Electrical impedance tomography for hand gesture recognition for HMI interaction applications

Electrical impedance tomography (EIT) is based on the physical principle of bioimpedance defined as the opposition that biological tissues exhibit to the flow of a rotating alternating electrical current. Consequently, here, we propose studying the characterization and classification of bioimpedance patterns based on EIT by measuring, on the forearm with eight electrodes in a non-invasive way, the potential drops resulting from the execution of six hand gestures. The starting point was the acquisition of bioimpedance patterns studied by means of principal component analysis (PCA), validated through the cross-validation technique, and classified using the k-nearest neighbor (kNN) classification algorithm. As a result, it is concluded that reduction and classification is feasible, with a sensitivity of 0.89 in the worst case, for each of the reduced bioimpedance patterns, leading to the following direct advantage: a reduction in the numbers of electrodes and electronics required. In this work, bioimpedance patterns were investigated for monitoring subjects’ mobility, where, generally, these solutions are based on a sensor system with moving parts that suffer from significant problems of wear, lack of adaptability to the patient, and lack of resolution. Whereas, the proposal implemented in this prototype, based on the so-called electrical impedance tomography, does not have these problems.Peer ReviewedPostprint (published version

Fractional-Order Electrical Modeling of Aluminum Coated via Plasma Electro-Oxidation and Thermal Spray Methods to Optimize Radiofrequency Medical Devices

Active medical devices rely on a source of energy that is applied to the human body for specific purposes such as electrosurgery, ultrasounds for breaking up kidney stones (lithotripsy), laser irradiation, and other medical techniques and procedures that are extensively used. These systems must provide adequate working power with a commitment not to produce side effects on patients. Therefore, the materials used in these devices must effectively transmit energy, allow for security control, sense real-time variations in case of any issues, and ensure the implementation of closed-loop systems for control. This work extends to the experimental data adjustment of some different coating techniques based on plasma electro-oxidation (PEO) and thermal spray (TS) using fractional-order models. According to the physical structure of the coating in different coating techniques, Cole family models were selected. The experimental data were obtained by means of a vector network analyzer (VNA) in the frequency spectrum from 0.3 MHz to 5 MHz. The results show that some models from the Cole family (the single-dispersion model and inductive model) offered a goodness of fit to the experimental impedance in terms of RMSE error and a squared error R2 close to unity. The use of this type of fractional-order electrical model allows an adjustment with a very small number of elements compared to integer-order models, facilitating its use and a consequent reduction in instrumentation cost and the development of control devices that are more robust and easily miniaturized for embedded applications. Additionally, fractional-order models allow for more accurate assessment in industrial and medical applications

Salud comunitaria confinada: Reflexiones y experiencias desde la salud pública local

This paper aims to share the reflections related to the community actions in which the Agència de Salut Pública de Barcelona has been involved during the emergency of COVID-19. The tasks carried out can be arranged in three stages, frequently overlapping: detection of needs and problems; contact with key stakeholders to assess what to do and how to do it; adaptation of the interventions to the “new normal” and generation of new responses. The emerging problems included: not being able to do the confinement (due to homelessness, material conditions, living in a situation of violence); digital gap (lack of knowledge, devices, access to Wifi); greater exposure to COVID-19 in the essential but precarious, feminized and racialized jobs (care, cleaning, food shops) that are the most frequent in the neighborhoods in where we work; language and cultural barriers that preclude to follow recommendations; to lose employment; insufficient income to cover basic needs; social isolation; and the deterioration of emotional health caused by the situation. During the process, some interventions were adapted to be delivered on-line. Solidarity networks and local resources were key to meet basic needs, but also other needs related to lack of digital knowledge or device. Community action in health, from a critical, intersectional and local perspective, and with intersectoral work and community participation, can contribute to: facilitate a contextualized response in the event of a health crisis; mitigate the effects derived from its economic and social crisis.Este artículo pretende compartir las reflexiones sobre la acción comunitaria en que la Agència de Salut Pública de Barcelona ha estado involucrada en la emergencia de COVID-19. El trabajo realizado puede ordenarse en tres etapas, frecuentemente solapadas: detectar necesidades o problemas, e informar; contactar con las personas participantes y agentes territoriales para valorar qué hacer y cómo hacerlo; y adaptar las intervenciones a la “nueva normalidad” y generar respuestas con los activos comunitarios a las necesidades detectadas. Los problemas emergentes incluyeron: no poder realizar el confinamiento (por falta de casa, condiciones materiales, vivir en situación de violencia); brecha digital (falta de conocimientos, dispositivos, acceso a Wifi); mayor exposición al COVID-19 en los trabajos esenciales pero precarizados, feminizados y racializados (cuidados, limpieza, alimentación), frecuentes en los barrios en que trabajamos; barreras idiomáticas y culturales para seguir las recomendaciones; pérdida de empleo; ingresos insuficientes para cubrir necesidades básicas; dificultades de conciliación; aislamiento social; y deterioro de la salud emocional provocado por la situación. Durante el proceso, algunas intervenciones se adaptaron para continuar de forma telemática, y se intentaron cubrir las necesidades primarias sobre conocimientos y dispositivos de algunas personas participantes a través de las redes solidarias y recursos existentes. La acción comunitaria en salud, desde una mirada crítica, interseccional y local, mediante trabajo intersectorial y la participación de la comunidad, puede contribuir a: facilitar una respuesta adaptada al contexto en caso de crisis sanitaria y mitigar los efectos derivados de esta crisis económica y social