Regarding the establishment of the anti-burn «Fenix-MS» bed conformity with the requirements of quality and safety standards

The standards that anti-burn beds must meet are given. The design of the domestically produced anti-burn «Phoenix-MS» bed, which has improved design and technological indicators, is briefly described. The main test results of this bed, obtained in the process of independent conformity assessment, are presented. Their analysis showed that the product meets quality standards and ensures the safety of patients and medical personnel during its operation in medical institutions. It is noted that the manufacturer needs to carry out a more complete clinical evaluation of the product, taking into account the strengthening of this requirement in the new EU Regulation 2017/745 on medical devices.


Introduction
The task of health care and the provision of medical services to the population largely depends on the quality, efficiency, and safety of medical products that enter our domestic market and are used for their intended purpose in medicine.Therefore, the problem of ensuring the quality and safety of medical products is a complex scientific-technical, economic, and social problem.As we know, standardization and certification is a regulatory and methodological basis for ensuring the quality of products.Product certification is primarily related to the quantitative assessment of its quality indicators, which is carried out using measuring equipment.It is based on the tests conducted, the assessment of production requirements of certified products, and the supervision of product quality by an independent body.The safety of medical devices during their use means the exclusion of unacceptable potential risks, as a result of which significant harm can be caused to the health of patients and medical personnel, and both risks due to incorrect operation of medical equipment and its use not as intended [1,2] are considered.Depending on the potential risk of their use, medical products are divided into four classes: I, IIa, IIb, III.In all civilized countries, the strictest control is carried out over products of classes IIb (increased degree of risk) and III (high degree of risk).Anti-burn beds belong to risk group IIb due to their functional heated air and maintaining the optimal temperature regime.It ensures the removal of infected air from the patient area and has a lower cost and low operating costs per patient.
Tests of the specified bed were carried out in the process of independent assessment of compliance with the requirements of quality and safety standards in SE «Ukrmetrteststandart» (Kyiv).
The purpose of the article: based on the results of the tests of the domestic bed for the treatment of burn patients «Phoenix-MS», carried out according to the «type verification» procedure of the Technical Regulations, and the analysis of the obtained results, to establish the conformity of this product with the requirements of quality and safety standards.
As already mentioned, products are subject to conformity assessment both at the stages of development and production, and at the stage of post-marketing surveillance.Therefore, taking into account the requirements of the new EU Regulation on medical devices, the article additionally considers the issue of the sufficiency of clinical data obtained by the manufacturer after the release of the anti-burn bed «Phoenix-MS» on the market.

Design features of the anti-burn bed «Phoenix-MS»
The bed for the treatment of burn patients «Phoenix-MS» is a medical product intended for use in shock departments of burn centers of medical institutions for the treatment and care of patients with large (including circular) thermal lesions of the skin by creation of artificial aeration with heated air, as well as appropriate placement of the patient in a separate air zone [16] .The developed bed includes a bed frame on wheels, a saddle for installing the bed, a bed with an installed net, an air duct, a suspension for the legs, a stand under the body with a net, a footrest, an armrest with a net, a lifting trapeze, monorail, a collection cap, headboard, hinged curtains, connecting duct.The bed also has a heating fan designed to heat the air entering the patient's area.A network filter, a control board, a fan, a heater, and a digital thermometer are placed purpose and conditions of use.All electrical safety requirements that must be met by both anti-burn beds and their accompanying documentation are set out in the general standard DSTU EN 60601-1:2015 [2] , as well as supplemented in the relevant clauses of the subordered specified standard DSTU EN 60601-2-52 :2015 [3] and additional standards [4 -8] .It should be noted that from 26 May 2021, the new Regulation 2017/745 on medical devices is in effect in the EU [9] .For manufacturers of already approved medical devices, there is a transition period until 26 May 2024, during which products that have been certified in accordance with the domestic Technical Regulation on medical devices № 753 (developed on the basis of EU Council Directive 93/42/EEC 14 June 1993) can continue to be placed on the market, but are also subject to additional requirements under the new EU Regulation.In the new EU Regulation, more attention is paid to an approach that takes into account the entire life cycle of the product in terms of its use for its functional purpose without harming human health, which must be confirmed by clinical data, for example, clinical relevant information on post-registration surveillance, in particular, clinical observations after implementation [10] .
Technical, operational, and cost characteristics of the existing models of anti-burn beds are given in [11 -14] .A thorough analysis of the characteristics of anti-burn beds is conducted in [13] .Beds are manufactured, taking into account the experience of their practical use, and a number of shortcomings inherent in these beds are revealed.Anti-burn bed «Phoenix-MS» produced by LLC «NVP «Metekol» (Nizhyn) eliminates most of these shortcomings [15] .When developing the product, materials from the clinical ap-  Infected air, after contact with the patient's body, rises up into the area of the collector cap, from where it is removed into the existing exhaust ventilation ducts or outside through the wall (window) of the ward.The external view of the bed structure is presented in Fig. 1, and Fig. 2 shows the external view of the fan heater.pendix B of the general standard [2] .According to the operating instructions, the maximum ambient temperature is + 35 ºC. 1) thermocouples of the TXA(K) type, which are connected to the Agilent 34970A Data Acquisition / Switch Unit;

