Displaying publications 1 - 20 of 34 in total

Abstract:
Sort:
  1. Report of a rare case of tracheal foreign-body in an adult
    Majeed AR
    Med J Malaysia, 1978 Dec;33(2):146-8.
    PMID: 755166
  2. The anti-anesthetic action of idazoxan
    Majeed AB
    Biol Pharm Bull, 1996 Feb;19(2):203-8.
    PMID: 8850306
    A possible anti-anesthetic effect of idazoxan using the depth versus latency of cortical cellular response and somatosensory evoked potentials as indices of anesthesia was studied. With the administration of 10 mg/kg (i.p.) idazoxan, a potent and selective alpha 2-adrenoceptor antagonist, to an anesthetized rat with 1.25-1.5 g/kg (i.p.) urethane, the modal latency of somatosensory cortical responses to electrical stimulation of the forepaw (0-90 V, 1 Hz) was shortened to 87 +/- 3.6% (mean +/- S.D.; n = 3) of the baseline value. The number of units firing increased by 259 +/- 98.5% (n = 3). The combined parameter (1/L x Pi; L, latency; Pi, initial positive wave) of the somatosensory evoked potentials was enhanced to 125.0 +/- 16.2% (n = 19) versus saline (98.9 +/- 25.6%; n = 18) during the desynchronized electroencephalogram (EEG). The initial negative component (Ni) of the somatosensory cortical response was increased to 192.0 +/- 83.1% (n = 19) and 134.8 +/- 36.9% (n = 19) during the synchronized and desynchronized EEG, respectively. Thus idazoxan appears to produce effects resembling a "lightening of anesthesia." This may provide the impetus for further studies on the possibility of using alpha 2-adrenoceptor antagonists in the recovery from certain types of anesthetic agents.
  3. Fulltext Improving medication safety in UK care homes: challenges and current perspective
    Fahrni ML, Franklin BD, Rawaf S, Majeed A
    JRSM Open, 2014 Feb;5(2):2042533313515475.
    PMID: 25057369 DOI: 10.1177/2042533313515475
    In the UK, there are policy and regulatory concerns regarding the governance of care homes and healthcare provision within these homes. From a public health perspective, these issues can pose significant challenges to the provision of safe and quality medication use services to care home residents. The objective of this paper is to highlight an important and neglected issue for the growing population of institutionalized older adults. We reviewed relevant literature for the years 2000 to present and identified recent efforts undertaken to improve medication safety standards in UK care homes. We consider the limitations and reasons for the National Health Service's restricted role and lack of leadership in providing medical services for this institutionalized population. The efforts taken by the Department of Health and other healthcare authorities targeting medication safety in care homes are also highlighted. In order to improve the quality of healthcare, specifically in areas related to medication safety and quality use of medicines, interventions need to be taken by the national government and similarly by local authorities and NHS commissioners.
  4. pH dependent poly[2-(methacryloyloxyethyl)trimetylammonium chloride-co-methacrylic acid]hydrogels for enhanced targeted delivery of 5-fluorouracil in colon cancer cells
    Mishra RK, Ramasamy K, Ahmad NA, Eshak Z, Majeed AB
    J Mater Sci Mater Med, 2014 Apr;25(4):999-1012.
    PMID: 24398912 DOI: 10.1007/s10856-013-5132-x
    Stimuli responsive hydrogels have shown enormous potential as a carrier for targeted drug delivery. In this study we have developed novel pH responsive hydrogels for the delivery of 5-fluorouracil (5-FU) in order to alleviate its antitumor activity while reducing its toxicity. We used 2-(methacryloyloxyethyl) trimetylammonium chloride a positively charged monomer and methacrylic acid for fabricating the pH responsive hydrogels. The released 5-FU from all except hydrogel (GEL-5) remained biologically active against human colon cancer cell lines [HT29 (IC50 = 110-190 μg ml(-1)) and HCT116 (IC50 = 210-390 μg ml(-1))] but not human skin fibroblast cells [BJ (CRL2522); IC50 ≥ 1000 μg ml(-1)]. This implies that the copolymer hydrogels (1-4) were able to release 5-FU effectively to colon cancer cells but not normal human skin fibroblast cells. This is probably due to the shorter doubling time that results in reduced pH in colon cancer cells when compared to fibroblast cells. These pH sensitive hydrogels showed well defined cell apoptosis in HCT116 cells through series of events such as chromatin condensation, membrane blebbing, and formation of apoptotic bodies. No cell killing was observed in the case of blank hydrogels. The results showed the potential of these stimuli responsive polymer hydrogels as a carrier for colon cancer delivery.
