Remotely Supervised Cranial Electrical Stimulation and Clinical Pain for Older Adults With Knee Osteoarthritis

Knee osteoarthritis (KOA) is one of the most prominent causes of chronic pain, functional impairment, and disability in older adults. The current standards of care for KOA are aimed toward reducing pain and are largely comprised of analgesic medications, but existing pharmacologic approaches often produce significant adverse effects. Moreover, recent evidence suggests that KOA pain is characterized by alterations in pain-related brain mechanisms. Cranial electrical stimulation (CES), which delivers a low-amplitude alternating electric current to the brain, can facilitate the reversal of maladaptive brain function. Portable CES devices can be used at home with real-time monitoring through a secure videoconferencing platform to facilitate high adherence. Thus, the purpose of this pilot clinical study was to examine the preliminary efficacy of remotely supervised CES on clinical pain severity in older adults with KOA. Thirty participants with KOA were randomly assigned to receive 10 daily sessions of remotely supervised CES with 0.1 mA at a frequency of 0.5 Hz for 60 minutes (n=15) or sham CES (n=15). We measured clinical pain severity using the numeric rating scale (NRS; range, 0 – 100). Participants (67% female) had a mean age of 59 years. Active CES significantly reduced scores on the NRS (Cohen’s d = 1.43, P < 0.01). Participants tolerated CES well without any adverse events. Our findings demonstrate the promising clinical efficacy of remotely supervised CES for older adults with KOA. Future studies with larger-scale randomized controlled trials with follow-up assessments are needed to validate and extend our findings.

Angle Magnetization Rotation Method for Characterizing Co-Rich Amorphous Ferromagnetic Microwires

A low-frequency model of the magnetization reversal of a microwire is developed for those cases when the microwire magnetization response can go beyond the linear approximation. The analysis of the influence of external magnetic fields on the process of magnetization reversal of the microwire, including the hysteresis mode, was performed. The characteristic dependences of the amplitude of the electromotive force, U2f, arising in the pick-up coil wound around the microwire are obtained. It was established that, in the region of relatively small-acting circular and longitudinal magnetic fields, the U2f signal could have a region with the opposite sign. An extended small-angle magnetization rotation method was used to verify the proposed model and test glass-coated, amorphous, Co-rich microwires. During the experiments, the amplitude of the second harmonic, U2f, arising in the pick-up coil when an alternating electric current with the frequency f flows through the microwire, was measured as a function of the applied longitudinal magnetic field at various mechanical tensile stresses. The effective anisotropy field, the magnetostriction constant, and the residual quenching stress of the investigated microwires were determined by comparing the theoretical and experimental data.

Dynamics of a Conductor with Unclosed Alternative Electric Current

The ponderomotive interaction of displacement currents and conduction currents in an open conductor through which an alternating electric current flows is considered. The calculation is performed for a flat conductor of arbitrary shape. It has been shown that the displacement current does not create a nonzero force that would act on an open conductor. The so-called force of self-action, with which the conductor acts on itself, is compensated by the force of Abraham, transmitted to the electromagnetic field. The absolutely exact fulfillment of the law of conservation of momentum, which includes the latent momentum of the field, has been demonstrated. The density of Abraham's force is determined by the vector product of the derivative of the electric field in-duction by the magnetic field induction. As an example, a numerical calculation of the self-force and the Abraham force for a thin ring conductor is carried out. The ratio of Abraham's force to the square of the conduction current depends only on the relative dimensions of the conductor. The maximum Abraham's force is observed for a conductor representing half of a flat ring.

Mathematical model of the process of drying fine dispersed materials under the influence of alternating electric current

Purpose. Establishing the dependences and determining rational parameters of the process of drying fine materials by direct influence of an electric current. Methodology. In the work, theoretical, analytical, empirical, and experimental methods as well as methods of mathematical statistics are used. Mathematical modeling of the process occurring during drying of finely dispersed materials by direct influence of alternating current is carried out. Findings. As a result of the research on the basis of physical representations of the process of drying capillary-porous material, a mathematical model is designed connecting temperature and moisture content in a plate from capillary-porous material by means of equations of mathematical physics. Originality. For the first time dependence has been obtained on the temperature and moisture content of the time and spatial coordinates of drying by passing an electric current through the layer of moist capillary-porous material, a feature which is both simultaneous accounting of thermal and diffusion processes in the material that can increase the accuracy of calculations and establish rational parameters of drying. Practical value. The obtained dependences are used when developing calculation methods and designing an industrial drying plant.

