compression set
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The performance of ECG signals compression is influenced by many things. However, there is not a single study primarily focused on the possible effects of ECG pathologies on the performance of compression algorithms. This study evaluates whether the pathologies present in ECG signals affect the efficiency and quality of compression. Single-cycle fractal-based compression algorithm and compression algorithm based on combination of wavelet transform and set partitioning in hierarchical trees are used to compress 125 15-leads ECG signals from CSE database. Rhythm and morphology of these signals are newly annotated as physiological or pathological. The compression performance results are statistically evaluated. Using both compression algorithms, physiological signals are compressed with better quality than pathological signals according to 8 and 9 out of 12 quality metrics, respectively. Moreover, it was statistically proven that pathological signals were compressed with lower efficiency than physiological signals. Signals with physiological rhythm and physiological morphology were compressed with the best quality. The worst results reported the group of signals with pathological rhythm and pathological morphology. This study is the first one which deals with effects of ECG pathologies on the performance of compression algorithms. Signal-by-signal rhythm and morphology annotations (physiological/pathological) for the CSE database are newly published.
- MeSH
- algoritmy MeSH
- databáze faktografické MeSH
- elektrokardiografie metody MeSH
- fraktály MeSH
- komprese dat metody MeSH
- lidé MeSH
- vlnková analýza MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Compression of the rostral ventrolateral medulla oblongata (RVLM) by an abnormally located artery is regarded as one possible cause of arterial hypertension. There exists a limited set of data suggesting that increased sympathetic activity in patients with RVLM compression may lead to arterial hypertension. Accordingly, we decided to assess the sympathetic activity in patients with severe arterial hypertension and to investigate any correlation with the presence of RVLM compression. Sixty-four patients with severe arterial hypertension were enrolled in our study. Sympathetic activity was evaluated using 24-hour urinary norepinephrine as measured by high-pressure liquid chromatography with electrochemical detection. The presence of RVLM compression was assessed with magnetic resonance imaging. Neurovascular compression of the RVLM was identified in 40 patients, 27 of whom presented left-sided compression. Twenty-four hour urinary norepinephrine averaged 263.6±135.9 nmol in patients with neurovascular compression - 255.6±137.3 nmol in those with left-sided compression and 251.6±138.5 nmol in patients without RVLM compression. We did not identify any increase in urinary norepinephrine in patients with severe arterial hypertension and neurovascular compression of the RVLM. Our results do not support the hypothesis that neurovascular compression of RVLM may exhibit a sympathetically mediated increase in blood pressure.
- MeSH
- časové faktory MeSH
- dospělí MeSH
- elektrochemické techniky MeSH
- financování organizované MeSH
- hypertenze moč patofyziologie patologie MeSH
- krevní tlak MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- medulla oblongata patofyziologie patologie MeSH
- noradrenalin moč MeSH
- senioři MeSH
- stupeň závažnosti nemoci MeSH
- sympatický nervový systém metabolismus patofyziologie MeSH
- úžinové syndromy moč patofyziologie patologie MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
Nejčastější formou úmrtí na ischemickou chorobu srdeční je náhlá srdeční smrt. Základním předpokladem léčby je kardiopulmonální resuscitace. Při kardiopulmonální resuscitaci jsou nejdůležitější manuální komprese hrudníku s dostatečnou frekvencí a hloubkou stlačení. Přesto tento požadavek není často splněn ani školenými profesionály. Zajištění kvalitní masáže během transportu k provedení dalších život zachraňujících úkonů, např. primární koronární angioplastiky, je manuálně prakticky nemožné. Smyslem mechanizované srdeční masáže je poskytnout pacientům masáž hrudníku bez přerušování, bez ovlivnění kvality únavou zachránců a současně uvolnit zachránce pro další úkony. V současnosti jsou nejpoužívanější dva systémy – LUCAS® a AutoPulse®, které prokazatelně zajišťují kvalitní srdeční masáž a nezvyšují riziko iatrogenních komplikací.
Sudden cardiac death is the most common cause of death due to coronary artery disease. The mainstay of therapy is the cardiopulmonary resuscitation where the thoracic compressions at an adequate rate play the major role. Despite very good evidence on the efficacy of adequate chest compression the reality is more than suboptimal. The performance of adequate chest compressions is impossible in transport settings or at the catheterisation laboratory. The mechanical chest compression systems are safe and efficient tools to provide chest compressions without interruption and rescuers fatigue. Two systems of mechanical chest compression devices are in use in the clinical practice. The provide a high quality chest compressions and do not increase the number of complications.