  5. Fulltext Surface Reconstruction from Parallel Curves with Application to Parietal Bone Fracture Reconstruction
    Majeed A, Mt Piah AR, Ridzuan Yahya Z
    PLoS One, 2016;11(3):e0149921.
    PMID: 26967643 DOI: 10.1371/journal.pone.0149921
    Maxillofacial trauma are common, secondary to road traffic accident, sports injury, falls and require sophisticated radiological imaging to precisely diagnose. A direct surgical reconstruction is complex and require clinical expertise. Bio-modelling helps in reconstructing surface model from 2D contours. In this manuscript we have constructed the 3D surface using 2D Computerized Tomography (CT) scan contours. The fracture part of the cranial vault are reconstructed using GC1 rational cubic Ball curve with three free parameters, later the 2D contours are flipped into 3D with equidistant z component. The constructed surface is represented by contours blending interpolant. At the end of this manuscript a case report of parietal bone fracture is also illustrated by employing this method with a Graphical User Interface (GUI) illustration.
  6. Fulltext Craniofacial reconstruction using rational cubic ball curves
    Majeed A, Mt Piah AR, Gobithaasan RU, Yahya ZR
    PLoS One, 2015;10(4):e0122854.
    PMID: 25880632 DOI: 10.1371/journal.pone.0122854
    This paper proposes the reconstruction of craniofacial fracture using rational cubic Ball curve. The idea of choosing Ball curve is based on its robustness of computing efficiency over Bezier curve. The main steps are conversion of Digital Imaging and Communications in Medicine (Dicom) images to binary images, boundary extraction and corner point detection, Ball curve fitting with genetic algorithm and final solution conversion to Dicom format. The last section illustrates a real case of craniofacial reconstruction using the proposed method which clearly indicates the applicability of this method. A Graphical User Interface (GUI) has also been developed for practical application.
  7. Fulltext Conductometric and volumetric studies of atorvastatin in aqueous solution of arginine from 298.15 to 313.15 K
    Affandi MM, Tripathy M, Majeed AB
    J Adv Pharm Technol Res, 2016 Jul-Sep;7(3):80-6.
    PMID: 27429926 DOI: 10.4103/2231-4040.184589
    Categorized as a Biopharmaceutics Classification System Class II drugs, atorvastatin (ATV) exhibits low aqueous solubility and bioavailability thus presenting an obstacle and great challenge to formulation researchers. Numerous studies are available in regard to the solubility enhancement of ATV, but very few actually describe this phenomenon in terms of thermodynamics and the solute-solvent interaction. Arginine (ARG) is an amino acid that has been reported to enhance the solubility of the highly insoluble wheat protein gluten through hydrogen bonding and π electron-cation interaction. To our knowledge, ARG has never been investigated as a solubility enhancement agent of aqueous insoluble drugs. Thus, this study aimed to elucidate the solute-solvent and solute-cosolute interactions and derive thermodynamic parameters that bolstered the solubility of ATV in the presence of ARG. We examined the electrolytic conductance and densities of ATV-ARG binary system covering the temperature ranging from 298.15 K to 313.15 K. Conductometric and volumetric parameters such as limiting molar conductance, association constants, limiting partial molar volumes, and expansibility values were calculated. Additionally, thermodynamic parameters (ΔG(0), ΔH(0), ΔS(0), and Es) involved in the association process of the solute in the aqueous solution of ARG were also determined.
  8. Thermodynamics and solute-solvent interactions of lovastatin in an aqueous arginine solution
    Zolkiflee NF, Affandi MMRMM, Majeed ABA
    Eur J Pharm Sci, 2020 Jan 01;141:105111.