Anti
2) limitations specified in the manufacturer's specification (operating temperature); 3) normal operating mode of the fan heater for two hours: 10 s -heating, 8 s -pause (when setting the temperature regulator to the «Max» position, supply voltage 242 V, ambient air temperature + 25 °С); 4) a single violation: blocking the operation of the fan (a bimetallic automatic thermal switch after 30 s opens the electrical circuit of the heater, and after 6 min it closes it again)/or blocking all ventilation openings on the body of the fan heater.provided by the manufacturer.The following procedure was applied when forming conclusions about the conformity of the product: a binary conclusion (meets or does not meet the requirements) for a simple decision-making rule (without taking into account the influence of measurement uncertainty) [16] .
At the same time, measuring devices that meet the requirements of the document OD-5014 [17]    (Kyiv), an assessment of the biological compatibility of the bed for the treatment of burn patients «Phoenix-MS» was also carried out, with the exception of the requirement for cytotoxicity, the study of which was not carried out at that time.It was determined that not only the mesh made of polyamide fiber on which the patient is placed but also the bed, as a whole, meets the established requirements for biocompatibility [7] .Since the beginning of production, the enterprise has manufactured 32 beds for the treatment of burn patients «Phoenix-MS», which were installed in 11 regions of Ukraine and in the city of Kyiv.According to the results of the operation of these beds, positive feedback was received from the leading combustiologists of Dnipropetrovsk, Poltava, and other regions of Ukraine.Given that there were no issues related to the cytotoxicity of the polyamide fiber net during the operation of the beds, the manufacturer determined the risk of its use to be acceptable and noted it in its risk management file.Moreover, the new EU Regulation introduces stronger requirements for clinical evaluation: it requires the establishment of a systematic and planned process for the continuous acquisition, collection, analysis, and evaluation of clinical data on the product to verify its safety and effectiveness, including the clinical benefit of the prod-uct [9] .Therefore, we believe that the manufacturer, in order to improve the competitiveness of the product, should apply additional measures to fulfill the increased requirements for clinical evaluation given in the new EU Regulation.

Fig. 2 .Fig. 1 .
Fig. 2. External view of the fan heater: a -from the front side; b -from the back side -burn bed «Fenix-MS», as indicated in its Operation Manual, meets the requirements of standard DSTU EN 60601-1:2015 for class II products with type BF working parts in terms of the degree of protection against electric shock.The obtained test results of the developed bed, including the measurement data of the main parameters of the bed, which are related to the safety of patients and the attending medical personnel, are given in Tables 1-4.The tests were carried out in the sequence given in Ap- are used to measure temperature, leakage currents, and set the test voltage.The most time-consuming tasks are temperature measurements and testing of the product for mechanical hazards and strength.If, for various reasons, the temperature measurement during medical device tests, including certification tests, is performed inaccurately and not in full, then this can negatively affect their indicators, such as efficiency, reliability, consumption, and, as a result, quality.The temperature of the bed parts was measured using a Testo 925 digital contact thermometer and an Agilent 34970A data acquisition and switching system with an Agilent 34901A module (for 20 channels), and the BenchLink Data Logger 3 Version 4.3 software package.A set of calibrated thermocouples of the TXA (K) type of the first accuracy class was connected to the system.Calibration of both thermocouples and the Agilent 34970A data collection and switching system with the Agilent 34901A module was carried out at SE «Ukrmetrteststandart» (Kyiv) at 20 °C and 200 °C according to the method [18] .It should be noted that the product has negligible leakage currents to the enclosure and to the patient, which do not exceed 10 μA both in the normal state and in the conditions of a single fault.The measurement of the leakage currents of the product was carried out using the electrical safety analyzer QA-90 MKII, and testing of the electrical strength of the insulation of the product was carried out using the Chroma 19032-P electrical safety analyzer.Analysis of the obtained results of developed bed tests showed that: -the main electrical parameters of the bed (leakage currents, electrical insulation strength) meet the requirements of subclauses 8.7 and 8.8 of the general standard; -creepage distances and clearances in the product meet the requirements of subclause 8.9.1 of the general standard; -detailed tests of the product for mechanical hazards and strength, carried out according to subsections 9.4, 9.8, and 15.3 of the general standard, do not lead to damage that leads to unacceptable risks; -the temperature of the bed parts in all operating modes meets the requirements of subclause 11.1 of the general standard.

1 . 3 .
The analysis of the results of the tests carried out during the independent assessment of the conformity of the anti-burn bed «Phoenix-MS» showed that it meets all the requirements established in the current standards of Ukraine, has the appropriate quality and ensures the safety of patients and medical personnel during its operation in medical institutions.2. It is noted that the improved mobile design of the domestic bed for the treatment of burn patients «Phoenix-MS» has improved design and technological indicators and corresponds to the modern technical level.The bed is adapted to the patient, with all necessary accessories for effective treatment of burn patients, as well as the ability to remove infected air from the patient's area.It was determined that the manufacturer needs to conduct a more complete clinical evaluation of the product, taking into account the strengthening of this requirement in the new EU Regulation 2017/745 on medical devices.

Table 1 .
The dielectric strength of solid electrical insulation of equipment 1 -fan heater; 2 -footrest; 3 -suspension for legs; 4 -bed net; 5 -stand for hand; 6 -stand for the body; 7 -exhaust ward fanPower supply data: nominal voltage 220 V, frequency 50 Hz, nominal power consumption 2200 W. The electrical strength of the insulation of the product was checked immediately after heating the product to operating temperature, after previous exposure to moisture, and after each necessary sterilization process.

Table 2 .
Creepage distances and clearances of equipment inside the fan heater.Control of the air temperature at the heater outlet is carried out using a compact digital temperature sensor based on the DS18B20 microcircuit manufactured by Dallas Semiconductor.The fan heater does not have electrical contacts with the bed and is installed on a bracket located on the back of the bed on the side of the leg part and is connected to the air duct of the bed by means of a connecting air duct.
The test methods are given in the above standards, the tests were

Table 3 .
Temperature of parts of the bed

Table 4 .
Product testing for mechanical hazards and strength carried out taking into account the data of the risk management file of the anti-burn bed «Phoenix-MS»,

Table 4 .
Product testing for mechanical hazards and strength(Continuation)