Displaying publications 41 - 60 of 101 in total

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  1. Adli Azam MR, Raja Amin RM
    Malays J Med Sci, 2015 Jan-Feb;22(1):70-3.
    PMID: 25892952 MyJurnal
    Malignant chest wall tumour is rare. The presentation is usually aggressive that requires extensive resection to prevent recurrence. However, the extensive resection is to the expense of causing defect on the chest wall and hence, respiratory mechanics. Two cases of chest wall tumour are discussed including the surgical approach of radical tumour resection which was combined with placement of titanium mesh and Tranverse Rectus Abdominis Myocutaneus (TRAM) flap to cover the defect and preserve respiratory mechanical functions. The morbidity of using titanium mesh demonstrated in the case series were infection and injury to surrounding tissue due to its rigidity and large size which required its removal. However the formation of 'pseudopleura' made the thoracic cage return back as closed cavity even after the removal of the titanium mesh and allow normal respiratory functions.
    Matched MeSH terms: Prostheses and Implants
  2. Arifin N, Hasbollah HR, Hanafi MH, Ibrahim AH, Rahman WAWA, Aziz RC
    Malays J Med Sci, 2017 Oct;24(5):106-111.
    PMID: 29386978 MyJurnal DOI: 10.21315/mjms2017.24.5.12
    The incidence of lower limb amputation is high across the globe and continues to be a major threat to morbidity and mortality. Consequently, the provision of high quality and effective prosthetics services have been known as an essential component for a successful rehabilitation outcome. In Malaysia, amputation prevalence has been increasing in which several main components of service delivering aspects (such as service intervention, prosthetic personnel) should be anticipated to accommodate for the increasing demand. This article highlights the hurdles experienced in providing prosthetic services in Malaysia from multiple aspects such as financial burden to acquire the prosthesis and lack of expertise to produce quality prosthesis. This paramount issues consequently justify for the urgency to carry out national level survey on the current statistics of lower limb amputation and to ascertain the available workforce to provide a quality prosthetics services. Only with accurate and current information from the national survey, strategies and policies aimed at enhancing the outcome from prosthetics services can be achieved.
    Matched MeSH terms: Prostheses and Implants
  3. Hannan MA, Hussein HA, Mutashar S, Samad SA, Hussain A
    Sensors (Basel), 2014;14(12):23843-70.
    PMID: 25615728 DOI: 10.3390/s141223843
    With the development of communication technologies, the use of wireless systems in biomedical implanted devices has become very useful. Bio-implantable devices are electronic devices which are used for treatment and monitoring brain implants, pacemakers, cochlear implants, retinal implants and so on. The inductive coupling link is used to transmit power and data between the primary and secondary sides of the biomedical implanted system, in which efficient power amplifier is very much needed to ensure the best data transmission rates and low power losses. However, the efficiency of the implanted devices depends on the circuit design, controller, load variation, changes of radio frequency coil's mutual displacement and coupling coefficients. This paper provides a comprehensive survey on various power amplifier classes and their characteristics, efficiency and controller techniques that have been used in bio-implants. The automatic frequency controller used in biomedical implants such as gate drive switching control, closed loop power control, voltage controlled oscillator, capacitor control and microcontroller frequency control have been explained. Most of these techniques keep the resonance frequency stable in transcutaneous power transfer between the external coil and the coil implanted inside the body. Detailed information including carrier frequency, power efficiency, coils displacement, power consumption, supplied voltage and CMOS chip for the controllers techniques are investigated and summarized in the provided tables. From the rigorous review, it is observed that the existing automatic frequency controller technologies are more or less can capable of performing well in the implant devices; however, the systems are still not up to the mark. Accordingly, current challenges and problems of the typical automatic frequency controller techniques for power amplifiers are illustrated, with a brief suggestions and discussion section concerning the progress of implanted device research in the future. This review will hopefully lead to increasing efforts towards the development of low powered, highly efficient, high data rate and reliable automatic frequency controllers for implanted devices.
    Matched MeSH terms: Prostheses and Implants*
  4. Mutashar S, Hannan MA, Samad SA, Hussain A
    Sensors (Basel), 2014;14(7):11522-41.
