Now showing 1 - 4 of 4
  • Publication
    Muscle fatigue in the three heads of triceps Brachii during intensity and speed variations of triceps push-down exercise
    (Frontiers Media SA, 2020)
    Jawad Hussain
    ;
    Kenneth Sundaraj
    ;
    Indra Devi Subramaniam
    ;
    The objective of this study was to investigate the effects of changes in exercise intensity and speed on the three heads of the triceps brachii (TB) during triceps push-down exercise until task failure. Twenty-five subjects performed triceps push-down exercise at three different intensities (30, 45, and 60% 1RM) and speeds (slow, medium, and fast) until failure, and surface electromyography (sEMG) signals were recorded from the lateral, long and medial heads of the TB. The endurance time (ET), number of repetitions (NR) and rate of fatigue (ROF) were analyzed. Subsequently, the root-mean-square (RMS), mean power frequency (MPF) and median frequency (MDF) under no-fatigue (NF) and fatigue (Fa) conditions were statistically compared. The findings reveal that ROF increases with increase in the intensity and speed, and the opposite were obtained for the ET. The ROF in the three heads were comparable for all intensities and speeds. The ROF showed a significant difference (P < 0.05) among the three intensities and speeds for all heads. The three heads showed significantly different (P < 0.05) MPF and MDF values for all the performed exercises under both conditions, whereas the RMS values were significantly different only under Fa conditions. The current observations suggest that exercise intensity and speed affect the ROF while changes in intensity do not affect the MPF and MDF under Fa conditions. The behavior of the spectral parameters indicate that the three heads do not work in unison under any of the conditions. Changes in the speed of triceps push-down exercise affects the lateral and long heads, but changes in the exercise intensity affected the attributes of all heads to a greater extent.
  • Publication
    Mechanomyography: an insight to muscle physiology
    (Springer, 2020)
    Irsa Talib
    ;
    Kenneth Sundaraj
    ;
    ;
    Md. Asraf Ali
    ;
    Jawad Hussain
    The aim of this review article is to highlight an important application of mechanomyography as a tool to study muscle physiology related issues. Skeletal muscles are of vital significance in our body and contribute well towards all type of movements. Although, there are other techniques in vogue used for non-invasive assessment of muscle. But mechanomyography (MMG) do offer shear benefits for reliable muscle study. So, a substantial number of related articles were searched for this technical review from various databases including SCOPUS, PubMed, ScienceDirect, IEEE Xplore and springer link. Records were screened according to the selection criteria. The studies related to muscle physiology aspects analyzed using MMG were only selected for detailed analysis. During in depth analysis of records finally selected for this article, physiology aspects investigated via MMG were divided into seven sections including muscle stiffness, Parkinson disease, effect of dehydration, muscle contractile properties, muscle contraction mechanics, muscle temperature and muscle hypertrophy. The findings of this review suggest that MMG is a useful and reliable tool to investigate muscle physiology and it has significant applications in sports and medicine. Muscle contractile properties can be employed for future investigation on muscle fatigue, stiffness, atrophy and even functional mechanics of muscle. This review might fill the gap in knowledge in understanding of muscle physiology using MMG.
  • Publication
    Analysis of wheeze sounds during tidal breathing according to severity levels in asthma patients
    (Taylor & Francis, 2019)
    Fizza Ghulam Nabi
    ;
    Kenneth Sundaraj
    ;
    ;
    Rajkumar Palaniappan
    Objective: This study aimed to statistically analyze the behavior of time-frequency features in digital recordings of wheeze sounds obtained from patients with various levels of asthma severity (mild, moderate, and severe), and this analysis was based on the auscultation location and/or breath phase. Method: Segmented and validated wheeze sounds were collected from the trachea and lower lung base (LLB) of 55 asthmatic patients during tidal breathing maneuvers and grouped into nine different datasets. The quartile frequencies F25, F50, F75, F90 and F99, mean frequency (MF) and average power (AP) were computed as features, and a univariate statistical analysis was then performed to analyze the behavior of the time-frequency features. Results: All features generally showed statistical significance in most of the datasets for all severity levels [χ2 = 6.021–71.65, p < 0.05, η2 = 0.01–0.52]. Of the seven investigated features, only AP showed statistical significance in all the datasets. F25, F75, F90 and F99 exhibited statistical significance in at least six datasets [χ2 = 4.852–65.63, p < 0.05, η2 = 0.01–0.52], and F25, F50 and MF showed statistical significance with a large η2 in all trachea-related datasets [χ2 = 13.54–55.32, p < 0.05, η2 = 0.13–0.33]. Conclusion: The results obtained for the time-frequency features revealed that (1) the asthma severity levels of patients can be identified through a set of selected features with tidal breathing, (2) tracheal wheeze sounds are more sensitive and specific predictors of severity levels and (3) inspiratory and expiratory wheeze sounds are almost equally informative.
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  • Publication
    A systematic review of phacoemulsification cataract surgery in virtual reality simulators
    ( 2013-01-27) ;
    Kenneth Sundaraj
    ;
    Mohd Nazri Sulaiman
    The aim of this study was to review the capability of virtual reality simulators in the application of phacoemulsification cataract surgery training. Our review included the scientific publications on cataract surgery simulators that had been developed by different groups of researchers along with commercialized surgical training products, such as EYESI® and PhacoVision®. The review covers the simulation of the main cataract surgery procedures, i.e., corneal incision, capsulorrhexis, phacosculpting, and intraocular lens implantation in various virtual reality surgery simulators. Haptics realism and visual realism of the procedures are the main elements in imitating the actual surgical environment. The involvement of ophthalmology in research on virtual reality since the early 1990s has made a great impact on the development of surgical simulators. Most of the latest cataract surgery training systems are able to offer high fidelity in visual feedback and haptics feedback, but visual realism, such as the rotational movements of an eyeball with response to the force applied by surgical instruments, is still lacking in some of them. The assessment of the surgical tasks carried out on the simulators showed a significant difference in the performance before and after the training.
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