7 resultados para quality index
em Aston University Research Archive
Resumo:
The long-term foetal surveillance is often to be recommended. Hence, the fully non-invasive acoustic recording, through maternal abdomen, represents a valuable alternative to the ultrasonic cardiotocography. Unfortunately, the recorded heart sound signal is heavily loaded by noise, thus the determination of the foetal heart rate raises serious signal processing issues. In this paper, we present a new algorithm for foetal heart rate estimation from foetal phonocardiographic recordings. A filtering is employed as a first step of the algorithm to reduce the background noise. A block for first heart sounds enhancing is then used to further reduce other components of foetal heart sound signals. A complex logic block, guided by a number of rules concerning foetal heart beat regularity, is proposed as a successive block, for the detection of most probable first heart sounds from several candidates. A final block is used for exact first heart sound timing and in turn foetal heart rate estimation. Filtering and enhancing blocks are actually implemented by means of different techniques, so that different processing paths are proposed. Furthermore, a reliability index is introduced to quantify the consistency of the estimated foetal heart rate and, based on statistic parameters; [,] a software quality index is designed to indicate the most reliable analysis procedure (that is, combining the best processing path and the most accurate time mark of the first heart sound, provides the lowest estimation errors). The algorithm performances have been tested on phonocardiographic signals recorded in a local gynaecology private practice from a sample group of about 50 pregnant women. Phonocardiographic signals have been recorded simultaneously to ultrasonic cardiotocographic signals in order to compare the two foetal heart rate series (the one estimated by our algorithm and the other provided by cardiotocographic device). Our results show that the proposed algorithm, in particular some analysis procedures, provides reliable foetal heart rate signals, very close to the reference cardiotocographic recordings. © 2010 Elsevier Ltd. All rights reserved.
Resumo:
The purpose of this paper is twofold: first, we compute quality-adjusted measures of productivity change for the three most important diagnostic technologies (i.e., the Computerised Tomography Scan, Electrocardiogram and Echocardiogram) in the major Portuguese hospitals. We use the Malmquist–Luenberger index, which allows to measure productivity growth while controlling for the quality of the production. Second, using non-parametric tests, we analyse whether the implementation of the Prospective Payment System may have had a positive impact on the movements of productivity over time. The results show that the PPS has helped hospitals to use these tools more efficiently and to improve their effectiveness.
Resumo:
BACKGROUND: The use of quality of life (QoL) instruments in menorrhagia research is increasing but there is concern that not enough emphasis is placed on patient-focus in these measurements, i.e. on issues which are of importance to patients and reflect their experiences and concerns (clinical face validity). The objective was to assess the quality of QoL instruments in studies of menorrhagia. STUDY DESIGN: A systematic review of published research. Papers were identified through MEDLINE (1966-April 2000), EMBASE (1980-April 2000), Science Citation Index (1981-April 2000), Social Science Citation Index (1981-April 2000), CINAHL (1982-1999) and PsychLIT (1966-1999), and by manual searching of bibliographies of known primary and review articles. Studies were selected if they assessed women with menorrhagia for life quality, either developing QoL instruments or applying them as an outcome measure. Selected studies were assessed for quality of their QoL instruments, using a 17 items checklist including 10 items for clinical face validity (issues of relevance to patients' expectations and concerns) and 7 items for measurement properties (such as reliability, responsiveness, etc.). RESULTS: A total of 19 articles, 8 on instrument development and 11 on application, were included in the review. The generic Short Form 36 Health Survey Questionnaire (SF36) was used in 12/19 (63%) studies. Only two studies developed new specific QoL instruments for menorrhagia but they complied with 7/17 (41%) and 10/17 (59%) of the quality criteria. Quality assessment showed that only 7/19 (37%) studies complied with more than half the criteria for face validity whereas 17/19 (90%) studies complied with more than half of the criteria for measurement properties (P = 0.0001). CONCLUSION: Among existing QoL instruments, there is good compliance with the quality criteria for measurement properties but not with those for clinical face validity. There is a need to develop methodologically sound disease specific QoL instruments in menorrhagia focussing both on face validity and measurement properties.
