Eugen Gallasch - Academia.edu (original) (raw)
Papers by Eugen Gallasch
Zentralblatt für Bakteriologie, Mikrobiologie und Hygiene. Serie B, Umwelthygiene, Krankenhaushygiene, Arbeitshygiene, präventive Medizin
The effect of stress caused by aircraft noise was studied on 14 female and 11 male volunteers, wh... more The effect of stress caused by aircraft noise was studied on 14 female and 11 male volunteers, who were of a age ranging from 21 to 42 years and of a mean age of 25 years. The volunteers were exposed to an aircraft simulator that stimulated the low level flight of an air force plane and produced a maximum noise level of 105 dB(A) for 3 sec. in a short time. Before and immediately after the exposure, the concentration of ACTH was measured by means of a radioimmunoassay. The ACTH is a hormone, responsible for initiating a chain reaction that is characteristic for a stress reaction. In 100% of the cases the concentration of this hormone increased. It reached a pathological level in 28% of the cases. The effect on the lipid metabolism was expressed by an increase of total cholesterol and a decrease of the triglycerides in the serum. A slight increase in blood sugar which, together with the free fatty acids, is relatively quickly reduced to energy, could be determined. The aircraft noise did not influence the activity of the liver transaminases in any way. A short-term exposure to aircraft noise is able to stimulate a stress reaction, whereby, the determination of the ACTH offers valuable informations.
Musik- Tanz und Kunsttherapie
The Journal of the Acoustical Society of America, 1999
International Journal of Hygiene and Environmental Health, 2010
Cells Tissues Organs, 1986
Fifteen ligaments taken from individuals aged between 60 and 80 years were used for the study of ... more Fifteen ligaments taken from individuals aged between 60 and 80 years were used for the study of the histological structure, the composition of the ground substance and the biomechanical behavior. Remnants of the original duct are recognizable in the ligament as artery of the muscular type. What had been the intima is thickened and consists mainly of cell-poor, fiber-rich connective tissue, which often shows chondrification along with calcification. The biomechanical behavior of the ligaments, evaluated with the force-length and force-relaxation test, was similar to that of peripheral arteries.
Biomedizinische Technik/Biomedical Engineering, 2000
Biomedizinische Technik/Biomedical Engineering, 2000
Biomedizinische Technik/Biomedical Engineering, 2000
Tensile tests on longitudinal and circumferential strips of the rabbit aorta have been performed.... more Tensile tests on longitudinal and circumferential strips of the rabbit aorta have been performed. Stress-strain and relaxation parameters have been estimated with respect to four stress levels and three positions on the aorta. Stress-strain data indicate that in longitudinal direction the aorta becomes more compliant with distance from the aortic arch. The opposite tendency is found for the circumferential direction. Stress-relaxation is found to be strongly dependent on the stress level. The results are discussed with regard to arterial dynamics.
Electroencephalography and Clinical Neurophysiology, 1996
Medical Biological Engineering Computing, Oct 1, 2002
A moving magnet galvanometer equipped with lever and indentor was evaluated for mechanomyography ... more A moving magnet galvanometer equipped with lever and indentor was evaluated for mechanomyography (MMG). First, the precision of the galvanometer was tested on a piezo-electric disc actuator. Using a 50 mm lever, synthesised micromotions with an amplitude of 1 microm could be detected (noise level < 0.2 microm) at static indentation forces ranging from 0.1 to 2 N. Then the galvanometer was mounted on an isometric ankle dynamometer to sense calf-muscle responses (N = 6). In the first protocol, twitch contractions were elicited by electrical stimulation while the indentation force was increased. Twitch amplitudes, twitch contraction times and twitch half-relaxation times were analysed from the surface and contraction responses. With indentation force (0.1-0.5 N), the amplitude of the surface responses increased (+61%), contraction and half-relaxation times, however, were not influenced. The mean twitch contraction time from the surface responses (60 +/- 11 ms) was shorter than that from the contraction responses (115 +/- 7 ms), indicating more fast-contracting fibres under the indented area. In the second protocol, voluntary target contractions were produced, and the surface responses were simultaneously recorded on an accelerometer. After double differentiation of the galvanometer signal, both acceleration MMGs showed a high coincidence in the time and frequency domains. With an indentation force of 2 N applied on the accelerometer, the signal amplitude (-10%) and the mean frequency (-19%) decreased. A specific application of this galvanometer-dynamometer test system is the assessment of regeneration processes in paraplegics with long-term denervated muscles.
