ОЦЕНКА СТАТИСТИЧЕСКИХ ХАРАКТЕРИСТИК МИОГРАФИЧЕСКОЙ ПОМЕХИ ПРИ МНОГОКАНАЛЬНОЙ РЕГИСТРАЦИИ ЭЛЕКТРОКАРДИОСИГНАЛА

Electromyographic noise is one of the most common noises in electrocardiogram. In case of several electrocardiogram leads, electromyographic noise affects each lead to different extent. It can be taken into account when developing algorithms for multilead electrocardiogram record processing. However, in the existing literature, there is no information about the relationship of electromyographic noise in various ECG leads and their joint probability distribution. The purpose of this paper is to study statistical characteristics of electromyographic noise in ECG signal, from which the electromyographic noise is extracted. The paper proposes a method for extracting electromyographic noise from electrocardiogram signal, based on a polynomial approximation of electrocardiogram signal fragments in sliding window with overlapping fragment subsequent weight averaging. Using this method, fragments of electromyographic noise are extracted from multichannel electrocardiogram records. Based on the obtained data, a joint probability distribution function of electromyographic noise in two adjacent leads is selected, and the correlation relationships between the electromyographic noise in various ECG leads are investigated. The results show that the joint probability distribution function of electromyographic noise in two adjacent leads in the first approximation can be described using bivariate normal distribution. In addition, between the samples of electromyographic noise from two adjacent leads quite strong correlation relationships can be observed.Миографическая помеха является одной из самых распространенных помех, присутствующих в электрокардиосигнале. В случае использования нескольких отведений электрокардиосигнала миографическая помеха в разной степени оказывает влияние на каждое из отведений. Это влияние может быть учтено при построении алгоритмов обработки многоканальных записей электрокардиосигнала. Однако в существующей литературе недостаточно полно исследован анализ взаимосвязей отсчетов миографической помехи в различных отведениях электрокардиосигнала. Цель работы – эмпирическое исследование статистических характеристик миографической помехи, выделенной из зашумленных фрагментов электрокардиосигнала. Предложен метод выделения миографической помехи из записей электрокардиосигнала. Метод основан на полиномиальной аппроксимации фрагментов электрокардиосигнала в скользящем окне с последующим весовым усреднением перекрывающихся фрагментов. С использованием данного метода из многоканальных записей электрокардиосигнала были выделены фрагменты миографической помехи. На основе выделенных фрагментов подобрано совместное распределение отсчетов миографической помехи в двух смежных отведениях, а также исследованы корреляционные взаимосвязи между отсчетами миографической помехи в различных отведениях электрокардиосигнала. В результате установлено, что совместное распределение отсчетов миографической помехи в двух смежных отведениях в первом приближении может быть описано с помощью двумерного нормального закона. Кроме того, между отсчетами миографической помехи из двух смежных отведений могут наблюдаться довольно сильные корреляционные взаимосвязи

EVALUATION OF ELECTROMYOGRAPHIC NOISE STATISTICAL CHARACTERISTICS IN MULTICHANNEL ECG RECORDINGS

Electromyographic noise is one of the most common noises in electrocardiogram. In case of several electrocardiogram leads, electromyographic noise affects each lead to different extent. It can be taken into account when developing algorithms for multilead electrocardiogram record processing. However, in the existing literature, there is no information about the relationship of electromyographic noise in various ECG leads and their joint probability distribution. The purpose of this paper is to study statistical characteristics of electromyographic noise in ECG signal, from which the electromyographic noise is extracted. The paper proposes a method for extracting electromyographic noise from electrocardiogram signal, based on a polynomial approximation of electrocardiogram signal fragments in sliding window with overlapping fragment subsequent weight averaging. Using this method, fragments of electromyographic noise are extracted from multichannel electrocardiogram records. Based on the obtained data, a joint probability distribution function of electromyographic noise in two adjacent leads is selected, and the correlation relationships between the electromyographic noise in various ECG leads are investigated. The results show that the joint probability distribution function of electromyographic noise in two adjacent leads in the first approximation can be described using bivariate normal distribution. In addition, between the samples of electromyographic noise from two adjacent leads quite strong correlation relationships can be observed

Inhibition of JAK1,2 Prevents Fibrotic Remodeling of Pulmonary Vascular Bed and Improves Outcomes in the Rat Model of Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of acute pulmonary embolism with poor clinical outcomes. Therapeutic approaches to prevention of fibrotic remodeling of the pulmonary vascular bed in CTEPH are limited. In this work, we tested the hypothesis that Janus kinase 1/2 (JAK1/2) inhibition with ruxolitinib might prevent and attenuate CTEPH in a rat model. CTEPH was induced by repeated embolization of the pulmonary artery with partially biodegradable 180 ± 30 μm alginate microspheres. Two weeks after the last injection of microspheres, ruxolitinib was administered orally at doses of 0.86, 2.58, and 4.28 mg/kg per day for 4 weeks. Prednisolone (1.475 mg/kg, i.m.) was used as a reference drug. Ruxolitinib in all doses as well as prednisolone reduced pulmonary vascular wall hypertrophy. Ruxolitinib at a dose of 2.58 mg/kg and prednisolone reduced vascular wall fibrosis. Prednisolone treatment resulted in decreased right ventricular systolic pressure. Pulmonary vascular resistance was lower in the prednisolone and ruxolitinib (4.28 mg/kg) groups in comparison with the placebo group. The plasma level of brain natriuretic peptide was lower in groups receiving ruxolitinib at doses of 2.58 and 4.28 mg/kg versus placebo. This study demonstrated that JAK1/2 inhibitor ruxolitinib dose-dependently reduced pulmonary vascular remodeling, thereby preventing CTEPH formation in rats