    PMID: 24984057 DOI: 10.3390/s140711522
    The use of wireless communication using inductive links to transfer data and power to implantable microsystems to stimulate and monitor nerves and muscles is increasing. This paper deals with the development of the theoretical analysis and optimization of an inductive link based on coupling and on spiral circular coil geometry. The coil dimensions offer 22 mm of mutual distance in air. However, at 6 mm of distance, the coils offer a power transmission efficiency of 80% in the optimum case and 73% in the worst case via low input impedance, whereas, transmission efficiency is 45% and 32%, respectively, via high input impedance. The simulations were performed in air and with two types of simulated human biological tissues such as dry and wet-skin using a depth of 6 mm. The performance results expound that the combined magnitude of the electric field components surrounding the external coil is approximately 98% of that in air, and for an internal coil, it is approximately 50%, respectively. It can be seen that the gain surrounding coils is almost constant and confirms the omnidirectional pattern associated with such loop antennas which reduces the effect of non-alignment between the two coils. The results also show that the specific absorption rate (SAR) and power loss within the tissue are lower than that of the standard level. Thus, the tissue will not be damaged anymore.
    Matched MeSH terms: Prostheses and Implants*
  5. Jaganathan SK, Supriyanto E, Murugesan S, Balaji A, Asokan MK
    Biomed Res Int, 2014;2014:459465.
    PMID: 24895577 DOI: 10.1155/2014/459465
    Cardiovascular biomaterials (CB) dominate the category of biomaterials based on the demand and investments in this field. This review article classifies the CB into three major classes, namely, metals, polymers, and biological materials and collates the information about the CB. Blood compatibility is one of the major criteria which limit the use of biomaterials for cardiovascular application. Several key players are associated with blood compatibility and they are discussed in this paper. To enhance the compatibility of the CB, several surface modification strategies were in use currently. Some recent applications of surface modification technology on the materials for cardiovascular devices were also discussed for better understanding. Finally, the current trend of the CB, endothelization of the cardiac implants and utilization of induced human pluripotent stem cells (ihPSCs), is also presented in this review. The field of CB is growing constantly and many new investigators and researchers are developing interest in this domain. This review will serve as a one stop arrangement to quickly grasp the basic research in the field of CB.
    Matched MeSH terms: Prostheses and Implants*
  6. Buzayan MM
    Prosthet Orthot Int, 2014 Feb;38(1):62-7.
    PMID: 23625838 DOI: 10.1177/0309364613484052
    Mid-facial defect is one of the most disfiguring and impairing defects. A design of prosthesis that is aesthetic and stable can be precious to a patient who has lost part of his face due to surgical excision. Prosthesis can restore the patients' self-esteem and confidence, which affects the patients and their life style. The aim of this case report is to describe a technique of mid-facial silicone prosthesis fabrication.
    Matched MeSH terms: Prostheses and Implants*
  7. Saravanan S, Vivek AS
    Med J Malaysia, 2007 Dec;62(5):418-9.
    PMID: 18705481 MyJurnal
    This is to report on the use of growing endoprosthesis, also known as lengthening prosthesis in the management of four patients in the paedriatic age group in the Orthopaedic Oncolgy Unit at University Malaya Medical Centre. These are custom made prosthesis, designed and made in India based on measured roentrograms. The ages of these patients vary from 6 to 13 years old. These are cases of Osteosarcoma and Ewing's sarcoma around the knee. This is the first time these custom made prosthesis have ever been used in Malaysia. We feel that this is a feasible option for limb salvage in the treatment of primary bone tumours in growing children.
    Matched MeSH terms: Prostheses and Implants*
  8. Inayat-Hussain SH, Rajab NF, Roslie H, Hussin AA, Ali AM, Annuar BO
    Med J Malaysia, 2004 May;59 Suppl B:176-7.
    PMID: 15468875
    Biomaterials intended for end-use application as bone-graft substitutes have to undergo safety evaluation. In this study, we investigated the in vitro cytotoxic effects especially to determine the mode of death of two hydroxyapatite compounds (HA2, HA3) which were synthesized locally. The methods used for cytotoxicity was the standard MTT assay whereas AO/PI staining was performed to determine the mode of cell death in HA treated L929 fibroblasts. Our results demonstrated that both HA2 and HA3 were not significantly cytotoxic as more than 75% cells after 72 hours treatment were viable. Furthermore, we found that the major mode of cell death in HA treated cells was apoptosis. In conclusion, our results demonstrated that these hydroxyapatite compounds are not cytotoxic where the mode of death was primarily via apoptosis.
