Noor Azuan Abu Osman graduated from University of Bradford, UK with a B.Eng. Hons. in Mechanical Engineering, followed by MSc. and Ph.D. in Bioengineering from University of Strathclyde,UK. Practicing Engineer and Professor of Biomechanics with Faculty of Engineering, University of Malaya, Malaysia. The research who are interests in quite wide-ranging under the general umbrella of biomechanics. However, the main interests are the measurements of human movement, prosthetics design, the development of instrumentation for forces and joint motion, and the design of prosthetics, orthotics and orthopaedic. Prior to joining University of Malaya in 1995, works as Mechanical and Electrical Engineer and actively involved in many consultancy projects, especially in the field of biomechanics and bio-mechanical engineering. Address: Department of Biomedical Engineering, Faculty of Engineering Building, University of Malaya, 50603 Kuala Lumpur, MALAYSIA
An Automated Rapid Maxillary Expander (ARME) is a specially designed microcontroller-based orthod... more An Automated Rapid Maxillary Expander (ARME) is a specially designed microcontroller-based orthodontic appliance to overcome the shortcomings imposed by the traditional maxillary expansion appliances. This new device is operates by automatically widening the maxilla (upper jaw) by expanding the midpalatal suture [1]. The ARME appliance that has been developed is a combination of modified butterfly expander appliance, micro gear, micro motor, and microcontroller to automatically produce light and continuous pressure to expand the maxilla. For this study, the functionality of the system is verified through laboratory tests by measure the forced applied to the teeth each time the maxilla expands. The laboratory test results show that the developed appliance meets the desired performance specifications consistently.
Bioactive ceramics such as hydroxyapatite (HA) can mimic the organic structure of human bone. HA ... more Bioactive ceramics such as hydroxyapatite (HA) can mimic the organic structure of human bone. HA was successfully synthesized from animal bones, corals, and eggshells which have been studied for bone repairing treatment and as implant coatings. This study aims to synthesize nanorod HA from cockle shells via two routes: calcination and the hydrothermal method. The raw cockle shells were converted to calcite by calcination method at 450 oC (CS450) and 800 oC (CS800) for 2 hrs. The calcite calcium carbonate samples were reacted with diammonium hydrogen phosphate and hydrothermally treated at 110 oC. The pH of the solution was kept at 10.5 throughout the synthesis step by adding drops of ammonia. Product obtained was labelled as HA450 and HA800 containing HA powder. Presence of calcite phase in the raw cockle shells was characterized by utilizing Thermogravimetric analysis (TGA), X-ray Diffraction (XRD) and Fourier transforms infrared spectrophotometer (FTIR) analyses and morphologicall...
Most transtibial prosthesis users always experience pain sensation at the distal of the residual ... more Most transtibial prosthesis users always experience pain sensation at the distal of the residual limb due to bony prominences and nerve endings. Many initiatives have been taken to resolve this problem, including using softer materials such as silicone or gel liner and designing a distal off load prosthetic socket. Another promising approach is to incorporate polyurethane foam in the manufacturing of prosthetic liner. This study aimed to design a new prosthetic liner using polyurethane at the anterior-distal part of the residual limb as a Pelite replacement and to compare the biomechanical gait analysis between the new modified polyurethane liner and the common Pelite liner. A unilateral transtibial amputee was recruited as the subject. Two Patellar Tendon Bearing transtibial prostheses with different liners were fabricated for the subject, which were Pelite liner and a modified polyurethane foam liner. The modified liner using polyurethane foam consisted of Ethylene vinyl-acetate –...
A systematic review of the mechanical design of powered ankle–foot prostheses developed from 2000... more A systematic review of the mechanical design of powered ankle–foot prostheses developed from 2000 to 2019 was conducted through database and manual searches. A total of ten English and two Chinese databases were searched using the same keywords. Moreover, information on commercialized prostheses was collected through a manual search. A total of 8729 publications were obtained from the database search, and 83 supplementary publications and 49 online product introductions were accumulated through the manual search. A total of 91 powered ankle–foot prostheses were extracted from 159 publications and online information after exclusion. The mechanical design characteristics of the prostheses were described briefly and compared after they were categorized into 11 subclassifications. This review revealed that a considerable number of powered ankle–foot prostheses were developed in the last 20 years. The development of such prostheses was characterized by alternative modes, that is, from pn...
Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, 2020
Many studies have shown that medical compression products produce different levels of interface p... more Many studies have shown that medical compression products produce different levels of interface pressure during the usage of the products. However, limited studies have explored the pattern of interface pressure exerted by orthotic garments. This case study aimed to investigate the pattern of interface pressure exerted by two types of orthotic garments on a child with cerebral palsy. A 13-year-old child diagnosed with ataxic spastic diplegia cerebral palsy has difficulty to perform sit-to-stand motion even with a walking frame due to his truncal ataxia. A TheraTogsTM orthosis and a Dynamic Lycra® Fabric Orthosis (DLFO) were prepared for the child. The child’s sit-to-stand ability without and with the usage of orthoses was recorded using five sit-to-stand tests. The garments’ interface pressure was measured using F-scan (9811E) and F-scan 6.5.1 version software. The pressure was recorded when the child was in sitting position and performing sit-to-stand-to-sit motion. Overall, the ch...
Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, 2020
The conservative techniques of treating knee osteoarthritis (kOA) include wearing orthoses such a... more The conservative techniques of treating knee osteoarthritis (kOA) include wearing orthoses such as knee braces and laterally wedged insoles and applying gait modification techniques such as toe-in gait and toe-out gait. This study aimed at assessing the immediate effects of these techniques in improving physical function of healthy and kOA participants. Five Osteoarthritis Research Society International (OARSI) recommended performance-based tests were randomly applied to measure physical function: (1) 30-second chair stand test (30CST), (2) 40-m (4 × 10) fast-paced walk test (40FPW), (3) stair climb test (SCT), (4) timed up and go test (TUGT) and (5) 6-minute walk test (6MWT) during a single-visit on 20 healthy and 20 kOA patients (age: 59.5 ± 7.33 and 61.5 ± 8.63 years, BMI: 69.95 ± 9.86 and 70.45 ± 8.80 kg/m2). The interventions included natural gait, toe-out gait, toe-in gait, laterally wedged insoles and knee brace. Analysis was performed through repeated-measures ANOVA and inde...
International Journal of Advanced Robotic Systems, 2018
This article presents a novel sensorless control system of assistive robotic ankle-foot prosthesi... more This article presents a novel sensorless control system of assistive robotic ankle-foot prosthesis, two estimation algorithms were developed and an analogy between them has been made. The system actuator’s motor is a permanent magnet synchronous motor, unlike other powered ankle-foot, where the brushless DC motor and DC motor were used. Utilizing the permanent magnet synchronous motor will reduce the torque ripples and increase system ability to be overloaded compared to systems which utilize the brushless DC motor. Moreover, the ability of the machine to operate in all speed range makes this machine more suitable for the application. Both estimation algorithms are built using C-code and assessed in MATLAB Simulink. The estimation algorithms are used to provide motor and powered ankle-foot’s angular speed and position. Two-level control system is used to evaluate the estimation algorithms; the control system role is to mimic biological ankle-foot performance during normal ground lev...
