bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of cold plasma on proliferation rate of mammalian cells in vitro
Authors: Shershunova E A , Moshkunov S I , Nebogatkin S V , Rogovaya O S
Published: November 2021

Human keratinocytes HaCaT and human carcinoma cells A431 have been treated in vitro by a cold argon plasma jet with an average power value of 0.72 mW/cm2. There were made estimations of proliferation rate and cell viability in a day after the exposition. In contrast to the cell viability of both cell lines there were revealed significant differences in proliferation rates of keratinocytes and cancer cells after plasma treatment.
Production of nanopowders of bismuth oxide doped with silver by pulsed electron beam evaporation in vacuum
Authors: Ilves V G , Sokovnin S Y , Uimin M A
Published: November 2021

Various bismuth containing compounds are promising in many applications, including for creating photocatalysts based on them using a visible range of light. However, strong polymorphism (9 polymophic phases of Bi2O3), thermal instability and changes in the properties of bismuth oxide during long-term storage significantly complicate work with it. One way to increase stability and improve photocatalytic properties is by doping Bi2O3with various metals. Ag doped Bi2O3nanoparticles (NPs) are typically produced using chemical techniques often associated with the presence of toxic chemicals. The present paper used an environmentally friendly method of producing NPs using the method of pulsed electron beam evaporation in vacuum. The evaporation target was obtained by solid phase synthesis in an electric furnace on air using silver nitrate additives (1 and 5 wt.%). Textural, thermal and magnetic properties of the obtained NPs have been studied. Was found that the Ag-Bi2O3NPs have a specific surface area (SSA) of 23.7 m2/g, which was almost 2 times bigger than the SSA of the pure Bi2O3(13.2 m2/g) obtained previously. The thermal stability of the Ag-doped Bi2O3samples was maintained to the temperature 350°C. While further heating on air took place the phase transitionβ → α
Investigation of changes in field electron emission characteristics of industrial fine-grained graphite when operated in an argon atmosphere up to 10–2 Pa
Authors: Chepusov A S , Komarskiy A A , Korzhenevskiy S R
Published: November 2021

Studying of field electron emission properties of carbon cathodes operating under technical vacuum conditions is a promising scientific field. Massive cathode made of commercial fine-grained graphite of MG (Russian abbreviation) grade is being investigated. Experiments on obtaining current-voltage characteristics and long-term testing are being carried out. The emitter made of fine-grained graphite demonstrates good emission properties under technical vacuum conditions. Carbon cathode is capable of operating at pressures up to 2×10–2 Pa. Increased pressure in the vacuum chamber leads to deterioration of cathode emission properties. Electric field enhancement factors were calculated for all stages of studies. Analysis of experimental data demonstrates decrease in enhancement factor due to ion bombardment of cathode surface during exploitation. This results in higher electric field for operation of investigated graphite cold cathodes.
Processes of chemical transformations in heavy aromatic hydrocarbons of the Surakhan oil under the action of UV rays
Authors: Yolchuyeva U J , Jafarova R A , Abbasov V M , Mursalov N I , Hajiyeva G A , Ibragimova R A
Published: November 2021

Photooxidative transformations and mechanisms of oxidative reactions in aromatic groups of hydrocarbons isolated from heavy Surakhan (Azerbaijan) petroleum under atmospheric conditions have been investigated. Polycyclic aromatic hydrocarbons, which are part of the aromatic components of heavy Surakhan petroleum, after irradiation with UV rays for 1÷11 hours in the presence of oxygen undergo chemical transformations: endoperoxides polycyclic aromatic hydrocarbons, quinones, etc. are formed. It was found that oxidation products under atmospheric conditions can be formed as follows: during the oxidation of acenes (naphthalene, anthracene), which are part of the aromatic groups of petroleum components, excited aromatic hydrocarbons (donor) interact with atmospheric oxygen (acceptor) in the triplet state with the transition of the acceptor to excited state with the formation of singlet oxygen 1O2, in this case the donor molecule returns to the ground state. When phenanthrene is photooxidized, quinones are formed (the reaction is irreversible).
Electric arc in plasma flow of gas discharge with a liquid electrolyte
Authors: Tazmeev G K , Tazmeev A K , Tazmeev B K
Published: November 2021

The properties of an electric arc ignited in a gas discharge plasma flow with a liquid electrolyte cathode are experimentally investigated. Aqueous solutions of sodium chloride with a specific electrical conductivity of 10-15 mS/cm were used as a liquid electrolyte. The distance between the anode and the liquid electrolyte cathode was set in the range of 5-60 mm, and the distance between the anode and the metal cathode was varied in the range of 2-30 mm. The current of gas discharge with a liquid electrolyte cathode was set in the range of 5-10 A, and the arc current varied in the range of 1-10 A. The conditions under which the arc burns with the formation of a contracted channel are revealed.
Anorthite-reducing glass-crystalline materials synthesized in plasma
Authors: Shekhovtsov V V , Skripnikova N K , Semenovykh M A , Bakshanskii R Yu
Published: November 2021

