Showing papers by "Narula Institute of Technology published in 2021"

Hexagonal fuzzy number and its distinctive representation, ranking, defuzzification technique and application in production inventory management problem

Abstract: In this article, we envisage the hexagonal number from various distinct rational perspectives and viewpoints to give it a look of a conundrum. Hexagonal fuzzy number is used as an authoritative logic to ease understanding of vagueness information. This article portrays an impression of different representation, ranking, defuzzification and application of hexagonal fuzzy number. Additionally, disjunctive types of linear and nonlinear hexagonal fuzzy numbers both with symmetry and asymmetry are addressed here along with its graphical representation. Further, a new ranking method is established and two different kinds of approaches to computing the defuzzification of hexagonal fuzzy number are fabricated in this research arena. Finally, one production inventory management problem has been analyzed and solved in the hexagonal fuzzy environment along with the numerical sensitivity analysis tables. This real-life problem plays a crucial role to demonstrate the effectiveness of this method compared to the usual results in crisps environment. This noble thought will help us to solve a plethora of daily-life problems in uncertainty arena.

Different linear and non-linear form of trapezoidal neutrosophic numbers, de-neutrosophication techniques and its application in time-cost optimization technique, sequencing problem

Abstract: In this research article, we envisage the neutrosophic number from various distinct rational perspectives & viewpoints to give it a look of a conundrum. We focused & analysed various types of linear and non-linear generalized trapezoidal neutrosophic numbers which serves an indispensable role for uncertainty concept related problem. We also introduce the idea of de-neutrosofication for trapezoidal neutrosophic number using an influx of different logical & innovative methods by which we move with a manifesto to convert a neutrosophic number into a crisp number. Using this concept of de-neutrosophication, we analyze some real-life problem like networking Crash model problem and job-sequencing problem of operation research field when the numbers are in trapezoidal neutrosophic ambience. We also compare our specified result with previously defined score and accuracy function and try to present some interesting and better result without any possible fiasco. This noble thought will help us to solve a plethora of daily life problems in neutrosophic arena.

III–V super-lattice SPST/SPMT pin switches for THz communication: theoretical reliability and experimental feasibility studies

Abstract: A physics-based Quantum-Modified CLassical Drift–Diffusion (QMCLDD) non-linear mathematical model has been developed for design and characterisation of GaN/AlGaN asymmetrical superlattice pin based single-pole single-throw (SPST) and single-pole multi-throw (SPMT) switches for sub-MM wave communication systems The simulator has incorporated several important physical phenomena that arise in superlattice structure, including quantum confinement effects, generation-recombination and tunnelling generation of carriers as well as scattering limited carrier mobility and velocity in GaN/AlGaN structure In order to reduce the dislocation density and in turn the series resistance in GaN/AlGaN heterostructure, thin AlN nucleation layer and a buffer layer are considered in the simulation It is observed that the RF series resistance of the pin device, operating around 02 THz frequency regime, reduces in case of proposed superlattice structure The advantages of super-lattice pin diode over the conventional Si devices are the faster reverse recovery time (~ 9 vs 35 ns) and lowering of forward RF series resistances (039 vs 120 Ω) This study also reveals that SPST and SPMT switches made up with super-lattice devices are characterized by low insertion loss (~ 013 and 015 dB, respectively) and high isolation (~ 654 and 825 dB, respectively) A good agreement between theory and experiment establishes the superiority of the present model over the others A comparative analysis of Si and GaN/AlGaN super-lattice pin SPST and SPMT switches establishes the potential of the later for its application in high-frequency THz-communication In addition to this, a detailed thermal modelling of the device has also been done to make the analysis more realistic The junction temperature of the designed GaN/AlGaN superlattice pin switch will be as high as 377 K, which is quite moderate compared to its flat profile counterpart To the best of authors’ knowledge, this is the first ever report on QMCLDD non-linear modelling of pin SPST and SPMT switches (series-shunt combination) at THz-arena