    PMID: 31629916 DOI: 10.1016/j.ejps.2019.105111
    Lovastatin (LVS) is an effective therapeutic and prophylactic agent in several cardiovascular disorders. However, it has low bioavailability. This study investigated solute-solvent and solute-cosolute interactions and assessed thermodynamic parameters that contributed to LVS solubility enhancement in the presence of arginine (ARG) as a hydrotropic agent. The electrolytic conductance of LVS-ARG binary system was measured at temperatures from 298.15 K to 313.15 K. Conductometric parameters such as limiting molar conductance was evaluated. Additionally, thermodynamic parameters (ΔG0, ΔH0, ΔS0 and ES) involved in the association process of the solute in the aqueous solution of ARG solution were determined systematically. Solubility markedly improved 43-fold in the LVS-ARG complex compared to LVS alone. The analysed data from values of molar conductance and activation energy suggested favourable solubilisation, with a stronger solute-solvent interaction between LVS-ARG in water at higher temperatures. ARG and LVS complexation caused by strong molecular interactions was confirmed by spectral results. Hence, the addition of ARG as a co-solute was proven to enhance LVS solubility in water. The obtained data will ultimately enable the development of desired highly soluble, more efficient and safer LVS preparations.
  9. Antimicrobial and in vitro wound healing properties of novel clay based bionanocomposite films
    Mishra RK, Ramasamy K, Lim SM, Ismail MF, Majeed AB
    J Mater Sci Mater Med, 2014 Aug;25(8):1925-39.
    PMID: 24831081 DOI: 10.1007/s10856-014-5228-y
    The present study investigates the development of methyl cellulose (MC)-sodium alginate (SA)-montmorillonite (MMT) clay based bionanocomposite films with interesting wound healing properties. The differential scanning calorimetry analysis of the composite films revealed presence of single glass transition temperature (Tg) confirming the miscible nature of the ternary blended films. The increase in MMT ratio in the composite films reduced the mobility of biopolymer chains (MC/SA) which increased the Tg of the film. Thermogravimetric analysis showed that dispersion of clay (MMT) at nano level significantly delayed the weight loss that correlated with higher thermal stability of the composite films. It was observed that the developed films were able to exhibit antimicrobial activity against four typical pathogenic bacteria found in the presence of wound. The developed films were able to significantly inhibit (10 mg/ml) the growth of Enterococcus faecium and Pseudomonas aeruginosa. In vitro scratch assay indicated potential wound closure activities of MC-2-4 bionanocomposite films at their respective highest subtoxic doses. In conclusion, these ternary bionanocomposite films were found to be promising systems for wound healing applications.
  10. A prospective study on the pattern of medication use for schizophrenia in the outpatient pharmacy department, Hospital Tengku Ampuan Rahimah, Selangor, Malaysia
    Ponto T, Ismail NI, Abdul Majeed AB, Marmaya NH, Zakaria ZA
    Methods Find Exp Clin Pharmacol, 2010 Jul-Aug;32(6):427-32.
    PMID: 20852752 DOI: 10.1358/mf.2010.32.6.1477907
    Schizophrenia is a chronic psychiatric disorder and pharmacotherapy plays a major role in its management. The 1950s and early 1960s saw milestones in the introduction of psychotropic drugs in clinical practice. A review of drug prescriptions in different settings provides an insight into the pattern of drug use, identifies drug-related problems and may be used to compare recommended guidelines with actual practice. This effort led to the evaluation of the drug prescribing pattern of antipsychotics in patients attending the psychiatric clinic at a government hospital. The data from 371 antipsychotic medication prescriptions that included 200 prescriptions for schizophrenia were collected during one month (1rst-31rst August 2008) at the outpatient pharmacy department. The mean age of patients was 35.0 years (SD = 1.131), with a male to female ratio of 2:1. The most widely used oral antipsychotic was haloperidol (16.3%) while the most common depot preparation prescribed was zuclopenthixol decanoate (8.8%). The daily dose of the average antipsychotic prescribed in this clinic was 342.06 mg equivalent of chlorpromazine. There was no relation between the doses received and ethnicity of the patient (Malay, Chinese or Indian). However, there was a significant relationship between the prescribed dose and patient age (P < 0.042). Nearly 32% of the schizophrenia patients were prescribed with atypical antipsychotics such as olanzapine (10.8%), risperidone (10.0%), quetiapine (7.6%) and clozapine (3.2%). Monotherapy was given to 73.0% of the schizophrenia patients. The majority of patients also received antidepressants. To conclude, this study gave evidence that physicians had a strong preference for monotherapy with conventional antipsychotic drugs while the use of atypical drugs was less prevalent.