    Matched MeSH terms: Prostheses and Implants*
  9. Rajab NF, Yaakob TA, Ong BY, Hamid M, Ali AM, Annuar BO, et al.
    Med J Malaysia, 2004 May;59 Suppl B:170-1.
    PMID: 15468872
    Hydroxyapatite is the main component of the bone which is a potential biomaterial substance that can be applied in orthopaedics. In this study, the biocompatibility of this biomaterial was assessed using an in vitro technique. The cytotoxicity and genotoxicity effect of HA2 and HA3 against L929 fibroblast cell was evaluated using the MTT Assay and Alkaline Comet Assay respectively. Both HA2 and HA3 compound showed low cytotoxicity effect as determined using MTT Assay. Cells viability following 72 hours incubation at maximum concentration of both HA2 and HA3 (200 mg/ml) were 75.3 +/- 8.8% and 86.7 +/- 13.1% respectively. However, the cytotoxicity effect of ZnSO4.7H2O as a positive control showed an IC50 values of 46 mg/ml (160 microM). On the other hand, both HA2 and HA3 compound showed a slight genotoxicity effect as determined using the Alkaline Comet Assay following incubation at the concentration 200 mg/ml for 72 hours. This assay has been widely used in genetic toxicology to detect DNA strand breaks and alkali-labile site. The percentage of the cells with DNA damage for both substance was 27.7 +/- 1.3% and 15.6 +/- 1.0% for HA2 and HA3 respectively. Incubation of the cells for 24 hours with 38 microg/ml (IC25) of positive control showed an increase in percentage of cells with DNA damage (67.5 +/- 0.7%). In conclusion, our study indicated that both hydroxyapatite compounds showed a good biocompatibility in fibroblast cells.
    Matched MeSH terms: Prostheses and Implants*
  10. Kannan TP, Nik Ahmad Shah NL, Azlina A, Samsudin AR, Narazah MY, Salleh M
    Med J Malaysia, 2004 May;59 Suppl B:168-9.
    PMID: 15468871
    The present study is aimed at finding the mutagenicity and cytotoxicity of dense form of synthetic hydroxyapatite (Source: School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia) in the blood of sheep. The biomaterial was implanted in the tibia of Malin, an indigenous sheep breed of Malaysia. Blood was collected from the sheep before implantation of the biomaterial, cultured and a karyological study was made. Six weeks after implantation, blood was collected from the same animal, cultured and screened for chromosome aberrations. The mitotic indices and karyological analysis indicated that the implantation of synthetic hydroxyapatite (dense form) did not produce any cytotoxicity or chromosome aberrations in the blood of sheep.
    Matched MeSH terms: Prostheses and Implants*
  11. Hassan MH
    Med J Malaysia, 2004 May;59 Suppl B:164-5.
    PMID: 15468869
    There has been, and is still, concern about the high elastic modulus of Ti alloys compared to bone. Any reduction in the Young's modulus value of the implant is expected to enhance stress redistribution to the adjacent bone tissues, minimize stress shielding and eventually prolong device lifetime. Dynamic Monte Carlo simulation is used to predict the gradual reduction in Young's modulus values between the bulk of Ti alloys and the modified surface layers due to Ca ion implantation. The simulation can be used as a screening step when applying new alloys and/or coatings.
    Matched MeSH terms: Prostheses and Implants*
  12. Tan SA, Ahmad Fauzi MN, Luay BH, Radzali O
    Med J Malaysia, 2004 May;59 Suppl B:162-3.
    PMID: 15468868
    In this work, nanometer HA crystals have been synthesized via wet chemical precipitation and characterized. This research studies how key synthesis parameters affect the size and phase purity of the produced HA. Characterization work was carried out using X-ray powder diffraction method and scanning electron microscopy for phase identification and particle sizing, respectively.
    Matched MeSH terms: Prostheses and Implants*
  13. Loqman MY, Wong CM, Hair-Bejo M, Zuki AB, Hafeez YM
    Med J Malaysia, 2004 May;59 Suppl B:113-4.