The paper presents the experimental results of the glass-ceramic material production using the low-temperature plasma. The dependences are suggested for the main physical-and-mechanical properties (compressive and flexural strengths, density, linear thermal expansion coefficient) of products and the mixture compositions. The centers of secondary recrystallization are identified for the anorthite phase (CaAl2Si2O8). These inclusions chaotically locate on the surface of the synthesis products and resemble dendritic microinclusions up to 90 nm in size. A comparative analysis is given to the properties of glass-ceramic materials produced by the low-temperature plasma and traditional methods.
Simulation of charged particle beam dynamics extracted from a plasma source
Authors: Kanshin I A
Published: November 2021

This paper presents the results of computer simulation in COMSOL Multiphysics of the hydrogen isotopes beam dynamics extracted from a plasma source of small linear accelerator. The beam energy was 100 keV. The simulation was carried out taking into account the charge exchange of ions on neutral gas molecules in the accelerating system. At the same time, the calculations took into account the process of secondary ion-electron emission from the surfaces of the accelerating system that are bombarded with both fast and slow ions. Consideration of this process made it possible to determine that the value of the electronic load is at least 50% of the main beam current of 100 μA. The inclusion in the trajectory analysis the magnetic field simulation in the secondary electrons generation area made it possible to determine the magnetic field strength, which effectively blocks secondary electrons on the target (3000 Gauss). Then it has been experimentally demonstrated that the discharge current in a plasma source automatically increases by 20% when using the magnetic suppression system on the target node (magnetic field strength is 3000 Gauss).
Measurement of the electron beam energy in a source with a plasma anode and the beam extraction into the atmosphere through a foil window
Authors: Abdullin E N , Basov G F
Published: November 2021

Measurements of the energy of an electron beam in an electron beam source with an explosive-emission cathode, a plasma anode and a foil window, providing the extraction of an electron beam with a cross-section of (100–200) cm2 into the atmosphere, have been performed. The high voltage source was a Marx generator based long lines with matched loads. The energy values were calculated from the results of measurements of the temperature of a beam collector placed in vacuum using thermistors and an infrared imager. At an accelerating voltage of ~ 200 kV, a current of (1–2) kA, and an electron beam duration of 5 μs, the maximum values of the energy released in the collector with a cross section of 74 cm2 were (650–850) J/pulse. A decrease in the current and energy of the beam was recorded approximately by a factor of two after passing through an AMG-2n aluminum-magnesium foil with a thickness of 30 μm. The use of infrared imager for recording the beam structure in the plane of the output window in air has been tested.
Efficiency of electron beam extraction to the atmosphere in an accelerator based on ion-electron emission
Authors: Doroshkevich S Yu , Vorobyov M S , Torba M S , Koval N N , Sulakshin S A , Levanisov V A , Ekavyan A A , Chistyakov A V
Published: November 2021

The use of a modern element base makes it possible to create power supplies with a transition from a direct mode of generation of an auxiliary discharge to a pulse-periodic mode with a pulse repetition rate at the level of several tens of kHz. This allows for a more flexible adjustment of the discharge parameters, keeping the average value of its current, but changing its amplitude with a corresponding change in the pulse duty cycle. In this work, using an electron accelerator based on ion-electron emission, generating a wide-aperture electron beam, we research the effect of auxiliary discharge generation mode (direct and pulse-periodic) on the efficiency of electron beam extraction into the ambient atmosphere. It is shown that, in a direct mode of electron beam generation at an accelerating voltage of 150 kV, the beam extraction coefficient does not exceed 0.25. The possibility of increasing the extraction coefficient to K = 0.55 at the same accelerating voltage of 150 kV was demonstrated without making changes to the design of the accelerator, but switching to a pulsed-periodic mode of emission plasma generation.
Effect of extinction beam-plasma discharge while the injection thermoelectrons during transportation of the electron beam in the forevacuum pressure range
Authors: Zenin A A , Bakeev I Y , Klimov A S
Published: November 2021

The article presents the results of experiments aimed at studying the effect of low-energy thermoelectrons on the parameters of the beam plasma and plasma of the beam-plasma discharge generated during the transportation of a powerful electron beam in the pressure range of the medium vacuum. It is shown that the injection of a sufficiently small current of low-energy thermoelectrons is capable of violating the conditions for the combustion of the beam-plasma discharge and reducing the power loss of the electron beam for SPR generation. In this case, the plasma concentration decreases by almost an order of magnitude (to 1015 m–3) and the temperature of plasma electrons decreases by almost three (to 0.3 eV).
Features of glow discharge ignition through a small hole in the hollow cathode of a large volume
Authors: Klimov A S , Bakeev I Y , Zenin A A
Published: November 2021

The influence of the size of a cathode gap on the initiation of the effect of a hollow cathode in a glow discharge system with an extended hollow cathode in the forevacuum pressure range is shown. It was found that the threshold current for the transition of the discharge to the burning mode with a hollow cathode is determined by the ratio of the longitudinal and transverse dimensions of the cathode slit. With a decrease in the width of the slot, the threshold current increases disproportionately; at the same time, with an increase in the length of the slot, this current sharply decreases.
Effect of working gas pressure on mass-to-charge composition of plasma ions in high-current planar magnetron discharge
Authors: Shandrikov M V , Vizir A V , Klimov A S , Oks E M , Frolova V P
Published: November 2021

