Icaro dos Santos

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We measured specific heat directly by heating a sample uniformly between two electrodes by an electric generator. We minimized heat loss by styrofoam insulation. We measured temperature from multiple thermocouples at temperatures from 25 degrees C to 80 degrees C while heating the sample, and corrected for heat loss. We confirm method accuracy with a 2.5%(More)
BACKGROUND One of the current shortcomings of radiofrequency (RF) tumor ablation is its limited performance in regions close to large blood vessels, resulting in high recurrence rates at these locations. Computer models have been used to determine tissue temperatures during tumor ablation procedures. To simulate large vessels, either constant wall(More)
We measured the specific heat of liver tissue in vitro by uniformly heating liver samples between two electrodes. We insulated the samples by expanded polystyrene, and corrected for heat loss and water loss. The specific heat of the liver is temperature-dependent, and increases by 17% at 83.5 degrees C (p < 0.05), compared to temperatures below 65 degrees(More)
This article describes the design of a microcontrolled bioinstrumentation system for active control of leg prostheses, using 4-channel electromyographic signal (EMG) detection and a single-channel electrogoniometer. The system is part of a control and instrumentation architecture in which a master processor controls the tasks of slave microcontrollers,(More)
The objective of this work was the study and the development of techniques for acquiring and processing electromyographic signals that can be used for analysis of the behavior of electromyographic variables during fatiguing dynamic activities. Two of the techniques were the RMS value and the MPF, which are commonly used for the analysis of electromyographic(More)
This paper presents a myoelectric knee joint angle estimation algorithm for control of active transfemoral prostheses, based on feature extraction and pattern classification. The feature extraction stage uses a combination of time domain and frequency domain methods (entropy of myoelectric signals and cepstral coefficients, respectively). Additionally, the(More)
Ablative therapies such as radio-frequency (RF) ablation are increasingly used for treatment of tumours in liver and other organs. Often large vessels limit the extent of the thermal lesion, and cancer cells close to the vessel survive resulting in local tumour recurrence. Accurate estimates of the heat convection coefficient h for large vessels will help(More)
Thermodilution is widely used to measure cardiac output, ejection fraction and end diastolic volume. Even though the method is based on dynamic temperature measurements, little attention has been paid to the characterization of the dynamic behavior of the temperature sensor and to its influence on the accuracy of the method. This paper presents several(More)
Spatial filtering has become a common way to improve the resolution of surface electromyographic signals (SEMG) when used in connection with electrode arrays. The goal of this study is to observe the behavior of S-EMG amplitude and spectral descriptors when signals are submitted to a longitudinal quadruple differentiating spatial filter. Signals were(More)
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