    PMID: 15468844
    A study was conducted to investigate the effectiveness of freeze-dried bovine pericardium (FDBP) as a biomaterial in diaphragmatic herniorrhapy in dogs. Eight adult dogs were randomly selected and divided into two equal groups. In FDBP group, a diaphragmatic defect was induced and repaired with an identical size of FDBP. In the control group, a diaphragmatic wall was incised at three-side border creating a flap and sutured. Grossly, only mild intrathoracic adhesion was observed for most of the animals, and no herniation occured. Microscopically, the biomaterial incorporated into the host's tissue by ingrowth of young muscle fiber and massive new blood vessel formation in between the fibrous tissue.
    Matched MeSH terms: Prostheses and Implants*
  14. Samsudin AR
    Med J Malaysia, 2004 May;59 Suppl B:6.
    PMID: 15468791
    Matched MeSH terms: Prostheses and Implants*
  15. Rampal S, Tan EK, Gendeh HS, Prahaspathiji LJ, Zainal S, Amir S
    Med J Malaysia, 2020 01;75(1):80-82.
    PMID: 32008027
    A 68-year-old female presented with a 1-month history of lower back pain with right-sided radiculopathy and numbness. She was diagnosed with lumbar spondylosis and treated conservatively with analgesia and physiotherapy. Imaging showed multiple susuk, a metal alloy, in the lower back region and other regions of the body. The patient had undergone traditional medicine consultation 10 years earlier when the susuk was inserted in the lower back as talisman. The practice of the insertion of susuk is popular in rural East Malaysia and Indonesia. These foreign bodies act as possible causes of chronic inflammation and granuloma formation. In addition, the localised heighten peril upon imaging. This report suggests that the insertion of multiple susuk as talisman carries risk to safety of patients when imaging, and this practice complicates the management of musculoskeletal disorders.
    Matched MeSH terms: Prostheses and Implants/adverse effects*
  16. Mohd Khalid H, Jauhari I, Mohamad Wali HA, Abdulrazzaq Mahmod S
    Biomed Mater, 2017 01 25;12(1):015019.
    PMID: 28120816 DOI: 10.1088/1748-605X/aa4f8b
    In this in vivo study, Sprague Dawley (SD) rats were used to investigate the bioactivity as well as the microstructural and mechanical properties of Ti-6Al-4V samples embedded with hydroxyapatite (HA) using two different coating methods-superplastic embedment (SPE) and superplastic deformation (SPD). The HA layer thickness for the SPE and SPD samples increased from 249.1  ±  0.6 nm to 874.8  ±  13.7 nm, and from 206.1  ±  5.8 nm to 1162.7  ±  7.9 nm respectively, after 12 weeks of implantation. The SPD sample exhibited much faster growth of newly formed HA compared to SPE. The growth of the newly formed HA was strongly dependent on the degree of HA crystallinity in the initial HA layer. After 12 weeks of implantation, the surface hardness value of the SPE and SPD samples decreased from 661  ±  0.4 HV to 586  ±  1.3 HV and from 585  ±  6.6 HV to 425  ±  86.9 HV respectively. The decrease in surface hardness values was due to the newly formed HA layer that was more porous than the initial HA layer. However, the values were still higher than the substrate surface hardness of 321  ±  28.8 HV. Wear test results suggest that the original HA layers for both samples were still strongly intact, and to a certain extent the newly grown HA layers also were strongly bound with the original HA layers. This study confirms the bioactivity and mechanical stability of the HA layer on both samples in vivo.
    Matched MeSH terms: Prostheses and Implants*
  17. Farook TH, Jamayet NB, Asif JA, Din AS, Mahyuddin MN, Alam MK
    Sci Rep, 2021 04 19;11(1):8469.