American journal of physical medicine & rehabilitation / Association of Academic Physiatrists, Jan 16, 2015
To the Editor: We would like to thank Dr Dillon, Ms Richardson, and Dr Hafner for their insightfu... more To the Editor: We would like to thank Dr Dillon, Ms Richardson, and Dr Hafner for their insightful comments and the opportunity to clarify a number of points from our work. In their letter to editor, Dillon et al. were concerned about the questions adopted from the Prosthetic Evaluation Questionnaire and justification to support the focus on discrete aspects of the user experience. To clarify, as it was also cited in our article, we followed the method of Van de Weg and Van der Windt in adoption of the questions. A question measuring both donning and doffing under the Bability to don and doff[ was added in their study. This has been addressed in a later study published by the authors. With regard to the statistical analysis, although it was chosen based on the consultation with a statistics expert, it might not be the only applicable method of analysis. We had first performed repeated-measures analysis of variance. Next, the paired-samples t test was used to find the significant differences between each two of the suspension systems, which was reported in the article. However, we agree with Dillon et al. that post hoc analysis could decrease the error as it was used in our recent study. The inconsistency of works is not unexpected, despite the same adaptation of the Prosthetic Evaluation Questionnaire, as the sample population has changed over the course of time. Moreover, responses to qualitative surveys may change over time because of changes in mobility level, psychological changes, patient experience, and adaptability. The authors acknowledge that it was a preliminary study on a small number of subjects as pointed out in the limitation statement. It was emphasized at the end that BSatisfaction, particularly with donning and doffing, should also be taken into account when choosing a prosthetic suspension system for a lower limb amputee,[ which is a general statement without stressing on a specific system. Although positive and negative results were yielded, the conclusions were also drawn based on our subjects_ experience that is a common practice and of such value that it is taken into account in evidence-based practice. It is evidently accepted that, regardless of the statistical method used, questionnaire surveys should be conducted on a large population to be able to completely rely on the results. Yet,most of the studies in the field of prosthetics are conducted on a limited number of subjects, especially when it comes to new technologies that are still in the prototype level. Future studies can certainly improve on what we have done. In the end, again, wewould like to express our gratitude to Dillon et al. for their invaluable comments and providing us with the opportunity to discuss our research. We will consider the invaluable comments in our future works.
Biomedical Engineering: Applications, Basis and Communications, 2015
The kinematic and kinetic differences between obese and slim people when climbing a staircase at ... more The kinematic and kinetic differences between obese and slim people when climbing a staircase at their self-selected speed are compared. A four-step wooden stair instrumented with two force plates were used as the action platform whilst the kinematic and kinetic recordings were collected and analyzed using a six-camera and two-force plate three-dimensional motion analysis system. Ten obese adults, six males and four females, and ten lean adults, six males and four females, volunteered for the study. The results showed that the obese people are able to reduce the knee joint flexion moment when climbing stair compared to the normal slim people. In the frontal plane, no significant differences were found in the knee adduction moment. Moreover, obese individuals have identified some kinematics adaptations including slower velocity and longer stance phase, compared to slim individuals. The obese individuals might adjust their gait characteristics in response to their heavy bodies to redu...
The measurements of postural balance often involve measurement error, which affects the analysis ... more The measurements of postural balance often involve measurement error, which affects the analysis and interpretation of the outcomes. In most of the existing clinical rehabilitation research, the ability to produce reliable measures is a prerequisite for an accurate assessment of an intervention after a period of time. Although clinical balance assessment has been performed in previous study, none has determined the intrarater test-retest reliability of static and dynamic stability indexes during dominant single stance. In this study, one rater examined 20 healthy university students (female = 12, male = 8) in two sessions separated by 7 day intervals. Three stability indexes—the overall stability index (OSI), anterior/posterior stability index (APSI), and medial/lateral stability index (MLSI) in static and dynamic conditions—were measured during single dominant stance. Intraclass correlation coefficient (ICC), standard error measurement (SEM) and 95% confidence interval (95% CI) wer...
... Page 2. 852 HN Shasmin, NA Abu Osman and L. Abdul Latif _____ IFMBE Proceedings Vol. ... REFE... more ... Page 2. 852 HN Shasmin, NA Abu Osman and L. Abdul Latif _____ IFMBE Proceedings Vol. ... REFERENCES 1. HN Shasmin, NA Abu Osman, L Abd Latif, J Usman and WAB Wan Abas (2007). ...
