Wan Abu Bakar Wan Abas | University of Malaya, Malaysia (original) (raw)
Papers by Wan Abu Bakar Wan Abas
PLoS One, 2013
Background: The deep tendon reflex assessments that are essential to the accurate diagnosis of ne... more Background: The deep tendon reflex assessments that are essential to the accurate diagnosis of neurological or neuromuscular disorders are conducted subjectively in clinical neurology. Our aim was to assess deep tendon reflexes objectively with a new reflex quantification method. Methodology/Principal Findings: The present study used a motion analysis technique to collect quantitative measurements for both the input and output of normal patellar tendon reflex. Reflex responses were measured as knee angles. The patellar tendon reflexes of 100 healthy subjects were examined using 6 levels of tendon taps, where all the assessments were captured using motion capture system. A linear relationship was found between the experimental maximum tapping velocity and tapping angle (coefficient of determination = 0.989), which was consistent with the theoretical values. Tapping velocities were predictable according to tapping angles. The findings proved the reproducibility of tapping method in producing consistent input. The reflex amplitude was consistent between two randomly assigned groups, and linearly proportionate to the tapping velocity. Conclusions/Significance: The findings on reflex amplitude indicate that motion analysis is a valid and reliable method of assessing and measuring deep tendon reflexes. © 2013 Tham et al.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3567131/pdf/pone.0055702.pdf
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0055702#pone-0055702-g004
4th Kuala Lumpur International Conference on Biomedical Engineering 2008, Biomed 2008, 2008
The purpose of this study is to validate of a new external finger fixator components by using fin... more The purpose of this study is to validate of a new external finger fixator components by using finite element analysis (FEA). The new external finger fixator consists of proximal, middle and distal phalanges support sections and means for rigidly connecting each support to a hinge and its corresponding attached to phalanx through the movements of flexion or extension. The results from the analysis found that the entire components of the fixator conform to the performance based on the requirements for general duty (500 N load applied on uniformly distributed load). This analysis shows that the new external fixator is able to restore full function and dynamic range of motion for patients with flexion deformity at the finger joints without failure. © 2008 Springer-Verlag.
http://link.springer.com/chapter/10.1007/978-3-540-69139-6_118
Journal of Biomedical Engineering, 1982
The application of uniaxial tension in vivo is a common test method for investigating mechanical ... more The application of uniaxial tension in vivo is a common test method for investigating mechanical properties of the skin. This paper reports an investigation of the strain distributions on the skin surface produced by such a test method. The strains were shown to be non-homogeneous with major concentrations being present near the area of load application. At all sites within the test area, axial, lateral and shear strains were present but their magnitude depended both on their position within the test site and the overall extension. The axial and lateral strains were largest and most uniformly distributed within the area bounded by th loading tabs. The shear strains, however, were smallest in the are bounded by the tabs. The distribution of the three strains became similar if they were referred to the principal axes. The area of skin within the strained area became larger as the overall deformation increased because additional skin was recruited from the sites lateral to the strained area. The general form of the load/strain relations and lateral contractions were site- and extension-dependent, but were similar to those found in vitro.
http://www.ncbi.nlm.nih.gov/pubmed/7078145
http://www.sciencedirect.com/science/article/pii/0141542582900292
Journal of Rehabilitation Research and Development, Dec 1, 2012
Poor suspension increases slippage of the residual limb inside the socket during ambulation. The ... more Poor suspension increases slippage of the residual limb inside the socket during ambulation. The main purpose of this article is to evaluate the pistoning at the prosthetic liner-socket interface during gait and assess patients' satisfaction with two different liners. Two prostheses with seal-in and lock-ing liners were fabricated for each of the 10 subjects with transtibial amputation. The Vicon motion system was used to measure the pistoning during gait. The subjects were also asked to complete a Prosthesis Evaluation Questionnaire. The results revealed higher pistoning inside the socket during gait with the locking liner than with the seal-in liner (p < 0.05). The overall satisfaction with the locking liner was higher (p < 0.05) because of the relative ease with which the patients could don and doff the device. As such, pistoning may not be the main factor that determines patients' overall satisfaction with the prosthesis and other factors may also contribute to comfort and satisfaction with prostheses. The article also verifies the feasi-bility of the Vicon motion system for measuring pistoning dur-ing gait.
http://www.ncbi.nlm.nih.gov/pubmed/23408214
http://eds.b.ebscohost.com/ehost/detail?sid=14da0d52-3122-463e-b2a9-9d1ebd3b7aeb%40sessionmgr115&vid=1&hid=110&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d
Clinical Biomechanics, Jan 1, 2012
Background: The method of attachment of prosthesis to the residual limb (suspension) and socket f... more Background: The method of attachment of prosthesis to the residual limb (suspension) and socket fitting is a critical issue in the process of providing an amputee with prosthesis. Different suspension methods try to minimize the pistoning movement inside the socket. The Seal-In (R) X5 and Dermo (R) Liner by Ossur are new suspension liners that intend to reduce pistoning between the socket and liner. Since the effects of these new liners on suspension are unclear, the objective of this study was to compare the pistoning effect of Seal-In (R) X5 and Dermo (R) Liner by using Vicon Motion System. Methods: Six transtibial amputees, using both the Iceross Seal-In (R) X5 and the Iceross Demo (R) Liner, participated in the study. The vertical displacement (pistoning) was measured between the liner and socket in single limb support on the prosthetic limb (full-weight bearing), double limb support (semi-weight bearing), and non-weight bearing on the prosthetic limb, and also under three static vertical loading conditions (30 N. 60 N, and 90 N). Findings: The results demonstrated that the pistoning within the socket when Seal-In (R) X5 was used, decreased by 71% in comparison to the Iceross Dermo (R) Liner. In addition, a significant difference between the two liners under different static conditions was found (p<0.05). Interpretation: Participants needed to put in extra effort for donning and doffing the prosthesis with Seal-In (R) X5; however, this type of liner provided less pistoning. The new approach that uses the motion analysis system in this study might be an alternative for measuring the pistoning effect in the prosthetic socket. (C) 2011 Elsevier Ltd. All rights reserved.
