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McColm L, Asbalaili EE, Khandakar T, Razak NA, Yuyi AT, Yau JD. 710 A Novel Ventriculoperitoneal Shunt Design Aiming to Reduce Shunt Failure Rates. Br J Surg 2021. [DOI: 10.1093/bjs/znab134.211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
Introduction
Ventriculoperitoneal (VP) shunt insertion is the most common surgical treatment for hydrocephalus. While shunt obstructions are frequent and subsequent revision operations carry significant morbidity, there is limited advancement in shunt design to address this problem.
Method
A literature review of aetiology and mechanism of shunt blockage was performed. Design concepts of current medical and non-medical grade devices were studied. Design improvements to VP shunt were focused on the proximal catheter and lumen configuration. Concept dimensions and computer flow simulations using different diameters were generated.
Results
An improved prototype VP shunt design was proposed. It has multiple lumens and communicating channels between neighbouring lumens to provide alternative routes for cerebrospinal fluid drainage in the event of individual lumen obstruction. Our design also features a novel cone-shaped proximal end to minimise occlusion by nearby choroid plexus.
Conclusions
By targeting common causes of VP shunt blockage through proposed novel design, the mean service-life of shunts can be extended, necessitating fewer revision procedures and reducing both patient health and financial burdens. Further investigation, optimisation, and validation of this proposed shunt design is required before further product development.
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Affiliation(s)
- L McColm
- Medical Student, University of Edinburgh, School of Medicine and Veterinary Sciences, Edinburgh, United Kingdom
| | - E E Asbalaili
- Engineering Student, School of Engineering, University of Edinburgh, Edinburgh, United Kingdom
| | - T Khandakar
- Engineering Student, School of Engineering, University of Edinburgh, Edinburgh, United Kingdom
| | - N A Razak
- Engineering Student, School of Engineering, University of Edinburgh, Edinburgh, United Kingdom
| | - A T Yuyi
- Medical Student, University of Edinburgh, School of Medicine and Veterinary Sciences, Edinburgh, United Kingdom
| | - J D Yau
- Foundation Doctor, Royal Infirmary of Edinburgh, Edinburgh, United Kingdom
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Matore MEEM, Khairani AZ, Razak NA, Mohamad M. Improving the psychometric properties of the Mooney problem checklist by using Rasch measurement model. J Fundam and Appl Sci 2018. [DOI: 10.4314/jfas.v9i6s.32] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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May KN, Razak NA. Relationship between sleep and mood states among student-athlete of Majlis Sukan Negeri (MSN), Perak. J Fundam and Appl Sci 2018. [DOI: 10.4314/jfas.v9i6s.99] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Mokhtar NH, Abas A, Razak NA, Hamid MNA, Teong SL. Effect of different stent configurations using Lattice Boltzmann method and particles image velocimetry on artery bifurcation aneurysm problem. J Theor Biol 2017; 433:73-84. [PMID: 28844907 DOI: 10.1016/j.jtbi.2017.08.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 08/10/2017] [Accepted: 08/15/2017] [Indexed: 12/15/2022]
Abstract
Proper design of stent for application at specific aneurysm effect arteries could help to reduce the issues with thrombosis and aneurysm. In this paper, four types of stent configuration namely half-Y (6 mm), half-Y (4 mm), cross-bar, and full-Y configuration will implanted on real 3D artery bifurcation aneurysm effected arteries. Comparisons were then conducted based on the flow patterns after stent placement using both LBM-based solver and PIV experimental findings. According to the data obtained from all 4 stent designs, the flow profiles and the computed velocity from both methods were in agreement with each other. Both methods found that half-Y (6 mm) stent configuration is by far the best configuration in reducing the blood velocity at the vicinity of the aneurysm sac. The analysis also show that the half-Y (6 mm) stent configuration recorded the highest percentage of velocity reduction and managed to substantially reduce the pressure at the bifurcation region. This high flow velocity reduction through the use of half-Y stent could consequently promote the formation of thrombus thereby reducing the risk of rupture in the aneurysm sac.
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Affiliation(s)
- N Hafizah Mokhtar
- School of Mechanical Engineering, Universiti Sains Malaysia, Engineering Campus, Nibong Tebal, Penang 14300, Malaysia
| | - Aizat Abas
- School of Mechanical Engineering, Universiti Sains Malaysia, Engineering Campus, Nibong Tebal, Penang 14300, Malaysia.
| | - N A Razak
- School of Aerospace Engineering, Universiti Sains Malaysia, Engineering Campus, Nibong Tebal, Penang 14300, Malaysia
| | | | - Soon Lay Teong
- School of Mechanical Engineering, Universiti Sains Malaysia, Engineering Campus, Nibong Tebal, Penang 14300, Malaysia
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Razak NA, Hashim S, Mhareb MHA, Alajerami YSM, Azizan SA, Tamchek N. Impact of Eu3+ Ions on Physical and Optical Properties of Li2O-Na2O-B2O3 Glass. CHINESE J CHEM PHYS 2016. [DOI: 10.1063/1674-0068/29/cjcp1511226] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Abstract
One of the major flow phenomena associated with low Reynolds number flow is the formation of separation bubbles on an airfoil's surface. NACA4415 airfoil is commonly used in wind turbines and UAV applications. The stall characteristics are gradual compared to thin airfoils. The primary criterion set for this work is the capture of laminar separation bubble. Flow is simulated for a Reynolds number of 120,000. The numerical analysis carried out shows the advantages and disadvantages of a few turbulence models. The turbulence models tested were: one equation Spallart Allmars (S-A), two equation SST K-ω, three equation Intermittency (γ) SST, k-kl-ω and finally, the four equation transition γ-Reθ SST. However, the variation in flow physics differs between these turbulence models. Procedure to establish the accuracy of the simulation, in accord with previous experimental results, has been discussed in detail.
