Innovative Approach to the Creation of Textile Materials with Antimicrobial Properties

Introduction. In recent years, there has been a constant search for more advanced and environmentally friendlymeans for antimicrobial treatment of cellulose-containing tissues of various intended uses in the textile industry.Problem Statement. The problem of protection of textile materials and products from microbiological destruction is complex and multifaceted and needs to be solved. Today, one of the methods of protection is to provide textile materials with biocidal properties, which not only prevents the growth of bacteria, but can also ensure a high level of tissue safety. Therefore, we are faced with the task of finding new safe biocidal products.Purpose. The research has been made to determine the level of safety of textile materials treated by biocidalsubstances with the thiosulfonate structure including Ethylthiosulfanilate, Methylthiosulfanilate and Allylthiosulfanilate.Materials and Methods. The fabrics of different chemical composition were used in the study, designed for themanufacture of overalls. New preparations of thiosulfonate structure were chosen for impregnation: ethylthiosulfanilate (ETS), methylthiosulfanilate (MTS) and allylthiosulfanilate (ATS). The presence of heavy metals and pesticides was determined by atomic absorption spectrometry with the use of a ZEENIT 650P spectrometer (Germany).Results. It has been established that the detected level of heavy metals and pesticides in the studied textile materials is insignificant and is within the regulatory requirements. It has been confirmed that the studied biocidal substances are low-toxic and environmentally friendly, because before and after treatment they did not change the hygienic parameters of tissues. A method for imparting biocidal properties to textile materials for the manufacture of overalls, in particular by impregnating textile materials with an alcoholic solution of biocidal products, has been developed. Also due to this treatment, the water absorption of materials decreases by an average of 40%.Conclusions. The treatment of textile materials with biocidal preparations of the thiosulfonate structure allowsobtaining simultaneously two desired effects for these fabrics: the appropriate bioresistance and water resistance.

Wireless Power Transfer Techniques for Implantable Medical Devices: A Review

Wireless power transfer (WPT) systems have become increasingly suitable solutions for the electrical powering of advanced multifunctional micro-electronic devices such as those found in current biomedical implants. The design and implementation of high power transfer efficiency WPT systems are, however, challenging. The size of the WPT system, the separation distance between the outside environment and location of the implanted medical device inside the body, the operating frequency and tissue safety due to power dissipation are key parameters to consider in the design of WPT systems. This article provides a systematic review of the wide range of WPT systems that have been investigated over the last two decades to improve overall system performance. The various strategies implemented to transfer wireless power in implantable medical devices (IMDs) were reviewed, which includes capacitive coupling, inductive coupling, magnetic resonance coupling and, more recently, acoustic and optical powering methods. The strengths and limitations of all these techniques are benchmarked against each other and particular emphasis is placed on comparing the implanted receiver size, the WPT distance, power transfer efficiency and tissue safety presented by the resulting systems. Necessary improvements and trends of each WPT techniques are also indicated per specific IMD.

Towards a Miniaturized 3D Receiver WPT System for Capsule Endoscopy

The optimization, manufacturing, and performance characterization of a miniaturized 3D receiver (RX)-based wireless power transfer (WPT) system fed by a multi-transmitter (multi-TX) array is presented in this study for applications in capsule endoscopy (CE). The 200 mm outer diameter, 35 μm thick printed spiral TX coils of 2.8 g weight, is manufactured on a flexible substrate to enable bendability and portability of the transmitters by the patients. The 8.9 mm diameter—4.8 mm long, miniaturized 3D RX—includes a 4 mm diameter ferrite road to increase power transfer efficiency (PTE) and is dimensionally compatible for insertion into current endoscopic capsules. The multi-TX is activated using a custom-made high-efficiency dual class-E power amplifier operated in subnominal condition. A resulting link and system PTE of 1% and 0.7%, respectively, inside a phantom tissue is demonstrated for the proposed 3D WPT system. The specific absorption rate (SAR) is simulated using the HFSSTM software (15.0) at 0.66 W/kg at 1 MHz operation frequency, which is below the IEEE guidelines for tissue safety. The maximum variation in temperature was also measured as 1.9 °C for the typical duration of the capsule’s travel in the gastrointestinal tract to demonstrate the patients’ tissues safety.

Zero mean waveforms for neural stimulation

Biphasic charge balanced waveforms do not minimise faradaic processes at the electrode-electrolyte boundary and do not leave electrodes neutral with respect to the tissue. Superior waveforms for electrode health (and consequently tissue safety) exist and may also offer better performance in terms of power consumption and stimulation effectiveness within charge injection limits. This paper aims to provide intuitive insight into the limitations of biphasic waveforms and presents a simple method for assessing how well other waveforms will perform, as well as methods for designing waveforms to theoretically give zero residual voltage and zero net faradaic charge transfer.