Design and characterization of asymetrical super-lattice Si/4H-SiC pin photo diode array: a potential opto-sensor for future applications in bio-medical domain

Abstract: Photo-sensors are integral part of different bio-medical diagnostic equipment. Each type of bio-molecules possess unique spectral fingerprint in visible wavelength region of electro-magnetic spectrum. Now-a-days, the enhancement of quantum-efficiency and photo-responsivity of such bio-medical opto-sensors, for accurate identification of virus/anti-bodies in blood by optical means, is a big challenge to medical-device Engineers. The authors have addressed this issue in this research paper by proposing a novel structure of asymmetrical Si/4H-SiC super-lattice pin diode array for the development of high-sensitive visible light (300–800 nm) sensor on native substrate. The simulation experiment is carried out by developing a generalized large-signal quantum modified drift–diffusion simulator incorporating three different modes of carrier generation-recombination under light and dark conditions: avalanching, tunneling and photo-irradiation. The validity of the model has been established by comparing the simulation results with those of experimental observations. A good agreement between theory and experiment, under similar biasing conditions, establishes the validity of the developed model. The characteristics analysis depicts that the quantum efficiency of the designed single photo-sensor is ~ 65% within 400–700 nm wavelength region, whereas, the same enhances to nearly ~ 90% with a 3 × 3 photo-sensor array based on asymmetrical super-lattice single pin devices. In visible wavelength region, the simulated photo-sensors (both single and array) have demonstrated significant photo responsivity. The photo-responsivity values, at 500 nm wavelength of incident radiation, are observed to be 0.65 A/W for a single photo-diode and 0.85 A/W for a 3 × 3 combination of photo-diode array. This clearly establishes the potentiality of the asymmetrical super-lattice pin-array as a visible photo-sensor for future application in developing medical instruments. A comparative analysis of Si and Si/4H-SiC asymmetrical super-lattice photo-sensors establishes the superiority of the later as a high-sensitive visible light-sensor in terms of better photo-responsivity and quantum efficiency. To the best of authors’ knowledge, this is the first report on Si/4H-SiC super-lattice pin photo-sensor array in the visible range of optical irradiation. The experimental feasibility of the device and a proposed circuit for future bio-medical implementation are also incorporated in the present research-paper for further development.

Classification of trapezoidal bipolar neutrosophic number, de-bipolarization technique and its execution in cloud service-based MCGDM problem

Abstract: Neutrosophic set can deal with the uncertainties related to the information of any decision making problem in real life scenarios, where fuzzy set may fail to handle those uncertainties properly. In this study, we present the perception of trapezoidal bipolar neutrosophic numbers and its classification in different frame. We introduce the idea of disjunctive structures of trapezoidal bipolar neutrosophic numbers namely type-1 trapezoidal bipolar neutrosophic number, type-2 trapezoidal bipolar neutrosophic numbers, and type-3 trapezoidal bipolar neutrosophic number based on the perception of dependency among membership functions in neutrosophic set. In any neutrosophic decision-making problem, the decision maker uses the comparison of neutrosophic numbers to choose among alternatives solutions. Here, we introduce a ranking method, i.e., De-bipolarization scheme for trapezoidal bipolar neutrosophic number (TrBNN) using removal area technique. We also describe the utility of trapezoidal bipolar neutrosophic number and its appliance in a multi criteria group decision making problem (MCGDM) for distinct users in trapezoidal bipolar arena which is more ethical, precise and reliable in neutrosophic field.

New exponential operational law for measuring pollution attributes in mega-cities based on MCGDM problem with trapezoidal neutrosophic data

Abstract: In the modern era of fuzzy theory, trapezoidal neutrosophic number is an essential tool to seize the ambiguity and inaccuracy of many real-life problems. In this article, exponential operational law has been defined for trapezoidal neutrosophic numbers where the base is a positive real number and the corresponding weight is a trapezoidal neutrosophic number. The different algebraic properties of the said exponential operational law have been studied thoroughly. Two important operators namely trapezoidal neutrosophic weighted exponential arithmetic operator and trapezoidal neutrosophic weighted exponential geometric operator have been constructed by utilizing the said exponential operational law and its corresponding algebraic properties. Furthermore, the said aggregation operators are used to manifest a new multi-criteria group decision making technique which has been successfully applied to measure pollution attributes in different mega-cities. Finally, rigorous sensitivity analysis is performed to show the utility of the proposed operational law and manifested multi-criteria group decision making technique.