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Affiliation(s)
- S. M. A. Aftab
- Dept of Aerospace Engineering, Universiti Putra Malaysia, Selangor, 43400, Malaysia
| | - A. S. Mohd Rafie
- Dept of Aerospace Engineering, Universiti Putra Malaysia, Selangor, 43400, Malaysia
| | - N. A. Razak
- School of Aerospace Engineering, Engineering Campus, Universiti Sains Malaysia, Nibong Tebal, 14300, Pulau Pinang, Malaysia
| | - K. A. Ahmad
- Dept of Aerospace Engineering, Universiti Putra Malaysia, Selangor, 43400, Malaysia
- * E-mail:
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Razak NA, Hashim S, Mhareb MHA, Tamchek N. Photoluminescence and thermoluminescence properties of Li₂O-Na₂O-B₂O₃ glass. LUMINESCENCE 2015; 31:754-9. [PMID: 26333749 DOI: 10.1002/bio.3020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 07/27/2015] [Accepted: 07/27/2015] [Indexed: 11/11/2022]
Abstract
UNLABELLED Influence of Nd(3+) concentration on the optical and thermoluminescence (TL) properties of melt-annealed synthesized 10 Na2O: 20 Li2O: (70-x) B2O3 : xNd2O3, where 0.1≤ x ≤0.7 (LNB) glasses are determined. The absence of sharp peaks in X-ray diffraction patterns confirms the amorphous nature of the prepared glasses. The photoluminescence spectra under 800 nm laser excitations at room temperature exhibit three prominent peaks centred at 538, 603 and 675 nm corresponding to the transitions of (4)G(7/2) → (4)I(9/2), [(4)G(7/2) → (4)I(11/2), (4)G(5/2) → (4)I(9/2)] and [(4)G(7/2) → (4)I(13/2), (4)G(5/2) → (4)I(11/2)], respectively. The TL glow curve exhibits a prominent peak (T(m)) at 180°C. The best performance of the prepared glass was found at 0.5 mol% of Nd2O3. We achieved a good linearity of TL response against dose between 0.5 to 4.0 Gy. The calculated value of the effective atomic number, Z(eff), is 7.55 which is nearly tissue equivalent (Z(eff) = 7.42). These promising features demonstrate the capability of the aforementioned glass to be used as a radiation dosimeter. HIGHLIGHTS The thermoluminescence and optical properties of new compositions of lithium sodium borate glasses doped with Nd(3+) ions were reported. Attractive features were obtained from the TL, PL and UV-Vis light analysis. Three upconversion luminescences permitting green, orange and red emissions were observed.
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Affiliation(s)
- N A Razak
- Department of Physics, Universiti Teknologi Malaysia, 81310, Skudai, Johor, Malaysia
| | - S Hashim
- Department of Physics, Universiti Teknologi Malaysia, 81310, Skudai, Johor, Malaysia
| | - M H A Mhareb
- Department of Physics, Universiti Teknologi Malaysia, 81310, Skudai, Johor, Malaysia.,Radiation Protection Directorate, Energy and Minerals Regulatory Commission, 11183, Amman, Jordan
| | - N Tamchek
- Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400, UPM Serdang, Selangor, Malaysia
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Gholizadeh H, Abu Osman NA, Eshraghi A, Ali S, Razak NA. Transtibial prosthesis suspension systems: systematic review of literature. Clin Biomech (Bristol, Avon) 2014; 29:87-97. [PMID: 24315710 DOI: 10.1016/j.clinbiomech.2013.10.013] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Revised: 10/18/2013] [Accepted: 10/21/2013] [Indexed: 02/07/2023]
Abstract
BACKGROUND Today a number of prosthetic suspension systems are available for transtibial amputees. Consideration of an appropriate suspension system can ensure that amputee's functional needs are satisfied. The higher the insight to suspension systems, the easier would be the selection for prosthetists. This review attempted to find scientific evidence pertaining to various transtibial suspension systems to provide selection criteria for clinicians. METHODS Databases of PubMed, Web of Science, and ScienceDirect were explored to find related articles. Search terms were as follows: "Transtibial prosthesis (32), prosthetic suspension (48), lower limb prosthesis (54), below-knee prosthesis (58), prosthetic liner (20), transtibial (193), and prosthetic socket (111)". Two reviewers separately examined the papers. Study design (case series of five or more subjects, retrospective or prospective), research instrument, sampling method, outcome measures and protocols were reviewed. FINDINGS Based on the selection criteria, 22 articles (15 prospective studies, and 7 surveys) remained. Sweat control was found to be a major concern with the available suspension liners. Donning and doffing procedures for soft liners are also problematic for some users, particularly those with upper limb weakness. Moreover, the total surface bearing (TSB) socket with pin/lock system is favored by the majority of amputees. INTERPRETATION In summary, no clinical evidence is available to suggest what kind of suspension system could have an influential effect as a "standard" system for all transtibial amputees. However, among various suspension systems for transtibial amputees, the Iceross system was favored by the majority of users in terms of function and comfort.
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Affiliation(s)
- H Gholizadeh
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Malaysia.
| | - N A Abu Osman
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Malaysia
| | - A Eshraghi
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Malaysia
| | - S Ali
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Malaysia
| | - N A Razak
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Malaysia
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Razak NA, Samad MYA, Basri M, Yunus WMZW, Ampon K, Salleh AB. Thermostable extracellular protease of Bacillus stearothermophilus: factors affecting its production. World J Microbiol Biotechnol 1994; 10:260-3. [DOI: 10.1007/bf00414858] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 09/16/1993] [Accepted: 09/23/1993] [Indexed: 10/26/2022]
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