Influence of ozone generated by pulsed alternating electric current on the viability of representatives of oral microflora involved in the development of prosthetic stomatitis

Topicality. When using removable dentures, in 84.26±1.19 % of cases patients have various changes in the mucous membrane of the prosthetic bed with pronounced changes in microbial ecology which are exacerbated by poor oral hygiene and removable dentures. Ozone therapy is a new and promising area of treatment of microbial lesions of the oral mucosa. It has antiseptic, anti-inflammatory, analgesic, immunomodulatory effects and promotes activation of intracellular metabolism, improvement of rheological properties and microcirculation of blood; it also strengthens reparative ability of the injured tissues. The aim of the study is to evaluate the in vitro effect of ozone generated by the device for use in dental practice on the survival of the representatives of aerobic and facultative anaerobic microflora of the oral cavity, which are important in the development of prosthetic stomatitis. Materials and methods of research. In vitro experiments helped to study the effect of ozone generated by pulsed alternating electric current (Ozone DTA device for use in dental practice) on the survival of the representatives of aerobic and facultative anaerobic microflora of the oral cavity, which may be potential factors in inflammatory processes in prosthetic bed tissues and the development of prosthetic stomatitis. The results were processed by the method of variation statistics and two-way analysis of variance ANOVA (MS Excel 2003). Results. A direct dependence of the influence of the survival level of S. aureus in suspension on the ozone generation capacity and the time of exposure to ozone was established. Different types of oral microorganisms differ in their sensitivity to ozone. Cultures of S. epidermidis, β-hemolytic Streptococcus group G, α-hemolytic streptococci S. sanguinis and S. oralis, yeast-like fungi Candida tropicalis are characterized by relatively higher sensitivity to the generated ozone. Conclusion. The obtained experimental results microbiologically substantiate the possibility and expediency of using ozone therapy to prevent the occurrence and treatment of prosthetic stomatitis. Based on the performed experiments, the optimal mode of ozone therapy with the Ozone DTA device was established to ensure the antimicrobial effect at the level of 98.8–100%. Key words: ozone, microorganisms, antimicrobial action, oral cavity.

Barra lateral del artículo PDF Publicado: nov 30, 2021 Palabras clave: Bioimpedancia coeficiente de variación espectroscopía flujo sanguíneo movimiento corporal Contenido principal del artículo D. Campo Universisdad Autónoma de Occidente, Cali, Colombia C. A. Romero-Beltrán Universisdad Autónoma de Occidente, Cali, Colombia/Institución Universitaria Antonio José Camacho, Cali, Colombia J. J. Cabrera-López Universisdad Autónoma de Occidente, Cali, Colombi A. Rodríguez Lopez Universidad Politécnica Santa Rosa Jauregui, Querétaro, México F. E. Mercader-Trejo Universidad Politécnica Santa Rosa Jauregui, Querétaro, México R. Antaño López Centro de Investigación y Desarrollo Tecnológico en Electroquímica, Querétaro, México E. R. Larios-Durán Universidad de Guadalajara CUCEI, Guadalajara, México Resumen Electrical bioimpedance is a technique commonly used to analyze the electrical properties of biological tissues. For this purpose, an alternating electric current signal of controlled magnitude and variable frequency must be applied to the tissue; the measured response corresponds to an electric potential. Several factors can affect the variability of the measurements, in this case, we seek to analyze the effect of blood flow and body movement on this variability, for which measurements were performed in a test subject with the Gamry reference 3000 Potentiostat/Galvanostat, following a 2k experimental design and a standardized measurement protocol. An equivalent circuit was proposed from the data obtained, whose parameters in each case of the study were estimated through an adjustment performed in the Zview software. Average values, standard deviation, and coefficient of variation were obtained for the mentioned parameters. However, the proposed experimental test is insufficient to record the physiological effects of interest, so it is proposed to perform simulations with finite elements to establish better measurement conditions. Detalles del artículo Cómo citar Campo, D., Romero Beltran, C. A., Cabrera López, J. J., Rodríguez López, A., Mercader Trejo, F. E., Antaño López, R. ., & Larios Durán, . E. R. (2021). Efecto del Flujo Sanguíneo y el Movimiento Corporal en la Variabilidad de las Mediciones de Bioimpedancia. Memorias Del Congreso Nacional De Ingeniería Biomédica, 8(1), 178–181. Recuperado a partir de http://memorias.somib.org.mx/index.php/memorias/article/view/899 MÁS FORMATOS DE CITA DESCARGAR CITA Número Vol. 8 Núm. 1 (2021): Memorias del XLIV Congreso Nacional de Ingeniería Biomédica Sección Bioinstrumentación, Biosensores, Bioimpedancia y Micro/Nano Tecnologías DERECHOS DE AUTOR Y DERECHOS CONEXOS, las MEMORIAS CONGRESO NACIONAL DE INGENÍERIA BIOMÉDICA es una publicación editada por la Sociedad Mexicana de Ingeniería Biomédica A.C., Plaza Buenavista, núm. 2, Col. Buenavista, Delegación Cuauhtémoc, C.P. 06350, México, D.F., Tel. +52 (555) 574-4505, www.somib.org.mx, correo-e: [email protected]. Editor responsable: Elliot Vernet Saavedra. Reserva de Derechos al Uso Exclusivo No. 04-2015-011313082200-01, ISSN: 2395-8928, ambos otorgados por el Instituto Nacional de Derechos de Autor. Sitio Web del Congreso Nacional de Ingeniería Biomédica #CNIB