Klinische Pädiatrie
Because of the growing demand to evaluate cardiorespiratory dysfunctions the short-time oxycardio... more Because of the growing demand to evaluate cardiorespiratory dysfunctions the short-time oxycardiorespirography becomes a more and more important and powerful tool in the daily clinical routine. Therefore, from about one hour lasting records we studied the distribution of MA-values (mean apnea duration), duration of the longest apnea, percentage of periodic breathing time, lowest heart rate values, lowest transcutaneous PO2 values and highest transcutaneous PCO2 values in an obstetrical optimal low-risk group of 90 infants and a obstetrical non-optimal group of 152 infants between four and ten weeks of age. Percentiles of each variable were calculated, and we suggest the 90th percentiles as new threshold values to judge these short-time recordings. In comparison to relevant data from the literature we could demonstrate that deviating threshold values have to be applied to short-time recordings in comparison to long-time recordings. In addition, the respiratory behaviour of the optimal group is compared to that of the non-optimal group of the same age. Interestingly enough, no difference in the respiratory behaviour between these groups could be demonstrated.
Absfracf- Small mechanical 8-12 Hz osctllatlons, phasecoupled to the heartbeat, are found on all ... more Absfracf- Small mechanical 8-12 Hz osctllatlons, phasecoupled to the heartbeat, are found on all relaxed ann segments. To investigate the dynamics of ann segments in relation to mechanical stimuli, a linear model was developed based on a tbree segment tonional pendulum. Simulation showed that the impact of heartbeat possibly leads to small oscillations in the hand but not in the upper and lower arm segments. It is proposed that spindle excitetion by the heartbeat may produce small 8-12 HZ oscillationr In the ann stretch sewo. Contraction in the upper arm muscles, estimated fmm tbe model, is found in the range of 0.015 Yo MVC - it is therefore conceivable that resting tone in upper am muscles transforms the impulse ercitatton of heartbeat into oscillatory excitation to the arm segments.
AJP Regulatory Integrative and Comparative Physiology
Microgravity was used to study accelerometrically recorded microvibration (MV) and postural tremo... more Microgravity was used to study accelerometrically recorded microvibration (MV) and postural tremor (PT) at reduced muscle tone on one cosmonaut before, during, and after an 8-day space flight on the Russian Mir station. MV of the relaxed forearm in the 1 g environment showed the typical 7- to 13-Hz resonance oscillations triggered by the heart beat. In 0 g, these pulsations shifted to below 5 Hz and the waveform became similar to an ultralow frequency acceleration ballistocardiogram. PT of the arm stretched forward showed an irregular waveform in 1 g. In 0 g, the higher-frequency components were reduced and again an ultralow frequency ballistocardiogram emerged. As a control, hand force tremor was recorded as well; it was not affected by the gravity condition. A second-order analog with muscle stiffness (C) as parameter was used to evaluate the measurements. For MV it could be shown that cardiac impacts produce damped resonance oscillations when C is high enough (1 g). At low C (0 g...
Biomedizinische Technik
To study cardiorespiratory and neuromotor functions in cosmonauts a novel belt with embedded poly... more To study cardiorespiratory and neuromotor functions in cosmonauts a novel belt with embedded polygraphic sensors and a force sensing expander were developed. The sensors are: a three-electrode ECG/impedance plethysmographic system to capture cardiac and respiratory activity, two triaxial accelerometers to record limb micromotions and an IR reflex-sensor to detect peripheral pulse waves. The expander consists of an elastic cable in series with a load cell to measure the extension force and to adjust the extensions by visual feedback. The cable stiffness was chosen rather high (150-200 N/m) in order to induce involuntary limb oscillations at higher extension levels. The equipment was tested in MIR spaceflights and is projected for physiological tests on the ISS.
