Search results for " processing"
showing 10 items of 7549 documents
Left ventricular ejection fraction calculation from automatically selected and processed diastolic and systolic frames in short-axis cine-MRI
2005
International audience; Abstract: The calculation of the left ventricular ejection fraction (LVEF) is dependent upon the accurate measurement of diastolic and systolic left ventricular volumes. Although breath-hold cine magnetic resonance imaging (MRI) allows coverage of the whole cardiac cycle with an excellent time resolution, many authors rely on the visual selection of diastolic and the systolic short-axis slices in order to reduce the postprocessing time. An automatic method was developed to detect the endocardial contour on each image, allowing an automatic selection of the systolic frame. The calculated ejection fraction was compared with radionuclide ventriculography (RNV). Sixty-fi…
Are different kinds of acoustic features processed differently for speech and non-speech sounds?
2001
This study examined how changes in different types of acoustic features are processed in the brain for both speech and non-speech sounds. Event-related potentials (ERPs) were recorded in native Finnish speakers presented with sequences of repetitive vowels (/e/) or complex harmonical tones interspersed with infrequent changes in duration, frequency and either a vowel change (/o/ for vowel sequences) or a double deviant (frequency+duration change for tone sequences). The stimuli were presented monaurally in separate blocks to either the left or right ear. The results showed that speech stimuli were more efficiently processed than harmonical tones as reflected by an enhanced mismatch negativi…
Single-Sided Deafness: Impact of Cochlear Implantation on Speech Perception in Complex Noise and on Auditory Localization Accuracy.
2017
Objective To assess auditory localization accuracy and speech reception threshold (SRT) in complex noise conditions in adult patients with acquired single-sided deafness, after intervention with a cochlear implant (CI) in the deaf ear. Study design Nonrandomized, open, prospective patient series. Setting Tertiary referral university hospital. Patients Eleven patients with late-onset single-sided deafness (SSD) and normal hearing in the unaffected ear, who received a CI. All patients were experienced CI users. Intervention Unilateral cochlear implantation. Main outcome measures Speech perception was tested in a complex multitalker equivalent noise field consisting of multiple sound sources. …
Measuring postural-related changes of spontaneous baroreflex sensitivity after repeated long-duration diving: Frequency domain approaches
2012
Sustained water immersion is thought to modulate orthostatic tolerance to an extent dependent on the duration and repetition over consecutive days of the diving sessions. We tested this hypothesis investigating in ten healthy subjects the potential changes in the cardiovascular response to head-up tilt induced by single and multiple resting air dives. Parametric cross-spectral analysis of spontaneous RR interval and systolic arterial pressure variability was performed in three experimental sessions: before diving (BD), after single 6-hour dive (ASD), and after multiple 6-hour dives (AMD, 5 consecutive days with 18-hour surface interval). From this analysis, baroreflex sensitivity (BRS) was …
Lymph flow dynamics in exercising human skeletal muscle as detected by scintography
1997
1. The effects of dynamic and isometric muscle contractions on the lymph flow dynamics in human skeletal muscle were studied with a scintographic method. 2. Radioactively labelled human serum albumin (99mTc-HSA) was injected bilaterally into the vastus lateralis muscles of eight men (n = 16), four of whom had had an endurance training background. The subjects performed 100 submaximal contractions in 10 min as (i) dynamic knee extensions (CONS), (ii) isometric contractions with the knees at full extension (IMExt), or (iii) isometric contractions with knees fixed at 90 deg angle flexion (IMFlex). The exercises were separated by 65 min periods in supine rest. The level of radioactivity at the …
Regular rhythmic primes boost P600 in grammatical error processing in dyslexic adults and matched controls
2020
International audience; Regular musical rhythms orient attention over time and facilitate processing. Previous research has shown that regular rhythmic stimulation benefits subsequent syntax processing in children with dyslexia and specific language impairment. The present EEG study examined the influence of a rhythmic musical prime on the P600 late evoked-potential, associated with grammatical error detection for dyslexic adults and matched controls. Participants listened to regular or irregular rhythmic prime sequences followed by grammatically correct and incorrect sentences. They were required to perform grammaticality judgments for each auditorily presented sentence while EEG was recor…
Automatic processing of rare versus novel auditory stimuli reveal different mechanisms of auditory change detection
2012
Automatic detection of rare stimuli or changes in an auditory stimulation can distract ongoing task processing by attracting attention away from task relevant information. Typically, the effectiveness of auditory change detection is tested by rare and unpredictable deviations (compared with an otherwise regular auditory presentation) or by rare environmental sounds. The present study demonstrates that both types of stimuli are capable of triggering automatic orientation of attention and that rare environmental sounds are more effective than deviations in distraction of attention. This finding suggests different mechanisms underlying the detection of auditory change. Moreover, novelty as con…
Central and Peripheral Contributions to Fatigue after Electrostimulation Training
2006
Purpose: We examined the effect of 4 (WK4) and 8 wk (WK8) of neuromuscular electrical stimulation (NMES) training on both endurance time and mechanisms contributing to task failure. Methods: Ten males performed a fatiguing isometric contraction with the knee extensor muscles at 20% of maximal voluntary contraction (MVC) until exhaustion before (B), at WK4, and at WK8 of NMES training. The electromyographic (EMG) activity and muscle activation obtained under MVC were recorded before and after the fatiguing task to assess central fatigue. Torque and EMG responses obtained under electrically evoked contractions were examined before and after the fatiguing task to analyze peripheral fatigue. Re…
Centrifugal (inside-out) enhancement of liver hemangiomas: a possible atypical appearance on contrast-enhanced US.
2007
Abstract Objective To report the prevalence and to describe the atypical centrifugal (inside-out) appearance of contrast-enhancement of liver hemangiomas on contrast-enhanced sonography. Materials and methods Baseline and SonoVue ® -enhanced ultrasonography of 92 patients with 158 liver hemangiomas – considered atypical at grey-scale examination and confirmed by computed tomography, magnetic resonance imaging and ultrasound follow-up – were reviewed in consensus by two experienced radiologists, who evaluated baseline echogenicity and the dynamic enhancement pattern of each lesion looking for the presence of central enhancing foci in the arterial phase followed by a centrifugal (inside-out) …
Microcirculation in the healing of surgical wounds in the oral cavity.
2013
Abstract. The aim of this research is to evaluate in vivo the characteristics of microcirculation after taking a biopsy sample from the oral mucosa. 20 patients were recruited to the study and all underwent an oral mucosa biopsy for the excision of benign neoformations. The modifications in the oral microcirculation were evaluated in vivo in correspondence to the surgical site through videocapillaroscopy at three different times: 30 min before the biopsy; 48 h after the biopsy; and 7 days after the biopsy. The statistical significance was checked with the Mann–Whitney U-test (P < 0.05). The analysis of videocapillaroscopic patterns showed statistically significant variations relative to the…