Search results for "Dynamic"
showing 10 items of 12329 documents
Quantifying changes in EEG complexity induced by photic stimulation.
2009
Summary Objectives: This study aims to characterize EEG complexity, measured as the prediction error resulting from nonlinear prediction, in healthy humans during photic stimulation. Methods: EEGs were recorded from 15 subjects with eyes closed (EC) and eyes open (EO), during the baseline condition and during stroboscopic photic stimulation (PS) at 5, 10, and 15 Hz. The mean squared prediction error (MSPE) resulting from nearest neighbor local linear prediction was taken as complexity index. Complexity maps were generated interpolating the MSPE index over a schematic scalp representation. Results: Statistical analysis revealed that: i) EEG shows good predictability in all conditions and see…
Effects of muscle action type on corticospinal excitability and triceps surae muscle-tendon mechanics.
2018
This study investigated whether the specific motor control strategy reported for eccentric muscle actions is dependent on muscle mechanical behavior. Motor evoked potentials, Hoffman reflex (H-reflex), fascicle length, pennation angle, and fascicle velocity of soleus muscle were compared between isometric and two eccentric conditions. Ten volunteers performed maximal plantarflexion trials in isometric, slow eccentric (25°/s), and fast eccentric (100°/s) conditions, each in a different randomized testing session. H-reflex normalized by the preceding M wave (H/M) was depressed in both eccentric conditions compared with isometric ( P < 0.001), while no differences in fascicle length and pe…
Axis Rotation and Visually Induced Motion Sickness: The Role of Combined Roll, Pitch, and Yaw Motion
2011
A well-known phenomenon in aviation and in virtual environments such as simulators or computer games is motion sickness (MS). The amount of sensory conflict is thought to be responsible for the severity of MS, which should increase with the complexity of the simulated motion. The focus of the present study is on the direction and complexity of simulated body rotations in the genesis and severity of visually induced MS. The methods utilized for this study are as follows: Three simulated rollercoaster rides including translational movement in the fore-aft axis and additional rotational motion either in pitch only, along the pitch and roll axes, or in pitch, roll, and yaw were generated. The a…
Psychodynamic focal group treatment for psychosomatic inpatients--with an emphasis on work-related conflicts.
2006
Conflicts arising from the work setting have remained a neglected issue in psychotherapy. To address this, the present study investigated the effectiveness of a manualized focal group treatment for psychotherapeutic inpatients suffering from vocational strains and conflicts and identified predictors of outcome. Cohorts of patients were assigned either to a treatment (N=144) or control condition (N=135). The group therapy intervention was found to be highly accepted by participants who were also more optimistic about returning to work and more favorable in their evaluations of treatment than patients in the treatment-as-usual condition. Group climate was found to be a predictor of favorable …
Hemodynamic Effects of Nonionic Contrast Bolus Injection and Oxygen Inhalation During Pulmonary Angiography in Patients With Chronic Major-Vessel Thr…
1996
Background Pulmonary angiography is the gold standard for the diagnosis of chronic thromboembolic pulmonary hypertension; however, major complications have been reported. This study evaluates the hemodynamic effects of direct pulmonary nonionic contrast bolus injection and oxygen inhalation in patients with chronic thromboembolic pulmonary hypertension. Methods and Results In 33 patients, hemodynamic parameters were measured after oxygen inhalation and during bolus injection of nonionic contrast medium in a control group (group 1, n=11), in a group of patients with moderately severe pulmonary hypertension (group 2, n=9), and in a group with severe pulmonary hypertension (group 3, n=13). Ox…
Improvement of tricuspid regurgitation after pulmonary thromboendarterectomy
2002
For patients with chronic thromboembolic pulmonary hypertension who undergo pulmonary thromboendarterectomy (PTE) it has not yet been systematically investigated how operation affects the severity of tricuspid regurgitation (TR). This study sought (1) to evaluate the extent of TR reversibility after operation, (2) to identify potential predictors of the reversibility of TR, and (3) to investigate the influence of geometric and hemodynamic alterations on the extent of TR severity.Thirty-nine patients (55+/-12 years) undergoing PTE without tricuspid valve repair were investigated before and 13+/-8 days after operation by Doppler color flow mapping. Geometry of the tricuspid valve as well as r…
Outcome of patients with right heart thrombi: the Right Heart Thrombi European Registry
2015
Our aim was the assessment of the prognostic significance of right heart thrombi (RiHT) and their characteristics in pulmonary embolism in relation to established prognostic factors.138 patients (69 females) aged (mean±sd) 62±19 years with RiHT were included into a multicenter registry. A control group of 276 patients without RiHT was created by propensity scoring from a cohort of 963 contemporary patients. The primary end-point was 30-day pulmonary embolism-related mortality; the secondary end-point included 30-day all-cause mortality. In RiHT patients, pulmonary embolism mortality was higher in 31 patients with systolic blood pressure <90 mmHg than in 107 normotensives (42% versus 12%,…
Altered reflex sensitivity after repeated and prolonged passive muscle stretching.
1999
Experiments were carried out to test the effect of prolonged and repeated passive stretching (RPS) of the triceps surae muscle on reflex sensitivity. The results demonstrated a clear deterioration of muscle function immediately after RPS. Maximal voluntary contraction, average electromyographic activity of the gastrocnemius and soleus muscles, and zero crossing rate of the soleus muscle (recorded from 50% maximal voluntary contraction) decreased on average by 23.2, 19.9, 16.5, and 12.2%, respectively. These changes were associated with a clear immediate reduction in the reflex sensitivity; stretch reflex peak-to-peak amplitude decreased by 84.8%, and the ratio of the electrically induced m…
Peripapillary Choroidal Thickness and Choroidal Area in Glaucoma, Ocular Hypertension and Healthy Subjects by SD-OCT.
2015
Background: The exact pathogenesis of open angle glaucoma and ocular hypertension remains unclear. Hemodynamic influences are discussed as potential risk factors and the choroid may play an important role in the pathogenesis of open angle glaucoma or ocular hypertension. The current study investigates peripapillary choroidal thickness and choroidal area in patients with open angle glaucoma, subjects with ocular hypertension and healthy subjects using spectral-domain OCT. It furthermore assesses the association between peripapillary choroidal thickness and age, central corneal thickness, refractive error and intraocular pressure. Patients and Methods: Prospectively recorded data of 213 eyes …
Photodynamic therapy with verteporfin for subfoveal choroidal neovascularization secondary to pathologic myopia: long-term study.
2006
Purpose: To assess the safety and effectiveness of photodynamic therapy (PDT) with verteporfin for subfoveal choroidal neovascularization (CNV) secondary to pathologic myopia (PM). Methods: Sixty-two patients (62 eyes) with PM underwent PDT according to the guidelines of the Verteporfin in Photodynamic Therapy Study. Clinical evaluations performed at all study visits included measurement of best-corrected Snellen visual acuity, slit-lamp biomicroscopy, and fundus fluorescein angiography. Patients were followed up at 1 month and 3 months after treatment and thereafter at 3-month intervals. Results: The final visual acuity of the study patients, after a median follow-up of 31 months, improved…