http://ac.els-cdn.com/S0268003311001859/1-s2.0-S0268003311001859-main.pdf?_tid=82dd2720-a019-11e3-952c-00000aab0f01&acdnat=1393551905_7c6f57e23f3b01c0a079afa004aac1b0
http://www.ncbi.nlm.nih.gov/pubmed/21794965
http://www.sciencedirect.com/science/article/pii/S0268003311001859
Clinical Biomechanics, Jan 1, 2012
Background: The method of attachment of prosthesis to the residual limb (suspension) and socket f... more Background: The method of attachment of prosthesis to the residual limb (suspension) and socket fitting is a critical issue in the process of providing an amputee with prosthesis. Different suspension methods try to minimize the pistoning movement inside the socket. The Seal-In (R) X5 and Dermo (R) Liner by Ossur are new suspension liners that intend to reduce pistoning between the socket and liner. Since the effects of these new liners on suspension are unclear, the objective of this study was to compare the pistoning effect of Seal-In (R) X5 and Dermo (R) Liner by using Vicon Motion System. Methods: Six transtibial amputees, using both the Iceross Seal-In (R) X5 and the Iceross Demo (R) Liner, participated in the study. The vertical displacement (pistoning) was measured between the liner and socket in single limb support on the prosthetic limb (full-weight bearing), double limb support (semi-weight bearing), and non-weight bearing on the prosthetic limb, and also under three static vertical loading conditions (30 N. 60 N, and 90 N). Findings: The results demonstrated that the pistoning within the socket when Seal-In (R) X5 was used, decreased by 71% in comparison to the Iceross Dermo (R) Liner. In addition, a significant difference between the two liners under different static conditions was found (p<0.05). Interpretation: Participants needed to put in extra effort for donning and doffing the prosthesis with Seal-In (R) X5; however, this type of liner provided less pistoning. The new approach that uses the motion analysis system in this study might be an alternative for measuring the pistoning effect in the prosthetic socket. (C) 2011 Elsevier Ltd. All rights reserved.
http://ac.els-cdn.com/S0268003311001859/1-s2.0-S0268003311001859-main.pdf?_tid=82dd2720-a019-11e3-952c-00000aab0f01&acdnat=1393551905_7c6f57e23f3b01c0a079afa004aac1b0
http://www.ncbi.nlm.nih.gov/pubmed/21794965
http://www.sciencedirect.com/science/article/pii/S0268003311001859
5th Kuala Lumpur International Conference on Biomedical Engineering, BIOMED 2011, Held in Conjunction with the 8th Asian Pacific Conference on Medical and Biological Engineering, APCMBE 2011, 2011
Spatial and temporal variability in the execution of skills has been analyzed in many sports. An ... more Spatial and temporal variability in the execution of skills has been analyzed in many sports. An expert performer is commonly referred to as being more consistent in the execution of skills compared to a novice. The purpose of this study was to analyze temporal characteristics and variability of the final delivery phase and examine how it is related to bowling level and performance. Two level of bowlers were used in this study - 18 elite (Male=10, Female=8; Bave 213.2±6.80; BRvel 17.66±0.85mph) and 12 semi-elite bowlers (Male=7, Female=5; Bave 181.3±9.36; BRvel 16.90±1.46mph). The final delivery phase consisted of three major events which were the arm swing, front foot slide and ball release. The temporal variable that was measured was execution time and the between-trial temporal variability, while average bowling score and ball release velocity represented the performance criteria. In general, the results indicate that the temporal characteristic between the two groups were quite similar, but in terms of relationship to bowling performance, front foot slide time was correlated with bowling average. Variability wise, the elite group was less consistent in front foot slide execution time. There were no significant differences or correlations for the other variables. It was concluded that lower temporal variability was not indicative of higher playing level or better bowling performance. © 2011 Springer-Verlag.
http://download.springer.com/static/pdf/882/chp%253A10.1007%252F978-3-642-21729-6_59.pdf?auth66=1393724504_75b19e1f75f2ee54b5de9c06e4fe0294&ext=.pdf
http://link.springer.com/chapter/10.1007/978-3-642-21729-6_59
Bio-Medical Materials and Engineering, 1995
The response of human skin to ''stress relaxation'' tests at low loads in vitro was investigated.... more The response of human skin to ''stress relaxation'' tests at low loads in vitro was investigated. A number of behaviours, other than those already well established and documented, were observed. The significant behaviours are pure recovery and relaxation-recovery. Other behaviours observed are temporary stress recovery during the relaxation process, and momentary sudden non-linear drop in stress value followed by a second relaxation. The pure recovery and relaxation-recovery responses are repeatable. The latter represents the transitional response between the well-known behaviour of stress relaxation and the behaviour of stress recovery.
http://www.ncbi.nlm.nih.gov/pubmed/7655319
American Journal of Physical Medicine and Rehabilitation, Jan 14, 2014
This report compares wrist supination and pronation and flexion and extension movements with the ... more This report compares wrist supination and pronation and flexion and extension movements with the common body-powered prosthesis and a new biomechatronics prosthesis with regard to patient satisfaction and problems experienced with the prosthesis. Fifteen subjects with traumatic transradial amputation who used both prosthetic systems participated in this study. Each subject completed two questionnaires to evaluate their satisfaction and problems experienced with the two prosthetic systems. Satisfaction and problems with the prosthetic's wrist movements were analyzed in terms of the following: supination and pronation; flexion and extension; appearance; sweating; wounds; pain; irritation; pistoning; smell; sound; durability; and the abilities to open a door, hold a cup, and pick up or place objects. This study revealed that the respondents were more satisfied with the biomechatronics wrist prosthesis with regard to supination and pronation, flexion and extension, pain, and the ability to open a door. However, satisfaction with the prosthesis showed no significant differences in terms of sweating, wounds, irritation, pistoning, smell, sound, and durability. The abilities to hold a cup and pick up or place an object were significantly better with the body-powered prosthesis. The results of the survey suggest that satisfaction and problems with wrist movements in persons with transradial amputation can be improved with a biomechatronics wrist prosthesis compared with the common body-powered prosthesis.
http://www.ncbi.nlm.nih.gov/pubmed/24429510
American Journal of Physical Medicine and Rehabilitation, Dec 1, 2012
OBJECTIVE: The objectives of this study were to compare the effects of a newly designed magnetic ... more OBJECTIVE: The objectives of this study were to compare the effects of a newly designed magnetic suspension system with that of two existing suspension methods on pistoning inside the prosthetic socket and to compare satisfaction and perceived problems among transtibial amputees. DESIGN: In this prospective study, three lower limb prostheses with three different suspension systems were fabricated for ten transtibial amputees. The participants used each of the three prostheses for 1 mo in random order. Pistoning inside the prosthetic socket was measured by motion analysis system. The Prosthesis Evaluation Questionnaire was used to evaluate satisfaction and perceived problems with each suspension system. RESULTS: The lowest pistoning motion was found with the suction system compared with the other two suspension systems (P < 0.05). The new suspension system showed peak pistoning values similar to that of the pin lock system (P = 0.086). The results of the questionnaire survey revealed significantly higher satisfaction rates with the new system than with the other two systems in donning and doffing, walking, uneven walking, stair negotiation, and overall satisfaction (P < 0.05). CONCLUSIONS: The new suspension system has the potential to be used as an alternative to the available suspension systems. The pistoning motion was comparable to that of the other two systems. The new system showed compatible prosthetic suspension with the other two systems (suction and pin lock). The satisfaction with donning and doffing was high with the magnetic system. Moreover, the subjects reported fewer problems with the new system. Copyright © 2012 by Lippincott Williams & Wilkins.
