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

In this paper, a tunable mixer having a tunable range from 868 MHz to 2.4 GHz is proposed. The structure consists of a modified tunable 3 dB double section hybrid coupler along with a tunable 3rd order low pass filter. The tunibility is achieved by varying the reverse biased voltage of the varactor diode. In the proposed circuit, only one control voltage is applied with RF choke inductors. For mixing operation, two schottky diodes are used. Working methodologies of the proposed mixer is established with extensive simulation results. Finally, proposed design gives wide tuning range, high port isolation, good return loss throughout the frequency range over 868 MHz to 2.4 GHz. © 2023 IEEE.

World University root node

Department of Electrical Engineering

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

Novel Tunable Mixer Using Double Section Hybrid Coupler for Extended ISM Band Applications

Abstract: We are aiming to develop an electrochemical microcatheter sensor for the detection and real-time continuous monitoring of propofol (PPF), which is an anesthetic drug majorly used during medical treatment. This proposed microcatheter-based sensing strategy meets the challenge of real-time periodic and continuous monitoring of propofol by using d-Ti3C2Tx-rGO-chi-modified carbon paste microcatheter sensor transducer. The sensing methodology relies on voltammetry and chronoamperometry transduction methods. The reusable microcatheter sensor was fabricated by embedding the three electrodes into a few millimeters-wide Teflon tube. The nanocomposite was characterized using advanced analytical instruments such as XRD, FE-SEM, EDX, Raman spectroscopy, and XPS. Further, electrode interfacial properties were characterized with voltammetry and electrochemical impedance spectroscopy. The electroanalytical performance of the modified microcatheter sensor was tested for the detection of PPF in phosphate buffer by using chronoamperometry with a wide linear range of 5 to 110 µM (at an applied potential of 0.3 V vs. Ag/AgCl). The sensor’s practical potency was confirmed in human serum with a dynamic linear range of 10 to 130 µM. The sensor exhibited a good limit of detection values in phosphate buffer (2 µM) and natural human plasma (4 µM). The new sensor displays different dimensions of information while displaying high sensitivity, selectivity, and long-term stability. The outstanding analytical performance of the developed sensor holds considerable promise for the continuous monitoring of propofol, its effective management, and optimization of the doses in the patient's body. Graphical Abstract: [Figure not available: see fulltext.] © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.

Department of Chemistry

Microchimica Acta

Ti3C2Tx-rGO-chitosan-based microcatheter sensor for real-time continuous monitoring of propofol: toward improved anesthetic management

Objective. In ultrasound (US) guided interventions, the accurate visualization and tracking of needles is a critical challenge, particularly during in-plane insertions. An inaccurate identification and localization of needles lead to severe inadvertent complications and increased procedure times. This is due to the inherent specular reflections from the needle with directivity depending on the angle of incidence of the US beam, and the needle inclination. Approach. Though several methods have been proposed for improved needle visualization, a detailed study emphasizing the physics of specular reflections resulting from the interaction of transmitted US beam with the needle remains to be explored. In this work, we discuss the properties of specular reflections from planar and spherical wave US transmissions respectively through multi-angle plane wave (PW) and synthetic transmit aperture (STA) techniques for in-plane needle insertion angles between 15 degrees-50 degrees. Main Results. The qualitative and quantitative results from simulations and experiments reveal that the spherical waves enable better visualization and characterization of needles than planar wavefronts. The needle visibility in PW transmissions is severely degraded by the receive aperture weighting during image reconstruction than STA due to greater deviation in reflection directivity. It is also observed that the spherical wave characteristics starts to alter to planar characteristics due to wave divergence at large needle insertion depths. Significance. The study highlights that synergistic transmit-receive imaging schemes addressing the physical properties of reflections from the transmit wavefronts are imperative for the precise imaging of needle interfaces and hence have strong potential in elevating the quality of outcomes from US guided interventional practices.

BIOMEDICAL PHYSICS \& ENGINEERING EXPRESS

On the physics of ultrasound transmission for in-plane needle tracking in guided interventions

In this work, we propose a model that captures the dynamic characteristics of metal-insulator-semiconductor (MIS)-based non-volatile memory (NVM). The main focus of our study is to investigate the dependence of the barrier profile (and hence, the dominant transport mechanism) on the write speed and write voltage. We evaluate the results from our model with experimental data from literature. The model and its framework can provide useful insights into the design of MIS-based NVMs with optimized performance. © 2023 IEEE.

2023 IEEE Nanotechnology Materials and Devices Conference, NMDC 2023

Modeling the Dynamic Characteristics of Metal-Insulator-Semiconductor based Non-Volatile Memories

The design and synthesis of dansyl-appended fluorescent sequence-defined oligomers (SDOs) for the selective detection of toxic Hg2+ ions in water is reported. The system incorporates dithiocarbamate (DTC) to act as the binding unit and hydroxy group at the terminal site to improve water solubility. The sensor exhibited positive solvatochromism. This platform has the advantage of systematically increasing the number of DTC units to improve the sensitivity and in doing so, a 100-fold enhancement in sensitivity was obtained by increasing the number of DTC from one to two. A very low detection limit of 60 pM was achieved with the two DTC system and this platform has scope to improve LOD further. Moreover, visual detection and fabrication of paper strip for easy detection of Hg2+ ions are also possible. The sensor selectively binds to Hg2+ ions even in presence of competitive ions and was applied for detection of Hg2+ contamination in lake and tap water samples. Further, we successfully used our sensor for cell imaging in MCF-7 and HeLa cancer cell lines and detect Hg2+ using fluorescence microscopy. The same system was also capable of removing Hg2+ ions from water with an efficiency &gt; 95%. © 2023 Elsevier B.V.