An IoT-Based Congestion Control Framework for Intelligent Traffic Management System

Abstract: The concept of smart city helps to improve the quality of urban life of the citizens while keeping in mind the environmental impacts. Smart and sustainable transportation system is one of the major contributors in order to make the city smart. Major cities around the world face enormous vehicular growth due to socioeconomic growth and rural to urban migration of the people. These results in high traffic congestion on road, road accidents, delay and have an adverse environmental impact, thus effecting smooth mobility of the citizens. Hence, traffic management authorities face difficulties to manage and reduce traffic congestion, road accidents and air pollution. In order to overcome the above-mentioned challenges, this paper proposes a framework for managing road traffic congestion in intelligent traffic management system which utilizes the available infrastructures and resources in an optimum way. The proposed framework comprises of four different modules, namely data collection module, data storage module, data processing module and business application module.

A new approach to evaluate linear programming problem in pentagonal neutrosophic environment

Abstract: In this paper, authors disclose a new concept of pentagonal neutrosophic (PN) approach to solve linear programming (LP) problem. To best of our insight, there is no approach for solving PNLP problem. For the first time, we take up the PNLP problem where the objectives, constraints are considered as pentagonal neutrosophic numbers (PNN). To deign our algorithm, we described the PN arithmetic operation laws and mathematical computation in PNN environment. This proposed method is based on ranking function and convert to its equivalent crisp LP (CrLP) problem. The obtained CrLP issue is presently being tackled by any LP method which is effectively accessible. To legitimize the proposed technique, some numerical tests are given to show the adequacy of the new model.

Cubic versus hexagonal SiC vertical pin SPST/SPDT/SPMT switches for MMW communication systems: a modified quantum drift-diffusion model for switching characteristics analysis

Abstract: A modified quantum drift-diffusion (QDD) model is developed for non-linear analysis of SiC (4H, 6H and 3C polytypes) pin semiconductor diodes at W-band frequency regime. Effects of incorporation of a buffer layer (n-type), in between substrate and low doped active region of the hexagonal (4H and 6H) pin (p++-p+-n−-n-n++) vertical mesa structure is thoroughly studied in this paper for the improvement of MM-wave performance of the single device. Also, a thin layer of Ge has been introduced in between Si substrate and n+ cubic-SiC layer in 3C-SiC pin-device for minimising the lattice mismatch issue in between Si/3C-SiC interface. The comprehensive analysis establish that the forward characteristics, reverse recovery time (1 ns) and breakdown voltage (171 Volt) in case of 4H-SiC device are quite good in comparison to its cubic (3C) and other hexagonal (6H) counterparts, however, the switching characteristics of 3C-SiC pin diode array is comparatively better than its hexagonal counterparts. This observation could be explained in terms of lowest series resistance in 3C-SiC based single pin device that has been achieved by incorporating Ge layer in mesa structure. The authors have made a comparative analysis among SPST, SPDT and SPMT pin switches made up with 4H, 6H and 3C-SiC poly-types. At 94 GHz, W-band central frequency, series resistance in 4H-SiC single device is 0.59 Ω, whereas, the same is much lower (0.27 Ω) in case of 3C-SiC. Insertion loss and isolation in 3C-SiC pin array of switches are found to be 0.18 dB and 38 dB (SPST switch), 0.19 dB and 67 dB (SPDT switch), 0.20 dB and 90 dB (SPMT shunt type switching array) and 0.23 dB and 74 dB (SPMT series-shunt type switching array). This newly proposed QDD model validation is done through comparative studies between experiment and analytical results for 4H-SiC SPST switches in low-frequency Microwave region. The validated QDD model, coupled with PSpice and Comsol Multi-physics simulator, then used for designing of the W-band devices and corresponding switches. However, as far as author’s knowledge is concerned, no experiment is yet done with SiC pin diodes at W-band frequencies, in literature for comparison. From simulation point of view also such an extensive study on hexagonal and cubic SiC pin diode switches at W-band region has not yet been done by any other researcher group. This paper, for the first time, establishes the feasibility and potentiality of IV-IV group semiconductor based pin (p++-p+-n−-n-n++) switches for W-band applications. Comparative analysis also reveals that 3C-SiC based shunt type pin (p++-p+-n−-n-n++) SPMT switches are the best for MMW-communication systems. Thermal modelling of the designed devices are also compared and reported in this paper. The quasi-3D thermal analysis is done to optimize the mesa and heat-sink diameter/dimensions so as to minimize the thermal runaway issues. The results may further be used for developing low-cost and fast semiconductor switches for potential application in THz communication systems.