http://graphics.tx.ovid.com/ovftpdfs/FPDDNCLBPCEOKH00/fs047/ovft/live/gv024/00002060/00002060-201212000-00003.pdf
http://www.ncbi.nlm.nih.gov/pubmed/23168378
American Journal of Physical Medicine and Rehabilitation, Dec 1, 2012
OBJECTIVE: The objectives of this study were to compare the effects of a newly designed magnetic ... more OBJECTIVE: The objectives of this study were to compare the effects of a newly designed magnetic suspension system with that of two existing suspension methods on pistoning inside the prosthetic socket and to compare satisfaction and perceived problems among transtibial amputees. DESIGN: In this prospective study, three lower limb prostheses with three different suspension systems were fabricated for ten transtibial amputees. The participants used each of the three prostheses for 1 mo in random order. Pistoning inside the prosthetic socket was measured by motion analysis system. The Prosthesis Evaluation Questionnaire was used to evaluate satisfaction and perceived problems with each suspension system. RESULTS: The lowest pistoning motion was found with the suction system compared with the other two suspension systems (P < 0.05). The new suspension system showed peak pistoning values similar to that of the pin lock system (P = 0.086). The results of the questionnaire survey revealed significantly higher satisfaction rates with the new system than with the other two systems in donning and doffing, walking, uneven walking, stair negotiation, and overall satisfaction (P < 0.05). CONCLUSIONS: The new suspension system has the potential to be used as an alternative to the available suspension systems. The pistoning motion was comparable to that of the other two systems. The new system showed compatible prosthetic suspension with the other two systems (suction and pin lock). The satisfaction with donning and doffing was high with the magnetic system. Moreover, the subjects reported fewer problems with the new system. Copyright © 2012 by Lippincott Williams & Wilkins.
http://graphics.tx.ovid.com/ovftpdfs/FPDDNCLBPCEOKH00/fs047/ovft/live/gv024/00002060/00002060-201212000-00003.pdf
http://www.ncbi.nlm.nih.gov/pubmed/23168378
5th Kuala Lumpur International Conference on Biomedical Engineering, BIOMED 2011, Held in Conjunction with the 8th Asian Pacific Conference on Medical and Biological Engineering, APCMBE 2011, 2011
This study collected quantitative measurements of the patellar tendon reflex using 3-dimensional ... more This study collected quantitative measurements of the patellar tendon reflex using 3-dimensional motion analysis. The study was conducted in the Motion Analysis Laboratory, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia. Patellar tendon reflex of a group of healthy subjects involving 28 males and 22 females was examined. The left and right patellar tendons were tapped by a Queen Square reflex hammer with three different angles where the reflex hammer was released. The phenomenon of Jendrassik maneuver was tested by tapping on the tendon with the hammer raised to an angle of 60°. The purpose of this was to investigate the effect of reinforcement method on reflex responses. Results of the study showed that the patellar tendon reflex response of male subjects were higher at higher tapping force. Reflex response of the left and the right side did not show any significant difference. The study of tapping force on reflex response showed greater response at increasing tapping force. The reinforcement method named Jendrassik maneuver increased patellar tendon reflex response for both legs. © 2011 Springer-Verlag.
http://download.springer.com/static/pdf/875/chp%253A10.1007%252F978-3-642-21729-6_52.pdf?auth66=1393724480_718bef5a1f77779a23d9904c975770ba&ext=.pdf
http://link.springer.com/chapter/10.1007/978-3-642-21729-6_52
5th Kuala Lumpur International Conference on Biomedical Engineering, BIOMED 2011, Held in Conjunction with the 8th Asian Pacific Conference on Medical and Biological Engineering, APCMBE 2011, 2011
This study maps bones and joints, relate them to the vertical ground reaction forces on gait. The... more This study maps bones and joints, relate them to the vertical ground reaction forces on gait. Their localities are charted in the form of graph. This is then being exploited as arguments to reason the design of prosthetic foot. The mathematical model is developed and is based on the relationship among the anatomy of bones and joints, the vertical ground reaction forces on certain points as well as the sequence when these points experience the vertical ground reaction forces. Using the model, a custom design prosthetic foot is built using a male subject of size 5 scanned foot image. It is concluded that proper mappings and modeling of foot structure can be used as reference in design and development of prosthetic feet. © 2011 Springer-Verlag.
http://download.springer.com/static/pdf/535/chp%253A10.1007%252F978-3-642-21729-6_187.pdf?auth66=1393724488_78d6437ca2e8f6455fa2b71566e1ba10&ext=.pdf
http://link.springer.com/chapter/10.1007/978-3-642-21729-6_187
4th Kuala Lumpur International Conference on Biomedical Engineering 2008, Biomed 2008, 2008
The electromyography (EMG) activity of the biceps femoris, rectus femoris, gastrocnemius, and fou... more The electromyography (EMG) activity of the biceps femoris, rectus femoris, gastrocnemius, and fourth lumbar (L4) and fifth lumbar (L5) muscles of 5 male subjects was measured during a series of maneuvers which include standing, bowing, prostration, and sitting. Raw EMG was processed by root-mean-square (RMS) technique using a time constant of 50 ms. The results show that the gastrocnemius is the most active. The series of standing to prostration maneuvers showed 13.21±10.67 RMS, μV (mean±standard deviation), standing to bowing, 11.97± 4.89, sitting to prostration, 8.36±12.55. Preliminary EMG profiles in this study demonstrated that subjects used relatively higher levels of gastrocnemius muscle compare to the biceps femoris, rectus femoris, and fourth lumbar (L4) and fifth lumbar (L5) muscles to perform the set of moderate exercises. © 2008 Springer-Verlag.
