Search results for "volunteers"
showing 10 items of 248 documents
FMRI of the Cerebellum: Rostral Paravermal Activation in Tongue and Lip
1998
We investigated with fMRI the cerebellar representation of articulatory vertical movements of the tongue and orofacial muscles in healthy volunteers and its correspondence to the area known to be affected in cerebellar dysarthria. fMRI stimulation is mainly unilateral in agreement with the frequent occurrence of dysarthria in unilateral infarction.
Scientific approach for ozone absorption in blood during systemic indirect endovenous ozonetherapy
2018
Introduction.
 Reading reference ozone books from Dra. Menendez, Dra. Viebhan, Dra. Borrelli and Dr. Bocci, proper timing for mixing ozone in blood during autohemotherapy is not calculated in a scientific way, having only an estimation of it based on changes in the blood color, more related to oxygen absorption than on ozone itself.
 
 Material and methods.
 We decided to reproduce a reduced model of great autohemotherapy or recently renamed as systemic indirect endovenous ozonotherapy (SIEVO) by the World Federation of Ozone Therapy – WFOT, using syringes to simplify the experiment. Our model consisted of a 20 mL syringe filled with 10 mL of blood withdrawn from healthy…
Realization of administration unit for3He with gas recycling
2011
Hyperpolarized (HP) noble gases (3He,129Xe) are used for MR-imaging of the lung. In the majority of case the HP gas is filled in Tedlarbags and directly inhaled by the patients. Starting from an earlier pilot device, an administration unit was built respectively to the Medical Devices Law to administer patients HP noble gas boli in defined quantities and at a predefined time during inspiration with high reproducibility and reliability without reducing MR-quality. The patient's airflows are monitored and recorded. It is possible to use gas admixtures, measure the polarization on-line and collect the exhaled gas for later recycling. The first images with healthy volunteers were taken with thi…
Optical multichannel sensing of skin blood pulsations
2004
Time resolved detection and analysis of the skin back-scattered optical signals (reflection photoplethysmography or PPG) provide information on skin blood volume pulsations and can serve for cardiovascular assessment. The multi-channel PPG concept has been developed and clinically verified in this study. Portable two- and four-channel PPG monitoring devices have been designed for real-time data acquisition and processing. The multi-channel devices were successfully applied for cardiovascular fitness tests and for early detection of arterial occlusions in extremities. The optically measured heartbeat pulse wave propagation made possible to estimate relative arterial resistances for numerous …
Magnesium concentration in saliva — an indicator of digitalis toxicity
1981
In a prospective study salivary magnesium was measured by atomic absorption spectrophotometry in 168 patients on chronic digoxin therapy. Magnesium concentration in saliva was correlated with clinical data and plasma digoxin levels. A significant elevation in salivary magnesium concentration was caused by digoxin therapy (0.58 +/- 0.39 mmol/l, n = 93) in comparison to patients with no digitalis treatment (0.17 +/- 0.07 mmol/l, n = 35). Magnesium concentrations in saliva were significantly higher in toxic patients (1.1 +/- 0.68 mmol/l, n = 32) than in nontoxic patients. Possibly toxic patients showed a magnesium level of saliva of 0.63 +/- 0.39 mmol/l (n = 40). In 89% of the intoxicated pati…
Scalp, basal epidural and intravascular far-field recordings after median nerve stimulation: evidence for a separate N18a potential
2000
Far-field somatosensory evoked potentials (SSEPs) after median nerve stimulation were recorded from scalp- (Fz), epidural- (ED) and intravascular electrodes (basilar artery [Bas]) to study the nature of the controversial N18a component of the widespread N18 potential. In healthy volunteers frequently an N18a potential was recorded at Fz. Simultaneous Fz and ED recordings at the pontomesencephalic junction as well as Bas-recordings at the caudal basilar artery showed N18a components identical in latency and shape. With intravascular recordings the shapes differed between the top of the basilar artery and the caudal artery recordings. These findings support the existence of a separate N18a po…
Measurement Invariance and Construct Validity of the Satisfaction With Life Scale (SWLS) in Community Volunteers in Vietnam.
2022
Worldwide, the Satisfaction With Life Scale (SWLS) has become the most widely used measure of life satisfaction. Recently, an authorized Vietnamese-language version has been introduced. Using a convenience sample comprising community volunteers from Ho Chi Minh City (N = 1073), confirmatory support was found for the cross-national constancy of the one-dimensional structure underlying the SWLS. Corrected item–total polyserial correlations and Omega coefficient were satisfactory. Using multi-group confirmatory factor analysis, configural, metric, and scalar invariance of the SWLS factorial structure were tested by gender, age, marital status, income, and educational level. Strong evidence of …
Explaining the unique nature of individual gait patterns with deep learning
2019
Machine learning (ML) techniques such as (deep) artificial neural networks (DNN) are solving very successfully a plethora of tasks and provide new predictive models for complex physical, chemical, biological and social systems. However, in most cases this comes with the disadvantage of acting as a black box, rarely providing information about what made them arrive at a particular prediction. This black box aspect of ML techniques can be problematic especially in medical diagnoses, so far hampering a clinical acceptance. The present paper studies the uniqueness of individual gait patterns in clinical biomechanics using DNNs. By attributing portions of the model predictions back to the input …
Quantification of Myocardial Blood Flow Using Magnetic Resonance Imaging with Different accelerated Pulse Sequences
2009
The aim of this study was to compare SRTurboFLASH, SR-TrueFISP, and SR-segEPI pulse sequences using a twofold TSENSE-acceleration with regard to their use in quantification of myocardial blood flow (MBF). Six healthy volunteers were examined at 1.5T by first pass myocardial perfusion MRI at rest using all three TSENSE-accelerated pulse sequences. For absolute quantifi-cation of MBF XSIM software with the MMID4 model has been used. MBF analyses revealed significant MBF differences between SRTurboFLASH and SR-segEPI compared to SR-TrueFISP (p<0.005 and p<0.001, respectively). Differences between SRTurboFLASH and SR-segEPI were not statistically significant. The median MBF values for SR-TurboF…
Multilevel assessment of mental stress via network physiology paradigm using consumer wearable devices
2019
Mental stress is a physiological condition that has a strong negative impact on the quality of life, affecting both the physical and the mental health. For such a reason, accurate measurements of stress level can be helpful to provide mechanisms for prevention and treatment. This paper proposes a procedure for the classification of different mental stress levels by using physiological signals provided by low invasive wearable devices. 17 healthy volunteers participated in this study. Three different mental states were elicited in them: a resting condition, a stressful cognitive state, and a sustained attention task. The acquired physiological signals were: a one lead electrocardiogram (ECG)…