    PMID: 33875672 DOI: 10.1038/s41598-021-87240-9
    Palatal defects are rehabilitated by fabricating maxillofacial prostheses called obturators. The treatment incorporates taking deviously unpredictable impressions to facsimile the palatal defects into plaster casts for obturator fabrication in the dental laboratory. The casts are then digitally stored using expensive hardware to prevent physical damage or data loss and, when required, future obturators are digitally designed, and 3D printed. Our objective was to construct and validate an economic in-house smartphone-integrated stereophotogrammetry (SPINS) 3D scanner and to evaluate its accuracy in designing prosthetics using open source/free (OS/F) digital pipeline. Palatal defect models were scanned using SPINS and its accuracy was compared against the standard laser scanner for virtual area and volumetric parameters. SPINS derived 3D models were then used to design obturators by using (OS/F) software. The resultant obturators were virtually compared against standard medical software designs. There were no significant differences in any of the virtual parameters when evaluating the accuracy of both SPINS, as well as OS/F derived obturators. However, limitations in the design process resulted in minimal dissimilarities. With further improvements, SPINS based prosthetic rehabilitation could create a viable, low cost method for rural and developing health services to embrace maxillofacial record keeping and digitised prosthetic rehabilitation.
    Matched MeSH terms: Prostheses and Implants/statistics & numerical data*
  18. Abd Razak NA, Abu Osman NA, Gholizadeh H, Ali S
    Biomed Eng Online, 2014;13:134.
    PMID: 25208636 DOI: 10.1186/1475-925X-13-134
    Understanding of kinematics force applied at the elbow is important in many fields, including biomechanics, biomedical engineering and rehabilitation. This paper provides a comparison of a mathematical model of elbow joint using three different types of prosthetics for transhumeral user, and characterizes the forces required to overcome the passive mechanical of the prosthetics at the residual limb.
    Matched MeSH terms: Prostheses and Implants*
  19. Al-Fakih E, Abu Osman NA, Mahamd Adikan FR
    Sensors (Basel), 2012 Sep 25;12(10):12890-926.
    PMID: 23201977 DOI: 10.3390/s121012890
    In recent years, fiber Bragg gratings (FBGs) are becoming increasingly attractive for sensing applications in biomechanics and rehabilitation engineering due to their advantageous properties like small size, light weight, biocompatibility, chemical inertness, multiplexing capability and immunity to electromagnetic interference (EMI). They also offer a high-performance alternative to conventional technologies, either for measuring a variety of physical parameters or for performing high-sensitivity biochemical analysis. FBG-based sensors demonstrated their feasibility for specific sensing applications in aeronautic, automotive, civil engineering structure monitoring and undersea oil exploration; however, their use in the field of biomechanics and rehabilitation applications is very recent and its practicality for full-scale implementation has not yet been fully established. They could be used for detecting strain in bones, pressure mapping in orthopaedic joints, stresses in intervertebral discs, chest wall deformation, pressure distribution in Human Machine Interfaces (HMIs), forces induced by tendons and ligaments, angles between body segments during gait, and many others in dental biomechanics. This article aims to provide a comprehensive overview of all the possible applications of FBG sensing technology in biomechanics and rehabilitation and the status of ongoing researches up-to-date all over the world, demonstrating the FBG advances over other existing technologies.
    Matched MeSH terms: Prostheses and Implants*
  20. Jaganathan SK, Mohandas H, Sivakumar G, Kasi P, Sudheer T, Avineri Veetil S, et al.
    Biomed Res Int, 2014;2014:963149.
    PMID: 24955370 DOI: 10.1155/2014/963149
    Blood compatibility of metallocene polyethylene (mPE) was investigated after modifying the surface using hydrochloric acid. Contact angle of the mPE exposed to HCl poses a decrease in its value which indicates increasing wettability and better blood compatibility. Surface of mPE analyzed by using FTIR revealed no significant changes in its functional groups after treatment. Furthermore, scanning electron microscope images supported the increasing wettability through the modifications like pit formations and etching on the acid rendered surface. To evaluate the effect of acid treatment on the coagulation cascade, prothrombin time (PT) and activated partial thromboplastin time (APTT) were measured. Both PT and APTT were delayed significantly (P < 0.05) after 60 min exposure implying improved blood compatibility of the surfaces. Hemolysis assay of the treated surface showed a remarkable decrease in the percentage of lysis of red blood cells when compared with untreated surface. Moreover, platelet adhesion assay demonstrated that HCl exposed surfaces deter the attachment of platelets and thereby reduce the chances of activation of blood coagulation cascade. These results confirmed the enhanced blood compatibility of mPE after HCl exposure which can be utilized for cardiovascular implants like artificial vascular prostheses, implants, and various blood contacting devices.
    Matched MeSH terms: Prostheses and Implants/adverse effects; Prostheses and Implants/ultrastructure*
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