http://link.springer.com/chapter/10.1007/978-3-540-69139-6_114
Clinics, Sep 1, 2013
OBJECTIVE: This study provides an experimental and finite element analysis of knee-joint structur... more OBJECTIVE: This study provides an experimental and finite element analysis of knee-joint structure during extended-knee landing based on the extracted impact force, and it numerically identifies the contact pressure, stress distribution and possibility of bone-to-bone contact when a subject lands from a safe height. METHODS: The impact time and loads were measured via inverse dynamic analysis of free landing without knee flexion from three different heights (25, 50 and 75 cm), using five subjects with an average body mass index of 18.8. Three-dimensional data were developed from computed tomography scans and were reprocessed with modeling software before being imported and analyzed by finite element analysis software. The whole leg was considered to be a fixed middle-hinged structure, while impact loads were applied to the femur in an upward direction. RESULTS: Straight landing exerted an enormous amount of pressure on the knee joint as a result of the body's inability to utilize the lower extremity muscles, thereby maximizing the threat of injury when the load exceeds the height-safety threshold. CONCLUSIONS: The researchers conclude that extended-knee landing results in serious deformation of the meniscus and cartilage and increases the risk of bone-to-bone contact and serious knee injury when the load exceeds the threshold safety height. This risk is considerably greater than the risk of injury associated with walking downhill or flexion landing activities. © 2013 CLINICS.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3782736/pdf/cln-68-09-1180.pdf
https://www.scienceopen.com/document_file/875d3659-9f8e-4dda-baca-494190fd73c1/PubMedCentral/875d3659-9f8e-4dda-baca-494190fd73c1.pdf
5th Kuala Lumpur International Conference on Biomedical Engineering, BIOMED 2011, Held in Conjunction with the 8th Asian Pacific Conference on Medical and Biological Engineering, APCMBE 2011, 2011
This paper describes the outcome based education (OBE) implementation and continuous quality impr... more This paper describes the outcome based education (OBE) implementation and continuous quality improvement (CQI) process plan in the Department of Biomedical Engineering, University of Malaya. The implementation of CQI plan is a part of the Outcome - based Education (OBE) approach required by the Engineering Accreditation Council (EAC) for recognition of Biomedical Engineering program and as a graduate student for Board of Engineer Malaysia (BEM) and Institute of Engineer Malaysia (IEM) membership registration. This approach was first introduced to Biomedical Engineering Department since 2005. The measurement on Programme Outcomes (POs) which will be evaluated upon graduation is done based on the results of sub-Programme Outcome (subPOs) which are evaluated at the end of each course. The improvement on assessment and evaluation process are continuously done to obtain the better achievement of POs and programme educational objectives (PEO)s in the department of Biomedical Engineering. © 2011 Springer-Verlag.
http://download.springer.com/static/pdf/750/chp%253A10.1007%252F978-3-642-21729-6_11.pdf?auth66=1393724410_c7708d4685fd6be2e3fdd4b9f6aa9ef3&ext=.pdf
http://link.springer.com/chapter/10.1007/978-3-642-21729-6_11
IEEE Transactions on Instrumentation and Measurement, Feb 1, 2005
This paper introduces a novel approach to classify the risk in dengue hemorrhagic fever (DHF) pat... more This paper introduces a novel approach to classify the risk in dengue hemorrhagic fever (DHF) patients using the bioelectrical impedance analysis (BIA) technique. This in vivo technique involves the application of a small average constant current of less than 1 mA at a single frequency of 50 kHz through the human body, and measurement of the body's bioelectrical resistance (R), phase angle (α), body capacitance (BC) and capacitive reactance (Xc) via four surface electrodes. BIA measurements have been conducted on 184 (97 males and 87 females) serological confirmed dengue patients during their hospitalization in University Kebangsaan Malaysia Hospital, Malaysia. The patients included in the study were DHF I-IV according to World Health Organization criteria. Univariate analysis of variance is used for assessing the relationship between gender and group with the bioelectrical tissue conductivity (BETC) parameters. Experimental findings show that BETC, as reflected by reactance, is the key determinant indicator for classifying risk category in the DHF patients. Hence, this novel approach of the BIA technique can provide a rapid, noninvasive, and promising method for classifying and evaluating the risk of the DHF patients.© 2005 IEEE.
http://ieeexplore.ieee.org/ielx5/19/30128/01381820.pdf?tp=&arnumber=1381820&isnumber=30128
http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=1381820&tag=1
5th Kuala Lumpur International Conference on Biomedical Engineering, BIOMED 2011, Held in Conjunction with the 8th Asian Pacific Conference on Medical and Biological Engineering, APCMBE 2011, 2011
The quality of suspension in lower limb prosthetics has significant role in amputee's satisfactio... more The quality of suspension in lower limb prosthetics has significant role in amputee's satisfaction. Good suspension lessens the pistoning movement of the residual limb inside the prosthetic socket. A number of methods are used for measuring pistoning; however most of them are difficult to be performed inside the prosthetic clinic and by every prosthetist. The purpose of this study was to introduce a new simple method for measuring pistoning in Transtibial prosthesis in static position. This method was developed in-house at Össur for the first time. In this study we used this technique to measure pistoning between socket and liner in three subjects. The result showed that this method can be an alternative method for measuring pistoning. Moreover, that makes it simple for prosthetists to test pistoning in the clinic and is a safe method for the subject. © 2011 Springer-Verlag.
http://download.springer.com/static/pdf/504/chp%253A10.1007%252F978-3-642-21729-6_177.pdf?auth66=1393724134_c9c685562defb784352c426b49cf3ca1&ext=.pdf
http://link.springer.com/chapter/10.1007/978-3-642-21729-6_177
Prosthetics and Orthotics International, Dec 1, 2011
Background: Good suspension lessens the pistoning (vertical displacement) of the residual limb in... more Background: Good suspension lessens the pistoning (vertical displacement) of the residual limb inside the prosthetic socket. Several methods are used for measuring the pistoning. Study Design: Clinical trial. Objectives: To introduce and evaluate a new simple method for measuring the pistoning between the soft liner and socket in transtibial prostheses. Methods: Five transtibial prostheses with Iceross silicone liner and shuttle lock were made for the subjects. The pistoning was measured between the liner and socket by a photographic method in single limb support on the prosthetic limb (full weight bearing), non-weight bearing and under three static axial loading conditions (30, 60 and 90 N). Results: This new method enabled us to measure the pistoning between the liner and prosthetic socket. The reproducibility of measurements in different trials of one session and between two sessions by two observers was shown to be high. The average of displacement between the liner and socket was about 9 mm in non-weight bearing compared with full weight bearing. Furthermore, as we expected, the average of pistoning increased consistently by adding the loads. Conclusions: This new method provides for easy and inexpensive determination of pistoning between the liner and socket by every prosthetist in clinical settings. © The International Society for Prosthetics and Orthotics 2011.
http://poi.sagepub.com/content/35/4/360.full.pdf
http://www.ncbi.nlm.nih.gov/pubmed/21975850
Physiological Measurement, Jun 1, 2004
This paper describes a model for predicting hemoglobin (Hb) by using bioelectrical impedance anal... more This paper describes a model for predicting hemoglobin (Hb) by using bioelectrical impedance analysis (BIA) in dengue patients in the Hospital Universiti Kebangsaan Malaysia (HUKM). Bioelectrical impedance measurements were conducted on 83 (47 males and 36 females) serologically confirmed dengue fever (DF) and dengue hemorrhagic fever (DHF) patients during their hospitalization. The predictive equation for Hb was derived using multivariate analysis. We investigated all the parameters in BIA, patients' symptom and demographic data. In this developed model, four predictors (reactance (Xc), sex, weight and vomiting) were found to be the best predictive factors for modeling Hb in dengue patients. However, the model can only explain approximately 42% of the variation in Hb status, thus single frequency bio-impedance stand-alone technique is insufficient to monitor Hb for the DF and DHF patients. Further investigation using multi-frequency BIA is recommended in modeling Hb to achieve the most parsimonious model.
