One of the most important problems of creating new and also modernizing and operating the existing industrial equipment is to provide it with technical diagnostic tools. In modern systems, most diagnostic problems are solved by vibration monitoring methods, and they form the basis of this process. For several years already, when creating new responsible equipment, many manufacturers have completed it with monitoring and diagnostic systems, often integrating them functionally with automatic control systems. This paper discusses the methods of servicing industrial equipment, focusing on predictive maintenance, also known as actual maintenance (maintenance according to the actual technical condition).The rationale for the use of wireless systems for data collection and processing is presented. The principles of constructing wireless sensor networks and the data transmission protocols used to collect statistical information on the state of the elements of industrial equipment, depending on the field of application, are analyzed. The purpose of the study is to substantiate the feasibility of using wireless sensor networks as technical diagnostic tools from both economic and technical points of view. The result is the proposed concept of the predictive maintenance system. The paper substantiates the model of optimization of predic-tive repair using wireless sensor networks. This approach is based on minimizing the costs of maintenance of equipment. The presented concept of a system of predictive maintenance on the basis of sensor networks allows real-time analysis of the state of equipment. The approach allows implementing smart management of technologies in companies for ensuring stability of functioning.

The present article studies the approach to building the distributed wireless sensor networks. It shows that, for RFID-based wireless sensor networks, the first thing to determine is the field it is intended to be used for, the far or the near one. The operating frequency value determines the size of the antenna, and the correlation is inverse. The operational contradiction analysis shows, that to increase the operating range of the tags, it makes sense to select the systems with an active power supply. But from the energy efficiency perspective, the passive tags are better to be used, and for increasing the range of data transmission, coordinators that collect and transmit the data to the central unit are preferable. Wireless sensor networks technology is the only wireless technology that can be used for solving some surveillance and control issues, where the time of processing of the sensor readings is critical. United into a wireless network with the suggested method, the sensors make up a spatially distributed self-organized system of collection, processing and transmission of information. A special attention is paid to the structural solution for temperature control in the wireless sensor networks elements. In the conclusion, recommendations on using radio frequency identification technology-based sensor systems are provided.

Relevance. The development of the modern principles of combined tumor treatment has significantly improved the survival of the patients. For these patients, the organ-preserving surgerybecomes now the mainstream tactics. For the restoration of the lower limb support ability and the hip function, the hip arthroplasty is now the most used type of surgery. Purpose of the study. The purpose of this work was to evaluate the long-term results of hip arthroplasty in the patients with extensive proximal femur defects caused by tumors and tumor-like lesions. Materials and Methods. The data on 126 patients with proximal femur tumors, undergone the surgical treatment in 2000-2013, were collected and summarized. The average age of the patients was 53.8 years (26-74), 94 women (74.6%), and 32 men (25.4%). There were 16 primary malignant bone tumors (12.7%), 10 benign aggressive (7.9%); 92 metastatic (73%), and 8 tumor-like lesions (6.4%). The average follow-up after the surgery was 72.6 months. The complications classification and analysis were performed according to the criteria of the International Society of Limb Salvage 2014 (ISOLS 2014). For the assessment of the functional result, patients were divided into 4 groups. In this context, the following indicators were taken into account: whether the acetabular component or the bipolar head were used, and the method of the soft tissues fixation to the femoral component of the endoprosthesis. Functional outcome was evaluated using the international Musculoskeletal Tumor Society (MSTS) scoring system at 3, 6, and 12 months. Results. The total number of complications, identified during the observation period from 2000 to 2018, was 26 (20.6%). The oncological complications, represented by local recurrence, were detected on average after 11.5 months. The total number of local recurrences is 6 (4.7%) which amounted to 23% in the structure of all complications. Dislocations of the endoprosthesis became the most frequent complication-13 (10.3%) observations, 50% in the structure of all complications. Only one patient with aseptic instability of the femoral component was identified over the entire follow-up period. There were 4 (3.1%) patients with complications due to the destruction of metal constructions. All of them had an endoprosthesis stem fracture. The average period of onset of these complications was 122.5 months. Prosthetic joint infection was observed in 2 (1.6%) patients (7.2% of all complications), on the 14th and 31st days. The patient with the latter onset of infection underwent a twostaged revision arthroplasty. Functional result by the MSTS scale: 3 months-74.8%, 6 months-79%, 12 months-81.8%. In the patients under investigation, 5-, 10-, and 15-year survival for aggressive benign tumors and tumorlike lesions was 95%, 84%, 62%; for malignant primary tumors-88%, 65%, 24%; for secondary bone lesions-55%, 43%, 12%, respectively. Conclusion. The use of a bipolar head made it possible to reduce the likelihood of an endoprosthesis dislocation. The fixation of the preserved...

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Abstract. This paper describes the main principles of constructing innovative MEMS flow meters for gaseous working fluids. MEMS flow meter contains hot-wire thermoanemometrisc sensor which response to the temperature change caused by convective working fluid heat transfer from a hot-wire. The advantages of using hot-wire thermoanemometric sensors were analyzed. The main emphasis of this work is on speed, construction simplicity and small size of the sensor. The new approach to the solution of a problem of sensor output signal relation with the working fluid temperature is presented. This approach is based on adding an extra temperature sensor and a special scheme for thermal compensation to the hot-wire sensor. The temperature scale between temperature sensors (thermistors) corresponds to the flow speed and the flow rate. MEMS flow meters for gaseous working fluids analysisThe problem of precise gas flow calculation is important not only for modern industry but also for many people every day. The most well-known mechanical flow meters [1,2] are turbine and paddlewheel meters. These flow meters need additional components when they are used in innovative embedded systems, such as "smart house". The disadvantages of mechanical flow meters are small lifetime caused by mechanical parts runout and sticking of fluid impurities to the sensor which leads to the corruption of measurement results. Moving parts of mechanical flow meters obstruct the gaseous or liquid flow creating an extra aerodynamic resistance which enlarges the measurement error.Nowadays we can see an increasing need of modern sensors and transducers in all areas of human endeavour. The technology of silicon sensors constructing can be a solution of a problem of sensor integration into the digital signal processing system. The tendency of using silicon technology for precise sensors is also in modern digital flow meters design. The most common method for gas flow measuring [3-6] is a thermoanemometric method. This method uses convective working fluid heat transfer from hot-wire. The heat transfer is a function of gaseous working fluid speed. The advantages of the thermoanemometric sensor are high sensitivity, high speed, and construction simplicity. The use of silicon technology makes it possible to make the sensor so small that it does not affect the working fluid flow. Now let's see some innovative, constructive solutions which are used to create thermal MEMS flow meter for gaseous working fluids. Constructive solutions for MEMS flow meter for gaseous working fluids creationThe main problem which occurs while gas flow is measuring with the thermoanemometric sensor is output signal relation with the working fluid temperature. Adding an extra temperature sensor and a