Several studies have presented technological ensembles of active knee systems for transfemoral pr... more Several studies have presented technological ensembles of active knee systems for transfemoral prosthesis. Other studies have examined the amputees’ gait performance while wearing a specific active prosthesis. This paper combined both insights, that is, a technical examination of the components used, with an evaluation of how these improved the gait of respective users. This study aims to offer a quantitative understanding of the potential enhancement derived from strategic integration of core elements in developing an effective device. The study systematically discussed the current technology in active transfemoral prosthesis with respect to its functional walking performance amongst above-knee amputee users, to evaluate the system’s efficacy in producing close-to-normal user performance. The performances of its actuator, sensory system, and control technique that are incorporated in each reported system were evaluated separately and numerical comparisons were conducted based on th...
An Automated Rapid Maxillary Expander (ARME) is a specially designed microcontroller-based orthod... more An Automated Rapid Maxillary Expander (ARME) is a specially designed microcontroller-based orthodontic appliance to overcome the shortcomings imposed by the traditional maxillary expansion appliances. This new device is operates by automatically widening the maxilla (upper jaw) by expanding the midpalatal suture [1]. The ARME appliance that has been developed is a combination of modified butterfly expander appliance, micro gear, micro motor, and microcontroller to automatically produce light and continuous pressure to expand the maxilla. For this study, the functionality of the system is verified through laboratory tests by measure the forced applied to the teeth each time the maxilla expands. The laboratory test results show that the developed appliance meets the desired performance specifications consistently.
Bioactive ceramics such as hydroxyapatite (HA) can mimic the organic structure of human bone. HA ... more Bioactive ceramics such as hydroxyapatite (HA) can mimic the organic structure of human bone. HA was successfully synthesized from animal bones, corals, and eggshells which have been studied for bone repairing treatment and as implant coatings. This study aims to synthesize nanorod HA from cockle shells via two routes: calcination and the hydrothermal method. The raw cockle shells were converted to calcite by calcination method at 450 oC (CS450) and 800 oC (CS800) for 2 hrs. The calcite calcium carbonate samples were reacted with diammonium hydrogen phosphate and hydrothermally treated at 110 oC. The pH of the solution was kept at 10.5 throughout the synthesis step by adding drops of ammonia. Product obtained was labelled as HA450 and HA800 containing HA powder. Presence of calcite phase in the raw cockle shells was characterized by utilizing Thermogravimetric analysis (TGA), X-ray Diffraction (XRD) and Fourier transforms infrared spectrophotometer (FTIR) analyses and morphologicall...
Most transtibial prosthesis users always experience pain sensation at the distal of the residual ... more Most transtibial prosthesis users always experience pain sensation at the distal of the residual limb due to bony prominences and nerve endings. Many initiatives have been taken to resolve this problem, including using softer materials such as silicone or gel liner and designing a distal off load prosthetic socket. Another promising approach is to incorporate polyurethane foam in the manufacturing of prosthetic liner. This study aimed to design a new prosthetic liner using polyurethane at the anterior-distal part of the residual limb as a Pelite replacement and to compare the biomechanical gait analysis between the new modified polyurethane liner and the common Pelite liner. A unilateral transtibial amputee was recruited as the subject. Two Patellar Tendon Bearing transtibial prostheses with different liners were fabricated for the subject, which were Pelite liner and a modified polyurethane foam liner. The modified liner using polyurethane foam consisted of Ethylene vinyl-acetate –...
A systematic review of the mechanical design of powered ankle–foot prostheses developed from 2000... more A systematic review of the mechanical design of powered ankle–foot prostheses developed from 2000 to 2019 was conducted through database and manual searches. A total of ten English and two Chinese databases were searched using the same keywords. Moreover, information on commercialized prostheses was collected through a manual search. A total of 8729 publications were obtained from the database search, and 83 supplementary publications and 49 online product introductions were accumulated through the manual search. A total of 91 powered ankle–foot prostheses were extracted from 159 publications and online information after exclusion. The mechanical design characteristics of the prostheses were described briefly and compared after they were categorized into 11 subclassifications. This review revealed that a considerable number of powered ankle–foot prostheses were developed in the last 20 years. The development of such prostheses was characterized by alternative modes, that is, from pn...
Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, 2020
Many studies have shown that medical compression products produce different levels of interface p... more Many studies have shown that medical compression products produce different levels of interface pressure during the usage of the products. However, limited studies have explored the pattern of interface pressure exerted by orthotic garments. This case study aimed to investigate the pattern of interface pressure exerted by two types of orthotic garments on a child with cerebral palsy. A 13-year-old child diagnosed with ataxic spastic diplegia cerebral palsy has difficulty to perform sit-to-stand motion even with a walking frame due to his truncal ataxia. A TheraTogsTM orthosis and a Dynamic Lycra® Fabric Orthosis (DLFO) were prepared for the child. The child’s sit-to-stand ability without and with the usage of orthoses was recorded using five sit-to-stand tests. The garments’ interface pressure was measured using F-scan (9811E) and F-scan 6.5.1 version software. The pressure was recorded when the child was in sitting position and performing sit-to-stand-to-sit motion. Overall, the ch...
Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, 2020
The conservative techniques of treating knee osteoarthritis (kOA) include wearing orthoses such a... more The conservative techniques of treating knee osteoarthritis (kOA) include wearing orthoses such as knee braces and laterally wedged insoles and applying gait modification techniques such as toe-in gait and toe-out gait. This study aimed at assessing the immediate effects of these techniques in improving physical function of healthy and kOA participants. Five Osteoarthritis Research Society International (OARSI) recommended performance-based tests were randomly applied to measure physical function: (1) 30-second chair stand test (30CST), (2) 40-m (4 × 10) fast-paced walk test (40FPW), (3) stair climb test (SCT), (4) timed up and go test (TUGT) and (5) 6-minute walk test (6MWT) during a single-visit on 20 healthy and 20 kOA patients (age: 59.5 ± 7.33 and 61.5 ± 8.63 years, BMI: 69.95 ± 9.86 and 70.45 ± 8.80 kg/m2). The interventions included natural gait, toe-out gait, toe-in gait, laterally wedged insoles and knee brace. Analysis was performed through repeated-measures ANOVA and inde...
International Journal of Advanced Robotic Systems, 2018
This article presents a novel sensorless control system of assistive robotic ankle-foot prosthesi... more This article presents a novel sensorless control system of assistive robotic ankle-foot prosthesis, two estimation algorithms were developed and an analogy between them has been made. The system actuator’s motor is a permanent magnet synchronous motor, unlike other powered ankle-foot, where the brushless DC motor and DC motor were used. Utilizing the permanent magnet synchronous motor will reduce the torque ripples and increase system ability to be overloaded compared to systems which utilize the brushless DC motor. Moreover, the ability of the machine to operate in all speed range makes this machine more suitable for the application. Both estimation algorithms are built using C-code and assessed in MATLAB Simulink. The estimation algorithms are used to provide motor and powered ankle-foot’s angular speed and position. Two-level control system is used to evaluate the estimation algorithms; the control system role is to mimic biological ankle-foot performance during normal ground lev...
