Hardeep Singh Ryait

Interpretations of Wrist/Grip Operations From SEMG Signals at Different Locations on Arm

Surface electromyogram (SEMG) is a common method of measurement of muscle activity. It is noninvasive and is measured with minimal risk to the subject. The analysis of SEMG signal depends on a number of factors, such as amplitude as well as time- and frequency-domain properties. In the present investigation, the study of SEMG signals at different below elbow muscles for four operations of the hand wrist/grip-like opening (op)/closing (cl)/down (d)/up (u) was carried out. Myoelectric signals were extracted by using a single-channel SEMG amplifier consisting of a differential amplifier, noninverting amplifier, and interface module. Matlab softscope was used to acquire the SEMG signal from the hardware. After acquiring the data from six selected locations, interpretations were made for the estimation of parameters of the SEMG using the Matlab-filter algorithm and the fast Fourier transform technique. An interpretation of wrist/grip operations using principal component analysis (PCA) was carried out. PCA was used to identify the best SEMG signal capturing system out of two-channel, three-channel, and four-channel systems. Two acupressure points (on wrist) were also selected for the analysis with other points on the arm. SEMG signals study at different locations, including pressure points, will be a very helpful tool for the researchers in understanding the behavior of SEMG for the development of the prosthetic hand.

Study of issues in the development of surface EMG controlled human hand.

In the process of improvement of prosthetic devices, there have been efforts to develop satisfactorily working artificial hands but still lots of work is to be done to meet the accuracy and requirements of the human hand movement. The EMG signal has been most promising signal in development of artificial limbs. The present review paper gives the historical developments in three main sections. First part describes the EMG signal properties. Second part deals with the mathematical models developed till now for EMG signal analysis. In the third part different design approaches have been reviewed for artificial hand. First approach discussed here is on the body-powered terminal devices which are controlled by the user’s pull on the control cable to open the hand or hook and for the grip strength. Other being myoelectric controls type, an externally-powered system which uses electrical impulses, generated by contraction of the amputees own remaining muscles to operate a motor in a mechanical hand, hook or elbow. This paper presents a brief overview of above mentioned issues with regard to artificial hands.

SEMG signal analysis at acupressure points for elbow movement

Surface electromyography signals (SEMG) are the most common form of non-invasive-measurement of muscle activities. To acquire proper SEMG for particular limb function, the placement of electrodes on the skin over respective active group of muscles becomes very important. Measurement of SEMG depends on a number of factors/parameters like amplitude, time and frequency domain properties. In the present investigation, analysis was carried firstly; to study the grip force vs. SEMG parameters at acupressure points on arm, using single channel approach. At all the selected acupressure points a linear increment of SEMG was observed. Secondly; to discriminate four elbow movements from different locations on arm using two channel approach with single parameter. The parameter for the analysis chosen was the root of mean of square (RMS) value of SEMG. Further; principal component analysis was used to verify the elbow movement discrimination. Extension and supination were the two operations which were observed to be easy to realize by prosthetic devices. The selection of these locations was done on the basis of acupressure points and anatomy of elbow. Matlab-softscope was used for acquiring the SEMG from line-in input port of PC-sound card. This study will also be helpful for the researchers in understanding the behavior of SEMG for elbow movement in development of prosthetic or exoskeleton devices.

A novel algorithm to predict knee angle from EMG signals for controlling a lower limb exoskeleton

This paper presents an algorithm for estimation of the intended knee joint angle from sEMG signals acquired from four muscles of upper limb. The algorithm was evaluated by experiments showing the calculated intended motion while performing a simple daily life activity of sitting in a squat position and standing from a squat position. The proposed algorithm uses Mean Absolute Value (MAV) and Root Mean square (RMS) as features and a multi-layer Back Propagation Neural Network (BPN) for predicting the knee angle. Proposed algorithm along with the experimental results are presented. The predicted knee angle can be used to control a lower limb exoskeleton.

Realisation of SEMG-based multifunctional prototype elbow prosthesis

Prosthetic devices employing myoelectric control systems are now widely accepted by upper-limb-deficient individuals. However, such devices are successfully fitted to below-elbow amputees to control a single function-opening or closing a prosthetic hand. In above-elbow amputees, the multifunctional control of artificial prosthetic device using myoelectric signals is of major importance. In this work, RMS value (Vrms) of SEMG was used to realise microcontroller-based artificial elbow. Microcontroller-based artificial elbow was designed to carter four elbow operations, i.e., elbow flexion, extension, pronation and supination movements. Myoelectric signals were recorded using Ag-AgCl surface electrodes from biceps and triceps branchii. A prototype was developed with control from single-channel and two-channel approaches.

Analyzing DWDM System with Different Modulation Formats and Channel Spacing

Abstract Different modulation formats for 64×20-GB/s dense wavelength division multiplexed (DWDM) system has been compared and simulated using Optsim. Various performance parameters including Q-factor, bit error rate, jitter, eye opening & eye closure are observed and analyzed. It is reported that RZ Soliton format is a better choice among the tested formats. Also, for the proposed system, minimum channel spacing should be 50 GHz.

Investigations of Different Amplifiers in 16 × 40 Gb/S WDM System

Abstract Different fiber amplifiers such as semiconductor optical amplifier, erbium-doped fiber amplifier and erbium ytterbium-co-doped fiber amplifier (EYCDFA) are investigated for 16×40 GB/s wavelength division multiplexing system. Various performance parameters including Q-factor, bit error rate, jitter, eye opening and eye closure are observed and analyzed. It is reported that EYCDFA is a better choice among the tested amplifiers. The proposed system is also investigated in terms of transmission distance.

Combating/eliminating dispersion-induced fading using suppressed carrier link for OFDM signal

ABSTRACT We investigate the performance of 20-GHz radio over fibre (RoF) system having orthogonal frequency division multiplexed (OFDM) as radio signal using two modulation techniques – balanced detection for intensity modulation direct detection (IMDD) and coherent heterodyne detection suppressed carrier (SC) modulation. Dispersion-induced power fading is seen in conventional IMDD links due to the dependence of dispersion over frequency-dependent refractive index of the fibre. SC link is seen to compensate the power fading by terminating the direct current and even-order harmonics with the suppression of carrier along with balanced detection.

Simulative analysis of different modulation formats for RoF Transmission System

Abstract This paper has represented the operating conditions for radio-over-fiber (RoF) transmission system such as Q factor, received optical power and BER at different fiber lengths. This paper also investigated optical loss, optical power spectrum and electrical power spectrum at different frequencies for different modulation formats and optical loss at different radio frequencies for varying fiber length.

Performance Analysis of Different Modulation Formats in Optical Communication

Abstract In this paper, we demonstrated the variation of different parameters with quadrature amplitude modulation (QAM) and differential phase shift key (DPSK) sequence generator, which generates modulated signals, in data transmission for communication and analysed that how the difference of these sequence generators effect its resonant frequency (RF) value, eye diagram and electrical constellation representation of the system.