Frontiers in Human Neuroscience, 2015
This study examines with transcranial magnetic stimulation (TMS) and with functional magnetic res... more This study examines with transcranial magnetic stimulation (TMS) and with functional magnetic resonance imaging (fMRI) whether 20 min of repetitive peripheral magnetic stimulation (rPMS) has a facilitating effect on associated motor controlling regions. Trains of rPMS with a stimulus intensity of 150% of the motor threshold (MT) were applied over right hand flexor muscles of healthy volunteers. First, with TMS, 10 vs. 25 Hz rPMS was examined and compared to a control group. Single and paired pulse motor evoked potentials (MEPs) from flexor carpi radialis (FCR) and extensor carpi radialis (ECR) muscles were recorded at baseline (T0), post rPMS (T1), 30 min post (T2), 1 h post (T3) and 2 h post rPMS (T4). Then, with fMRI, 25 Hz rPMS was compared to sham stimulation by utilizing a finger tapping activation paradigm. Changes in bloodoxygen level dependent (BOLD) contrast were examined at baseline (PRE), post rPMS (POST1) and 1 h post rPMS (POST2). With TMS facilitation was observed in the target muscle (FCR) following 25 Hz rPMS: MEP recruitment curves (RCs) were increased at T1, T2 and T3, and intracortical facilitation (ICF) was increased at T1 and T2. No effects were observed following 10 Hz rPMS. With fMRI the BOLD contrast at the left sensorimotor area was increased at POST1. Compared to inductions protocols based on transcutaneous electrical stimulation and mechanical stimulation, the rPMS induced effects appeared shorter lasting.
2009 ICME International Conference on Complex Medical Engineering, 2009
ABSTRACT As a part of the EU-project “RISE” a pendulum test was applied to evaluate the effect of... more ABSTRACT As a part of the EU-project “RISE” a pendulum test was applied to evaluate the effect of functional electrical stimulation (FES) on denervated degenerated anterior thigh muscles. A sensor-actuator system was connected to the lower leg via an adjustable lever to hold the subject’s knee joint align with the pivot of the test device. The actuator (DC motor) of the pendulum system allowed to compensate static torques due to electrical stimulation and gravity. The tests were performed at two initial positions (knee angle of 90° and 120°). First passive measurements were taken and secondly FES was applied up to ±60V. A second-order dynamical model was applied to extract stiffness and viscous parameters from the recorded damped oscillation. The pendulum test was proved a sensitive method to detect even weak contractile capacity of long-term denervated and degenerated muscles. Therefore, the pendulum test is a useful clinical tool to assess muscle performance in denervated paraplegics.
Zentralblatt für Bakteriologie, Mikrobiologie und Hygiene. Serie B, Umwelthygiene, Krankenhaushygiene, Arbeitshygiene, präventive Medizin
The effect of stress caused by aircraft noise was studied on 14 female and 11 male volunteers, wh... more The effect of stress caused by aircraft noise was studied on 14 female and 11 male volunteers, who were of a age ranging from 21 to 42 years and of a mean age of 25 years. The volunteers were exposed to an aircraft simulator that stimulated the low level flight of an air force plane and produced a maximum noise level of 105 dB(A) for 3 sec. in a short time. Before and immediately after the exposure, the concentration of ACTH was measured by means of a radioimmunoassay. The ACTH is a hormone, responsible for initiating a chain reaction that is characteristic for a stress reaction. In 100% of the cases the concentration of this hormone increased. It reached a pathological level in 28% of the cases. The effect on the lipid metabolism was expressed by an increase of total cholesterol and a decrease of the triglycerides in the serum. A slight increase in blood sugar which, together with the free fatty acids, is relatively quickly reduced to energy, could be determined. The aircraft noise did not influence the activity of the liver transaminases in any way. A short-term exposure to aircraft noise is able to stimulate a stress reaction, whereby, the determination of the ACTH offers valuable informations.
Musik- Tanz und Kunsttherapie
The Journal of the Acoustical Society of America, 1999
International Journal of Hygiene and Environmental Health, 2010
Cells Tissues Organs, 1986
Fifteen ligaments taken from individuals aged between 60 and 80 years were used for the study of ... more Fifteen ligaments taken from individuals aged between 60 and 80 years were used for the study of the histological structure, the composition of the ground substance and the biomechanical behavior. Remnants of the original duct are recognizable in the ligament as artery of the muscular type. What had been the intima is thickened and consists mainly of cell-poor, fiber-rich connective tissue, which often shows chondrification along with calcification. The biomechanical behavior of the ligaments, evaluated with the force-length and force-relaxation test, was similar to that of peripheral arteries.
