Context. The problem of localization of the effect of errors in data transmission channels when using compression and noiseimmune coding methods in the conditions of compliance with the speed of data delivery in infocommunication systems of the aerosegment. The object of the study is coding methods for increasing the reliability of video information resources in infocommunication networks using airmobile platforms. Objective. The goal of the work is to methodology development of increasing the reliability of video information in the infocommunication networks of the aerosegment. Method. The use of noise-immune coding methods to ensure the required level of reliability of video information transmitted in infocommunication systems of the aerosegment has a number of significant disadvantages: it leads to a significant increase in the bit volume of compactly presented video data; the time delay for the delivery of video information is growing, which is critical in the conditions of using airmobile platforms. An increase in time delays in the process of delivering video information leads to the fact that the video information will not be transmitted in full and, as a consequence, in the conditions of aeromonitoring, to the loss of data reliability; time for processing video data increases. The advantage of using compression coding technologies to solve the problem of increasing the reliability of video information transmitted in infocommunication systems of the aerosegment is to reduce the bit volume of the video information resource. However, the existing video processing technologies are based on the use of statistical coding methods and the identification of a series of identical sequences of repeating elements. But the use of such technologies does not provide the required level of error localization. Restructuring method was developed based on identifying patterns in the internal binary structure of message elements by a quantitative attribute. The sign of the number of series of units in the binary structure of message elements is used as a tool for restructuring. Distinctive features of the method are that the restructuring of the information space is carried out without loss of integrity on the basis of structural features by the number of binary series. Results. The analysis of existing directions for solving the problem of increasing the level of reliability of video information transmitted in the infocommunication systems of the aerosegment was carried out. A method of internal data restructuring has been developed, which allows obtaining the following results: conditions are provided for additional reduction of structural redundancy of code representation of information due to significant reduction of information space capacity as a result of using internal data restructuring on the basis of the number of series of units; conditions are created for localization of errors in the process of reconstruction of video information resources; conditions are created to reduce the time for data processing, due to the fact that the developed method of data restructuring does not require transformations over the elements of the message. Conclusions. It is necessary to improve the existing compression coding technologies in the direction of identifying patterns, taking into account which will allow localizing the destructive effect of errors arising in the communication channel.
BackgroundAs life expectancy and quality of health improve, more and more people reach old age, and so does the number of heart diseases. One of the most urgent problems among elderly patients is degenerative stenosis of the aortic valve (AV). The conservative treatment of symptoms of chronic heart failure with AV stenosis improves the patient’s condition only for a while, whereas surgical treatment such as replacement of AV is recognized as the main effective method of treating a defect. Recently, alternative technologies for prosthetic AV have been developed, aimed at reducing adverse effects of artificial circulation (AC) in high-risk patients and minimizing the scope of surgical intervention.Aim of studyThe aim of the study was to evaluate the immediate results of surgical treatment of aortic stenosis using different methods in patients over 70.Material and methodsThe article presents the results of treatment of 64 patients over 70 with isolated AV stenosis, operated with different surgical techniques from July, 2016 to January, 2018. All patients were divided into three groups, differing in the severity of the initial condition and the method treatment. Group 1 (transcatheter implantation of the prosthetic AV, EuroSCORE II — 21.81%) consisted of 19 patients, Group 2 (non-suture implantation of a Perceval prosthetic valce under the AC, EuroSCORE II — 13.81%) consisted of 13 patients and Group 3 (“standard” prosthetics, EuroSCORE II — 9.89%) consisted of 32 patients.ResultsIn Group 1, two patients died, the hospital mortality was 10.5%. In Group 2 and Group 3, one patient died, the hospital mortality was 7.6 and 3.1%, respectively. Implantation of a permanent pacemaker was required in three patients (15.7%) from the TAVI group after installation of Medtronic Core Valve and two patients (15.3%) from the Perceval group.ConclusionThe obtained results of AV replacement by various methods allowed to expand indications for the management of AV stenosis in patients of the older age group with a high surgical risk of operation under AC conditions who had not previously been considered candidates for surgical treatment of aortic malformation due to the age and severity of the concomitant pathology.
Introduction. We present the clinical observation of a 72-year-old female patient with high surgical risk and structural degeneration of a bioprosthetic aortic valve (AV) cusps in the form of stenosis, accompanied by severe dysfunction. Transcatheter implantation of bioprosthesis Medtronic CoreValve™ Evolut™ R-23 was performed using the valve-in-valve technique. The choice of minimally invasive treatment tactics is substantiated, a preoperative examination algorithm and a specific bioprosthesis model for such intervention are provided. Materials and methods. Imaging – echocardiography (Echo), electrocardiography, multispiral computed tomography, coronary angiography. Bioprosthetic valve calcification and stenosis with critical parameters of the bioprosthetic AV peak pressure gradient according to Echo data were the indications for minimally invasive surgery. Results. Dynamic observation revealed a progressive deterioration in the function of the previously implanted bioprosthetic heart valve in the aortic position, and a critical deterioration in the patient’s condition. After additional examination of the patient and selection of a new prosthesis, valve-in-valve transcatheter aortic valve replacement was done. The positive dynamics of the general state of the patient was noted in the early postoperative period. Echo data showed that the bioprosthetic AV peak systolic pressure gradient decreased from 90 to 29 mmHg, average gradient – from 42 to 19 mmHg. Conclusion. The minimally invasive valve-in-valve transcatheter aortic valve replacement used to correct the dysfunction of a bioprosthetic AV that was previously implanted during an open surgery was shown to be safe and effective and can be considered as one of the options for repeat valve replacement.
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