Jorge Castiñeira Moreira

Simulation of a non-invasive glucometer based on a microwave resonator sensor

In this paper a simulation of a microwave resonator sensor for constructing a non-invasive blood glucose meter is presented. A relationship between changes of the dielectric permittivity of the blood and the frequency response of S parameters of the sensor is observed. This can lead to a measuring procedure in which the glucose level present has a correlation with the value of the frequency resonance of the sensor. The test bank consists of a planar spiral microwave resonator over which the individual under test places his/her finger. This modifies the initial frequency resonance of the resonator because of the change produced in the measuring procedure over the dielectric permittivity of the resonator. Simulations show a correlation between dielectric permittivity blood changes, and changes in the value of the frequency resonance, in the frequency response of S parameters of the resonator.

A development and implementation of a tinnitus treatment method

Tinnitus is a physiological phenomenon where a person listens sounds which have not been generated by any external source. Today, many people suffer this condition. Although, in very few cases therapeutic methods completely eliminate tinnitus, it is possible to apply a variety of techniques to improve the quality of life of people with this condition. One of the most used methods to treat tinnitus consists of masking the tinnitus using an external sound. The main goal of this work is to present the development of a tinnitus treatment method, which optimizes the synthesized sounds in order to improve the lifes quality of the user. Subjective tests and experimental results are used to analyze the performance of the method.

Noise generator for tinnitus treatment based on look-up tables

Treatment of tinnitus by means of masking sounds allows to obtain a significant improve of the quality of life of the individual that suffer that condition. In view of that, it is possible to develop noise synthesizers based on random number generators in digital signal processors (DSP), which are used in almost any digital hearing aid devices. DSP architecture have limitations to implement a pseudo random number generator, due to it, the noise statistics can be not as good as expectations. In this paper, a technique to generate additive white gaussian noise (AWGN) or other types of filtered noise using coefficients stored in program memory of the DSP is proposed. Also, an implementation of the technique is carried out on a dsPIC from Microchip®. Objective experiments and experimental measurements are performed to analyze the proposed technique.

Soft Distance Metric Decoding of Polar Codes

In this paper, we implement the Successive Cancellation SC decoding algorithm for Polar Codes by using Euclidean distance estimates as the metric of the algorithm. This implies conversion of the classic statistical recursive expressions of the SC decoder into a suitable form, adapting them to the proposed metric, and properly expressing the initialization values for this metric. This leads to a simplified version of the logarithmic SC decoder, which offers the advantage that the algorithm can be directly initialised with the values of the received channel samples. Simulations of the BER performance of the SC decoder, using both the classic statistical metrics, and the proposed Euclidean distance metric, show that there is no significant loss in BER performance for the proposed method in comparison with the classic implementation. Calculations are simplified at the initialization step of the algorithm, since neither is there a need to know the noise power variance of the channel, nor to perform complex and costly mathematical operations like exponentiations, quotients and products at that step. This complexity reduction is especially important for practical implementations of the SC decoding algorithm in programmable logic technology like Field Programmable Gate Arrays FPGAs.