- MeSH
- ischemická choroba srdeční MeSH
- kardiopulmonální resuscitace * metody MeSH
- lidé MeSH
- masáž srdce * přístrojové vybavení MeSH
- náhlá srdeční smrt MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Compression of ECG signal is essential especially in the area of signal transmission in telemedicine. There exist many compression algorithms which are described in various details, tested on various datasets and their performance is expressed by different ways. There is a lack of standardization in this area. This study points out these drawbacks and presents new compression algorithm which is properly described, tested and objectively compared with other authors. This study serves as an example how the standardization should look like. Single-cycle fractal-based (SCyF) compression algorithm is introduced and tested on 4 different databases-CSE database, MIT-BIH arrhythmia database, High-frequency signal and Brno University of Technology ECG quality database (BUT QDB). SCyF algorithm is always compared with well-known algorithm based on wavelet transform and set partitioning in hierarchical trees in terms of efficiency (2 methods) and quality/distortion of the signal after compression (12 methods). Detail analysis of the results is provided. The results of SCyF compression algorithm reach up to avL = 0.4460 bps and PRDN = 2.8236%.
We propose an efficient method for compressing Vietnamese text using n-gram dictionaries. It has a significant compression ratio in comparison with those of state-of-the-art methods on the same dataset. Given a text, first, the proposed method splits it into n-grams and then encodes them based on n-gram dictionaries. In the encoding phase, we use a sliding window with a size that ranges from bigram to five grams to obtain the best encoding stream. Each n-gram is encoded by two to four bytes accordingly based on its corresponding n-gram dictionary. We collected 2.5 GB text corpus from some Vietnamese news agencies to build n-gram dictionaries from unigram to five grams and achieve dictionaries with a size of 12 GB in total. In order to evaluate our method, we collected a testing set of 10 different text files with different sizes. The experimental results indicate that our method achieves compression ratio around 90% and outperforms state-of-the-art methods.
- MeSH
- algoritmy * MeSH
- Asijci * MeSH
- komprese dat * MeSH
- lidé MeSH
- slovní zásoba * MeSH
- slovníky jako téma * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
V léčbě lymfomů je základní léčebnou modalitou systémová onkologická terapie – chemoterapie, imunoterapie, radioterapie, transplantace krvetvorných buněk či jejich kombinace. Hlavní úloha chirurgie u lymfoproliferativních onemocnění spočívá v diagnostickém procesu v podobě biopsie a v brzkém umožnění přesné histologické verifikace. Jiná situace je ovšem u lymfomů, které se projeví jako náhlá příhoda břišní (NPB). Zde chirurgie již hraje zásadní roli v terapii podobně jako u NPB z jiných příčin. Náhlé příhody břišní spojené s lymfomy mají i shodné projevy: krvácení, obstrukce a perforace. Všechny tyto akutní stavy mohou být způsobeny jak primárně gastrointestinálními (extranodálními) lymfomy, tak pokročilými lymfomy uzlinovými – nodálními, které infiltrují nebo svojí velikostí či lokalizací utlačují gastrointestinální trakt (GIT). Perforace bývá také často spojena s efektem probíhající systémové onkologické léčby. Při léčbě NPB způsobených lymfomy je nutná multidisciplinární spolupráce všech zúčastněných oborů. Z chirurgického hlediska je nutno především minimalizovat riziko pooperačních komplikací pro umožnění brzké systémové onkologické léčby.
Surgical treatment of gastrointestinal solid tumors is the basic method with a curative potential. However, the first-line treatment modalities in lymphomas are systemic oncology therapy (chemotherapy, immunotherapy and hematopoietic stem cell transplantation), radiotherapy or their combination. Surgery in lymphomas is predominantly associated with acute disease and dominantly, surgery is still used mainly in diagnosing lymphomas. Acute abdomen associated with lymphoma can be divided into 3 groups: bleeding, obstruction and perforation of GIT due to lymphoma. All these conditions might be caused by both gastrointestinal (extranodal) lymphomas or advanced nodal lymphomas that directly infiltrate or compress gastrointestinal tract (GIT) as well. Perforation is also often associated with the effect of systemic chemotherapy administration. When treating acute abdomen conditions caused by lymphomas, multidisciplinary cooperation with all participating experts is necessary. From the surgical point of view, minimizing the risk of postoperative complications is crucial to ensure the possibility of early systemic oncological treatment administration.
