Search results for "Specificity."
showing 10 items of 2232 documents
Intraocular pressure after excimer laser myopic refractive surgery
2001
The aim of this study was to determine whether intraocular pressure (IOP), as measured by Goldmann applanation or non-contact tonometry, shows systematic changes in patients who have undergone photorefractive keratectomy (PRK) or laser in situ keratomileusis (LASIK). IOP was measured by central Goldmann and non-contact tonometry in 54 patients pre and post-PRK, and in 43 patients pre- and post-LASIK. An interval of 12 months was allowed after surgery. Patients were selected to have one of four specific initial values of refractive error (-2.5, -5.0, -7.5 and -10.0 D). Fellow unoperated eyes were used as controls. A paired Student's t-test and a one-way ANOVA test were used for statistical a…
Single region of interest versus multislice T2* MRI approach for the quantification of hepatic iron overload.
2011
Purpose To evaluate the effectiveness of the single ROI approach for the detection of hepatic iron burden in thalassemia major (TM) patients in respect to a whole liver measurement. Materials and Methods Five transverse hepatic slices were acquired by a T2* gradient-echo sequence in 101 TM patients and 20 healthy subjects. The T2* value was calculated in a single region of interest (ROI) defined in the medium-hepatic slice. Moreover, the T2* value was extracted on each of the eight ROIs defined in the functionally independent segments. The mean hepatic T2* value was calculated. Results For patients, the mean T2* values over segments VII and VIII were significantly lower. This pattern was su…
Evaluation of the anterior chamber angle in keratoconus and normal subjects.
2015
To evaluate the anterior chamber angle in keratoconus eyes by use of the Visante™ OCT and Orbscan™ II.Anterior chamber angle was measured with the Visante™ OCT and Orbscan™ II in 52 subjects, 26 KC subjects and 26 age and control subjects.When comparing the nasal and temporal angles obtained with the two techniques no correlation was found (R(2) always below 0.01) in either the control subjects or in the KC subjects. Despite this, there was an overall statistically significant difference in mean anterior chamber angles (p0.001) between Visante™ OCT and Orbscan™ II. There was no statistical difference (p0.05) between nasal and temporal anterior chamber angles when comparing controls and KC s…
Objective measurement of intraocular forward light scatter using Hartmann-Shack spot patterns from clinical aberrometers. Model-eye and human-eye stu…
2007
Purpose To apply software-based image-analysis tools to objectively determine intraocular scatter determined from clinically derived Hartmann-Shack patterns. Setting Aston Academy of Life Sciences, Aston University, Birmingham, United Kingdom, and Department of Optics, University of Valencia, Valencia, Spain. Methods Purpose-designed image-analysis software was used to quantify scatter from centroid patterns obtained using a clinical Hartmann-Shack analyzer (WASCA, Zeiss/Meditec). Three scatter values, as the maximum standard deviation within a lenslet for all lenslets in the pattern, were obtained in 6 model eyes and 10 human eyes. In the model-eye sample, patterns were obtained in 4 sessi…
The Fertility Quality of Life Questionnaire (FertiQoL) Relational subscale: psychometric properties and discriminant validity across gender.
2016
Study question Is the Fertility Quality of Life Questionnaire (FertiQoL)-Relational Scale a valid measure to assess the relational domain regarding quality of life in women and men undergoing infertility treatment? Summary answer The FertiQoL-Relational scale (FertiQoL-REL) showed good psychometric properties and captured core aspects of couple relationships. What is known already FertiQoL has become a gold standard for the assessment of infertility-related quality of life in patients undergoing assisted reproduction treatment (ART). Despite its growing importance, no previous studies have examined the convergent validity of the FertiQoL-REL and its discriminant validity across gender. Stud…
Usefulness of quantitative peritumoural perfusion and proton spectroscopic magnetic resonance imaging evaluation in differentiating brain gliomas fro…
2016
Objectives The purpose of our study was to evaluate whether peritumoural perfusion weighted and proton spectroscopic magnetic resonance imaging can be used in differentiating between primary gliomas and solitary metastases. Methods Ten low-grade gliomas, eight high-grade gliomas and 10 metastases were prospectively evaluated with magnetic resonance imaging, dynamic susceptibility contrast enhanced perfusion imaging and single-voxel proton magnetic resonance spectroscopy before surgical resection or stereotactic biopsy. Maximal relative cerebral blood volume values were calculated drawing three regions of interest of 2 cm2 in the non-enhancing peritumoural areas. Maximal relative cerebral bl…
Measurement of EMG activity with textile electrodes embedded into clothing.
2007
Novel textile electrodes that can be embedded into sports clothing to measure averaged rectified electromyography (EMG) have been developed for easy use in field tests and in clinical settings. The purpose of this study was to evaluate the validity, reliability and feasibility of this new product to measure averaged rectified EMG. The validity was tested by comparing the signals from bipolar textile electrodes (42 cm(2)) and traditional bipolar surface electrodes (1.32 cm(2)) during bilateral isometric knee extension exercise with two electrode locations (A: both electrodes located in the same place, B: traditional electrodes placed on the individual muscles according to SENIAM, n=10 person…
Variability in Lateral Positioning of Surface EMG Electrodes
2009
The positions of EMG electrodes over the knee extensor muscles were examined in 19 healthy men using MR images; electrodes were placed according to the SENIAM (surface electromyography for non-invasive assessment of muscles) guidelines. From axial images, the medial and lateral borders of the muscles were identified, and the arc length of the muscle surface was measured. The electrode location was expressed as a percentage value from the muscle’s medial border. EMGs were recorded during isometric maximal contraction, squat jumps, and countermovement jumps and analyzed for cross-correlation. The results showed that variations in lateral positioning were greatest in vastus medialis (47% SD 11…
Effect of innervation zones in estimating biceps brachii force-EMG relationship during isometric contraction
2012
Measuring muscle forces in vivo is invasive and consequently indirect methods e.g., electromyography (EMG) are used in estimating muscular force production. The aim of the present paper was to examine what kind of effect the disruption of the physiological signal caused by the innervation zone has in predicting the force/torque output from surface EMG. Twelve men (age 26 (SD ±3)years; height 179 (±6)cm; body mass 73 (±6)kg) volunteered as subjects. They were asked to perform maximal voluntary isometric contraction (MVC) in elbow flexion, and submaximal contractions at 10%, 20%, 30%, 40%, 50% and 75% of the recorded MVC. EMG was measured from biceps brachii muscle with an electrode grid of 5…
Assessment of brainstem function in Chiari II malformation utilizing brainstem auditory evoked potentials (BAEP), blink reflex and masseter reflex
2000
Brainstem dysfunction was evaluated in 67 patients with myelomeningocele and Chiari II malformation using brainstem auditory evoked potentials (BAEP), blink reflex (BR) and masseter reflex (MR). Signs and symptoms related to Chiari II malformation were observed in 18 patients while 49 patients had normal brainstem findings. BAEP and BR showed a higher sensitivity of brainstem involvement than MR (BAEP=1.0, BR=0.83, MR=0.50). BR, and in particular, MR were of higher accuracy (BR=0.52, MR=0.72) than BAEP (0.39) in separating patients with brainstem signs and symptoms related to Chiari II malformation. We feel that this is due to anatomic and physiologic peculiarities of the brainstem structur…