  11. Fulltext Solubility enhancement of simvastatin by arginine: thermodynamics, solute-solvent interactions, and spectral analysis
    Meor Mohd Affandi MM, Tripathy M, Shah SA, Majeed AB
    Drug Des Devel Ther, 2016;10:959-69.
    PMID: 27041998 DOI: 10.2147/DDDT.S94701
    We examined the solubility of simvastatin in water in 0.01 mol·dm(-3), 0.02 mol·dm(-3), 0.04 mol·dm(-3), 0.09 mol·dm(-3), 0.18 mol·dm(-3), 0.36 mol·dm(-3), and 0.73 mol·dm(-3) arginine (ARG) solutions. The investigated drug is termed the solute, whereas ARG the cosolute. Phase solubility studies illustrated a higher extent of solubility enhancement for simvastatin. The aforementioned system was subjected to conductometric and volumetric measurements at temperatures (T) of 298.15 K, 303.15 K, 308.15 K, and 313.15 K to illustrate the thermodynamics involved and related solute-solvent interactions. The conductance values were used to evaluate the limiting molar conductance and association constants. Thermodynamic parameters (ΔG (0), ΔH (0), ΔS (0), and E s) for the association process of the solute in the aqueous solutions of ARG were calculated. Limiting partial molar volumes and expansibilities were evaluated from the density values. These values are discussed in terms of the solute-solvent and solute-cosolute interactions. Further, these systems were analyzed using ultraviolet-visible analysis, Fourier-transform infrared spectroscopy, and (13)C, (1)H, and two-dimensional nuclear overhauser effect spectroscopy nuclear magnetic resonance to complement thermophysical explanation.
  12. Fulltext Information technology for patient safety
    Huckvale C, Car J, Akiyama M, Jaafar S, Khoja T, Bin Khalid A, et al.
    Qual Saf Health Care, 2010 Aug;19 Suppl 2:i25-33.
    PMID: 20693213 DOI: 10.1136/qshc.2009.038497
    BACKGROUND: Research on patient care has identified substantial variations in the quality and safety of healthcare and the considerable risks of iatrogenic harm as significant issues. These failings contribute to the high rates of potentially avoidable morbidity and mortality and to the rising levels of healthcare expenditure seen in many health systems. There have been substantial developments in information technology in recent decades and there is now real potential to apply these technological developments to improve the provision of healthcare universally. Of particular international interest is the use of eHealth applications. There is, however, a large gap between the theoretical and empirically demonstrated benefits of eHealth applications. While these applications typically have the technical capability to help professionals in the delivery of healthcare, inadequate attention to the socio-technical dimensions of their use can result in new avoidable risks to patients.

    RESULTS AND DISCUSSION: Given the current lack of evidence on quality and safety improvements and on the cost-benefits associated with the introduction of eHealth applications, there should be a focus on implementing more mature technologies; it is also important that eHealth applications should be evaluated against a comprehensive and rigorous set of measures, ideally at all stages of their application life cycle.

  13. Fulltext A machine learning approach of predicting high potential archers by means of physical fitness indicators
    Muazu Musa R, P P Abdul Majeed A, Taha Z, Chang SW, Ab Nasir AF, Abdullah MR
    PLoS One, 2019;14(1):e0209638.