Resumo:
Recently introduced surface nanoscale axial photonics (SNAP) makes it possible to fabricate high-Q-factor microresonators and other photonic microdevices by dramatically small deformation of the optical fiber surface. To become a practical and robust technology, the SNAP platform requires methods enabling reproducible modification of the optical fiber radius at nanoscale. In this Letter, we demonstrate superaccurate fabrication of high-Q-factor microresonators by nanoscale modification of the optical fiber radius and refractive index using CO laser and UV excimer laser beam exposures. The achieved fabrication accuracy is better than 2Å in variation of the effective fiber radius. © 2011 Optical Society of America.
Resumo:
BACKGROUND: The use of quality of life (QoL) instruments in menorrhagia research is increasing but there is concern that not enough emphasis is placed on patient-focus in these measurements, i.e. on issues which are of importance to patients and reflect their experiences and concerns (clinical face validity). The objective was to assess the quality of QoL instruments in studies of menorrhagia. STUDY DESIGN: A systematic review of published research. Papers were identified through MEDLINE (1966-April 2000), EMBASE (1980-April 2000), Science Citation Index (1981-April 2000), Social Science Citation Index (1981-April 2000), CINAHL (1982-1999) and PsychLIT (1966-1999), and by manual searching of bibliographies of known primary and review articles. Studies were selected if they assessed women with menorrhagia for life quality, either developing QoL instruments or applying them as an outcome measure. Selected studies were assessed for quality of their QoL instruments, using a 17 items checklist including 10 items for clinical face validity (issues of relevance to patients' expectations and concerns) and 7 items for measurement properties (such as reliability, responsiveness, etc.). RESULTS: A total of 19 articles, 8 on instrument development and 11 on application, were included in the review. The generic Short Form 36 Health Survey Questionnaire (SF36) was used in 12/19 (63%) studies. Only two studies developed new specific QoL instruments for menorrhagia but they complied with 7/17 (41%) and 10/17 (59%) of the quality criteria. Quality assessment showed that only 7/19 (37%) studies complied with more than half the criteria for face validity whereas 17/19 (90%) studies complied with more than half of the criteria for measurement properties (P = 0.0001). CONCLUSION: Among existing QoL instruments, there is good compliance with the quality criteria for measurement properties but not with those for clinical face validity. There is a need to develop methodologically sound disease specific QoL instruments in menorrhagia focussing both on face validity and measurement properties.
Resumo:
In this paper we attempt to assess the impact of journals in the field of forestry, in terms of bibliometric data, by providing an evaluation of forestry journals based on data envelopment analysis (DEA). In addition, based on the results of the conducted analysis, we provide suggestions for improving the impact of the journals in terms of widely accepted measures of journal citation impact, such as the journal impact factor (IF) and the journal h-index. More specifically, by modifying certain inputs associated with the productivity of forestry journals, we have illustrated how this method could be utilized to raise their efficiency, which in terms of research impact can then be translated into an increase of their bibliometric indices, such as the h-index, IF or eigenfactor score. © 2013 Elsevier Ltd.
Resumo:
Recently introduced surface nanoscale axial photonics (SNAP) makes it possible to fabricate high-Q-factor microresonators and other photonic microdevices by dramatically small deformation of the optical fiber surface. To become a practical and robust technology, the SNAP platform requires methods enabling reproducible modification of the optical fiber radius at nanoscale. In this Letter, we demonstrate superaccurate fabrication of high-Q-factor microresonators by nanoscale modification of the optical fiber radius and refractive index using CO laser and UV excimer laser beam exposures. The achieved fabrication accuracy is better than 2Å in variation of the effective fiber radius. © 2011 Optical Society of America.