http://iopscience.iop.org/0967-3334/25/3/002/pdf/0967-3334_25_3_002.pdf
http://iopscience.iop.org/0967-3334/25/3/002
PLoS One, 2013
Background: The deep tendon reflex assessments that are essential to the accurate diagnosis of ne... more Background: The deep tendon reflex assessments that are essential to the accurate diagnosis of neurological or neuromuscular disorders are conducted subjectively in clinical neurology. Our aim was to assess deep tendon reflexes objectively with a new reflex quantification method. Methodology/Principal Findings: The present study used a motion analysis technique to collect quantitative measurements for both the input and output of normal patellar tendon reflex. Reflex responses were measured as knee angles. The patellar tendon reflexes of 100 healthy subjects were examined using 6 levels of tendon taps, where all the assessments were captured using motion capture system. A linear relationship was found between the experimental maximum tapping velocity and tapping angle (coefficient of determination = 0.989), which was consistent with the theoretical values. Tapping velocities were predictable according to tapping angles. The findings proved the reproducibility of tapping method in producing consistent input. The reflex amplitude was consistent between two randomly assigned groups, and linearly proportionate to the tapping velocity. Conclusions/Significance: The findings on reflex amplitude indicate that motion analysis is a valid and reliable method of assessing and measuring deep tendon reflexes. © 2013 Tham et al.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3567131/pdf/pone.0055702.pdf
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0055702#pone-0055702-g004
4th Kuala Lumpur International Conference on Biomedical Engineering 2008, Biomed 2008, 2008
The purpose of this study is to validate of a new external finger fixator components by using fin... more The purpose of this study is to validate of a new external finger fixator components by using finite element analysis (FEA). The new external finger fixator consists of proximal, middle and distal phalanges support sections and means for rigidly connecting each support to a hinge and its corresponding attached to phalanx through the movements of flexion or extension. The results from the analysis found that the entire components of the fixator conform to the performance based on the requirements for general duty (500 N load applied on uniformly distributed load). This analysis shows that the new external fixator is able to restore full function and dynamic range of motion for patients with flexion deformity at the finger joints without failure. © 2008 Springer-Verlag.
http://link.springer.com/chapter/10.1007/978-3-540-69139-6_118
Journal of Biomedical Engineering, 1982
The application of uniaxial tension in vivo is a common test method for investigating mechanical ... more The application of uniaxial tension in vivo is a common test method for investigating mechanical properties of the skin. This paper reports an investigation of the strain distributions on the skin surface produced by such a test method. The strains were shown to be non-homogeneous with major concentrations being present near the area of load application. At all sites within the test area, axial, lateral and shear strains were present but their magnitude depended both on their position within the test site and the overall extension. The axial and lateral strains were largest and most uniformly distributed within the area bounded by th loading tabs. The shear strains, however, were smallest in the are bounded by the tabs. The distribution of the three strains became similar if they were referred to the principal axes. The area of skin within the strained area became larger as the overall deformation increased because additional skin was recruited from the sites lateral to the strained area. The general form of the load/strain relations and lateral contractions were site- and extension-dependent, but were similar to those found in vitro.
http://www.ncbi.nlm.nih.gov/pubmed/7078145
http://www.sciencedirect.com/science/article/pii/0141542582900292
Journal of Rehabilitation Research and Development, Dec 1, 2012
Poor suspension increases slippage of the residual limb inside the socket during ambulation. The ... more Poor suspension increases slippage of the residual limb inside the socket during ambulation. The main purpose of this article is to evaluate the pistoning at the prosthetic liner-socket interface during gait and assess patients' satisfaction with two different liners. Two prostheses with seal-in and lock-ing liners were fabricated for each of the 10 subjects with transtibial amputation. The Vicon motion system was used to measure the pistoning during gait. The subjects were also asked to complete a Prosthesis Evaluation Questionnaire. The results revealed higher pistoning inside the socket during gait with the locking liner than with the seal-in liner (p < 0.05). The overall satisfaction with the locking liner was higher (p < 0.05) because of the relative ease with which the patients could don and doff the device. As such, pistoning may not be the main factor that determines patients' overall satisfaction with the prosthesis and other factors may also contribute to comfort and satisfaction with prostheses. The article also verifies the feasi-bility of the Vicon motion system for measuring pistoning dur-ing gait.
http://www.ncbi.nlm.nih.gov/pubmed/23408214
http://eds.b.ebscohost.com/ehost/detail?sid=14da0d52-3122-463e-b2a9-9d1ebd3b7aeb%40sessionmgr115&vid=1&hid=110&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d
Clinical Biomechanics, Jan 1, 2012
Background: The method of attachment of prosthesis to the residual limb (suspension) and socket f... more Background: The method of attachment of prosthesis to the residual limb (suspension) and socket fitting is a critical issue in the process of providing an amputee with prosthesis. Different suspension methods try to minimize the pistoning movement inside the socket. The Seal-In (R) X5 and Dermo (R) Liner by Ossur are new suspension liners that intend to reduce pistoning between the socket and liner. Since the effects of these new liners on suspension are unclear, the objective of this study was to compare the pistoning effect of Seal-In (R) X5 and Dermo (R) Liner by using Vicon Motion System. Methods: Six transtibial amputees, using both the Iceross Seal-In (R) X5 and the Iceross Demo (R) Liner, participated in the study. The vertical displacement (pistoning) was measured between the liner and socket in single limb support on the prosthetic limb (full-weight bearing), double limb support (semi-weight bearing), and non-weight bearing on the prosthetic limb, and also under three static vertical loading conditions (30 N. 60 N, and 90 N). Findings: The results demonstrated that the pistoning within the socket when Seal-In (R) X5 was used, decreased by 71% in comparison to the Iceross Dermo (R) Liner. In addition, a significant difference between the two liners under different static conditions was found (p<0.05). Interpretation: Participants needed to put in extra effort for donning and doffing the prosthesis with Seal-In (R) X5; however, this type of liner provided less pistoning. The new approach that uses the motion analysis system in this study might be an alternative for measuring the pistoning effect in the prosthetic socket. (C) 2011 Elsevier Ltd. All rights reserved.