Stabilization method with the relativistic configuration-interaction calculation applied to two-electron resonances

Abstract: We applied a relativistic configuration-interaction (CI) framework to the stabilization method as an approach for obtaining the autoionization resonance structure of heliumlike ions. In this method, the ion is confined within an impenetrable spherical cavity, the size of which determines the radial space available for electron wave functions and electron-electron interactions. By varying the size of the cavity, one can obtain the autoinization resonance position and width. The applicability of this method is tested on the resonances of He atom while comparing with benchmark data available in the literature. The present method is further applied on the determination of the resonance structure of heliumlike uranium ion, where a relativistic framework is mandatory. In the strong-confinement region, the present method can be useful to simulate the properties of an atom or ion under extreme pressure. An exemplary application of the present method to determine the structure of ions embedded in dense plasma environment is briefly discussed.

A novel logarithmic operational law and aggregation operators for trapezoidal neutrosophic number with MCGDM skill to determine most harmful virus.

Abstract: In the current era, the theory of vagueness and multi-criteria group decision making (MCGDM) techniques are extensively applied by the researchers in disjunctive fields like recruitment policies, financial investment, design of the complex circuit, clinical diagnosis of disease, material management, etc. Recently, trapezoidal neutrosophic number (TNN) draws a major awareness to the researchers as it plays an essential role to grab the vagueness and uncertainty of daily life problems. In this article, we have focused, derived and established new logarithmic operational laws of trapezoidal neutrosophic number (TNN) where the logarithmic base μ is a positive real number. Here, logarithmic trapezoidal neutrosophic weighted arithmetic aggregation (Larm) operator and logarithmic trapezoidal neutrosophic weighted geometric aggregation (Lgeo) operator have been introduced using the logarithmic operational law. Furthermore, a new MCGDM approach is being demonstrated with the help of logarithmic operational law and aggregation operators, which has been successfully deployed to solve numerical problems. We have shown the stability and reliability of the proposed technique through sensitivity analysis. Finally, a comparative analysis has been presented to legitimize the rationality and efficiency of our proposed technique with the existing methods.

Crack identification in beam-type structural elements using a piezoelectric sensor

Abstract: A crack or any kind of damage induces a sharp discontinuity in the rotational displacement curve in a structure under load. However, if the beam is not loaded sufficiently or crack depth is very sm...