The mass-to-charge ion composition of a planar magnetron discharge plasma has been investigated. The measurements used a modified quadrupole mass-spectrometer and a time-of-flight spectrometer. The experiments were carried out on a copper magnetron target. Argon was used as a working gas. The operating pressure was 0.15÷1.3 Pa. The discharge current was 1÷20 A with a pulse duration of 30÷50 μs. The influence of main operating parameters (discharge current and working gas pressure) on mass-to-charge composition of plasma ions was measured. The mass-to-charge composition of plasma ions in the axial direction was measured as a function of working pressure. Plasma electron temperature was measured and its effect on the mass-to-charge composition of magnetron plasma ions was estimated.
Influence of accelerating gap configuration on parameters of a forevacuum plasma-cathode source of pulsed electron beam
Authors: Kazakov A V , Medovnik A V , Oks E M , Panchenko N A
Published: November 2021

The research of influence of accelerating gap configuration on parameters of a forevacuum plasma-cathode source of a pulsed low-energy (up to 10 keV) large-radius electron beam is presented. An increase in cell sizes of a mesh emission electrode increases electron emission efficiency, but leads to a decrease in electric strength of an accelerating gap. Larger cell sizes of a mesh extractor provide higher electron beam current. An increase in the length of the accelerating gap first leads to an increase in the electron emission efficiency, but when optimal value is reached, a further increase in the length leads to a decrease in the emission efficiency. This optimal length of the accelerating gap is about 25 mm. However, the electron emission efficiency changes relatively small (within 15%). The dependencies of maximum emission current and maximum operating gas pressure on the length of acceleration gap is similar to the dependence for the emission efficiency, but the gap length much stronger influences on these maximum values. Moreover, the optimal length, at which maximum emission current or maximum pressure is provided, is depended on gas pressure (for current) or emission current (for pressure), accelerating voltage and pulse duration.
Influence of electron emission on operation of a constricted arc discharge in a pulsed forevacuum plasma-cathode electron source
Authors: Kazakov A V , Oks E M , Panchenko N A
Published: November 2021

The research of influence of electron emission and processes associated with the formation of a pulsed large-radius electron beam on operation of a constricted arc discharge, which forms emission plasma in a forevacuum plasma-cathode electron source, is presented. Processes, occurring in case of generation of the electron beam at forevacuum pressure range 3–20 Pa, provide lower operating voltage of the constricted arc discharge. The constricted arc voltage decreases with increasing pressure and increasing accelerating voltage. However, at pressure more than 15 Pa, the arc voltage decreases until a certain minimum value is reached, and then arc voltage is almost independent on pressure and accelerating voltage. This minimum value of the constricted arc voltage is on average 1.5–2 times higher as compared with voltage of the cathodic arc at the same discharge current. The observed decrease of operating voltage of the constricted arc is most likely caused by accelerated back-streaming ions, which move toward the emission electrode from beam-produced plasma. These accelerated ions partially penetrate into the hollow anode of discharge system through the mesh emission electrode and facilitate formation of the arc plasma, and thus provides lower voltage of the constricted arc.
Investigation of a cold atmospheric plasma jet generation in single and multichannel planar devices
Authors: Gugin P P , Zakrevsky D E , Milakhina E V
Published: November 2021

A plasma source of atmospheric pressure with a planar geometry of the device and an adjustable number of planar discharge channels has been developed. The dependence of the recorded collector current on the amplitude of the applied voltage is investigated. It was found that the current in each of the channels consists of a set of independent current channels whose propagation does not depend on each other.
Optimum transfer characteristics of the Tesla transformer on the first and second half-waves of output voltage
Authors: Kladukhin V , Khramtsov S
Published: November 2021

The elements of the theory of the Tesla transformer are stated, the exact solution of the equations of the dynamics of currents and voltages in the transformer circuits through the generalized parameters of the circuits (Q-factors of the primary and secondary circuits, the coupling coefficient of the circuits and mismatching factor of the natural resonance frequencies of the circuits) is given, under the assumption of their constancy. The optimal transfer characteristics of the processes of charging the capacitive storage of the secondary circuit of the transformer on the first and second half-waves are given, demonstrating the capabilities of the Tesla transformer.
Identifying drug-resistant tuberculosis from chest X-ray images using a simple convolutional neural network
Authors: Ureta J , Shrestha A
Published: November 2021

Tuberculosis(TB) is one of the top 10 causes of death worldwide, and drug-resistant TB is a major public health concern especially in resource-constrained countries. In such countries, molecular diagnosis of drug-resistant TB remains a challenge; and imaging tools such as X-rays, which are cheaply and widely available, can be a valuable supplemental resource for early detection and screening. This study uses a specialized convolutional neural network to perform binary classification of chest X-ray images to classify drug-resistant and drug-sensitive TB. The models were trained and validated using the TBPortals dataset which contains 2,973 labeled X-ray images from TB patients. The classifiers were able to identify the presence or absence of drug-resistant Tuberculosis with an AUROC between 0.66–0.67, which is an improvement over previous attempts using deep learning networks.
Computer-aided Detection of Lung Tumors in Chest X-ray Images Using a Bone Suppression Algorithm and A Deep Learning Framework
Authors: Sato K , Kanno N , Ishii T , Saijo Y
Published: November 2021