http://ac.els-cdn.com/S0268003311001859/1-s2.0-S0268003311001859-main.pdf?_tid=82dd2720-a019-11e3-952c-00000aab0f01&acdnat=1393551905_7c6f57e23f3b01c0a079afa004aac1b0
http://www.ncbi.nlm.nih.gov/pubmed/21794965
http://www.sciencedirect.com/science/article/pii/S0268003311001859
Clinical Biomechanics, Jan 1, 2012
Background: The method of attachment of prosthesis to the residual limb (suspension) and socket f... more Background: The method of attachment of prosthesis to the residual limb (suspension) and socket fitting is a critical issue in the process of providing an amputee with prosthesis. Different suspension methods try to minimize the pistoning movement inside the socket. The Seal-In (R) X5 and Dermo (R) Liner by Ossur are new suspension liners that intend to reduce pistoning between the socket and liner. Since the effects of these new liners on suspension are unclear, the objective of this study was to compare the pistoning effect of Seal-In (R) X5 and Dermo (R) Liner by using Vicon Motion System. Methods: Six transtibial amputees, using both the Iceross Seal-In (R) X5 and the Iceross Demo (R) Liner, participated in the study. The vertical displacement (pistoning) was measured between the liner and socket in single limb support on the prosthetic limb (full-weight bearing), double limb support (semi-weight bearing), and non-weight bearing on the prosthetic limb, and also under three static vertical loading conditions (30 N. 60 N, and 90 N). Findings: The results demonstrated that the pistoning within the socket when Seal-In (R) X5 was used, decreased by 71% in comparison to the Iceross Dermo (R) Liner. In addition, a significant difference between the two liners under different static conditions was found (p<0.05). Interpretation: Participants needed to put in extra effort for donning and doffing the prosthesis with Seal-In (R) X5; however, this type of liner provided less pistoning. The new approach that uses the motion analysis system in this study might be an alternative for measuring the pistoning effect in the prosthetic socket. (C) 2011 Elsevier Ltd. All rights reserved.
http://ac.els-cdn.com/S0268003311001859/1-s2.0-S0268003311001859-main.pdf?_tid=82dd2720-a019-11e3-952c-00000aab0f01&acdnat=1393551905_7c6f57e23f3b01c0a079afa004aac1b0
http://www.ncbi.nlm.nih.gov/pubmed/21794965
http://www.sciencedirect.com/science/article/pii/S0268003311001859
5th Kuala Lumpur International Conference on Biomedical Engineering, BIOMED 2011, Held in Conjunction with the 8th Asian Pacific Conference on Medical and Biological Engineering, APCMBE 2011, 2011
Spatial and temporal variability in the execution of skills has been analyzed in many sports. An ... more Spatial and temporal variability in the execution of skills has been analyzed in many sports. An expert performer is commonly referred to as being more consistent in the execution of skills compared to a novice. The purpose of this study was to analyze temporal characteristics and variability of the final delivery phase and examine how it is related to bowling level and performance. Two level of bowlers were used in this study - 18 elite (Male=10, Female=8; Bave 213.2±6.80; BRvel 17.66±0.85mph) and 12 semi-elite bowlers (Male=7, Female=5; Bave 181.3±9.36; BRvel 16.90±1.46mph). The final delivery phase consisted of three major events which were the arm swing, front foot slide and ball release. The temporal variable that was measured was execution time and the between-trial temporal variability, while average bowling score and ball release velocity represented the performance criteria. In general, the results indicate that the temporal characteristic between the two groups were quite similar, but in terms of relationship to bowling performance, front foot slide time was correlated with bowling average. Variability wise, the elite group was less consistent in front foot slide execution time. There were no significant differences or correlations for the other variables. It was concluded that lower temporal variability was not indicative of higher playing level or better bowling performance. © 2011 Springer-Verlag.
http://download.springer.com/static/pdf/882/chp%253A10.1007%252F978-3-642-21729-6_59.pdf?auth66=1393724504_75b19e1f75f2ee54b5de9c06e4fe0294&ext=.pdf
http://link.springer.com/chapter/10.1007/978-3-642-21729-6_59
Bio-Medical Materials and Engineering, 1995
The response of human skin to ''stress relaxation'' tests at low loads in vitro was investigated.... more The response of human skin to ''stress relaxation'' tests at low loads in vitro was investigated. A number of behaviours, other than those already well established and documented, were observed. The significant behaviours are pure recovery and relaxation-recovery. Other behaviours observed are temporary stress recovery during the relaxation process, and momentary sudden non-linear drop in stress value followed by a second relaxation. The pure recovery and relaxation-recovery responses are repeatable. The latter represents the transitional response between the well-known behaviour of stress relaxation and the behaviour of stress recovery.
http://www.ncbi.nlm.nih.gov/pubmed/7655319
American Journal of Physical Medicine and Rehabilitation, Jan 14, 2014
This report compares wrist supination and pronation and flexion and extension movements with the ... more This report compares wrist supination and pronation and flexion and extension movements with the common body-powered prosthesis and a new biomechatronics prosthesis with regard to patient satisfaction and problems experienced with the prosthesis. Fifteen subjects with traumatic transradial amputation who used both prosthetic systems participated in this study. Each subject completed two questionnaires to evaluate their satisfaction and problems experienced with the two prosthetic systems. Satisfaction and problems with the prosthetic's wrist movements were analyzed in terms of the following: supination and pronation; flexion and extension; appearance; sweating; wounds; pain; irritation; pistoning; smell; sound; durability; and the abilities to open a door, hold a cup, and pick up or place objects. This study revealed that the respondents were more satisfied with the biomechatronics wrist prosthesis with regard to supination and pronation, flexion and extension, pain, and the ability to open a door. However, satisfaction with the prosthesis showed no significant differences in terms of sweating, wounds, irritation, pistoning, smell, sound, and durability. The abilities to hold a cup and pick up or place an object were significantly better with the body-powered prosthesis. The results of the survey suggest that satisfaction and problems with wrist movements in persons with transradial amputation can be improved with a biomechatronics wrist prosthesis compared with the common body-powered prosthesis.
http://www.ncbi.nlm.nih.gov/pubmed/24429510
American Journal of Physical Medicine and Rehabilitation, Dec 1, 2012
OBJECTIVE: The objectives of this study were to compare the effects of a newly designed magnetic ... more OBJECTIVE: The objectives of this study were to compare the effects of a newly designed magnetic suspension system with that of two existing suspension methods on pistoning inside the prosthetic socket and to compare satisfaction and perceived problems among transtibial amputees. DESIGN: In this prospective study, three lower limb prostheses with three different suspension systems were fabricated for ten transtibial amputees. The participants used each of the three prostheses for 1 mo in random order. Pistoning inside the prosthetic socket was measured by motion analysis system. The Prosthesis Evaluation Questionnaire was used to evaluate satisfaction and perceived problems with each suspension system. RESULTS: The lowest pistoning motion was found with the suction system compared with the other two suspension systems (P < 0.05). The new suspension system showed peak pistoning values similar to that of the pin lock system (P = 0.086). The results of the questionnaire survey revealed significantly higher satisfaction rates with the new system than with the other two systems in donning and doffing, walking, uneven walking, stair negotiation, and overall satisfaction (P < 0.05). CONCLUSIONS: The new suspension system has the potential to be used as an alternative to the available suspension systems. The pistoning motion was comparable to that of the other two systems. The new system showed compatible prosthetic suspension with the other two systems (suction and pin lock). The satisfaction with donning and doffing was high with the magnetic system. Moreover, the subjects reported fewer problems with the new system. Copyright © 2012 by Lippincott Williams & Wilkins.