Mathematical Modeling for the Prevention of Methanol Poisoning Through Ethanol by Impulsive Way

Abstract: Methanol (MeOH) poisoning is a burning issue mostly for the third world country. Toxic methanol is the major compound in impure alcohol when consumed. It causes severe health hazards and sometimes causes death. Methanol when breakdowns into formate in the presence of alcohol dehydrogenase enzymes in human liver, it becomes toxic. This enzyme catalyzes the substrate (MeOH) to produce toxic metabolites (i.e. formate). In methanol toxicity, ethanol is suggested to inhibit the metabolism of methanol as antidote. This is the most common treatment for averting toxicity of methanol in clinics. Based on the chemical kinetics of the reaction, we formulate a mathematical model for the treatment of methanol toxicity with the effects of a constant competitive substrate input (ethanol). Our mathematical study is revealed the dosing policy for administering ethanol as antidote for morbid intoxicated patient. We also find the minimal time interval of the antidote dosing which stops the harmful reaction in treated patient. Numerical simulation of the nonlinear model has confirmed our analytical studies.

Multifunctional Admittance-Type Sensor and Its Instrumentation for Simultaneous Measurement of Liquid Level and Temperature

Abstract: The admittance-type-level sensor is used for continuous level measurement in both metallic and nonmetallic tanks. However, the use of this sensor is limited because of the significant nonlinearity and cross-sensitivity. In this work, the authors have proposed the concept of a double-electrode admittance-type-level sensor. The said level sensor measures the level and the temperature of a conductive liquid. The multifunctional measurement is possible by the detection of the extent of cross-sensitivity using fuzzy logic and decomposition of the measurement variables. The experimental prototype of the sensor and associated instrumentation have been developed, and from the experimental results, it is found that the error in the measurement is consistently distributed and within the range of 1.86% for the level and 2.73% for temperature, which demonstrates the appropriateness of the design. This measurement system and sensor design can be implemented in the boiler-drum-level measurement for better drum-level control.

Evaluation and Repair of Cracks on Statically Loaded Beams Using Piezoelectric Actuation

Abstract: In the present work, damage produced by a crack in a statically loaded beam is first evaluated. Subsequently, an attempt is made to repair the effect of the crack by attaching a piezoelectric patch to the beam as an actuator. Static analysis of PZT patched cracked beam along with rotational spring is performed using Ritz method. Subsequently, a finite element analysis is performed by using ABAQUS 6.12 to collate the analytical results. It is shown in the study that when PZT patch is subjected to external electric field, it yields a local reactive moment, which counters the crack effects. An equation is procured in order to compute the required actuation voltage for repairing of cracks. A parametric study is performed for various boundary conditions and loading patterns. It is distinctly noticed that the technique nullifies the discontinuity in slope curve which develops due to a crack.

The design, analysis, and cost estimation of a generic adder and subtractor using the layered T (LT) logic reduction methodology with a quantum-dot cellular-automata-based approach

Abstract: The quantum-dot cellular automata (QCA) is considered to be one of the ground-breaking nanotechnologies developed over the last two decades. A layered T (LT) logic cell library is constructed herein, and the methodology is extended to generic adder and subtractor module designs. The two proposed algorithms lead to more efficient QCA layout designs for an n-bit ripple carry adder (RCA) and subtractor based on an effective clock zone assignment approach. The suggested one-, four-, and eight-bit RCAs and subtractors surpass most of their existing counterparts by offering lower effective area and cell complexity. A comparative analysis is presented regarding the complexity, irreversible power dissipation, and Costα of the proposed n-bit layouts from a cost estimation purview.

Fault Identification and Determination of Its Location in a HVDC System Based on Feature Extraction and Artificial Neural Network

Abstract: Detection of fault in a HVDC system is difficult and challenging The present paper focusses initially on the detection of the type of fault and its location in case of a six-pulse HVDC system The faults have been simulated on both the AC grid and DC transmission line The AC faults and the DC faults have been treated separately DC line-ground (DCLG) fault has been simulated at different locations on the entire HVDC Link Short circuit shunt faults have been simulated on the AC grid for different values of fault resistances, fault inception times and short circuit ratio (SCR) DOST has been implemented for obtaining features needed for fault classification from a PNN On the other hand, the features required for obtaining fault location have been extracted from the line-current signals of the HVDC link by implementing FDST and BPNN The proposed methodology has been further tested on the first CIGRE HVDC benchmark system that was proposed in 1985 The entire study has been repeated in the presence of noise In all the cases, the faults have been classified satisfactorily and the locations of DCLG faults have been obtained with convincing accuracy All the simulations have been done in MATLAB software