Electrical bioimpedance is a technique commonly used to analyze the electrical properties of biological tissues. For this purpose, an alternating electric current signal of controlled magnitude and variable frequency must be applied to the tissue; the measured response corresponds to an electric potential. Several factors can affect the variability of the measurements, in this case, we seek to analyze the effect of blood flow and body movement on this variability, for which measurements were performed in a test subject with the Gamry reference 3000 Potentiostat/Galvanostat, following a 2k experimental design and a standardized measurement protocol. An equivalent circuit was proposed from the data obtained, whose parameters in each case of the study were estimated through an adjustment performed in the Zview software. Average values, standard deviation, and coefficient of variation were obtained for the mentioned parameters. However, the proposed experimental test is insufficient to record the physiological effects of interest, so it is proposed to perform simulations with finite elements to establish better measurement conditions.

Prototype of a Low-Cost Impedance Tomography Based on the Open-Hardware Paradigm

Electrical Impedance Tomography (EIT) is a noninvasive, painless, and ionizing radiation-free technique for image acquisition of a region of interest. It is performed through electrical parameters. The method is based on the application of an alternating electric current pattern of low intensity through electrodes arranged around the surface region in order to obtain the image and also to measure the excitation electrical potentials. The aim of this study is to develop a device based in open hardware. Furthermore, the authors aim to build a prototype of a data acquisition system based on EIT. This device is the first step to obtain a complete and portable tomography equipment at a low cost.

Studies of excitation modes of thermoacoustic emitters of sound – of thermophones

В работе проведён анализ влияния режимов возбуждения термофона на его акустическую эффективность. В настоящее время для возбуждения современных термофонов используют два режима возбуждения соответствующих случаям, когда в активном элементе термофона текут: 1) постоянный электрический ток I0 и переменный электрический ток i(f) = Imsin(ωt); 2) только переменный ток i(f) = Imsin(ωt). В этих случаях термофон излучает звуковые волны, амплитуды колебательных скоростей которых um1 и um2 соответствуют номерам режимов. При этом показано, если выполняется неравенство I0 >> Im, то отношение колебательных скоростей um1 / um2 ≥ 28. Как следствие этого, уровень излучения звука при 1 режиме возбуждения более чем на 29 дБ выше, а мощность акустического излучения в 860 раз выше по сравнению со вторым режимом возбуждения. Таким образом, для создания мобильных эхолокационных систем, работающих в газах, могут быть использованы термофоны, в которых реализован первый режим возбуждения, имеющий более сложную схему электрического питания. The paper analyzes the influence of thermophone excitation modes on its acoustic efficiency. Currently, to excite modern thermophones, two excitation modes are used corresponding to cases when in the active element of the thermophone flows: 1) direct electric current I0 and alternating electric current i(f) = Imsin(ωt); 2) only alternating current i(f) = Imsin(ωt). In these cases, the thermophone emits sound waves whose vibrational speed amplitudes um1 and um2 correspond to the mode numbers. It is shown that if the inequality I0 >> Im, is satisfied, then the ratio of vibrational speeds um1 / um2 ≥ 28. As a result, the sound radiation level at 1 excitation mode is more than 29 dB higher, and the acoustic radiation power is 860 times higher compared to the second excitation mode. Thus, to create mobile echolocation systems operating in gases, thermophones can be used, in which the first excitation mode is implemented, which has a more complex electrical power supply scheme.