    PMID: 30605456 DOI: 10.1371/journal.pone.0209638
    k-nearest neighbour (k-NN) has been shown to be an effective learning algorithm for classification and prediction. However, the application of k-NN for prediction and classification in specific sport is still in its infancy. The present study classified and predicted high and low potential archers from a set of physical fitness variables trained on a variation of k-NN algorithms and logistic regression. 50 youth archers with the mean age and standard deviation of (17.0 ± 0.56) years drawn from various archery programmes completed a one end archery shooting score test. Standard fitness measurements of the handgrip, vertical jump, standing broad jump, static balance, upper muscle strength and the core muscle strength were conducted. Multiple linear regression was utilised to ascertain the significant variables that affect the shooting score. It was demonstrated from the analysis that core muscle strength and vertical jump were statistically significant. Hierarchical agglomerative cluster analysis (HACA) was used to cluster the archers based on the significant variables identified. k-NN model variations, i.e., fine, medium, coarse, cosine, cubic and weighted functions as well as logistic regression, were trained based on the significant performance variables. The HACA clustered the archers into high potential archers (HPA) and low potential archers (LPA). The weighted k-NN outperformed all the tested models at itdemonstrated reasonably good classification on the evaluated indicators with an accuracy of 82.5 ± 4.75% for the prediction of the HPA and the LPA. Moreover, the performance of the classifiers was further investigated against fresh data, which also indicates the efficacy of the weighted k-NN model. These findings could be valuable to coaches and sports managers to recognise high potential archers from a combination of the selected few physical fitness performance indicators identified which would subsequently save cost, time and energy for a talent identification programme.
  14. Fulltext Frequency of Root Canal Treatment among Patients Attending a Teaching Dental Hospital in Dammam, Saudi Arabia
    Khan SQ, Khabeer A, Al Harbi F, Arrejaie AS, Moheet IA, Farooqi FA, et al.
    Saudi J Med Med Sci, 2017 04 20;5(2):145-148.
    PMID: 30787773 DOI: 10.4103/1658-631X.204860
    Objective: The purpose of the study was to evaluate the frequency and status of root canal-treated teeth in patients treated at the College of Dentistry, University of Dammam in the Eastern Province of Saudi Arabia.

    Materials and Methods: A total of 3701 patients visited the clinics during the study period. Through the use of radiographs, 161 patients were initially selected who had endodontically treated teeth. However, after applying the inclusion criteria, the total number of eligible cases was reduced to 155. Patients were divided into three groups according to age (children 1-12 years, adults 13-65 years and geriatrics >65 years).

    Results: On average, each patient had 2.28 ± 1.88 root canal-treated teeth and 24.02 ± 5.03 teeth without root canal treatment. The average number of endodontically treated teeth increased with an increase in age. The adult group showed the highest number of root-filled teeth 314 (93.4%). Of the 336 endodontically treated teeth, only 75 (22.3%) teeth exhibited periapical radiolucency. First molars (28.43-36.36%) and second premolars (20.1-27.27%) were the most frequently root-filled teeth in both jaws, followed by the first maxillary premolars (11.76%). Periapical lesions showed an almost similar pattern with the highest number of radiolucencies found in the first molars in both jaws (29.3-33.3%) followed by the second premolars in the mandible (30.6%) and first premolars in both jaws (20.8-25%).

    Conclusion: The first molars and second premolars were the most frequently root-filled teeth in both jaws, followed by maxillary first premolars. Periapical lesions showed an almost similar pattern among teeth with a higher number of radiolucencies found in the first molars in both jaws, followed by the second premolars in the mandible and the first premolars in both jaws.

  15. Fulltext Surveillance of Injury Types, Locations, and Intensities in Male and Female Tennis Players: A Content Analysis of Online Newspaper Reports
    Musa RM, Hassan I, Abdullah MR, Azmi MNL, P P Abdul Majeed A, Abu Osman NA
    Int J Environ Res Public Health, 2021 12 01;18(23).