http://graphics.tx.ovid.com/ovftpdfs/FPDDNCLBPCEOKH00/fs047/ovft/live/gv024/00002060/00002060-201212000-00003.pdf
http://www.ncbi.nlm.nih.gov/pubmed/23168378
American Journal of Physical Medicine and Rehabilitation, Dec 1, 2012
OBJECTIVE: The objectives of this study were to compare the effects of a newly designed magnetic ... more OBJECTIVE: The objectives of this study were to compare the effects of a newly designed magnetic suspension system with that of two existing suspension methods on pistoning inside the prosthetic socket and to compare satisfaction and perceived problems among transtibial amputees. DESIGN: In this prospective study, three lower limb prostheses with three different suspension systems were fabricated for ten transtibial amputees. The participants used each of the three prostheses for 1 mo in random order. Pistoning inside the prosthetic socket was measured by motion analysis system. The Prosthesis Evaluation Questionnaire was used to evaluate satisfaction and perceived problems with each suspension system. RESULTS: The lowest pistoning motion was found with the suction system compared with the other two suspension systems (P < 0.05). The new suspension system showed peak pistoning values similar to that of the pin lock system (P = 0.086). The results of the questionnaire survey revealed significantly higher satisfaction rates with the new system than with the other two systems in donning and doffing, walking, uneven walking, stair negotiation, and overall satisfaction (P < 0.05). CONCLUSIONS: The new suspension system has the potential to be used as an alternative to the available suspension systems. The pistoning motion was comparable to that of the other two systems. The new system showed compatible prosthetic suspension with the other two systems (suction and pin lock). The satisfaction with donning and doffing was high with the magnetic system. Moreover, the subjects reported fewer problems with the new system. Copyright © 2012 by Lippincott Williams & Wilkins.
http://graphics.tx.ovid.com/ovftpdfs/FPDDNCLBPCEOKH00/fs047/ovft/live/gv024/00002060/00002060-201212000-00003.pdf
http://www.ncbi.nlm.nih.gov/pubmed/23168378
5th Kuala Lumpur International Conference on Biomedical Engineering, BIOMED 2011, Held in Conjunction with the 8th Asian Pacific Conference on Medical and Biological Engineering, APCMBE 2011, 2011
This study collected quantitative measurements of the patellar tendon reflex using 3-dimensional ... more This study collected quantitative measurements of the patellar tendon reflex using 3-dimensional motion analysis. The study was conducted in the Motion Analysis Laboratory, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia. Patellar tendon reflex of a group of healthy subjects involving 28 males and 22 females was examined. The left and right patellar tendons were tapped by a Queen Square reflex hammer with three different angles where the reflex hammer was released. The phenomenon of Jendrassik maneuver was tested by tapping on the tendon with the hammer raised to an angle of 60°. The purpose of this was to investigate the effect of reinforcement method on reflex responses. Results of the study showed that the patellar tendon reflex response of male subjects were higher at higher tapping force. Reflex response of the left and the right side did not show any significant difference. The study of tapping force on reflex response showed greater response at increasing tapping force. The reinforcement method named Jendrassik maneuver increased patellar tendon reflex response for both legs. © 2011 Springer-Verlag.
http://download.springer.com/static/pdf/875/chp%253A10.1007%252F978-3-642-21729-6_52.pdf?auth66=1393724480_718bef5a1f77779a23d9904c975770ba&ext=.pdf
http://link.springer.com/chapter/10.1007/978-3-642-21729-6_52
5th Kuala Lumpur International Conference on Biomedical Engineering, BIOMED 2011, Held in Conjunction with the 8th Asian Pacific Conference on Medical and Biological Engineering, APCMBE 2011, 2011
This study maps bones and joints, relate them to the vertical ground reaction forces on gait. The... more This study maps bones and joints, relate them to the vertical ground reaction forces on gait. Their localities are charted in the form of graph. This is then being exploited as arguments to reason the design of prosthetic foot. The mathematical model is developed and is based on the relationship among the anatomy of bones and joints, the vertical ground reaction forces on certain points as well as the sequence when these points experience the vertical ground reaction forces. Using the model, a custom design prosthetic foot is built using a male subject of size 5 scanned foot image. It is concluded that proper mappings and modeling of foot structure can be used as reference in design and development of prosthetic feet. © 2011 Springer-Verlag.
http://download.springer.com/static/pdf/535/chp%253A10.1007%252F978-3-642-21729-6_187.pdf?auth66=1393724488_78d6437ca2e8f6455fa2b71566e1ba10&ext=.pdf
http://link.springer.com/chapter/10.1007/978-3-642-21729-6_187
4th Kuala Lumpur International Conference on Biomedical Engineering 2008, Biomed 2008, 2008
The electromyography (EMG) activity of the biceps femoris, rectus femoris, gastrocnemius, and fou... more The electromyography (EMG) activity of the biceps femoris, rectus femoris, gastrocnemius, and fourth lumbar (L4) and fifth lumbar (L5) muscles of 5 male subjects was measured during a series of maneuvers which include standing, bowing, prostration, and sitting. Raw EMG was processed by root-mean-square (RMS) technique using a time constant of 50 ms. The results show that the gastrocnemius is the most active. The series of standing to prostration maneuvers showed 13.21±10.67 RMS, μV (mean±standard deviation), standing to bowing, 11.97± 4.89, sitting to prostration, 8.36±12.55. Preliminary EMG profiles in this study demonstrated that subjects used relatively higher levels of gastrocnemius muscle compare to the biceps femoris, rectus femoris, and fourth lumbar (L4) and fifth lumbar (L5) muscles to perform the set of moderate exercises. © 2008 Springer-Verlag.