- MeSH
- akutní bolest břicha * diagnóza klasifikace patologie MeSH
- cholecystitida diagnóza terapie MeSH
- diferenciální diagnóza MeSH
- gastrointestinální nádory diagnóza klasifikace terapie MeSH
- lidé středního věku MeSH
- lidé MeSH
- lymfom * diagnóza klasifikace MeSH
- nádory rekta diagnóza chirurgie MeSH
- senioři MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- Publikační typ
- kazuistiky MeSH
Popisujeme případ pacienta, u něhož koronarografické vyšetření pro infarkt myokardu bez elevací úseku ST pět měsíců po provedení aortokoronárního bypassu prokázalo těsnou stenózu v proximálním segmentu štěpu safény (saphenous vein graft, SVG), navíc s kompresí diagonální tepny v diastole. Segment SVG bezprostředně distálně ke stenóze vykazoval obstrukční dynamickou kompresi v diastole. Po úspěšné implantaci stentu skrze proximální stenózu došlo k vymizení dynamické stenózy dále po proudu. Jde o dosud třetí případ komprese segmentu SVG v diastole bez souvislosti s konstrikcí perikardu, jenž byl publikován v anglicky psané literatuře, a o první případ implantace balon-expandibilního stentu v léčbě významné organické stenózy, navíc s kompresí v diastole. V článku se zabýváme patofyziologickými charakteristikami tohoto případu a možnou využitelností současných stentových platforem v klinické praxi pro dostatečné vyztužení podobných dynamických lézí.
We present the case of a patient in whom coronary angiography performed for non-ST-segment elevation myocardial infarction five months after coronary artery bypass graft surgery disclosed a tight stenosis with superimposed diastolic compression in the proximal segment of a saphenous vein graft (SVG) to a diagonal artery. Furthermore, the SVG segment immediately distal to the stenosis exhibited obstructive dynamic compression during diastole. Stent implantation across the proximal stenosis was undertaken successfully with a consequent resolution of the dynamic downstream stenosis. This is the third case of diastolic segmental SVG compression not related to pericardial constriction ever reported in the English literature and the first case where implantation of a balloon-expandable stent was performed in an SVG to treat a significant organic stenosis with superimposed diastolic compression. We discuss the pathophysiologic characteristics of this case and the potential clinical utility of the current stent platforms to adequately scaffold such dynamic lesions.
- MeSH
- angioplastika metody MeSH
- infarkt myokardu chirurgie MeSH
- koronární bypass MeSH
- lidé středního věku MeSH
- lidé MeSH
- okluze cévního štěpu * diagnóza etiologie chirurgie MeSH
- vena saphena patologie transplantace MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
PURPOSE OF THE STUDY The success rate of the anterior cruciate ligament (ACL) reconstruction depends on the fixation of the graft, the surgical technique and, of course, on the experience of the operating surgeon. The authors present the development of the construction of the new instrumentation set designed to manage the ACL lesions using the hamstring (HS) tendons. The study is divided into two parts, of which part one focuses on construction, methods and work with new instruments, while part two presents the outcomes of the surgery. MATERIAL AND METHODS Fixation of hamstring grafts depends, contrary to the union of bone blocks in the Bone-Tendon-Bone (BTB) graft and the bone tunnel, on the method of tendon graft fixation and compression inside the bone tunnel. The instrumentation set for ACL reconstruction is designed to be used for hamstring tendons (semitendon and gracilis) forming four strands of the prepared graft. The system was designed as the fixation of the graft using the femoral screw with eyelet and a press-fit fixation using a metal interference screw in tibia. The easiest and fastest option has proven to be the pulling of the screw with eyelet through the tibial tunnel and intra-articular space to the femoral canal, where fixation by screwing in is done. The exact position of the inserted screw is verified by the measuring gauge. The screw is pulled in by the long version of the femoral screwdriver and Kirschner wire passing through the middle of the screw with eyelet. The advantage of this system consists in the subsequent insertion of the interference screw by the same wire, which guarantees its exact positioning in the centre between the individual strands of the graft (thanks to the specific way of ligament preparation). The possibility of later tensioning of the graft by tightening the femoral screw is another advantage. DISCUSSION Compared to other methods using the HS tendons, the advantages of the described operative technique consist in the simplicity of the used instrumentation procedure. The technique of graft fixation inside the femoral canal is not suitable for bioabsorbable materials. It is offset by the fixation stability and the possibility of final graft tensioning. CONCLUSIONS The newly developed instrumentation set for ACL reconstruction is fit for purpose, easy as to the surgical technique, and it guarantees the logical sequence of surgical steps reducing surgical errors to minimum. The instrumentation set is user-friendly, easy to handle and, once the operating surgeon masters the surgical procedure, it allows to reduce the duration of the surgery to approximately 30 minutes. There were no major complications or technical errors reported during the surgical procedures using these instrumentation set.
