Department of Electrical Engineering

Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

This work introduces a monopole antenna based on metamaterials for breast cancer identification. The put forward antenna is built on an FR4 substrate with a dielectric constant of 4.4, loss tangent 0.025 and thickness of 1.6 mm. For gain enhancement, the designed antenna is equipped with a frequency selective surface (FSS) on its back side. The suggested antenna obtains a broad bandwidth (S11 > 10 dB) between 2.3 and 22.3 GHz, with a apex gain of 9.3 dBi at 12 GHz. The put forward work also achieves a maximum gain enhancement of 5 dBi with the addition of FSS at the back side of the antenna. The Specific absorption Rate (SAR) study of the antenna with a realistic homogeneous breast phantom modelled in the simulator is performed to assess the effect of radiation on the breast. It is observed that the suggested antenna agrees with the International limits when averaged over 1g of tissue. © 2023 IEEE.

World University root node

2nd International Conference on Wireless, Antenna and Microwave Symposium, WAMS 2023

Monopole Antenna with Frequency Selective Surface for Microwave Breast Cancer Detection

Underwater acoustical 3D imaging is popular for underwater investigations due to its ability to give all the geometric information of the target. The computational complexity of the conventional time domain delay and sum beamforming (DAS) is a bottle neck for the real-time implementation of the acoustical 3D imaging. Many fast-beamforming techniques in frequency domain such as Chirp Zeta Transform beamforming (CZT) have been proposed to solve this problem. However, wideband pulse transmission for high resolution imaging makes frequency domain methods infeasible for the 3D acoustical imaging. In this work, we attempted to implement time domain delay and sum beamforming using software interpolation and compare it with the CZT beamforming. The simulation results show that software implementation of digital delay and sum beamforming is faster than CZT beamforming.

A Comparison of Time Domain Delay and Sum Beamforming and Chirp Zeta Transform Beamforming for Underwater 3D Acoustical Imaging

Photoplethysmography (PPG) signals play an important role for automatic measurement of pulse rate, blood pressure, non-invasive blood glucose level and respiration rate. Most of the PPG monitoring devices are prone to motion artifacts and noises under different PPG recording conditions. Thus, automatic assessment of PPG signal quality is most essential for discarding unacceptable PPG signals and reducing false alarms due to the noisy measurements. This paper presents a new PPG signal quality assessment (SQA) method by using the average degree feature extracted from the horizontal visibility graph (HVG) of the PPG signal and six different classifiers such as random forest (RF), Naive Bayes (NB), decision tree (DT), support vector machine (SVM), multilayer perceptron (MLP), convolutional neural network (CNN). On a wide variety of standard databases, evaluation results show that the CNN based SQA method had an overall accuracy of 99.24% that outperforms other five SQA methods in terms of overall accuracy. The NB based SQA method had an accuracy of 99.21% with lower memory space of 1 kB as compared to other SQA methods. © 2023 IEEE.

15th International Conference on Electronics, Computers and Artificial Intelligence, ECAI 2023 - Proceedings

Graph Signal Processing Based Classification of Noisy and Clean PPG Signals Using Machine Learning Classifiers for Intelligent Health Monitor

By considering the resource-constrained affordable wearable or portable health monitoring devices, in this paper, we present a lightweight digital compressed ECG sensing with recognition of fast/slow and regular/irregular heartbeat patterns by using beat-to-beat intervals (BBIs) directly computed from compressed sensing (CS) measurements without ECG reconstruction process. For extracting BBIs, we presented a fast straightforward R-peak detection method in the CS domain without using sets of search-back detection rules unlike other methods. On the standard MIT-BIH arrhythmia database, the CS-ECG based R-peak detection method had an average accuracy of 99.47% with false positives of 381 beats and false negatives of 195 beats for a total of 109021 beats. The CS-ECG based HR classification method, with three classes of bradycardia, tachycardia and normal, had an accuracy of 96.75%, 91.18% and 99.02% based on the feature of number of BBIs and an accuracy of 95.64%, 82.35% and 98.81% based on the feature of average BBIs. The CS-ECG based regular/irregular rhythm (RIR) recognition method had a sensitivity (SE) of 93.17%, specificity (SP) of 96.87% and accuracy (ACC) of 94.83% based on the variation between the BBIs that are determined by comparing the difference between the successive BBIs with a predefined BBI threshold. The proposed method can reduce computational resources and energy reduction of 75% with the CS-based data reduction factor of 4 that has a great potential in energy-efficiency of battery operated wearable devices in long-term continuous health monitoring environments. © 2023 IEEE.

