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Automated Detection (automate + detection)
Selected AbstractsAutomated detection of malaria by means of the haematology analyser Coulter® GEN.STMINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 6 2004C. FOURCADE Summary The haematology analysers Coulter® GEN.STM and LHTM give a set of data ,,positional parameters', which define each WBC population by mean of index values, the mean and the standard deviation (SD) of volume, conductivity and scatter, used to identify the WBC populations. These parameters were analysed in patients investigated for suspicion of malaria, in order to show a difference between malaria negative and malaria positive patients and to use it for malaria detection. The six parameters exhibiting a significant difference between the two groups were submitted to a ROC analysis, which showed both sensitivity >90% and specificity >60% for two parameters, lymphocyte and monocyte SDs of volumes. A discriminator combining the two parameters showed a sensitivity of 96.9% and a specificity of 82.5%. The cut off of the discriminative value was calculated. Because of the good stability and reproducibility of the parameters selected, the test can be used in order to detect patients having a high probability to be malaria positive and to pay particular attention to these blood smears. For more extensive diagnostic use, a standard control procedure of the positional parameters should be introduced. [source] Automated detection of malaria-associated intraleucocytic haemozoin by Cell-Dyn CD4000 depolarization analysisINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 2 2003C.S. Scott Summary Laboratory tests for malaria are only performed if there is clinical suspicion of the disease, and a missed diagnosis contributes substantially to morbidity and mortality. Malaria parasites produce haemozoin, which is able to depolarize light and this allows the automated detection of malaria during routine complete blood count analysis (CBC) with some Abbott Cell-Dyn instruments. In this study, we evaluated the Cell-Dyn CD4000 with 831 blood samples submitted for malaria investigations. Samples were categorized as malaria negative (n = 417), convalescent malaria (n = 64) or malaria positive (n = 350) by reference to thin/thick film microscopy, ,rapid test' procedures, polymerase chain reaction analysis and clinical history. With regard to CD4000 depolarization analysis, a malaria positive CD4000 pattern was ascribed to samples that showed one or more abnormal depolarizing purple events, which corresponded to monocytes containing ingested malaria pigment (haemozoin). Positive CD4000 patterns were observed in 11 of 417, 50 of 64 and 281 of 350 of malaria negative, convalescent malaria and malaria positive samples respectively. The specificity and positive predictive values for malaria (active and convalescent) were very high (97.4 and 96.8%, respectively), while sensitivity and negative predictive values were 80.0 and 83.0% respectively. Depolarization analysis was particularly effective for Plasmodium falciparum malaria but there was lower detection sensitivity for White compared with Black African patients. CD4000 90° depolarization vs 0° analysis revealed a proportion of samples with small nonleucocyte-associated depolarizing particles. Appearance of such events in the form of a discrete cluster was associated with P. vivax rather than P. falciparum infection. [source] A comparison of manual and automated methods of measuring conjunctival vessel widths from photographic and digital imagesOPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 2 2004Christopher G. Owen Abstract We investigated the application of a fully automated computer algorithm for identifying vessels of the conjunctiva from their scleral surround, and compared measures of vessel width with established methods. Vessel widths at 101 locations (ranging from 20 to 140 ,m), from 12 patients, were measured from film and digital images, using a variety of methods, and compared. Widths were measured manually, by semi-automated methods using grey level (densitometric) profiles taken from digital images, and by automated techniques set at different operating levels. Good intra-session repeatibility was obtained using the automated method with an operating sigma value of 3 pixels (16 ,m) (mean difference 0.5 ,m, 95% CI ,8.5 to 9.4 ,m) and manual calliper measurements from digitally created photographic slides (mean difference 0.4 ,m, ,9.3 to 10.1 ,m). For comparison with other measures of width, the latter was used as the gold standard. Widths measured from film were slightly larger than those measured directly from digital images, although this effect was small (5 ,m) for most vessels. Overall widths measured using the automated method, with a sigma value of 3 pixels, agreed best with the gold standard (inter-method repeatibility; mean difference 1.4 ,m, ,32.5 to 35.2 ,m) although the automated method overestimated small widths (<40 ,m) and underestimated larger vessel widths (>40 ,m). Automated detection of vessels of the conjunctiva from digital images avoids manual and operator involved measures which are time consuming, and which preclude large patient studies. The resulting data may help in monitoring the vascular response of the conjunctiva to surgical or pharmacological intervention, and in describing vascular changes in response to ocular or systemic