Multicentre evaluation of a new point-of-care test for the determination of NT-proBNP in whole blood

Background: The Roche CARDIAC proBNP point-of-care (POC) test is the first test intended for the quantitative determination of N-terminal pro-brain natriuretic peptide (NT-proBNP) in whole blood as an aid in the diagnosis of suspected congestive heart failure, in the monitoring of patients with compensated left-ventricular dysfunction and in the risk stratification of patients with acute coronary syndromes. Methods: A multicentre evaluation was carried out to assess the analytical performance of the POC NT-proBNP test at seven different sites. Results: The majority of all coefficients of variation (CVs) obtained for within-series imprecision using native blood samples was below 10% for both 52 samples measured ten times and for 674 samples measured in duplicate. Using quality control material, the majority of CV values for day-to-day imprecision were below 14% for the low control level and below 13% for the high control level. In method comparisons for four lots of the POC NT-proBNP test with the laboratory reference method (Elecsys proBNP), the slope ranged from 0.93 to 1.10 and the intercept ranged from 1.8 to 6.9. The bias found between venous and arterial blood with the POC NT-proBNP method was ≤5%. All four lots of the POC NT-proBNP test investigated showed excellent agreement, with mean differences of between −5% and +4%. No significant interference was observed with lipaemic blood (triglyceride concentrations up to 6.3mmol/L), icteric blood (bilirubin concentrations up to 582μmol/L), haemolytic blood (haemoglobin concentrations up to 62mg/L), biotin (up to 10mg/L), rheumatoid factor (up to 42IU/mL), or with 50 out of 52 standard or cardiological drugs in therapeutic concentrations. With bisoprolol and BNP, somewhat higher bias in the low NT-proBNP concentration range (<175ng/L) was found. Haematocrit values between 28% and 58% had no influence on the test result. Interference may be caused by human anti-mouse antibodies (HAMA) types 1 and 2. No significant influence on the results with POC NT-proBNP was found using volumes of 140-165μL. High NT-proBNP concentrations above the measuring range of the POC NT-proBNP test did not lead to false low results due to a potential high-dose hook effect. Conclusions: The POC NT-proBNP test showed good analytical performance and excellent agreement with the laboratory method. The POC NT-proBNP assay is therefore suitable in the POC setting. Clin Chem Lab Med 2006;44:1269-7

An Acoustic Study of the Emphatic Occlusive [ṭ] in School-Going Children with Cleft Palate or Cleft Lip

The aim of this acoustic study is to analyse the phoneme [ṭ] produced by school children surgically operated on for the cleft palate or cleft lip, in order to examine their vocal characteristics, to provide speech therapists with numerous concrete analyses of voice and speech, to effectively support them and to prevent some serious outcomes on their psychological and academic development. The motivation for this study was mainly stemming from the difficulties that Algerian schoolchildren with clefts encounter in the pronunciation of this phoneme. To carry out the study, several acoustic parameters were investigated in terms of the fundamental frequency F0, the first three formants F1, F2, and F3, the energy E0, the Voice Onset Time (VOT), the durations [CV] and [V] of the subsequent vowel [a]. For the analysis, further important parameters in the field of pathological speech were deployed, namely the degree of disturbance of F0 (jitter), the degree of disturbance of intensity (shimmer) and the HNR (Harmonics to Noise Ratio). Results revealed disturbance in the values of F1, F2, and F3 and stability in the values of F0. Another important reported aspect is the increase in the value of the VOT due to the difficulties in controlling the plosives’ successive closure and release

Kernel SVM Classifiers based on Fractal Analysis for Estimation of Hearing Loss

Hearing screening consists of analyzing the hearing capacity of an individual, regardless of age. It identifies serious hearing problems, degree, type and cause of the hearing loss and the needs of the person to propose a solution. Auditory evoked potentials (AEPs) which are detected on the EEG auditory cortex area are very small signals in response to a sound stimulus (or electric) from the inner ear to the primary auditory areas of the brain. AEPs are noninvasive methods used to detect hearing disorders and to estimate hearing thresholds level. In this paper, due to the nonlinear characteristics of EEG, Detrented Fluctuation Analysis (DFA) is used to characterize the irregularity or complexity of EEG signals by calculating the Fractal Dimension (FD) from the recorded AEP signals of the impaired hearing and the normal subjects. This is to estimate their hearing threshold. In order to classify both groups, hearing impaired and normal persons, support vector machine (SVM) is used. For comparably evaluating the performance of SVM classifier, three kernel functions: linear, radial basis function (RBF) and polynomial are employed to distinguish normal and the abnormal hearing subjects. Grid search technique is selected to estimate the optimal kernel parameters. Our results indicate that the RBF kernel SVM classifier is promising; it is able to obtain a high training as well as testing classification accuracy

