Impedance Spectroscopy (IS) has been shown to be a non-invasive and reliable technique for the electrical characterization of biological materials. This paper presents the design and implementation of reliable, reusable wells that are used to perform IS measurements of aqueous solutions. These reusable wells are detachable, easy to clean and low-cost and they are made up of a platen on a Printed Circuit Board (PCB) and the chambers are manufactured using 3D-printing technology. In this case, in order to verify its functionality, IS measurements of electrolytic and non-electrolytic aqueous solutions were carried out. Initially, as a reference, the impedance spectrum of a Hanks’ solution was obtained following a proposed measurement protocol. Then, we analyse this spectrum and we propose an Equivalent Electrical Model (EEM) for validating the reusable wells. Finally, IS measurements are carried out on aqueous solutions of molecular D-glucose and sodium chloride prepared in Hanks’ solution and deionized water, by considering physiological concentrations. The parameter values of the EEMs of each solution tested were obtained using genetic algorithms and Matlab and, from these values, it is possible to conclude that the measurements performed are unable to differentiate the physiological concentration of glucose in the aqueous solution used. Also, from these results, it can be concluded that the designed wells are suitable for IS measurements of aqueous solutions and that they can be used in Electrical Cell Impedance Sensing (ECIS) or applications that require electrical characterization of solutions.

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This article presents microneedles analyses where the design parameters studied included length and inner and outer diameter ranges. A mathematical model was also used to generalize outer and inner diameter ratios in the obtained ranges. Following this, the range of inner and outer diameters was completed by mechanical simulations, ranging from 30 μm to 134 μm as the inner diameter range and 208 μm to 250 μm as the outer diameter range. With these ranges, a mathematical model was made using fourth-order polynomial regressions with a correlation of 0.9993, ensuring a safety factor of four in which von Misses forces of the microneedle are around 17.931 MPa; the ANSYS software was used to analyze the mechanical behavior of the microneedles. In addition, the microneedle concept was made by 3D printing using a bio-compatible resin of class 1. The features presented by the microneedle designed in this study make it a promising option for implementation in a transdermal drug-delivery device.

Sub-slab depressurisation systems have proven to effectively mitigate radon entry. A poor understanding of the fluid physics underlying the technique has been shown to lower the success rate substantially. This article describes a study of pressure fields in a sub-slab gravel 2 bed induced by a soil depressurisation system consisting of perforated pipes run under the slab at a depth of 75 cm. The advantage of the approach is that pipes can be laid from outside the building to be protected. The study was conducted on a large-scale experimental facility where the variations in morphology and scope of pressure fields with different pipe combinations could be monitored and characterised. The findings showed that pressure was uniform across the entire area in the gravel bed, whereas the sensors buried in natural soil showed pressure to depend on distance from the source. Pressure transfer to the sub-slab plane was also observed to vary depending on the active pipe. Air-flow resistance studies in the layers of soil lying between the pipes and the gravel delivered different results for each pipe. That finding would appear to be related to the presence of preferential pathways in some parts of the soil. Total pressure when several pipes were activated was observed to be practically the same as the sum of the pressures transferred by each when working separately. The correlation between extraction fan power and pressure generated was also analysed. These and other factors are discussed and analysed from a perspective of the understanding of such highly effective techniques.

In this paper we propose an approach to the neuromotor language of the transfemoral amputee user. We do this by identifying the user's intention from the perception of both internal and external manifestations (to be explained into a next section) of Fixed Action Patterns (FAPs, by making use of artificial proprioception and exteroception of the prosthesis. The formalization of a General Expression of the Rhythmic Gesture, generation procedures for artificial FAPs, and a Response Algorithm for Gestures Development are presented. By identifying the user's intention through proprioceptive and exteroceptive information, the prosthesis discriminates between repertories of artificial FAPs and chooses the most suitable one to meet the users's requirements. Experimental data of tests carried out in healthy and amputee individuals showed high performance on identification (97.06 % of true identifications) of the user's intention and good tracking of gestures such as gait, walking up stairs, down stairs, up hill and down hill, independently of the speed of execution of the gesture. Keywords: Artificial fixed action pattern, identification algorithm, user's intention. ResumenEn este documento se propone una aproximación al entendimiento del lenguaje neuromotor de una persona con una amputación por encima de rodilla, mediante la identificación de su intención de movimiento a partir de la percepción de las manifestaciones tanto internas como externas de los Patrones de Acción Fija (PAF) mediante el uso de una propiocepción artificial y la exterocepción de su prótesis durante el desarrollo de diferentes gestos (marcha, subir y bajar escaleras y subir y bajar rampas). Se presentan la formalización de una expresión General del Gesto Rítmico, los procedimientos para la generación de PAF artificiales y un Algoritmo de Respuesta ante el Desarrollo de Gestos. Mediante la identificación de la intención del usuario a través de la información propioceptiva y exteroceptiva, la prótesis discrimina entre un repertorio de PAF artificiales y selecciona el más adecuado para satisfacer las necesidades de movimiento del usuario. Los datos experimentales de las pruebas desarrolladas en individuos sanos y amputados mostraron un alto desempeño en la identificación de la intención del usuario (97.06% de identificaciones correctas) y un buen seguimiento de los gestos de movimiento independientemente de la velocidad con que fueron ejecutados.Palabras Clave: Algoritmo de identificación, intención del usuario, patrón de acción fija artificial.