    PMID: 34886410 DOI: 10.3390/ijerph182312686
    The popularity of modern tennis has contributed to the increasing number of participants at both recreational and competitive levels. The influx of numerous tennis participants has resulted in a wave of injury occurrences of different types and magnitudes across both male and female players. Since tennis injury harms both players' economic and career development, a better understanding of its epidemiology could potentially curtail its prevalence and occurrences. We used online-based tennis-related injury reports to study the prevalence, location types, and injury intensities in both male and female tennis players for the past five years. It is demonstrated from the chi-square analysis that injury occurrences are significantly associated with a specific gender (χ2(18) = 50.773; p = 0.001), with male players having a higher risk of injury manifestation (68.10%) as compared with female players (31.90%). Nonetheless, knee, hip, ankle, and shoulder injuries are highly prevalent in both male and female players. Moreover, the injury intensities are distributed across gender (χ2(2) = 0.398; p = 0.820), with major injuries being dominant, followed by minor injuries, whilst a few cases of career-threatening injuries were also reported. It was similarly observed that male players recorded a higher degree of both major, minor, and career-threatening injuries than female players. In addition, male players sustained more elbow, hip, knee, shoulder, and thigh injuries than female players. Whereas, female players mostly suffered from Achilles and back injuries, ankle and hamstring injuries affected both genders. The usage of online newspaper reports is pivotal in characterizing the epidemiology of tennis-related injuries based on locations and gender to better understand the pattern and localization of injuries, which could be used to address the problem of modern tennis-related injuries.
  16. The identification of high potential archers based on fitness and motor ability variables: A Support Vector Machine approach
    Taha Z, Musa RM, P P Abdul Majeed A, Alim MM, Abdullah MR
    Hum Mov Sci, 2018 Feb;57:184-193.
    PMID: 29248809 DOI: 10.1016/j.humov.2017.12.008
    Support Vector Machine (SVM) has been shown to be an effective learning algorithm for classification and prediction. However, the application of SVM for prediction and classification in specific sport has rarely been used to quantify/discriminate low and high-performance athletes. The present study classified and predicted high and low-potential archers from a set of fitness and motor ability variables trained on different SVMs kernel algorithms. 50 youth archers with the mean age and standard deviation of 17.0 ± 0.6 years drawn from various archery programmes completed a six arrows shooting score test. Standard fitness and ability measurements namely hand grip, vertical jump, standing broad jump, static balance, upper muscle strength and the core muscle strength were also recorded. Hierarchical agglomerative cluster analysis (HACA) was used to cluster the archers based on the performance variables tested. SVM models with linear, quadratic, cubic, fine RBF, medium RBF, as well as the coarse RBF kernel functions, were trained based on the measured performance variables. The HACA clustered the archers into high-potential archers (HPA) and low-potential archers (LPA), respectively. The linear, quadratic, cubic, as well as the medium RBF kernel functions models, demonstrated reasonably excellent classification accuracy of 97.5% and 2.5% error rate for the prediction of the HPA and the LPA. The findings of this investigation can be valuable to coaches and sports managers to recognise high potential athletes from a combination of the selected few measured fitness and motor ability performance variables examined which would consequently save cost, time and effort during talent identification programme.
  17. Corrigendum to 'Single domain antibodies derived from ancient animals as broadly neutralizing agents for SARS-CoV-2 and other coronaviruses': Biomedical Engineering Advances 4 (2022) 100054
    Lim HT, Kok BH, Lim CP, Majeed ABA, Leow CY, Leow CH
    Biomed Eng Adv, 2023 Jun;5:100086.
    PMID: 37091500 DOI: 10.1016/j.bea.2023.100086
    [This corrects the article DOI: 10.1016/j.bea.2022.100054.].
  18. Fulltext Single domain antibodies derived from ancient animals as broadly neutralizing agents for SARS-CoV-2 and other coronaviruses
    Lim HT, Kok BH, Lim CP, Abdul Majeed AB, Leow CY, Leow CH
    Biomed Eng Adv, 2022 Dec;4:100054.
    PMID: 36158162 DOI: 10.1016/j.bea.2022.100054
    With severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as an emergent human virus since December 2019, the world population is susceptible to coronavirus disease 2019 (COVID-19). SARS-CoV-2 has higher transmissibility than the previous coronaviruses, associated by the ribonucleic acid (RNA) virus nature with high mutation rate, caused SARS-CoV-2 variants to arise while circulating worldwide. Neutralizing antibodies are identified as immediate and direct-acting therapeutic against COVID-19. Single-domain antibodies (sdAbs), as small biomolecules with non-complex structure and intrinsic stability, can acquire antigen-binding capabilities comparable to conventional antibodies, which serve as an attractive neutralizing solution. SARS-CoV-2 spike protein attaches to human angiotensin-converting enzyme 2 (ACE2) receptor on lung epithelial cells to initiate viral infection, serves as potential therapeutic target. sdAbs have shown broad neutralization towards SARS-CoV-2 with various mutations, effectively stop and prevent infection while efficiently block mutational escape. In addition, sdAbs can be developed into multivalent antibodies or inhaled biotherapeutics against COVID-19.