Detecting lung tumors in early stage by reading chest X-ray images is important for radical treatments of the disease. In order to decrease the risk of missed lung tumors, diagnosis support systems that can provide the accurate detection of lung tumors are in high demand, and the use of artificial intelligence with deep learning is one of the promising solutions. In our research, we aim to improve the accuracy of a deep learning-based system for detecting lung tumors by developing a bone suppression algorithm as a preprocessing for the machine-learning model. Our bone suppression algorithm was devised for conventional single-shot chest X-ray images, which do not rely on a specific type of imaging systems. 604 chest X-ray images were processed using the proposed algorithm and evaluated by combining it with a U-net deep learning model. The results showed that the bone suppression algorithm successfully improved the performance of the deep learning model to identify the location of lung tumors (Intersection over Union) from 0.085 (without the bone suppression algorithm) to 0.142, as well as the ability to classify the lung cancer (Area under Curve) that increased from 0.700 to 0.736. The bone suppression algorithm would be useful to improve the accuracy and the reliability of the deep learning-based diagnosis support systems for detecting lung cancer in mass medical examinations.
Synthesis and Characterization of Electrospun Polyvinylidene Fluoride-based (PVDF) Scaffolds for Renal Bioengineering
Authors: Sta. Agueda J R , Madrid J , Mondragon J M , Lim J , Tan A , Wang I , Duguran N , Bondoc A
Published: November 2021

With the continuous search for alternative treatment for End Stage Renal Disease (ESRD), the use of synthetic scaffolds as a prospect is becoming a forefront in regenerative medicine. This study aimed to fabricate and evaluate the effects of varying electrospinning parameters (the applied voltage, spinning distance and flowrate) to the fiber diameter and pore size of the scaffolds produced using polyvinylidene fluoride (PVDF). Electrospun scaffolds were subjected to scanning electron microscopy (SEM) and strain apparatus to assess structural and tensile properties. Results showed that applied voltage, spinning distance, and flowrate directly affect the overall pore size and fiber diameter of the electrospun scaffolds, as well as resulting in a direct effect to the tensile strength of the electrospun scaffold. The optimal values for the parameters in fabricating a PVDF electrospun scaffold would be a voltage of 20kV, a spinning distance of 100mm and a flowrate of 0.5ml/h. Results also show that spinning distance and flowrate have statistically more impact on the outcome of the fiber diameters, while applied voltage and spinning have statistically more impact on the outcome of the pore sizes. Moreover, the electrospun scaffolds acquired thinner fiber diameters and smaller pores sizes when compared to that of the native kidney tissue. Nonetheless, the promising mechanical integrity of the electrospun PVDF-based scaffolds offer a potential approach to addressing ESRD.
The Influences of Sintering Process on the Characteristics of Corbiculacea (Etok) Shells Based Hydroxyapatite Powder
Authors: Roslan M R M , Nasir N F M , Mohammad N F , Meng C E , Mohamed M S , Abdullah M N
Published: November 2021

Hydroxyapatite (HA) powders were prepared via chemical solution through aqueous solution of calcium hydroxide and phosphoric acid. The calcium precursor was extracted from the calcium carbonate of Corbiculacea shells while the phosphate precursor originated from the commercially available phosphoric acid. The final product of HA powders is then manipulated through the sintering process at 500°C while the other sample was used as it is. XRD result shows significant changes in its crystallinity, crystallite size and lattice parameters after the sintering process. By sintering the HA, the crystallite size and crystallinity were increases as much as 6.25% and 5.31% respectively. SEM on the other hand showed different morphology for both sintering and non-sintering HA powders. For the sintering HA, the grains size is higher which is 5.00μm compared to non-sintering HA which is 3.91μm due to the agglomeration.
Synthesis Methods of Doped Hydroxyapatite: A Brief Review
Authors: Baskaran Thivya , Mohammad Nur Farahiyah , Md Saleh Siti Shuhadah , Mohd Nasir Nashrul Fazli , Mohd Daud Farah Diana
Published: November 2021

Hydroxyapatite (HA) has drawn great attention to biomedical applications due to their bone mineral similarity, strong bioactivity, biocompatibility and osteoconductive. Despite the fact that HA has many advantages, several properties are still lacking, emphasising the crucial need for ion doping/substitution. Many attempts have been made to incorporate ions into HA structure to increase their physical, chemical, and biological properties. With such a diverse range of methods available for the synthesis of doped HA, this article discussed the importance of doping for HA and summarizes four common techniques used to prepare doped hydroxyapatites which include precipitation, hydrothermal, sol-gel and mechanochemical method.
Synthesis and Characterization of Nanoporous Biphasic Calcium Phosphate
Authors: Mohammad Nur Farahiyah , Mei Koo Li , Mohd Roslan Mohd Riza , Md Saleh Siti Shuhadah , Mohd Daud Farah Diana
Published: November 2021

