motor task used is simple, and the load is physiologically adequate and standardized.

Child↗
PubMed1976

[Psychophysiological studies in the framework of objective diagnosis of neuroses with factor and discrimination analyses].

This paper describes a complex method of collecting objective data to be used in the diagnosis of neuroses on the basis of clinical, experimental psychological, and objective psychophysiological parameters. The data collected was processsed using the methods of factor and discriminatory analysis. The results obtained clearly show that this approach to additional objective diagnosis may be successfully used in spite of some procedural difficulties.

Adult↗
PubMed1976

[Clinical, psychological, and psychophysiological characteristics of neurotic-functional, cardiovascular and neurotic-depressive syndromes].

A total of ninety women classified into three groups (with cardiovascular, depressive, and other principal symptoms) according to clinical criteria were characterized by clinico-anamnestic, psychological, and psychophysiological data with the goal of arriving at a practically oriented differentiation of neurotic syndromes. The relevant variables were determined by means of a factor analysis. The physiological reaction patterns determined in experiments on psychically strained individuals proved unsuitable for the differentiation of the two syndromes. The problems associated with a symptom-oriented classification are discussed.

Adjustment Disorders↗
PubMedDate not supplied

Biocybernetic investigations of pursuit and posture motor control--a strategy for a detailed characterization of movement disorders in brain-damaged children.

By means of a biocybernetic approach the pursuit and posture motor control of brain-damaged children with spastic hemiparesis and disturbed motor coordination of mild extent were investigated. The postural motor control system was loaded by pseudostochastic binary torque sequences applied to the wrist. The dynamics of this system were characterized on the basis of the parameters forearm displacement as well as surface-EMG of M. Biceps and Triceps (calculations of weight functions). The pursuit motor control was analyzed by a pursuit tracking method. By this way the motor capacity for fine and rough motor coordination, motor rhythm, motor adaptation, the maximal speed of movements and motor reaction time could be tested. Considering these results a characterization of movement control on different levels of motor regulation was possible (dynamics of muscular, spinal, and supraspinal components of motor control).

Brain Damage, Chronic↗