SIMPLE algorithm
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Image registration tasks are often formulated in terms of minimization of a functional consisting of a data fidelity term penalizing the mismatch between the reference and the target image, and a term enforcing smoothness of shift between neighboring pairs of pixels (a min-sum problem). Most methods for deformable image registration use some form of interpolation between matching control points. The interpolation makes it impossible to account for isolated discontinuities in the deformation field that may appear, e.g., when a physical slice of a microscopy specimen is ruptured by the cutting tool. For registration of neighboring physical slices of microscopy specimens with discontinuities, Janácek proposed an L¹-distance data fidelity term and a total variation (TV) smoothness term, and used a graph-cut (GC) based iterative steepest descent algorithm for minimization. The L¹-TV functional is nonconvex; hence a steepest descent algorithm is not guaranteed to converge to the global minimum. Schlesinger presented transformation of max-sum problems to minimization of a dual quantity called problem power, which is--contrary to the original max-sum functional--convex. Based on Schlesinger's solution to max-sum problems we developed an algorithm for L¹-TV minimization by iterative multi-label steepest descent minimization of the convex dual problem. For Schlesinger's subgradient algorithm we proposed a novel step control heuristics that considerably enhances both speed and accuracy compared with standard step size strategies for subgradient methods. It is shown experimentally that our subgradient scheme achieves consistently better image registration than GC in terms of lower values both of the composite L¹-TV functional, and of its components, i.e., the L¹ distance of the images and the transformation smoothness TV, and yields visually acceptable results even in cases where the GC based algorithm fails. The new algorithm allows easy parallelization and can thus be sped up by running on multi-core graphic processing units.
- MeSH
- algoritmy * MeSH
- hlava anatomie a histologie MeSH
- mikroskopie metody MeSH
- počítačové zpracování obrazu metody MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- MeSH
- algoritmy MeSH
- diagnostické zobrazování metody přístrojové vybavení využití MeSH
- histologie přístrojové vybavení trendy MeSH
- lidé MeSH
- mikroskopie metody využití MeSH
- počítačové zpracování obrazu metody využití MeSH
- statistika jako téma metody MeSH
- zobrazování trojrozměrné metody využití MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
We present a new algorithm to analyse information content in images acquired using automated fluorescence microscopy. The algorithm belongs to the group of autofocusing methods, but differs from its predecessors in that it can handle thick specimens and operate also in confocal mode. It measures the information content in images using a 'content function', which is essentially the same concept as a focus function. Unlike previously presented algorithms, this algorithm tries to find all significant axial positions in cases where the content function applied to real data is not unimodal, which is often the case. This requirement precludes using algorithms that rely on unimodality. Moreover, choosing a content function requires careful consideration, because some functions suppress local maxima. First, we test 19 content functions and evaluate their ability to show local maxima clearly. The results show that only six content functions succeed. To save time, the acquisition procedure needs to vary the step size adaptively, because a wide range of possible axial positions has to be passed so as not to miss a local maximum. The algorithm therefore has to assess the steepness of the content function online so that it can decide to use a bigger or smaller step size to acquire the next image. Therefore, the algorithm needs to know about typical behaviour of content functions. We show that for normalized variance, one of the most promising content functions, this knowledge can be obtained after normalizing with respect to the theoretical maximum of this function, and using hierarchical clustering. The resulting algorithm is more reliable and efficient than a simple procedure with constant steps.
Delay represents a significant phenomenon in the dynamics of many human-related systems-including biological ones. It has i.a. a decisive impact on system stability, and the study of this influence is often mathematically demanding. This paper presents a computationally simple numerical gridding algorithm for the determination of stability margin delay values in multiple-delay linear systems. The characteristic quasi-polynomial-the roots of which decide about stability-is subjected to iterative discretization by means of pre-warped bilinear transformation. Then, a linear and a quadratic interpolation are applied to obtain the associated characteristic polynomial with integer powers. The roots of the associated characteristic polynomial are closely related to the estimation of roots of the original characteristic quasi-polynomial which agrees with the system's eigenvalues. Since the stability border is crossed by the leading one, the switching root locus is enhanced using the Regula Falsi interpolation method. Our methodology is implemented on-and verified by-a numerical bio-cybernetic example of the stabilization of a human-being's movement on a controlled swaying bow. The advantage of the proposed novel algorithm lies in the possibility of the rapid computation of polynomial zeros by means of standard programs for technical computing; in the low level of mathematical knowledge required; and, in the sufficiently high precision of the roots loci estimation. The relationship to the direct search QuasiPolynomial (mapping) Rootfinder algorithm and computational complexity are discussed as well. This algorithm is also applicable for systems with non-commensurate delays.