For the past few years, many researchers are focusing on biomaterials fabrication in porous form. The research on porous calcium phosphate has been investigated due to its excellent biocompatibility and better osseointegration. This research paper presented nanoporous biphasic calcium phosphate (BCP) synthesised using chemical precipitation method. Triblock co-polymer F127 was used as pore directing agent. The chemical compositions of pure BCP samples were examined using X-ray diffraction (XRD) analysis which shows common peak of BCP. The pore size distribution (PSD) on the other hand shows that the pore size of the samples mainly distributed at 52.8 nm, 49.6 nm and 32 nm. BCP pellets were soaked in phosphates buffered saline (PBS) and distilled water (DW) for 15 days. The pH of the soaking medium decreases throughout the soaking period due to degradation of BCP pellets, which release hydrogen ions into the PBS and distilled water. BCP degrades faster in distilled water than in PBS. After soaking for 15 days, materials were examined with a scanning electron microscope (SEM) to assess the morphological structure before and after in vitro degradation. Apatite formation was discovered on the surface of the BCP pellet that had been immersed in the PBS solution.
Antibacterial Activity of Biodegradable Plastic from Chromolaena odorata (Pokok Kapal Terbang) Leaves
Authors: Mohamad C W S R , Cheng E M , Talib N A Abu
Published: November 2021

The aim of this research project was to develop antimicrobial films from blends of C. odorata and PVA and test the films for microbial activity using broth dilution methods for Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria. The result shows that CO/PVA80 successfully inhibit the growth of target bacteria. In antibacterial activity analysis, CO/PVA80 showed 50% higher compare with pure PVA film, PVA100. Other than that, the high percentage of PVA in the blend films, the greater the thickness, Tensile Strength (TS) and Young’s Modulus (YM), while the Elongation Break (EB) of the prepared films decreased. The 0.5 mm CO/PVA80 film shows a good result in mechanical properties which is TS 6.55 MPa, YM 182 MPa and EB is 7.47%. A CO/PVA80 were show a smooth texture, lacked of macropore and good characteristic with a SEM analysis. These results suggest that CO/PVA80 films have good compatibility to form an antimicrobial film as a new material for medical application especially for wound healing.
Customized Designs and Biomechanical Analysis of Transtibial Prosthetic Leg
Authors: Mubarak A J M , Rashid A M A , Wahab A A , Seng G H , Ramlee M H
Published: November 2021

A prosthetic leg is a technical mechanism that is designed as a substitution of the function of a missing limb or body part. This device has been effectively used as an essential tool for amputees. The traditional way of producing the prosthetic leg is very tedious and time consuming. Apart from that, comfortability issue is another problem if using casting method. Therefore, the main purpose of this study is to customize and biomechanically evaluate an prosthetic’s socket to produce a better construct for the improvement of performance. In this paper, the methods started with a definition of the construction of the finite element model which is divided into four parts: amputee leg, sockets model, pylon and socket. Later, modelling of the pylon and three-dimensional foot model was taken into consideration. The focus was on the design of the socket then moving to the biomechanical study using a finite element method which involved several analyses of the effects of socket designs as well as its material properties. The sockets were initially developed from a data of 3D scanning with an estimated uniform thickness of 5 mm. The results of the finite element study showed that the perforated socket configuration had better stability in terms of displacement (0.19 mm) and von Mises stress (1.15 MPa), as compared to the conventional socket (stress of 3.22 MPa), and the displacement of 0.19 mm. Meanwhile, open-sided socket experienced von Mises stress of 1.18 MPa and displacement of 0.22 mm. In conclusion, a customized design is a promising technique that can enhance the performance of user in terms of biomechanical aspect.
Knee Orthosis for Anterior Cruciate Ligament Injuries - Kinematics and Comfortability Study
Authors: Zainal Abidin N A , Shafie S N S , Azaman A , Ramlee M H
Published: November 2021

Knee orthosis is commonly used in supporting the knee movement and protecting the anterior cruciate ligament (ACL) injuries from worsening. In clinical practices, there are many types of ready-made orthoses that available in the market. However, different types of orthoses may provide different performances for patient’s knee joint. Therefore, this paper attempt to investigate the performance of knee orthoses for ACL-injured knee. Two groups took part in the study; (Group 1) six ACL-injured, (Group 2) four healthy participants, where two types of knee orthoses were adopted; (Brace 1) hinge brace, (Brace 2) sleeve brace with bilateral hinges. The knee joint motions were calculated using kinematics data while comfortability was conducted through surveys. From the findings, Brace 1 produced normal range of motion (ROM) for internal rotation at 5.47° while Brace 2 fall outside of the normal range at 2.165°. Meanwhile, the external rotation for Brace 1 (-13.25°) was lower than Brace 2 (-33.25°). Furthermore, the comfortability analysis suggested that Brace 1 (60%) was more effective than Brace 2 (40%). To conclude, Brace 1 portrayed optimal performance than Brace 2 during dynamic balance activities with reduction in ROM to prevent excessive knee rotation.
Effect of Arm Swing Direction on Forward and Backward Jump Performance Based on Biomechanical Analysis
Authors: Teoh L M , Sakeran Hamzah , Salleh A F , Salim M S , Wan Muhamad Wan Zuki Azman , Mohamed Shapie Mohamad Azlan
Published: November 2021