Biomedizinische Technik/Biomedical Engineering, 2000
Biomedizinische Technik/Biomedical Engineering, 2000
Biomedizinische Technik/Biomedical Engineering, 2000
Tensile tests on longitudinal and circumferential strips of the rabbit aorta have been performed.... more Tensile tests on longitudinal and circumferential strips of the rabbit aorta have been performed. Stress-strain and relaxation parameters have been estimated with respect to four stress levels and three positions on the aorta. Stress-strain data indicate that in longitudinal direction the aorta becomes more compliant with distance from the aortic arch. The opposite tendency is found for the circumferential direction. Stress-relaxation is found to be strongly dependent on the stress level. The results are discussed with regard to arterial dynamics.
Electroencephalography and Clinical Neurophysiology, 1996
Medical Biological Engineering Computing, Oct 1, 2002
A moving magnet galvanometer equipped with lever and indentor was evaluated for mechanomyography ... more A moving magnet galvanometer equipped with lever and indentor was evaluated for mechanomyography (MMG). First, the precision of the galvanometer was tested on a piezo-electric disc actuator. Using a 50 mm lever, synthesised micromotions with an amplitude of 1 microm could be detected (noise level < 0.2 microm) at static indentation forces ranging from 0.1 to 2 N. Then the galvanometer was mounted on an isometric ankle dynamometer to sense calf-muscle responses (N = 6). In the first protocol, twitch contractions were elicited by electrical stimulation while the indentation force was increased. Twitch amplitudes, twitch contraction times and twitch half-relaxation times were analysed from the surface and contraction responses. With indentation force (0.1-0.5 N), the amplitude of the surface responses increased (+61%), contraction and half-relaxation times, however, were not influenced. The mean twitch contraction time from the surface responses (60 +/- 11 ms) was shorter than that from the contraction responses (115 +/- 7 ms), indicating more fast-contracting fibres under the indented area. In the second protocol, voluntary target contractions were produced, and the surface responses were simultaneously recorded on an accelerometer. After double differentiation of the galvanometer signal, both acceleration MMGs showed a high coincidence in the time and frequency domains. With an indentation force of 2 N applied on the accelerometer, the signal amplitude (-10%) and the mean frequency (-19%) decreased. A specific application of this galvanometer-dynamometer test system is the assessment of regeneration processes in paraplegics with long-term denervated muscles.
Klinische Pädiatrie
Because of the growing demand to evaluate cardiorespiratory dysfunctions the short-time oxycardio... more Because of the growing demand to evaluate cardiorespiratory dysfunctions the short-time oxycardiorespirography becomes a more and more important and powerful tool in the daily clinical routine. Therefore, from about one hour lasting records we studied the distribution of MA-values (mean apnea duration), duration of the longest apnea, percentage of periodic breathing time, lowest heart rate values, lowest transcutaneous PO2 values and highest transcutaneous PCO2 values in an obstetrical optimal low-risk group of 90 infants and a obstetrical non-optimal group of 152 infants between four and ten weeks of age. Percentiles of each variable were calculated, and we suggest the 90th percentiles as new threshold values to judge these short-time recordings. In comparison to relevant data from the literature we could demonstrate that deviating threshold values have to be applied to short-time recordings in comparison to long-time recordings. In addition, the respiratory behaviour of the optimal group is compared to that of the non-optimal group of the same age. Interestingly enough, no difference in the respiratory behaviour between these groups could be demonstrated.
Absfracf- Small mechanical 8-12 Hz osctllatlons, phasecoupled to the heartbeat, are found on all ... more Absfracf- Small mechanical 8-12 Hz osctllatlons, phasecoupled to the heartbeat, are found on all relaxed ann segments. To investigate the dynamics of ann segments in relation to mechanical stimuli, a linear model was developed based on a tbree segment tonional pendulum. Simulation showed that the impact of heartbeat possibly leads to small oscillations in the hand but not in the upper and lower arm segments. It is proposed that spindle excitetion by the heartbeat may produce small 8-12 HZ oscillationr In the ann stretch sewo. Contraction in the upper arm muscles, estimated fmm tbe model, is found in the range of 0.015 Yo MVC - it is therefore conceivable that resting tone in upper am muscles transforms the impulse ercitatton of heartbeat into oscillatory excitation to the arm segments.