Compressed ECG Sensing Based Fast/Slow HR and Regular/Irregular Rhythm Recognition for Resource-Constrained Health Monitoring Devices

Electrocardiogram (ECG) derived heart rate variability (HRV) analysis is widely used in both physiological and psychological monitoring. For HRV analysis, an automatic R-peak to R-peak interval (RRI) determination is most essential and that is performed by processing the ECG signal. Continuous HRV analysis is most essential for predicting health problems and stress levels, but HRV analysis devices are restricted with limited battery capacity. To increase the battery lifetime of monitoring devices, we present a simple energy-efficient R-peak detection approach by directly processing a few compressive measurements instead of processing the ECG signal sampled at the Nyquist rate. The proposed CS-ECG based HRV analysis method consists of: compressed sensing (CS) based data reduction, straightforward RRI determination without the use of searchback algorithm with sets of thresholds and the HRV parameter estimation. The accuracy and robustness of CS-ECG based time-domain HRV index extraction (7 HRV indexes) is evaluated using the MIT-BIH arrhythmia database, MIT-BIH polysomnographic database (slpdb) and Apnea-ECG database. Evaluation results show that the estimated HRV parameters from RR intervals in the CS domain are comparable with the HRV parameters estimated from the RR intervals extracted from the uncompressed ECG signal. Using deterministic binary block diagonal (DBBD) based measurement generation with a compression factor of 4, the CS-ECG based RRI determination can reduce computational resources by 75% without significant estimation error. Thus, the CS-ECG based HRV analysis method has potential to reduce overall energy consumption, memory space and processing time by a factor of 4 as compared to the HRV analysis method with an uncompressed ECG signal. © 2023 IEEE.

ICSIMA 2023 - 9th IEEE International Conference on Smart Instrumentation, Measurement and Applications

Lightweight Time-Domain HRV Index Extraction from Compressive ECG Measurements for Resource Constrained Edge Health Computing Devices

The Internet of Things (IoT) enabled photoplethys-mogram (PPG) monitoring devices have gained more attention for understanding the initial health status, remotely monitoring health parameters over time and getting valuable clinical in-formation anytime, anywhere. Continuous transmission of PPG data wirelessly consumes a significant amount of energy, which is one of the constraints of battery-operated IoT devices. In this paper, we present a lightweight quality-aware waveform change detection (QA-WCD) method for enabling event-triggered communication protocol that can maximize the lifetime of connected devices. The QA-WCD method consists of preprocessing, Fourier transform (FT) based noise suppression and pulse rate (PR) estimation, onset-peak detection using derivative PPG (dPPG) and waveform change detection with five decision rules. On three standard databases, the proposed QA-WCD method achieves promising results in detecting waveform changes segment-wise and cycle-wise using the proposed PPG parameters. Evaluation results show that the method had a sensitivity and specificity of 100% in detecting cycle changes (CCs) and no cycle changes (NoCCs), respectively for the PPG signals with less prominent diastolic wave portions. The QA-WCD based data transmission protocol can increase the service lifetime of IoT devices and re-duce network/server traffic in remote personal health monitoring with huge IoT devices connected with health service providers. © 2023 IEEE.