  19. Fulltext The classification of movement intention through machine learning models: the identification of significant time-domain EMG features
    Mohd Khairuddin I, Sidek SN, P P Abdul Majeed A, Mohd Razman MA, Ahmad Puzi A, Md Yusof H
    PeerJ Comput Sci, 2021;7:e379.
    PMID: 33817026 DOI: 10.7717/peerj-cs.379
    Electromyography (EMG) signal is one of the extensively utilised biological signals for predicting human motor intention, which is an essential element in human-robot collaboration platforms. Studies on motion intention prediction from EMG signals have often been concentrated on either classification and regression models of muscle activity. In this study, we leverage the information from the EMG signals, to detect the subject's intentions in generating motion commands for a robot-assisted upper limb rehabilitation platform. The EMG signals are recorded from ten healthy subjects' biceps muscle, and the movements of the upper limb evaluated are voluntary elbow flexion and extension along the sagittal plane. The signals are filtered through a fifth-order Butterworth filter. A number of features were extracted from the filtered signals namely waveform length (WL), mean absolute value (MAV), root mean square (RMS), standard deviation (SD), minimum (MIN) and maximum (MAX). Several different classifiers viz. Linear Discriminant Analysis (LDA), Logistic Regression (LR), Decision Tree (DT), Support Vector Machine (SVM) and k-Nearest Neighbour (k-NN) were investigated on its efficacy to accurately classify the pre-intention and intention classes based on the significant features identified (MIN and MAX) via Extremely Randomised Tree feature selection technique. It was observed from the present investigation that the DT classifier yielded an excellent classification with a classification accuracy of 100%, 99% and 99% on training, testing and validation dataset, respectively based on the identified features. The findings of the present investigation are non-trivial towards facilitating the rehabilitation phase of patients based on their actual capability and hence, would eventually yield a more active participation from them.
  20. Fulltext The classification of motor imagery response: an accuracy enhancement through the ensemble of random subspace k-NN
    Rashid M, Bari BS, Hasan MJ, Razman MAM, Musa RM, Ab Nasir AF, et al.
    PeerJ Comput Sci, 2021;7:e374.
    PMID: 33817022 DOI: 10.7717/peerj-cs.374
    Brain-computer interface (BCI) is a viable alternative communication strategy for patients of neurological disorders as it facilitates the translation of human intent into device commands. The performance of BCIs primarily depends on the efficacy of the feature extraction and feature selection techniques, as well as the classification algorithms employed. More often than not, high dimensional feature set contains redundant features that may degrade a given classifier's performance. In the present investigation, an ensemble learning-based classification algorithm, namely random subspace k-nearest neighbour (k-NN) has been proposed to classify the motor imagery (MI) data. The common spatial pattern (CSP) has been applied to extract the features from the MI response, and the effectiveness of random forest (RF)-based feature selection algorithm has also been investigated. In order to evaluate the efficacy of the proposed method, an experimental study has been implemented using four publicly available MI dataset (BCI Competition III dataset 1 (data-1), dataset IIIA (data-2), dataset IVA (data-3) and BCI Competition IV dataset II (data-4)). It was shown that the ensemble-based random subspace k-NN approach achieved the superior classification accuracy (CA) of 99.21%, 93.19%, 93.57% and 90.32% for data-1, data-2, data-3 and data-4, respectively against other models evaluated, namely linear discriminant analysis, support vector machine, random forest, Naïve Bayes and the conventional k-NN. In comparison with other classification approaches reported in the recent studies, the proposed method enhanced the accuracy by 2.09% for data-1, 1.29% for data-2, 4.95% for data-3 and 5.71% for data-4, respectively. Moreover, it is worth highlighting that the RF feature selection technique employed in the present study was able to significantly reduce the feature dimension without compromising the overall CA. The outcome from the present study implies that the proposed method may significantly enhance the accuracy of MI data classification.
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links