disease. The application of this algorithm to the study of retinal vessels is yet to be realised. [source] Technical note: Standardized and semiautomated Harris lines detectionAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2008S. Suter Abstract Arrest in long bone growth and the subsequent resumption of growth may be visible as radiopaque transverse lines in radiographs (Harris lines, HL; Harris, HA. 1933. Bone growth in health and disease. London: Oxford University Press). The assessment of individual age at occurrence of such lines, as part of paleopathological skeletal studies, is time-consuming and shows large intra- and interobserver variability. Thus, a standardized, automated detection algorithm would help to increase the validity of such paleopathological research. We present an image analysis application facilitating automatic detection of HL. On the basis of established age calculation methods, the individual age-at-formation can be automatically assessed with the tool presented. Additional user input to confirm the automatic result is possible via an intuitive graphical user interface. Automated detection of HL from digital radiographs of a sample of late Medieval Swiss tibiae was compared to the consensus of manual assessment by two blinded expert observers. The intra- and interobserver variability was high. The quality of the observer result improved when standardized detection criteria were defined and applied. The newly developed algorithm detected two-thirds of the HL that were identified as consensus lines between the observers. It was, however, necessary to validate the last one-third by manual editing. The lack of a large test series must be noted. The application is freely available for further testing by any interested researcher. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc. [source] Hemodynamic Correlates of the Third Heart Sound and Systolic Time IntervalsCONGESTIVE HEART FAILURE, Issue 2006Sanjiv J. Shah MD Bedside diagnostic tools remain important in the care of patients with heart failure. Over the past two centuries, cardiac auscultation and phonocardiography have been essential in understanding cardiac pathophysiology and caring for patients with heart disease. Diastolic heart sounds (S3 and S4) and systolic time intervals have been particularly useful in this regard. Unfortunately, auscultation skills have declined considerably, and systolic time intervals have traditionally required carotid pulse tracings. Newer technology allows the automated detection of heart sounds and measurement of systolic time intervals in a simple, inexpensive, noninvasive system. Using the newer system, the authors present data on the hemodynamic correlates of the S3 and abnormal systolic time intervals. These data serve as the foundation for using the system to better understand the test characteristics and pathophysiology of the S3 and systolic time intervals, and help to define their use in improving the bedside diagnosis and management of patients with heart failure. [source] Automated detection of malaria-associated intraleucocytic haemozoin by Cell-Dyn CD4000 depolarization analysisINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 2 2003C.S. Scott Summary Laboratory tests for malaria are only performed if there is clinical suspicion of the disease, and a missed diagnosis contributes substantially to morbidity and mortality. Malaria parasites produce haemozoin, which is able to depolarize light and this allows the automated detection of malaria during routine complete blood count analysis (CBC) with some Abbott Cell-Dyn instruments. In this study, we evaluated the Cell-Dyn CD4000 with 831 blood samples submitted for malaria investigations. Samples were categorized as malaria negative (n = 417), convalescent malaria (n = 64) or malaria positive (n = 350) by reference to thin/thick film microscopy, ,rapid test' procedures, polymerase chain reaction analysis and clinical history. With regard to CD4000 depolarization analysis, a malaria positive CD4000 pattern was ascribed to samples that showed one or more abnormal depolarizing purple events, which corresponded to monocytes containing ingested malaria pigment (haemozoin). Positive CD4000 patterns were observed in 11 of 417, 50 of 64 and 281 of 350 of malaria negative, convalescent malaria and malaria positive samples respectively. The specificity and positive predictive values for malaria (active and convalescent) were very high (97.4 and 96.8%, respectively), while sensitivity and negative predictive values were 80.0 and 83.0% respectively. Depolarization analysis was particularly effective for Plasmodium falciparum malaria but there was lower detection sensitivity for White compared with Black African patients. CD4000 90° depolarization vs 0° analysis revealed a proportion of samples with small nonleucocyte-associated depolarizing particles. Appearance of such events in the form of a discrete cluster was associated with P. vivax rather than P. falciparum infection. [source] Immunoliposomes Sandwich Fluorometric Assay (ILSF) for Detection of Escherichia coli O157:H7JOURNAL OF FOOD SCIENCE, Issue 6 2004Sungsu Park ABSTRACT: We report the development of automated flourometric immunoassay for the detection of Escherichia coli O157:H7, using antibody-directed liposomes (immunoliposomes) encapsulating fluorophore as an analytical reagent. Thiolated antibodies (anti- E. coli O157:H7) were coupled to malemide-tagged