American journal of physical medicine & rehabilitation / Association of Academic Physiatrists, Jan 16, 2015
To the Editor: We would like to thank Dr Dillon, Ms Richardson, and Dr Hafner for their insightfu... more To the Editor: We would like to thank Dr Dillon, Ms Richardson, and Dr Hafner for their insightful comments and the opportunity to clarify a number of points from our work. In their letter to editor, Dillon et al. were concerned about the questions adopted from the Prosthetic Evaluation Questionnaire and justification to support the focus on discrete aspects of the user experience. To clarify, as it was also cited in our article, we followed the method of Van de Weg and Van der Windt in adoption of the questions. A question measuring both donning and doffing under the Bability to don and doff[ was added in their study. This has been addressed in a later study published by the authors. With regard to the statistical analysis, although it was chosen based on the consultation with a statistics expert, it might not be the only applicable method of analysis. We had first performed repeated-measures analysis of variance. Next, the paired-samples t test was used to find the significant differences between each two of the suspension systems, which was reported in the article. However, we agree with Dillon et al. that post hoc analysis could decrease the error as it was used in our recent study. The inconsistency of works is not unexpected, despite the same adaptation of the Prosthetic Evaluation Questionnaire, as the sample population has changed over the course of time. Moreover, responses to qualitative surveys may change over time because of changes in mobility level, psychological changes, patient experience, and adaptability. The authors acknowledge that it was a preliminary study on a small number of subjects as pointed out in the limitation statement. It was emphasized at the end that BSatisfaction, particularly with donning and doffing, should also be taken into account when choosing a prosthetic suspension system for a lower limb amputee,[ which is a general statement without stressing on a specific system. Although positive and negative results were yielded, the conclusions were also drawn based on our subjects_ experience that is a common practice and of such value that it is taken into account in evidence-based practice. It is evidently accepted that, regardless of the statistical method used, questionnaire surveys should be conducted on a large population to be able to completely rely on the results. Yet,most of the studies in the field of prosthetics are conducted on a limited number of subjects, especially when it comes to new technologies that are still in the prototype level. Future studies can certainly improve on what we have done. In the end, again, wewould like to express our gratitude to Dillon et al. for their invaluable comments and providing us with the opportunity to discuss our research. We will consider the invaluable comments in our future works.
Biomedical Engineering: Applications, Basis and Communications, 2015
The kinematic and kinetic differences between obese and slim people when climbing a staircase at ... more The kinematic and kinetic differences between obese and slim people when climbing a staircase at their self-selected speed are compared. A four-step wooden stair instrumented with two force plates were used as the action platform whilst the kinematic and kinetic recordings were collected and analyzed using a six-camera and two-force plate three-dimensional motion analysis system. Ten obese adults, six males and four females, and ten lean adults, six males and four females, volunteered for the study. The results showed that the obese people are able to reduce the knee joint flexion moment when climbing stair compared to the normal slim people. In the frontal plane, no significant differences were found in the knee adduction moment. Moreover, obese individuals have identified some kinematics adaptations including slower velocity and longer stance phase, compared to slim individuals. The obese individuals might adjust their gait characteristics in response to their heavy bodies to redu...
The measurements of postural balance often involve measurement error, which affects the analysis ... more The measurements of postural balance often involve measurement error, which affects the analysis and interpretation of the outcomes. In most of the existing clinical rehabilitation research, the ability to produce reliable measures is a prerequisite for an accurate assessment of an intervention after a period of time. Although clinical balance assessment has been performed in previous study, none has determined the intrarater test-retest reliability of static and dynamic stability indexes during dominant single stance. In this study, one rater examined 20 healthy university students (female = 12, male = 8) in two sessions separated by 7 day intervals. Three stability indexes—the overall stability index (OSI), anterior/posterior stability index (APSI), and medial/lateral stability index (MLSI) in static and dynamic conditions—were measured during single dominant stance. Intraclass correlation coefficient (ICC), standard error measurement (SEM) and 95% confidence interval (95% CI) wer...
... Page 2. 852 HN Shasmin, NA Abu Osman and L. Abdul Latif _____ IFMBE Proceedings Vol. ... REFE... more ... Page 2. 852 HN Shasmin, NA Abu Osman and L. Abdul Latif _____ IFMBE Proceedings Vol. ... REFERENCES 1. HN Shasmin, NA Abu Osman, L Abd Latif, J Usman and WAB Wan Abas (2007). ...
Several studies have presented technological ensembles of active knee systems for transfemoral pr... more Several studies have presented technological ensembles of active knee systems for transfemoral prosthesis. Other studies have examined the amputees’ gait performance while wearing a specific active prosthesis. This paper combined both insights, that is, a technical examination of the components used, with an evaluation of how these improved the gait of respective users. This study aims to offer a quantitative understanding of the potential enhancement derived from strategic integration of core elements in developing an effective device. The study systematically discussed the current technology in active transfemoral prosthesis with respect to its functional walking performance amongst above-knee amputee users, to evaluate the system’s efficacy in producing close-to-normal user performance. The performances of its actuator, sensory system, and control technique that are incorporated in each reported system were evaluated separately and numerical comparisons were conducted based on th...