- MeSH
- algoritmy * MeSH
- lidé MeSH
- pohyb fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Akutní dušnost je závažný subjektivní symptom, který tvoří přibližně desetinu všech indikací výjezdů zdravotnické záchranné služby. Obvyklá diferenciální diagnostika akutní dušnosti s cílem stanovit nozologickou jednotku je často komplikovaná. Diagnosticko- terapeutický postup v přednemocniční neodkladné péči musí reflektovat reálné možnosti, a proto musí být kompromisem času stráveného ošetřením a realistické diagnostické přesnosti v úzkém vztahu k následné léčbě, kterou jsme schopni bezpečně poskytnout. Autor v článku prezentuje pragmatický algoritmus ošetření pacientů s akutní dušností v přednemocniční neodkladné péči, který vyvinul pro vlastní potřebu během let praxe, založený na jednoduchém poslechovém vyšetření plic s možným využitím Point-of-Care ultrasonografie.
Acute shortness of breath is a severe subjective symptom that accounts for approximately one-tenth of all indications of medical emergency services dispatches. The common approach to differential diagnostics targeted to determine the nosological unit is often complicated. Therefore, pre-hospital management must reflect real possibilities and must be a compromise of the time spent at the field and realistic diagnostic accuracy in close relation to the subsequent treatment we can safely provide. The author presents a pragmatic algorithm for the pre-hospital management of patients with acute shortness of breath based on a simple assessment of respiratory sounds with the possible implementation of Point-of-Care ultrasound.
- Klíčová slova
- Klíčová slova: dušnost – přednemocniční neodkladná péče – algoritmus,
- MeSH
- diferenciální diagnóza MeSH
- dyspnoe * diagnostické zobrazování diagnóza MeSH
- lidé MeSH
- pneumotorax diagnóza MeSH
- point of care testing MeSH
- příznaky a symptomy ústrojí dýchacího MeSH
- ultrasonografie metody MeSH
- urgentní zdravotnické služby MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
OBJECTIVE: The early, simple and reliable detection of pulmonary arterial hypertension (PAH) in SSc (DETECT) study described a new algorithm for early detection of PAH in patients with SSc. The aim of this retrospective, single-centre, cross-sectional study was to apply a modified DETECT calculator in patients with SSc in the East Bohemian region, Czech Republic, to assess the risk of PAH and to compare these results with PAH screening based on the European Society of Cardiology/European Respiratory Society (ESC/ERS) 2009 guidelines. METHODS: Sixty patients were recruited with a diagnosis of SSc (according to ACR criteria), aged 27-78 years. A modified DETECT algorithm using the modified parameter of (1.4 × right ventricle diameter)(2) in place of right atrium area was applied to all patients. Right heart catheterization (RHC) was performed in all patients with an estimated (by echocardiography) increased systolic pulmonary artery pressure ≥50 mm Hg in accordance with the ESC/ERS guidelines; however, RHC was not performed in patients solely recommended for RHC using the modified DETECT algorithm. RESULTS: Using the modified DETECT calculator, 24/58 (41.4%) patients were recommended for RHC, compared with 14/58 (24.1%) when applying the ESC/ERS 2009 guidelines. PAH was diagnosed in 7/58 (12.1%) patients. During follow-up, PAH was diagnosed in six patients. Of these, four were modified DETECT score-positive for 2 years and all for 1 year before PAH diagnosis. CONCLUSION: The modified DETECT algorithm detects all patients with PAH diagnosed according to ECS/ERS 2009 guidelines and RHC. Data of the 2-year follow-up indicate a possible positive predictive role for the modified DETECT calculator.
- MeSH
- algoritmy * MeSH
- časná diagnóza * MeSH
- centra terciární péče * MeSH
- dospělí MeSH
- echokardiografie MeSH
- incidence MeSH
- lidé středního věku MeSH
- lidé MeSH
- následné studie MeSH
- plicní hypertenze diagnóza epidemiologie etiologie MeSH
- průřezové studie MeSH
- retrospektivní studie MeSH
- senioři MeSH
- srdeční katetrizace MeSH
- systémová sklerodermie komplikace diagnóza MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
... Contents -- Graph Algorithms -- Chapter 17. ... ... Representation • 27 -- 17.5 Variations, Extensions, and Costs • 31 -- 17.6 Graph Generators • 40 -- 17.7 Simple ... ... • 228 -- 20.3 Prim’s Algorithm and Priority-First Search • 235 -- 20.4 Kruskal’s Algorithm • 246 -- ... ... 20.5 Boruvka’s Algorithm • 252 -- 20.6 Comparisons and Improvements • 255 -- 20.7 Euclidean MST • 261 ... ... Preflow-Push Maxflow Algorithms • 396 -- 22.4 Maxflow Reductions • 411 -- 22.5 Mincost Flows • 429 - ...
