A 64-channel inductively-powered neural recording sensor array

This paper reports a 64-channel inductively powered neural recording sensor array. Neural signals are acquired, filtered, digitized and compressed in the channels. Additionally, each channel implements a local auto-calibration mechanism which configures the transfer characteristics of the recording site. The system has two operation modes; in one case the information captured by the channels is sent as uncompressed raw data; in the other, feature vectors extracted from the detected neural spikes are transmitted. Data streams coming from the channels are serialized by an embedded digital processor and transferred to the outside by means of the same inductive link used for powering the system. Simulation results show that the power consumption of the complete system is 377μW.Ministerio de Ciencia e Innovación TEC2009-0844

A power efficient neural spike recording channel with data bandwidth reduction

This paper presents a mixed-signal neural spike recording channel which features, as an added value, a simple and low-power data compression mechanism. The channel uses a band-limited differential low noise amplifier and a binary search data converter, together with other digital and analog blocks for control, programming and spike characterization. The channel offers a self-calibration operation mode and it can be configured both for signal tracking (to raw digitize the acquired neural waveform) and feature extraction (to build a first-order PWL approximation of the spikes). The prototype has been fabricated in a standard CMOS 0.13μm and occupies 400μm×400μm. The overall power consumption of the channel during signal tracking is 2.8μW and increases to 3.0μW average when the feature extraction operation mode is programmed.Ministerio de Ciencia e Innovación TEC2009-08447Junta de Andalucía TIC-0281

A low-power reconfigurable ADC for biomedical sensor interfaces

This paper presents a 12-bit low-voltage low-power reconfigurable Analog-to-Digital Converter (ADC). The design employs Switched Capacitor (SC) techniques and implements a Successive Approximation (SA) algorithm. The ADC can be tuned to handle a large variety of biopotential signals, with digitally selectable resolution and input signal amplitude. It achieves 10.4-bit of effective resolution sampling at 56kS/s, with a power consumption below 3μW from a 1V voltage supply.Ministerio de Educación y Ciencia TEC2006-03022Junta de Andalucía TIC-0281

A self-calibration circuit for a neural spike recording channel

This paper presents a self-calibration circuit for a neural spike recording channel. The proposed design tunes the bandwidth of the signal acquisition Band-Pass Filter (BPF), which suffers from process variations corners. It also performs the adjustment of the Programmable Gain Amplifier (PGA) gain to maximize the input voltage range of the analog-to-digital conversion. The circuit, which consists on a frequency-controlled signal generator and a digital processor, operates in foreground, is completely autonomous and integrable in an estimated area of 0.026mm 2 , with a power consumption around 450nW. The calibration procedure takes less than 250ms to select the configuration whose performance is closest to the required one.Ministerio de Ciencia e Innovación TEC2009-08447Junta de Andalucía TIC-0281

The triangle assessment method: a new procedure for eliciting expert judgement

The Analytic Hierarchy Process (AHP) is one of the most widely used Multi-Criteria Decision-Making methods worldwide. As such, it is subject to criticisms that highlight some potential weaknesses. In this study, we present a new Multi-Criteria Decision-Making method denominated the “Triangular Assessment Method” (referred to by its Spanish abbreviation, MTC©). The MTC© aims to make use of the potential of AHP while avoiding some of its drawbacks. The main characteristics and advantages of the MTC© can be summarised as follows: (i) evaluation of criteria, and of the alternative options for each criterion, in trios instead of pairs; (ii) elimination of discrete scales and values involved in judgements; (iii) a substantial reduction in the number of evaluations (trios) relative to the corresponding number of pairs which would have to be considered when applying the AHP method; (iv) consistent decision-making; (v) introduction of closed cyclical series for comparing criteria and alternatives; and (vi) the introduction of opinion vectors and opinion surfaces. This new method is recommended for supporting decision-making with large numbers of subjective criteria and/or alternatives and also for group decisions where the consensus must be evaluated. The MTC© provides a different promising perspective in decision-making and could lead to new research lines in the field of information systems.This work was supported by the Galician Regional Government [“Programa de Consolidación e Estructuración de Unidades de Investigación Competitivas, modalidade de Grupos de Referencia Competitiva” for the period 2006–2017] and by the European Union [ERDF program]. Likewise, the authors thank Daniele de Rigo, Dora Henriques and Cesar Pérez-Cruzado, because his comments improved notably this manuscript.info:eu-repo/semantics/publishedVersio

A Triangular Assessment Method

A Triangular Assessment Method (Research in progress, abbreviated to MTC, from the initials of the Spanish name: Método del Triángulo de Calificaciones) is described. The proposed method is an improvement of the well known Analytic Hierarchy Process (AHP), which is a pairwise comparison technique developed by Saaty and often applied in complex decision making. The MTC basically consists of comparing criteria and alternative levels of each criterion in trios instead of in pairs. This overcomes some of the drawbacks of the AHP, such as the large number of pairs that must be analyzed when there are numerous criteria and alternatives