AJP Regulatory Integrative and Comparative Physiology
Microgravity was used to study accelerometrically recorded microvibration (MV) and postural tremo... more Microgravity was used to study accelerometrically recorded microvibration (MV) and postural tremor (PT) at reduced muscle tone on one cosmonaut before, during, and after an 8-day space flight on the Russian Mir station. MV of the relaxed forearm in the 1 g environment showed the typical 7- to 13-Hz resonance oscillations triggered by the heart beat. In 0 g, these pulsations shifted to below 5 Hz and the waveform became similar to an ultralow frequency acceleration ballistocardiogram. PT of the arm stretched forward showed an irregular waveform in 1 g. In 0 g, the higher-frequency components were reduced and again an ultralow frequency ballistocardiogram emerged. As a control, hand force tremor was recorded as well; it was not affected by the gravity condition. A second-order analog with muscle stiffness (C) as parameter was used to evaluate the measurements. For MV it could be shown that cardiac impacts produce damped resonance oscillations when C is high enough (1 g). At low C (0 g...
Biomedizinische Technik
To study cardiorespiratory and neuromotor functions in cosmonauts a novel belt with embedded poly... more To study cardiorespiratory and neuromotor functions in cosmonauts a novel belt with embedded polygraphic sensors and a force sensing expander were developed. The sensors are: a three-electrode ECG/impedance plethysmographic system to capture cardiac and respiratory activity, two triaxial accelerometers to record limb micromotions and an IR reflex-sensor to detect peripheral pulse waves. The expander consists of an elastic cable in series with a load cell to measure the extension force and to adjust the extensions by visual feedback. The cable stiffness was chosen rather high (150-200 N/m) in order to induce involuntary limb oscillations at higher extension levels. The equipment was tested in MIR spaceflights and is projected for physiological tests on the ISS.
Frontiers in Human Neuroscience, 2015
This study examines with transcranial magnetic stimulation (TMS) and with functional magnetic res... more This study examines with transcranial magnetic stimulation (TMS) and with functional magnetic resonance imaging (fMRI) whether 20 min of repetitive peripheral magnetic stimulation (rPMS) has a facilitating effect on associated motor controlling regions. Trains of rPMS with a stimulus intensity of 150% of the motor threshold (MT) were applied over right hand flexor muscles of healthy volunteers. First, with TMS, 10 vs. 25 Hz rPMS was examined and compared to a control group. Single and paired pulse motor evoked potentials (MEPs) from flexor carpi radialis (FCR) and extensor carpi radialis (ECR) muscles were recorded at baseline (T0), post rPMS (T1), 30 min post (T2), 1 h post (T3) and 2 h post rPMS (T4). Then, with fMRI, 25 Hz rPMS was compared to sham stimulation by utilizing a finger tapping activation paradigm. Changes in bloodoxygen level dependent (BOLD) contrast were examined at baseline (PRE), post rPMS (POST1) and 1 h post rPMS (POST2). With TMS facilitation was observed in the target muscle (FCR) following 25 Hz rPMS: MEP recruitment curves (RCs) were increased at T1, T2 and T3, and intracortical facilitation (ICF) was increased at T1 and T2. No effects were observed following 10 Hz rPMS. With fMRI the BOLD contrast at the left sensorimotor area was increased at POST1. Compared to inductions protocols based on transcutaneous electrical stimulation and mechanical stimulation, the rPMS induced effects appeared shorter lasting.
2009 ICME International Conference on Complex Medical Engineering, 2009
ABSTRACT As a part of the EU-project “RISE” a pendulum test was applied to evaluate the effect of... more ABSTRACT As a part of the EU-project “RISE” a pendulum test was applied to evaluate the effect of functional electrical stimulation (FES) on denervated degenerated anterior thigh muscles. A sensor-actuator system was connected to the lower leg via an adjustable lever to hold the subject’s knee joint align with the pivot of the test device. The actuator (DC motor) of the pendulum system allowed to compensate static torques due to electrical stimulation and gravity. The tests were performed at two initial positions (knee angle of 90° and 120°). First passive measurements were taken and secondly FES was applied up to ±60V. A second-order dynamical model was applied to extract stiffness and viscous parameters from the recorded damped oscillation. The pendulum test was proved a sensitive method to detect even weak contractile capacity of long-term denervated and degenerated muscles. Therefore, the pendulum test is a useful clinical tool to assess muscle performance in denervated paraplegics.