Satellite lines of helium-like ions in strongly coupled plasma environment

Abstract: We report the transition energies and probabilities of satellite lines due to 2 p 2 ( 3 P 0 , 1 , 2 ) → 1 s 2 p ( 3 P 0 , 1 , 2 ) transitions of He-like C , N e , A l and A r ions embedded in strongly coupled plasma (SCP) environment. The SCP environment is represented by the ion-sphere (IS) model and the IS radius is varied in such a way that plasma electron densities ( ∼ 10 20 − 10 26 per c m 3 ) cover a wide range of experimental interest. Both relativistic and non-relativistic energies of 2 p 2 ( 3 P ) and 1 s 2 p ( 3 P ) states are reported. The relativistic MCDF results are obtained by modified GRASP2K code and the non-relativistic variational results are done by using explicitly correlated Hylleraas basis. The relativistic results are in good agreement with experimental data available in literature. The positions of intercombination lines in presence of dense plasma can be calculated from present results which are comparable with experimental measurements. The partial pressures experienced by the plasma-embedded ions are analyzed in the purview of available experimental observations. An empirical relation is reported to estimate partial pressure on ions in dense plasma environment.

Tribological Characteristics of Thermomechanically Processed 7075 Al Alloy Through Nano-scratch Characterization:

Abstract: Age-hardenable Al–Zn–Mg–Cu (AA 7075) alloys can be fortified by precipitation solidifying because of precipitation of the MgZn2 intermetallic stages. Furthermore, grain refinement and high dislocat...

Pruning of Health Data in Mobile-Assisted Remote Healthcare Service Delivery

Abstract: The use of cloud computing and mobile devices is increasing in healthcare service delivery primarily because of the huge storage capacity of cloud, the heterogeneous structure of health data and the user-friendly interfaces on mobile devices. We propose a healthcare delivery scheme where a large knowledge base is stored in the cloud and user responses from mobile devices are input to this knowledge base to reach a preliminary diagnosis of diseases based on patients’ symptoms. However, instead of sending every response to the cloud and getting data from cloud server, it may often be desirable to prune a portion of the knowledge base that is stored in a graph form and download in to the mobile devices. Downloading data from cloud depends on the storage, battery power, processor of a mobile device, wireless network bandwidth and cloud processor capacity. In this paper, we focus on developing mathematical expressions involving the above mentioned criteria and show how these parameters are dependent on each other. The expressions built in this paper can be used in real-life scenarios to take decisions regarding the amount of data to be pruned in order to save energy as well as time.

A WBAN-Based Framework for Health Condition Monitoring and Faulty Sensor Node Detection Applying ANN

Abstract: Remote health monitoring framework using wireless body area network with ubiquitous support is gaining popularity. However, faulty sensor data may prove to be critical. Hence, faulty sensor detection is necessary in sensor-based health monitoring. In this paper, an artificial neural network (ANN)-based framework for learning about health condition of patients as well as fault detection in the sensors is proposed. This experiment is done based on human cardiac condition monitoring setup. Related physiological parameters have been collected using wearable sensors from different people. These data are then analyzed using ANN for health condition identification and faulty node detection. Libelium MySignals HW (eHealth Medical Development Shield for Arduino) v2 sensors such as ECG sensor, pulse oximeter sensor, and body temperature sensor have been used for data collection and ARDINO UNO R3 as microcontroller device. ANN method detects faulty sensor data with classification accuracy of 98%. Experimental results and analyses are given to prove the claim.

iCredit: A Credit Based Incentive Scheme to Combat Double Spending in Post-Disaster Peer-to-Peer Opportunistic Communication Over Delay Tolerant Network