Sensors and Actuators B: Chemical

Dansyl-appended sequence-defined oligomers for selective ultrasensitive detection of Hg2+ in water, paper strips, living cells and its efficient removal

In vitro experiments in which tumour cells are seeded in a gelatinous medium, or hydrogel, show how mechanical interactions between tumour cells and the tissue in which they are embedded, together with local levels of an externally-supplied, diffusible nutrient (e.g., oxygen), affect the tumour’s growth dynamics. In this article, we present a mathematical model that describes these in vitro experiments. We use the model to understand how tumour growth generates mechanical deformations in the hydrogel and how these deformations in turn influence the tumour’s growth. The hydrogel is viewed as a nonlinear hyperelastic material and the tumour is modelled as a two-phase mixture, comprising a viscous tumour cell phase and an isotropic, inviscid interstitial fluid phase. Using a combination of numerical and analytical techniques, we show how the tumour’s growth dynamics change as the mechanical properties of the hydrogel vary. When the hydrogel is soft, nutrient availability dominates the dynamics: the tumour evolves to a large equilibrium configuration where the proliferation rate of nutrient-rich cells on the tumour boundary balances the death rate of nutrient-starved cells in the central, necrotic core. As the hydrogel stiffness increases, mechanical resistance to growth increases and the tumour’s equilibrium size decreases. Indeed, for small tumours embedded in stiff hydrogels, the inhibitory force experienced by the tumour cells may be so large that the tumour is eliminated. Analysis of the model identifies parameter regimes in which the presence of the hydrogel drives tumour elimination. © 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.

Department of Mathematics

Fulltext

Journal of Mathematical Biology

Two-phase model of compressive stress induced on a surrounding hyperelastic medium by an expanding tumour

This work presents, a robust position tracking control of a 3-degrees of freedom 2PRP-PPR (P: Active Prismatic joint, P: Passive prismatic joint, R; Revolute joint) parallel motion mechanism. For controlling the motion of the defined platform, a simple method to develop a fuzzy logic controller called as robust single input fuzzy logic control (RSIFLC) algorithm is presented and used for the complex workspace trajectory tracking control problem with the existence of outside disturbances, variable uncertainties, and inner noises. The suggested control method comprises two sections: The first section considers a feed-forward expression to increase control action and a disturbance estimator to account for anonymous factors like outer disturbances and un-modeled dynamics. The second section employs single input fuzzy logic control as a feedback component to improve the system’s overall closed-loop stability. The experimental results demonstrate the superiority of the suggested control algorithm over traditional control schemes. © IMechE 2022.

Department of Mechanical Engineering

Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science

A simplified approach to develop fuzzy logic controller with disturbance estimator for control of a planar parallel (2PRP-PPR) motion platform

Patients with muscle atrophy undergo rehabilitation exercises by applying resistive force and obstructing foot movement to strengthen their muscles and engage with their neuromuscular system. This can be successfully accomplished without the intervention of a physiotherapist through the use of passive wearable ankle-foot exoskeleton. The existing devices in the market cannot offer bidirectional and variable resistance rehabilitation. This paper proposes the design and development of a passive ankle rehabilitation exoskeleton for bidirectional resistance training with variable stiffness element for ankle torque variation. The conceptual design of the exoskeleton with a variable stiffness element made of Grade 5 Titanium alloy (Ti6Al4V) has been presented along with its kinematic and static analysis. The fabricated prototype of the device was validated using surface electromyogram (sEMG), and the observation clearly depicted improvement in the signal energy during plantar flexion and dorsiflexion. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

Mechanisms and Machine Science

Development of a Passive Ankle-Foot Exoskeleton for Variable Force Resistance Training

This paper presents a graphical user interface system for a lower limb rehabilitation robot. The mechanism considered for this application is a stationary trainer based on Cartesian parallel manipulator. The trainer is configured with three legs of PRRR (prismatic-revolute-revolute-revolute) configuration connected to the end-effector. The end-effector of the mechanism is a footplate to which the subject’s foot can be attached for therapeutic procedures. The interactive simulator is designed primarily for carrying out the therapeutic procedures of PROM (passive range of motion) of the lower limb. Specifically, the application developed can demonstrate the mechanism motion for hip abduction–adduction, hip flexion–extension, knee flexion–extension and gait training. In addition to these options, the simulator also enables the user to vary the subject parameters like thigh and crus lengths. The proposed interactive simulator design is demonstrated and verified using computer-based numerical simulations. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Lecture Notes in Mechanical Engineering

A Graphical User Interface (GUI) System for a Stationary Trainer Used in Lower Limb Rehabilitation

In the present work, we investigate the accuracy and robustness of our in-house OpenMP parallelized direct-forcing immersed boundary–lattice Boltzmann (DF-IB-LB) solver by undertaking studies on accuracy, discrete conservation, Galilean invariance and quantification of spurious force oscillations (SFO). Our study reveals that DF-IB-LB exhibits first and second-order spatial accuracy for velocity and pressure errors, respectively, for generic moving boundary problems. The method is found to be Galilean invariant, while errors in discrete conservation and SFO decay linearly and superlinearly, respectively, with grid refinement. The numerical simulations with the proposed solver on a vast number of complex moving boundary problems involving imposed and induced motion highlight its efficacy as a fast, robust and accurate framework for single-phase flows with and without fluid–particle interactions. © 2022, The Author(s) under exclusive licence to OWZ.