2023 11th International Conference on Control, Mechatronics and Automation, ICCMA 2023

Lightweight Photoplethysmogram Waveform Change Detection for Resource-Constrained IoT Enabled Remote Health Monitoring Devices

This paper presents a novel time-domain clutter removal algorithm for microwave imaging of concealed objects using a new high gain ultra-wideband (UWB) antipodal antenna. Bistatic antenna setup is employed to image the objects like a gun prototype, knife and blade using UWB Gaussian modulated pulses. A synthetic aperture radar (SAR) beamforming algorithm with a new clutter removal method is adopted for microwave imaging of the objects inside and outside the anechoic chamber. The proposed algorithm successfully removes the unwanted clutter from the measured scanning data, with only single scanning of the target area. The proposed method along with windowing, envelope detection and finally image reconstruction results in effective reconstruction of the concealed target as compared to the existing methods in the literature. An UWB high gain antipodal antenna is designed for the proposed imaging setup with a peak gain of 26 dBi at 8.4 GHz, which is the highest among previously reported UWB antennas. The proposed antenna achieves a wide gain bandwidth over 6-14 GHz (80%) with a gain of >18 dBi. Simulation and measured results validate the design principle of the antenna with characteristics like high front to back ratio, narrow half-power beam width, and low cross-polarization. In the opinion of the authors, the proposed clutter removal algorithm is the simplest and effective method for single-time scanning of the concealed targets, in a realistic scenario. © 2015 IEEE.

IEEE Transactions on Computational Imaging

Microwave Imaging with Novel Time-Domain Clutter Removal Algorithm Using High Gain Antennas for Concealed Object Detections

Increase in the deployment levels of inverter-interfaced renewable energy resources (IIRERs) in the existing power systems have increased concerns among the protection engineers regarding the reliable operation of classical protection schemes presently existing in the system. This paper aims to do a comprehensive performance evaluation of directional relaying philosophies. In this regard, both the inverter control scheme along with the sequence based directional relaying schemes (SBDRS) are modeled in detail in PSCAD environment. The unpredictability observed in the values of sequence component contributions from IIRERs during faults have led to the mal-operations of SBDRS to correctly identify the direction of fault. A comparative assessment of the performance of SBDRS have been done considering contributions from conventional generators and IIRERs, in the presence and absence of grid codes. The performance of positive sequence based directional relaying scheme improves with the inclusion of grid codes with inverter control used being positive sequence current control. The performance of negative sequence based directional relaying scheme mal-operates whereas the performance of zero sequence based directional relaying scheme is dependent on interconnecting transformer connection and type of fault. © 2023 IEEE.

2023 2nd International Conference for Innovation in Technology, INOCON 2023

A Comprehensive Performance Evaluation of Sequence Component based Directional Relaying Philosophies for Inverter Integrated Power System

This letter proposes a technique for estimating the damping ratio and frequency of oscillatory modes with high accuracy. Traditional linear techniques such as the Prony Analysis (PA), matrix pencil (MP) method and Eigensystem realization algorithms (ERAs) are used to accurately estimate the damping ratio and damped frequency of the oscillatory modes through a window selection algorithm. The letter ensures the best damped (positive or negative) sinusoid representation of the modal components of the oscillatory power signals observed by the phasor measurement unit (PMU) through the consensus of traditional linear techniques applied to various scenarios from Kundur two-area system, ISO-NE and WECC 179 bus system. © 1963-2012 IEEE.

IEEE Transactions on Instrumentation and Measurement

Linear Estimation of Low-Frequency Modal Oscillations Parameters Through Nonlinear Characterization

This article evaluates the performance of a signal similarity index (SSI) based relaying scheme for fault detection in lines connected to inverter-based resources (IBRs). During fault events, the IBRs respond differently than conventional synchronous machine based sources. Due to various control schemes and power electronic protection implemented for IBRs, fault current is limited leading to failure in fault detection and isolation by traditional protection methods. In this article, six different SSIs are calculated using time-domain current signals at both the ends of the protected line and the performance of SSI-based line protection philosophy is evaluated for various operating conditions. The relaying schemes are extensively tested on two different test systems. The test results are utilized to perform a comparative assessment of the SSI-based protection scheme. The tradeoff between the performance of the relaying scheme based on processing time, fault resistance, threshold selection, presence of noise and presence of missing data are demonstrated thoroughly on three different test systems. © 2007-2012 IEEE.