Previous studies have examined the role of arm swing for various types of jumping technique, but none have been found to study about the gender differences in term of the role of arm swing on forward and backward jump. This study aimed to compare the jumping performance between male and female for forward and backward jump. Seven male and seven female subjects performed four trials of forward and backward jump with (FJA, BJA) and without arm swing (FJ, BJ) respectively. Qualisys Track Manager System, EEGO Sports, Visual3D and MATLAB software was used to record and analyze the performance. According to the result, the triceps brachii muscle is the most active muscle compared to other muscles during jumping. The normalized vGRF showed significant correlation with jump height when jumping forward and backward (p<0.01). The arm swing enhanced the jumping performance by increasing the jump height. Males demonstrated greater vGRF and jump height than females. When jump with arm swing, the left knee flexion angle of males increased whereas females decreased. These findings concluded there is different between males and females during jumping.
Recent Developments on Social Robots and Imitation Learning for Robotic Therapy
Authors: Ompico C D S , Bugtai N M , Munsayac F E T
Published: November 2021

The development of social robots has been notably increasing and gaining popularity in recent times. These are also being integrated into healthcare systems, as a means to accompany patients, provide mental health therapy, and entertainment in place of direct human intervention. This paper discusses the recent developments on imitation learning for robot therapy in the field of social robotics to gain knowledge about the importance of this approach as an alternative solution to mental health therapy. The integration of robots to the mental healthcare system is known as robot therapy, which is used as a substitute for animal assisted therapy. Therapy that makes use of animals has been proven to be effective in dealing with mental disorders. However, there are risks such as allergic reactions, bites, and scratches that come with animal assisted therapy, but not robot therapy. The goal for developing robots for this is to make them seem almost life-like--has a way of thinking and emotions. For this to happen, humanoids are being programmed to appear human-like. A solution for this is imitation learning, which is a way for machines to learn, not only tasks, but responses in certain situations, only by observing and imitating humans in an environment.
Modelling and Simulation using Finite Element Method of Surface Acoustic Wave Biosensor for Gas Detection Application
Authors: Noor A M , Norali A N , Zakaria Z , Mazalan M , Wahab Y
Published: November 2021

A surface acoustic wave (SAW) sensor detects changes in physical properties such as mass and density on its surface. Compared to other types of sensors, SAW sensor have a good stability, high selectivity and sensitivity, fast response, and low-cost. On the other hand, to design and optimize a SAW biosensor requires a long process including time and cost using conventional methods. Therefore, numerical simulation and computational modelling are useful and efficiently conduct analysis for the SAW biosensor. In this paper, a numerical simulation technique is used to analyse the SAW device sensitivity for the application of gas detection. The SAW biosensor can detect very small mass loading by changing its sensor resonance frequency. The two-dimensional (2D) device model is based on a two-port SAW resonator with a gas sensing layer. We made two design of SAW biosensor device with frequency of 872 MHz and 1.74 GHz. A gas with vary concentration from 1 to 100 ppm were used to determine the change of the device resonance frequency. As a result, the high frequency (1.74 GHz) device, shows that the resonance frequency is shifted larger than to the low frequency (872 MHz) device. In addition, the high frequency device offers five times more sensitivity than the low frequency device. By changing the sensor design, the sensor characteristics such as sensitivity can be altered to meet certain sensing requirements. Numerical simulation provides advantages for sensor optimization and useful for nearly representing the real condition.
Rapid prototyping of a temperature, humidity, and pressure monitor electronic layer for Pressure Ulcer wound patch
Authors: Sta. Agueda J R , Lim J , Mondragon J M , Madrid J , Belen M G , Eustaquio G M Y , Monjardin J G , Salud N
Published: November 2021

Pressure ulcer is a result of relieving pressure from skin or underlying tissues, causing localized injuries. In this study, a prototype of an electronic monitoring layer that can be placed on top of the wound patch is designed. The electronic layer is comprised of four force-sensitive pressure sensors, and an integrated temperature and humidity sensor to monitor the activities surrounding the wound site. In the simulated wound bed experiments, the results indicated that the utilization of the Bosch BME280 I2C module, when placed on top of a gauze pad, can deliver accurate and real-time monitoring of the temperature and humidity values. Furthermore, the force-sensitive resistors (FSR) installed can be utilized to detect external pressure beyond the set allowable force applied of 32 mmHg or 700g. Therefore, the electronic layer assembled from commercially available sensors can be used to monitor temperature and humidity while being able to detect externally applied pressure in real-time. However, improvements in the size and flexibility of the electronic layer are necessary to reduce the discomfort that patients suffering from pressure ulcers will experience.
Three-dimensional printed orthosis in biomedical application: A short review
Authors: Hasibuzzaman Md , Wahab Asnida Abdul , Seng Gan Hong , Ramlee Muhammad Hanif
Published: November 2021