Abstract: Recently, Delay Tolerant Network (DTN) is used to cope with disaster response environment where infrastructure is unavailable for a long run. In such situation, cooperation among nodes is very essential to forward urgent situational information from different disaster affected corners. However, due to existence of some selfish and non-cooperative nodes could cause catastrophic damage to cooperative communication and can jeopardize whole network. Researchers have devoted their work to address this problem by assigning reputation of nodes based on interaction pattern. The major drawback of these schemes is nodes with bad reputation are discarded which results less number of available nodes for delivering messages. To alleviate this problem, literatures suggest incentive based mechanism to stimulate nodal collaboration. Many incentive based schemes are proposed to motivate nodes to cooperate in data dissemination. Due to intermittent connectivity, DTN nodes can acquire correct information about the local transactions occurring in their neighbourhood but they have limited knowledge about the transactions occurring in other parts of the network. Therefore, possibility of double spending poses a serious threat in crypto currency based transactions occurring in post disaster communication network. A user may spend same single token more than once due to malevolence and ask for reimbursement multiple times. Here, credit based incentive scheme, iCredit is proposed that uses credits in terms of signed crypto_coin to motivate nodes to cooperate and to prevent double spending without involving trusted third party. Detailed analysis and extensive simulation results demonstrate the efficiency and efficacy of the proposed scheme.

Power Efficient Magnitude Comparator Using Adiabatic Logic and Gate Diffusion Technique

Abstract: In the advanced technology, designing of low power, high speed portable devices is a challenging issue. Power dissipation can be minimized by using adiabatic logic style. In compared to gate diffusion input technique, an adiabatic logic required more number of transistors, and more power is needed. This paper demonstrates the design and implementation of 2-bit magnitude comparator using different adiabatic logic styles and comparing with the gate diffusion input technique in terms of power consumption and transistor count. The simulation has been done by using the DSCH and Microwind software.

Design and Optimization of Reversible Logic Based Magnitude Comparator Using Gate Diffusion Input Technique

Abstract: The power optimization is one of the biggest challenging issues for designing of VLSI circuits within the advanced technology. The reversible logic is one among the best approaches for low power ap...

Brain Activation in Chronic Nonspecific Low Back Pain : A Systematic review and ALE Meta-analysis

Abstract: Pain, a protective mechanism turns into a pathologic response when it becomes chronic. Recent evidences are pointing towards neuroplastic brain changes as the primary factor for the persisting pain in chronic nonspecific low back pain (cLBP). To summarise the previous fMRI studies, a coordinate-based ALE meta-analysis of resting functional brain imaging studies is carried out to identify the clusters activated in the brain in cLBP. Literature survey: ‘PubMed’, ‘Scopus’ and ‘Sleuth’ were searched for studies with resting functional whole-brain imaging in cLBP. Till October 2020; 258, 238, and 7 studies were found respectively after search. The activity pattern was documented in ‘without stimulation’ and ‘with stimulation’ groups. The risk of bias was assessed by Joanna Briggs Institute critical appraisal checklist for analytical cross-section studies. Total seven (224 cLBP patients, 110 activation foci) and six studies (106 cLBP patients, 66 activation foci) were selected among 277 studies for metanalysis in the ‘without stimulation’ and ‘with stimulation’ group respectively. In the ‘without stimulation’ group 8 statistically significant clusters were found. The clusters are distributed in the prefrontal cortex, primary somatosensory cortex, and primary motor cortex, anterior cingulate cortex, insular cortex, putamen, claustrum, amygdala, and associated white matters in both hemispheres. On the other group, 3 statistically significant clusters were found in the frontal cortex, Parietal cortex, and Insula. In the ‘with stimulation’ group, significant lateralization was observed and most of the clusters were in the right hemisphere. The white matter involvement was more in the ‘with stimulation’ group (78.62% Vs 38.21%). The statistically significant clusters found in this study indicate a probable imbalance in GABAergic modulation of brain circuit and dysfunction in descending pain modulation system. This disparity in pain neuro-matrix is the source of spontaneous and persisting pain in cLBP.