liposomes encapsulating dye. To automate the assay, a fluorescence plate reader was included in the assay system to detect fluorophore released from lysed liposomes in a microplate. The detection limit of the current assay with pure cultures of the serotype was about 104 colony-forming units (CFU)/mL. The assay can detect E. coli O157 in ground beef samples inoculated with as few as 0.8 CFU/mL after a 12-h enrichment. These results demonstrate the feasibility of using fluorophore-encapsulated immunoliposomes in a microtiter plate for the rapid and automated detection of molecules with multivalent antigenic sites. [source] Denaturing capillary electrophoresis for automated detection of L858R mutation in exon 21 of the epidermal growth factor receptor gene in prediction of the outcome of lung cancer therapyJOURNAL OF SEPARATION SCIENCE, JSS, Issue 15 2010Lucie Benesova Abstract The presence of activating mutations within the tyrosine kinase domain of the epidermal growth factor receptor gene has been attributed to a positive response to biological therapy of lung cancer by small-molecular tyrosine kinase inhibitors, gefitinib and erlotinib. Among the two most significant mutation types are deletions in exon 19 and a single point substitution in exon 21 (termed L858R). The exon 19 deletions can readily be examined by fragment analysis, due to the characteristic length difference between the normal and mutated PCR product. Analysis of the L858R point mutation, however, presents a greater challenge. The current paper is aimed at developing a sensitive, yet simple, low-cost mutation detection assay directed at the L858R mutation using a method based on CE of heteroduplexes under partial denaturing conditions. We perform optimization of separation conditions on different commercial instruments including ones equipped with 8, 16 and 96 capillaries. We present normalized migration reproducibility in the range from 1 (8 and 16) to 5% (96) RSD. A reliable distinction of the R836R silent polymorphism from a potential presence of the L858R mutation is also demonstrated. In its implementation, the presented assay is just another application running on a conventional CE platform without the need of dedicated instrumentation. [source] Identification of fiber misalignment in continuous fiber compositesPOLYMER COMPOSITES, Issue 3 2003S. C. Barwick Misaligned fibers are invariably present in nominally unidirectional high-performance composites. Such misaligned fibers are known to affect key mechanical properties of the composite, such as the longitudinal compressive strength, longitudinal tensile modulus, fatigue endurance, shear strength, and delamination resistance (1). In this paper we present a method for the automated detection of large angle fiber misalignment (, > 40°) in continuous fiber-reinforced composite materials. The method relies on the application of a series of geometrical criteria based upon measurements routinely obtained during optical scanning of polished sample cross-sections. As such, the technique is ideal for the automated identification of highly misaligned fibers in large-area (, cm2) specimens that may contain several millions of individual fiber images. The criteria applied take into account the fact that prepared cross-sections of such materials contain many damaged fibers as a result of attrition during polishing. Data obtained from three pultruded unidirectional rods reinforced with continuous carbon filaments are used to illustrate the effectiveness of this method in identifying regions where large angle misalignment occurs. [source] Automatic detection of circular structures in high-resolution satellite images of agricultural landARCHAEOLOGICAL PROSPECTION, Issue 1 2009Řivind Due Trier Abstract Archaeological sites are sometimes visible in satellite images as soil or crop marks. At best, the marks are distinct, but they tend to have less contrast with the background than many other patterns in the images. Consequently, reliable automated detection based on pattern recognition is very difficult. Our method detects circle-shaped soil and crop marks in the panchromatic band of high-resolution satellite images of agricultural fields. Such circular marks may be caused by burial mounds. In our approach, local contrast enhancement is applied in order to make weak marks more distinct. The image is then convolved with ring templates of varying sizes, giving high absolute values at candidate circular mark locations. Each candidate mark is presented to an operator, who may reject it. We tested our method on Quickbird images from southeast Norway. The number of detected candidate marks could be varied by changing a threshold value. A reasonable compromise between not detecting too many false rings and at the same time detecting as many true rings as possible, might be when the number of false detections is approximately seven times the number of true detections. In this case, 11 out of 15, or 73%, of the strong rings were detected, and 5 out of 10, or 50%, of the fairly strong rings were detected. This is 16 out of 25 of the strong and fairly strong rings, or 64%. Archaeologists state that the software tool we developed will be helpful for locating potential cultural heritage sites. Although it makes many false detections, it will relieve the operators from time-consuming manual inspection of entire images. Copyright © 2008 John Wiley & Sons, Ltd. [source] | |||||||||||||