The three-dimensional (3D) printing in medical implants unlocks unparalleled opportunities to completely configure the product to the patient’s measurements and needs. To be noted, the use of personalized 3D printed orthosis used in regeneration for serious orthosis implants of specific patients is growing to date. The 3D printed is unique to the patient instruments that can be used to facilitate correct positioning of implants and improved functional outcomes. The 3D printing, also defined as ‘rapid prototyping’ and ‘additive manufacturing’ is widely regarded as the ‘second technological revolution. The orthosis is an “externally applied mechanism used to alter the structural and functional properties of the musculoskeletal and skeletal system”. Applications in orthosis healthcare that are pioneering the way 3D printing is performed, changing the orthosis implant markets. This paper is reporting literature on the development of orthosis using 3D printing technology that could make the users more comfortable and easier to maintain. From the literature search, this paper summarises some important information about the use of 3D printing for orthosis development where it focusses on specific regions of human body, the materials for the 3D printed orthosis and further directions of this technology and research. In conclusion, the findings from this review paper may lead to a future recommendation and study in providing better treatment for patients.
Initial Results on Primary Field Cancellation of Magnetic Induction Spectroscopy Technique for Fetal Acidosis Detection using COMSOL Multiphysics
Authors: Abdul Halim S F , Zakaria M H , Zakaria Z , Norali A N , Mohd Noor A , Ahmed A A , Pusppanathan J , Fazalul Rahiman M H , Mohd Muji S Z , Abdul Rahim R
Published: November 2021

Monitoring of fetal condition during labor could save hundred lives in a single year. During labor, fetus is at critical condition as acidosis may occur suddenly without any early symptoms. Invasive method such as Fetal Blood Sampling (FBS) has been used to detect the decline in pH level of fetus. However, fetal loss rate after FBS may range from 1.4% up to 25%. In this paper, magnetic field induction spectroscopy was implemented to determine fetal acidosis by using primary magnetic field cancellation technique. Magnetic Induction Spectroscopy (MIS) probe was design where transmitter coil (TX) is perpendicular to receiver coil (RX). The result shows that the secondary magnetic field produced have been successfully measured without any interruption from primary magnetic field. By using transmitter input 1A, it shows that voltage is inversely proportional to the blood pH due to the conductivity properties of blood.
A Comparative Study on Instantaneous and Mean Pulse Arrival Time for Cuffless Blood Pressure Estimation
Authors: Wan Zaki W S , Correia R , Korposh S , Hayes-Gill B R , Morgan S P
Published: November 2021

Pulse arrival time (PAT) is the delay time between the peak of the R-wave Electrocardiogram (ECG) signal and the peak of Photoplethysmogram (PPG) signals. This method is widely exploited for continuous cuffless blood pressure measurement. In the literature, the PAT was determined based on the mean at a certain number or certain period of heartbeats, but none of them deployed a single pulse wave for PAT calculation. Therefore, in this paper, a relationship between mean PAT (15 pulses ± Standard Deviation (SD)) and instantaneous PAT (a pulse) with blood pressure (BP) was investigated on thirteen healthy male volunteers (aged between 17 to 42 years) through a pedal exercise. The PAT is grouped into three (3) categories which depend on the spatial position of the PPG signal measured; finger (PATf), wrist (PATw), and underfoot (PATt). The ECG and the PPG signals were synchronized using a Nexus-10 MK II data acquisition device and Matlab software (R 2014b) for subsequent analysis. An oscillometric cuff-based blood pressure instrument (Ostar, P2) was used as a BP reference during the experiment. Statistical analysis showed no significant difference in the |r| value between mean (15 pulses ± SD) and instantaneous PAT-BP; hence both methods are applicable for BP estimation using the PAT-BP calibration technique.
Performance Analysis on the Effect of Noise in Inverse Surface Adaptive Thresholding (ISAT)
Authors: Yazid H , Mat Som M H , Basah S N , Abdul Rahim S , Mahmud M F , Arof H
Published: November 2021

Thresholding is one of the powerful methods in segmentation phase. Numerous methods were proposed to segment the foreground from the background but there is limited number of studies that analyse the effect of noise since the present of noise will affect the performance of the thresholding method. In this paper, the main idea is to analyse the effect of noise in Inverse Surface Adaptive Thresholding (ISAT) method. ISAT method is known as an excellent method to segment the image with the present of noise. The result of this analysis can be a guideline to researcher when implementing ISAT method especially in medical image diagnosis. Initially, several images with different noise variations were prepared and underwent ISAT method. In ISAT method, several image processing methods were incorporated namely edge detection, Otsu thresholding and inverse surface construction. The resulting images were evaluated using Misclassification Error (ME) to evaluate the performance of the segmentation result. Based on the obtained results, ISAT performance is consistent although the noise percentage increases from 5% to 25%.
DNA Microarray Image Segmentation Using Markov Random Field Algorithm
Authors: Mat Said K A , Jambek A B
Published: November 2021

A deoxyribonucleic acid (DNA) microarray image requires a three-stage process to enhance and preserve the image’s important information. These are gridding, segmentation, and intensity extraction. Of these three processes, segmentation is considered the most difficult, as its function is to differentiate between features in the foreground and background. The elements in the foreground form the object or the vital information of the image, while the background features less critical information for DNA microarray image analysis. This paper presents a study that utilises the Markov random field (MRF) segmentation algorithm on a DNA microarray image. The MRF algorithm evaluates the current pixel depends on its neighbouring pixels. The experimental results show that the MRF algorithm works effectively in the segmentation process for a DNA microarray image.
Large Amplitude Harmonic Vibration under Pulse Doppler Measurement
Authors: Hermawan N , Ishii T , Yamakoshi Y , Saijo Y
Published: November 2021

