Noreha Abdul Malik

High quality acquisition of surface electromyography – conditioning circuit design

The acquisition of Surface Electromyography (SEMG) signals is used for many applications including the diagnosis of neuromuscular diseases, and prosthesis control. The diagnostic quality of the SEMG signal is highly dependent on the conditioning circuit of the SEMG acquisition system. This paper presents the design of an SEMG conditioning circuit that can guarantee to collect high quality signal with high SNR such that it is immune to environmental noise. The conditioning circuit consists of four stages; consisting of an instrumentation amplifier that is used with a gain of around 250; 4th order band pass filter in the 20–500Hz frequency range as the two initial stages. The third stage is an amplifier with adjustable gain using a variable resistance; the gain could be changed from 1000 to 50000. In the final stage the signal is translated to meet the input requirements of data acquisition device or the ADC. Acquisition of accurate signals allows it to be analyzed for extracting the required characteristic features for medical and clinical applications. According to the experimental results, the value of SNR for collected signal is 52.4 dB which is higher than the commercial system, the power spectrum density (PSD) graph is also presented and it shows that the filter has eliminated the noise below 20 Hz.

Penetration Testing using Kali Linux: SQL Injection, XSS, Wordpres, and WPA2 Attacks

Applied Computing Technology (ACT), Universiti Tun Hussein Onn Malaysia (UTHM), Parit Raja, Batu Pahat, 86400 Johor, Malaysia. Faculty of Computer Science and Information Technology, Universiti Tun Hussein Onn Malaysia (UTHM), Parit Raja, Batu Pahat, 86400 Johor, Malaysia. Department of Management Information Systems, College of Commerce and Business Administrations, Dhofar University, Salalah, Oman.

Posture Characterization Based on Time and Frequency Domain Parameters for Erector Spine SEMG Signal

This work is based on obtaining surface EMG signals from lower back muscles using a data logger by Pico Log technology. The electrodes used are Ag/AgCl and applied after a clean surface washing by alcohol of erector spine muscle for a subject under two posture conditions. The conditioning circuit used in this paper is selectively choosing the 20-500Hz dominant frequency range and 0.4 to 2.4 Volts in amplitude. The data on signals are transported onto a PC into Excel file for processing its FFT representative of the target posture condition. The bow condition shows four times larger in magnitude of FFT compared to that of standing condition over a similar frequency range of 50-220Hz. The utility of the conditioning circuit is justified by reducing the power frequency noise to negligible level. The utility of this research work has potential in clinical diagnostic applications.

Acquisition of a Very Low Voltage and a Low Frequency Biomedical Signal - Frequency Selective Filter Design

In this paper we present a review on the frequency content and voltage level in biomedical signals beside showing how extraction of chosen features and parameters from these signals, are important for many medical diagnostic applications. A 4th order band-pass filter using high and low-pass Sallen Key active filters are proposed, and the values of passive component for different biomedical filters have been provided. The circuits are simulated and the frequency response is shown. The power spectrum density (PSD) of an EMG signals is presented where it becomes clear that the PSD graph can provide the value of the bandwidth for the signal of interest. The response of the filter is validated and the utility of the conditioning circuit is testified.

Performance characterization of inductive coupling system

The use of biomedical implants has been on the rise over the recent past years and this use is expected to increase exponentially over the comings years. Such devices are becoming the most feasible interface to monitor the betrothed parameters. Biomedical implants usually require a low input voltage which is provided making use of inductive coupling. Inductive coupling not only solves the powering issue but also helps to collect the data through non-invasive means. Power transfer efficiency of an inductive link system depends upon factors like mutual coupling, separation between the coils and most importantly the shape of the input voltage. The power transferred or signal received as a result of coil separation under optimum size conditions are reported in contemporary works. This paper comes is testing the effect of different shaped input voltages on the performance of inductive coupling system in terms of power transfer efficiency. Circuits have been tested for three different types of input waveforms of sine, square and ramp. Comparison of plots shows that the shape of input plays a major role on the entire performance of inductive coupling system.

Inductive Loops for Sensing Position as Signature Signals

In this paper, an inductive sensing technique made of a special shaped inductive loop is proposed. The inductive loop has an inner turn fitted within an outer turn, making a total inductance value 100μH. This loop is made to be shown with balanced response using three capacitance values of 0.068μF each when a sinusoidal voltage source of 5V peak-to-peak is applied. The variation of the relative permeability of the inductance of the inductive loop (AL) results in a variation of the overall inductance value (L+AL), that causes the output signal to change in term of shape and amplitude for variation of total inductance sweep over a given period of time. As a result of change in inductance value (lμH) there is a correspondence increase of 300mV. Theoretical derivations have showed in close agreement with the simulation plots obtained using Multisim software.