http://link.springer.com/chapter/10.1007/978-3-540-69139-6_114
Clinics, Sep 1, 2013
OBJECTIVE: This study provides an experimental and finite element analysis of knee-joint structur... more OBJECTIVE: This study provides an experimental and finite element analysis of knee-joint structure during extended-knee landing based on the extracted impact force, and it numerically identifies the contact pressure, stress distribution and possibility of bone-to-bone contact when a subject lands from a safe height. METHODS: The impact time and loads were measured via inverse dynamic analysis of free landing without knee flexion from three different heights (25, 50 and 75 cm), using five subjects with an average body mass index of 18.8. Three-dimensional data were developed from computed tomography scans and were reprocessed with modeling software before being imported and analyzed by finite element analysis software. The whole leg was considered to be a fixed middle-hinged structure, while impact loads were applied to the femur in an upward direction. RESULTS: Straight landing exerted an enormous amount of pressure on the knee joint as a result of the body's inability to utilize the lower extremity muscles, thereby maximizing the threat of injury when the load exceeds the height-safety threshold. CONCLUSIONS: The researchers conclude that extended-knee landing results in serious deformation of the meniscus and cartilage and increases the risk of bone-to-bone contact and serious knee injury when the load exceeds the threshold safety height. This risk is considerably greater than the risk of injury associated with walking downhill or flexion landing activities. © 2013 CLINICS.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3782736/pdf/cln-68-09-1180.pdf
https://www.scienceopen.com/document_file/875d3659-9f8e-4dda-baca-494190fd73c1/PubMedCentral/875d3659-9f8e-4dda-baca-494190fd73c1.pdf
5th Kuala Lumpur International Conference on Biomedical Engineering, BIOMED 2011, Held in Conjunction with the 8th Asian Pacific Conference on Medical and Biological Engineering, APCMBE 2011, 2011
This paper describes the outcome based education (OBE) implementation and continuous quality impr... more This paper describes the outcome based education (OBE) implementation and continuous quality improvement (CQI) process plan in the Department of Biomedical Engineering, University of Malaya. The implementation of CQI plan is a part of the Outcome - based Education (OBE) approach required by the Engineering Accreditation Council (EAC) for recognition of Biomedical Engineering program and as a graduate student for Board of Engineer Malaysia (BEM) and Institute of Engineer Malaysia (IEM) membership registration. This approach was first introduced to Biomedical Engineering Department since 2005. The measurement on Programme Outcomes (POs) which will be evaluated upon graduation is done based on the results of sub-Programme Outcome (subPOs) which are evaluated at the end of each course. The improvement on assessment and evaluation process are continuously done to obtain the better achievement of POs and programme educational objectives (PEO)s in the department of Biomedical Engineering. © 2011 Springer-Verlag.
http://download.springer.com/static/pdf/750/chp%253A10.1007%252F978-3-642-21729-6_11.pdf?auth66=1393724410_c7708d4685fd6be2e3fdd4b9f6aa9ef3&ext=.pdf
http://link.springer.com/chapter/10.1007/978-3-642-21729-6_11
IEEE Transactions on Instrumentation and Measurement, Feb 1, 2005
This paper introduces a novel approach to classify the risk in dengue hemorrhagic fever (DHF) pat... more This paper introduces a novel approach to classify the risk in dengue hemorrhagic fever (DHF) patients using the bioelectrical impedance analysis (BIA) technique. This in vivo technique involves the application of a small average constant current of less than 1 mA at a single frequency of 50 kHz through the human body, and measurement of the body's bioelectrical resistance (R), phase angle (α), body capacitance (BC) and capacitive reactance (Xc) via four surface electrodes. BIA measurements have been conducted on 184 (97 males and 87 females) serological confirmed dengue patients during their hospitalization in University Kebangsaan Malaysia Hospital, Malaysia. The patients included in the study were DHF I-IV according to World Health Organization criteria. Univariate analysis of variance is used for assessing the relationship between gender and group with the bioelectrical tissue conductivity (BETC) parameters. Experimental findings show that BETC, as reflected by reactance, is the key determinant indicator for classifying risk category in the DHF patients. Hence, this novel approach of the BIA technique can provide a rapid, noninvasive, and promising method for classifying and evaluating the risk of the DHF patients.© 2005 IEEE.
http://ieeexplore.ieee.org/ielx5/19/30128/01381820.pdf?tp=&arnumber=1381820&isnumber=30128
http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=1381820&tag=1
5th Kuala Lumpur International Conference on Biomedical Engineering, BIOMED 2011, Held in Conjunction with the 8th Asian Pacific Conference on Medical and Biological Engineering, APCMBE 2011, 2011
The quality of suspension in lower limb prosthetics has significant role in amputee's satisfactio... more The quality of suspension in lower limb prosthetics has significant role in amputee's satisfaction. Good suspension lessens the pistoning movement of the residual limb inside the prosthetic socket. A number of methods are used for measuring pistoning; however most of them are difficult to be performed inside the prosthetic clinic and by every prosthetist. The purpose of this study was to introduce a new simple method for measuring pistoning in Transtibial prosthesis in static position. This method was developed in-house at Össur for the first time. In this study we used this technique to measure pistoning between socket and liner in three subjects. The result showed that this method can be an alternative method for measuring pistoning. Moreover, that makes it simple for prosthetists to test pistoning in the clinic and is a safe method for the subject. © 2011 Springer-Verlag.
http://download.springer.com/static/pdf/504/chp%253A10.1007%252F978-3-642-21729-6_177.pdf?auth66=1393724134_c9c685562defb784352c426b49cf3ca1&ext=.pdf
http://link.springer.com/chapter/10.1007/978-3-642-21729-6_177
Prosthetics and Orthotics International, Dec 1, 2011
Background: Good suspension lessens the pistoning (vertical displacement) of the residual limb in... more Background: Good suspension lessens the pistoning (vertical displacement) of the residual limb inside the prosthetic socket. Several methods are used for measuring the pistoning. Study Design: Clinical trial. Objectives: To introduce and evaluate a new simple method for measuring the pistoning between the soft liner and socket in transtibial prostheses. Methods: Five transtibial prostheses with Iceross silicone liner and shuttle lock were made for the subjects. The pistoning was measured between the liner and socket by a photographic method in single limb support on the prosthetic limb (full weight bearing), non-weight bearing and under three static axial loading conditions (30, 60 and 90 N). Results: This new method enabled us to measure the pistoning between the liner and prosthetic socket. The reproducibility of measurements in different trials of one session and between two sessions by two observers was shown to be high. The average of displacement between the liner and socket was about 9 mm in non-weight bearing compared with full weight bearing. Furthermore, as we expected, the average of pistoning increased consistently by adding the loads. Conclusions: This new method provides for easy and inexpensive determination of pistoning between the liner and socket by every prosthetist in clinical settings. © The International Society for Prosthetics and Orthotics 2011.
http://poi.sagepub.com/content/35/4/360.full.pdf
http://www.ncbi.nlm.nih.gov/pubmed/21975850
Physiological Measurement, Jun 1, 2004
This paper describes a model for predicting hemoglobin (Hb) by using bioelectrical impedance anal... more This paper describes a model for predicting hemoglobin (Hb) by using bioelectrical impedance analysis (BIA) in dengue patients in the Hospital Universiti Kebangsaan Malaysia (HUKM). Bioelectrical impedance measurements were conducted on 83 (47 males and 36 females) serologically confirmed dengue fever (DF) and dengue hemorrhagic fever (DHF) patients during their hospitalization. The predictive equation for Hb was derived using multivariate analysis. We investigated all the parameters in BIA, patients' symptom and demographic data. In this developed model, four predictors (reactance (Xc), sex, weight and vomiting) were found to be the best predictive factors for modeling Hb in dengue patients. However, the model can only explain approximately 42% of the variation in Hb status, thus single frequency bio-impedance stand-alone technique is insufficient to monitor Hb for the DF and DHF patients. Further investigation using multi-frequency BIA is recommended in modeling Hb to achieve the most parsimonious model.
http://iopscience.iop.org/0967-3334/25/3/002/pdf/0967-3334_25_3_002.pdf
http://iopscience.iop.org/0967-3334/25/3/002