A flow velocity or tissue motion can be measured by pulse Doppler method. However, when the method is applied to a sinusoid motion or harmonic vibration, the estimation result is deviated. In this paper, the generalized theory of pulse Doppler measurement to the sinusoid motion is explained and the relation between the estimation deviation and the real value is given. Furthermore, a special case of binary velocity estimation is expanded and simulated with different parameters. This simulation result suggested that different selection of parameters may fundamentally affect the output of pulse Doppler estimation.
An Image Pre-Processing Improvement Procedure for Standardizing Multiple Colour Variations in the Astrocytoma Immunohistochemical Staining Images
Authors: Dzulkifli F A , Mashor M Y , Jaafar H
Published: November 2021

Colour variations in the histopathological images can occur when the acquired images came from different laboratories. This issue happens may be due to different protocols between each laboratory. Besides that, the usage of dye or staining is also different since it arrived from different manufacturers. Hence, it will affect the performance of a system, especially for an automated image diagnosis system. If this issue is taken lightly, the whole process of image analysis can produce a false diagnosis outcome, and thus, it will affect the patient’s treatment options and endanger the patient’s life. This paper proposed an automated image pre-processing procedure for standardizing the colour variations in immunohistochemical staining images. The proposed procedure was done by modifying the reference image, which will be used later for the stain standardization process. Based on 50 astrocytoma histopathological images, the proposed procedure showed a promising result, where the quality of the output images has been enhanced and standardized.
An Investigation of Brain Signal Characteristics between Hafiz/Hafizah Subjects and Non-Hafiz/Hafizah Subjects
Authors: Abdul Halim S F , Awang S A , Mohamaddan S
Published: November 2021

Tahfiz education has gain its popularity among Malaysians thus expand the circle of hafiz and hafizah all over the country. This study has been done to investigate effect of memorizing Al-Quran by determining the difference between hafiz/hafizah subjects and non-hafiz/hafizah subjects in terms of their focus using brain signal characteristics. 10 subjects (5 hafiz/hafizah and 5 non-hafiz/hafizah) have been participated in this study. Database of EEG was recorded by using EegoSport (ANT Neuro, ES-230, The Netherlands) while listening no music, rock music, instrumental music and Al-Quran audio simultaneously with Continuous Performance Task (CPT). The classification has been done by using machine learning method. Decision Tree method have obtained the highest accuracy (96.63%) for PSD Burg by using beta wave. The finding shows that hafiz/hafizah group were more focus in all given tasks compared to non-hafiz/hafizah group. Statistical analysis by using Wilcoxon Signed-Ranks Test found that the designed methodology was significant with 95% confidence interval.
A Biomedical Voice Measurement Diagnosis of Parkinson’s Disease through the utilization of Artificial Neural Network
Authors: Ayap N F M , Eugenio B A , Hinolan J I V , Puno J C V , Baldovino R G , Billones R K C
Published: November 2021

In 2016 alone, there were a total of 120,000 cases of PD diagnosed and documented, however, experts believe that there are still loss cases which remain to be undiagnosed because of external factors such as medical cost and accuracy of diagnosis. The detection and diagnosis of PD on its early onset has become a problem in the medical field because of the slow progression of its symptoms. With the advent of technology, different diagnosing methods are being introduced and explored - one of which is through the concept of Neural Network. This paper highlights the human voice of patients using Multilayer Perceptron Neural Network (MLP) to accurately diagnose individuals who are diagnosed with PD. It was seen that the MLP classification prediction has achieved an average of 91.5% accuracy.
Reliability of Electrocardiogram Signals during Feature Extraction Stage for Smart Textile Shirts
Authors: Mohd Nawawi MM , Sidek Khairul Azami , Azman Amelia Wong , Nashrul Fazli Mohd Nasir
Published: November 2021

Wearable smart textiles have garnered significant interest due to their high flexibility, reusability, convenience and ability to work on home-based, real-life and real-time monitoring. Wearable smart textiles are shirts with inbuilt textile sensors that enable electrocardiogram (ECG) data to be collected more comfortably and smoothly outside the laboratory and clinical environment for a continuous and longer duration for ECG data collection. However, the existing ECG wearable smart textile main challenge is maintaining the quality and reliability of data across multiple wearable smart textile shirts. Therefore, this research analyses the capability of ECG morphology during Feature Extraction stages for different wearable smart textile shirts. This paper reports the experiment conducted on eleven healthy volunteers, either wearing the Hexoskin smart shirt or the HeartIn Fit shirt or both. ECG data were recorded while they are doing normal daily routine activities for at least 45 minutes. The study demonstrates a significant possibility of reliability in Feature Extraction stages at different time instances among subject and wearable smart textiles shirts. With R peaks average between 0.543 to 1.194 mV and R-R interval average between 0.625 to 0.799 seconds, the study concludes that both wearable smart textiles do not significantly differ in Feature Extraction stages. Thus, both wearable smart textiles gave a significant result, although both are affected by their wearer’s motion artefacts during the shifting of body postures and the wearer’s body physical states. Furthermore, the ECG morphology in this study has yielded a promising result in real life and as on-the-go ECG smart textile biometric readiness for future explorations.