An Experimental Study of the Gemination in Arabic Language

In this paper, we report the results of an experimental study of the acoustic and articulatory features of the gemination in Modern Arabic language, pronounced by Algerian speakers. To extract the feature characteristics, we have carried out an acoustic analysis by computing the values of frequency formants, energy and durations of the consonants and subsequent vowels in the various [VCV] and [VCgV] utterances (Cg: geminate consonant). For the articulatory analysis, a range of kinematics parameters were analyzed from the phoneme productions including movement trajectories, distance, velocity, and duration of tongue movements. Among the most important results, we note a longer duration of the vowel following a geminate consonant, a decreasing in levels of F1 and F2 formants and a rising in level of F3 formant of this vowel

Objective Evaluation of the Pathological Voice Based on Deep Learning Neural Networks in an Algerian hospital environment

In this study, we propose a method based on Recurrent Neural Networks, to objectively evaluate the process of rehabilitation of the pathological voice, in an Algerian clinical environment. We choose Unilateral Laryngeal Paralysis as the pathology of the voice. In this paper, we used a Deep Learning system of pathological voice detection by Long Short Term Memory neural model (LSTM). As the dysphony studied in our work concerns essentially the laryngeal vibration, we choose the acoustic parameters based on the instability of the frequency and the amplitude of the laryngeal vibration: Jitter and Shimmer, Noise parameters and Cepstraux MFCC coefficients (Mel Frequency Cepstral Coefficients). A pathological voice detection rate of 88.65% shows important results brought by the rehabilitation technique adopted in Algerian clinical setting. The exclusive and abusive use of hearing to evaluate the effect of speech rehabilitation in the Algerian hospital environment remains insufficient. It is important to correlate perceptual data with objective methods based on detection and classification methods by introducing relevant acoustic parameters, for an effective and objective management of vocal pathology assessment

A study of sounds produced by Algerian esophageal speakers

Background: Total Laryngectomy is a mode of treatment of patients with advanced laryngeal cancer. It affects the voice and the speech communication.Objective: To present an acoustic analysis of the new voice after total laryngectomy in Algerian hospital environment.Methods: A corpus of sounds was collected from October 2008 to September 2009 and pronounced by eight male speakers who have undergone total laryngectomy. Minimum age of patients was 47 years and maximum age was 59 years with mean age 54.87 years. Recordings were made before the beginning of reeducation and after three, six, and eleven months using esophageal voice. The acoustic analysis includes the Pitch F0 (Hz), Formants, intensity, Jitter (%), Shimmer (dB), harmonic to noise ratio HNR (dB), and degree of unvoiced frames DUF (%).Results: We note a restriction in F0, increasing of Jitter and Shimmer, decreasing of HNR values, and reduced intensity compared to the voice of normal laryngeal speakers. In addition, we note a higher percentage of DUF during the pronunciation of sustained vowels.Conclusion: Some deficiencies were reported in the taking care of patients. Therefore, the acoustic analysis may be used in evaluating the reliability of the technique of reeducation.Key words: Total laryngectomy, pathological voice, acoustic analysis, Jitter, Shimmer

An Experimental Study of the Gemination in Arabic Language

In this paper, we report the results of an experimental study of the acoustic and articulatory features of the gemination in Modern Arabic language, pronounced by Algerian speakers. To extract the feature characteristics, we have carried out an acoustic analysis by computing the values of frequency formants, energy and durations of the consonants and subsequent vowels in the various [VCV] and [VCgV] utterances (Cg: geminate consonant). For the articulatory analysis, a range of kinematics parameters were analyzed from the phoneme productions including movement trajectories, distance, velocity, and duration of tongue movements. Among the most important results, we note a longer duration of the vowel following a geminate consonant, a decreasing in levels of F1 and F2 formants and a rising in level of F3 formant of this vowel