3rd ed. 482 s.
Úvod: Špičky prstů jsou nejčastěji poraněné anatomické struktury na horní končetině. Cílem této práce je představit naše zkušenosti s léčbou poranění prstů. Metody: Byli zahrnuti všichni pacienti s poraněním prstů ošetření na Oddělení plastické a rekonstrukční chirugie všeobecné nemocnice „Dr Manuel Gea Gonzalez” v Mexiku od července 2010 do června 2015; jsou popsány jejich demografické charakteristiky, typ úrazu a jeho management. Výsledky: Do studie bylo zahrnuto celkem 1 265 pacientů, 75 % mužů. Průměrný věk prezentovaných byl 20,5 ± 16,46 let; nejčastěji postižená věková skupina byla mladší 15 let (46,7 %). Zranění vpravo a vlevo se vyskytla ve stejné míře (51 vs. 49 %). Nejčastěji zraněnými prsty byly třetí (27,2 %) a druhé (25,8 %). Osmdesát sedm procent pacientů mělo izolované poranění. Nejčastějším typem poranění byly amputace prstů na prstech u 620 případů (49 %), poté následovaly jednoduché tržné rány prstem (574 případů, 45 %) a poranění nehtového lůžka v 71 případech (5,6 %). Chirurgická léčba byla nutná v 95,8 % případů. Závěr: Nejčastějším důvodem vyšetření u akutních stavů ruky jsou poranění prstů. K dosažení nejlepších klinických výsledků je nezbytný systematický přístup k jejich léčbě.
Background: Fingertips are the most commonly injured anatomical structures in the upper extremity. The aim of this work is to present our experience in the management of fingertip injuries. Methods: All patients with fingertip injuries managed by Plastic and Reconstructive Surgery Division of Hospital General “Dr Manuel Gea Gonzalez” in Mexico from July 2010 to June 2015 were included; their demographic characteristics were described, as well as patterns of injury and management. Results: A total of 1,265 patients were included in the study, 75% were males. The mean age of presentation was 20.5 ± 16.46 years; the age group most commonly affected was younger than 15 years (46.7%). Right and left-sided injuries were almost equally prevalent (51 vs. 49%). The most commonly injured fingers were the third (27.2%), and second (25.8%). Eighty-seven percent of the patients presented with single-digit injuries. Fingertip amputations were the most common type of injury with 620 cases (49%), followed by simple fingertip lacerations (574 cases, 45%), and nail bed injuries in 71 cases (5.6%). Surgical management was necessary in 95.8% of the cases. Conclusions: Fingertip injuries remain the most common reason for consultation in hand emergencies. A structured approach for their treatment is necessary to obtain the best clinical outcomes.
In our paper, we present a performance evaluation of image segmentation algorithms on microscopic image data. In spite of the existence of many algorithms for image data partitioning, there is no universal and 'the best' method yet. Moreover, images of microscopic samples can be of various character and quality which can negatively influence the performance of image segmentation algorithms. Thus, the issue of selecting suitable method for a given set of image data is of big interest. We carried out a large number of experiments with a variety of segmentation methods to evaluate the behaviour of individual approaches on the testing set of microscopic images (cross-section images taken in three different modalities from the field of art restoration). The segmentation results were assessed by several indices used for measuring the output quality of image segmentation algorithms. In the end, the benefit of segmentation combination approach is studied and applicability of achieved results on another representatives of microscopic data category - biological samples - is shown.
- MeSH
- algoritmy * MeSH
- mikroskopie * metody MeSH
- myši MeSH
- počítačové zpracování obrazu metody normy MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- MeSH
- algoritmy MeSH
- balistokardiografie metody přístrojové vybavení využití MeSH
- elektrokardiografie využití MeSH
- funkční vyšetření srdce metody přístrojové vybavení využití MeSH
- kardiografie impedanční metody přístrojové vybavení využití MeSH
- lidé MeSH
- nemocnice univerzitní využití MeSH
- počítačové zpracování signálu MeSH
- Check Tag
- lidé MeSH