Nanoporous PMMA: A novel system with different acoustic properties

The acoustic properties of closed cell nanoporous and microporous poly(methyl methacrylate) (PMMA) foams have been well characterized, showing that nanoporous PMMA exhibit a different absorption coefficient and transmission loss behavior in comparison with microporous PMMA. Experimental differences may be explained by the different wave propagation mechanism in the micro and nanoscale, which is determined by the confinement of both the gas (Knudsen regime) and the solid phases. These results place nanoporous materials as a new class of polymeric porous material with potential properties in the field of acoustics, especially in multifunctional systems requiring a certain degree of soundproofing

Self-calibration of neural recording sensors

This paper reports a calibration system for automatically adjusting the bandpass and gain characteristics of programmable E×G sensors. The calibration mechanism of the bandpass characteristic is based on a mixed-signal tuning loop which uses as feedback signal the output of the data converter following the signal conditioning of the E×G sensor. Intended high-pass and low-pass frequency poles of the transfer function are injected into the loop by means of a direct frequency synthesizer followed by a smoothing atenuator.Ministerio de Ciencia e Innovación TEC2012-3363

Risk-Based Framework for the Integration of RPAS in Non-Segregated Airspace

Remotely Piloted Aircraft Systems (RPAS) are new airspace users that require to be safely integrated into the non-segregated airspace. Currently, their integration is planned for the horizon 2025, but there is a lot of pressure by RPAS operators to fly as soon as possible. This research focuses on the development of a risk-based framework for the integration of RPAS in non-segregated airspace. The risk-based framework relies on a hierarchical methodology that is split into two time horizons: design and operation. Different operational and geometrical factors characterise each stage. Then, a set of risk and operational indicators are defined for each stage. These indicators evaluate the operational airspace state and provide information about how the integration of RPAS should be. Primary results provide information about geographical and temporary restrictions. Geographical restrictions refer to the airways that favour or inhibit the integration of RPAS, and temporary restrictions denote the time span when the RPAS can pierce into the airspace

Estudio hidrológico e hidráulico del río Viar en el entorno de Cantillana

Son múltipleslas herramientasde las que dispone un ingeniero a la hora de realizar el modelado hidráulico de una zona inundabley sus efectos. Programasdesarrollados por equipos profesionales,como HEC-RAS, Delft-3D, Iber, etc. permiten al usuario experimentado, establecer, con cierta precisión, los efectos de crecidas del nivel del agua, en el cauce de un río y en las zonas adyacentes a él, debido a procesos naturales y artificiales, así como, establecer efectos que puedan tener la presencia de sedimentos, estructuras y otros elementos en estos procesos.Ante la amplia variedad de opciones, a fin de establecer algunos criterios ante el planteamiento de estas cuestiones, este documento desarrolla el modelado de la zona correspondiente al río Viar a su paso por el municipio de Cantillana con varios softwares (Delft-3D, HEC-RAS 2D y HEC-RAS 1D). Para ello, se realizará un estudio hidrológico de la zona correspondiente a la cuenca del río Viar, mediante diferentes métodos, estableciendo lasituación más desfavorable, y posteriormente se realizarán los modelos propuestos en los programas anteriormente mencionados, estableciendo variantes dentro de la modelización de los mismos, con el objeto de establecer la influencia de las distintas formas de modelado dentro de los cálculos numéricos realizados por estos. Así mismo, seestableceráuna comparativa entre los distintos modelospropuestos,con el fin de esclarecer la idoneidad de cada uno para una mismacasuística propuesta, así como, establecer el tratamiento que cada uno da a las distintas características del terreno, aplicación de las modelos de cálculo, eficiencia computacional,tratamiento de los datos de entrada, etc.El objetivo final de este Trabajo de Fin de Grado consiste en, realizar un análisisde los resultados obtenidosde los modelosrealizadosy através de su comparativa, establecer ydisponer de unas pautas que establezcan,la relevancia de las distintas modelizaciones y parámetros escogidos,para el modelaje de la zona de estudio dentro del trabajorealizado y el grado de influencia de estos sobre los modelos numéricos estudiados.There are multiple tools available to an engineer when performing hydraulic modeling of a flood zone and its effects. Programs developed by professional teams, such as HEC-RAS, Delft-3D, Iber, etc. allow the experienced user to establish, with certain precision, the effects of flooding of the water level, in the riverbed and in the adjacent areas to it, due to natural and artificial processes, as well as, to establish effects that can have the presence of sediments, structures and other elements in these processes.In view of the wide variety of options, toestablish some criteria to deal with these issues, this document develops the modeling of the area corresponding to the Viar river as it passes through the municipality of Cantillana with several software (Delft-3D, HEC-RAS 2D and HEC-RAS 1D). For this purpose, a hydrological study of the area corresponding to the Viar river basin will be carried out using different methods, establishing the most unfavorablesituation, and subsequently the models proposed in the programswill be made, establishing variants within the modelling of these, with theaim of establishing the influence of the different forms of modelling within the numerical calculations made by these. Likewise, a comparison between the different models proposed will be established, toclarify the suitability of each one for the same proposed case, as well as to establish the treatment that each one gives to the different characteristics of the terrain, application of the calculation models, computational efficiency, treatment of the input data, etc. The final objective of this End of Degree Work is to analyze the results obtained from the models. Through its comparison, to establish and have some guidelines that establish the relevance of the different models and parameters chosen for the modeling of the study area within the work doneand the degree of influence of these on the numerical models studied.Universidad de Sevilla. Grado en Ingeniería Civi