WILEY, 111 RIVER ST, HOBOKEN 07030-5774, NJ USA, 2020
In the quest on improving composite formulations for environmental sustainability, maleic acid (M... more In the quest on improving composite formulations for environmental sustainability, maleic acid (MA) cross-linked poly(vinyl alcohol) (PVA)-alpha-chitin composites reinforced by oil palm empty fruit bunch fibers (OPEFB)-derived nanocellulose crystals (NCC) had been successfully prepared. Based on the Fourier transform infrared (FTIR) spectroscopic analysis, it was proven that molecular interactions of the cross-linker to the polymeric networks was through conjugated ester linkage. Differential scanning calorimetry (DSC) showed that the influence of MA was minimal toward crystallization in the PVA/chitin/NCC composite. Maximum tensile strength, elongation at break and Young's modulus of the respective PVA/chitin/NCC composites were achieved at different content of MA, dependent on the PVA/chitin mass ratio. Among all compositions, a maximum Young's modulus was achieved at 30 wt% MA loading in PVA/chitin-30/NCC, amounting to 2,413.81 +/- 167.36 MPa. Moreover, the mechanical properties and selected physicochemical properties (swelling, gel content, and contact angle) of the PVA/chitin/NCC composites could be tailored by varying the chitin content (10-30 wt%) and MA content (10-50 wt% based on total mass of composite). In brief, this chemically cross-linked PVA-based biocomposites formulated with sustainable resources exhibited tunable physicochemical and mechanical properties
Individuals with transtibial amputation exhibit altered movement strategy to sustain stability du... more Individuals with transtibial amputation exhibit altered movement strategy to sustain stability during quiet standing due to reduced proprioception on the amputated limb. The aim of this study is to determine the movement strategies in anterior-posterior and medial-lateral directions in predicting the overall postural stability. In this crossover study, postural stability of ten transtibial amputees was assessed using computed posturography while wearing different prosthetic foot types: solid ankle cushion heel (SACH), single axis (SA) and energy storage and return (ESAR). Three stability indices were measured during four conditions: standing with eyes opened and closed, standing on compliant surface and standing with tilted head. From the standard multiple regression analysis, 63% to 99% of the OSI score in all sensory conditions were explained from the MLSI score, while 11% to 56% from the APSI score. The Pearson's r indicated significant strong positive relationship between OSI and MLSI (r = 0.82-0.99; p <= 0.001) during all sensory conditions. The APSI score was significantly
ROUTLEDGE JOURNALS, TAYLOR & FRANCIS LTD, 2-4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND, 2020
Service is assumed important in table tennis because an effective service may allow the serving p... more Service is assumed important in table tennis because an effective service may allow the serving player to control over the game; hence, the aim of this study was to determine the contribution of arm segment rotations towards ball impact during forehand service. Sixteen shake-hand grip collegiate table tennis athletes had participated in the study. It was revealed that by increasing the radial deviation angular velocity will increase the ball and racket velocities during drop shot service. Furthermore, it was revealed that increasing the wrist palmar flexion and radial deviation will enhance the racket velocity at impact during long shot service. However, it was recommended to the players not to concern on racket speed and arm segment rotations during contact phase as it could not accelerate the ball at impact during long shot service. Although it was the same forehand service, different length of flight ball lead to different contributions of arm segment rotations towards ball impact. The present findings highlight several better postures to increase racket and ball speed at impact during forehand long shot and drop shot services among advanced and intermediate players. Other ranked players may find this study useful as a fundamental understanding on kinematics serving arm.
In powered ankle-foot prostheses, multilevel hierarchical control systems are usually used with p... more In powered ankle-foot prostheses, multilevel hierarchical control systems are usually used with predetermined parameters (tuned during the prosthesis trial). Therefore, control systems cannot adaptively interact with terrains variation where control systems is most effective for ground level walking and less effective for ascending or descending stair/slop. In order to address the control system performance in ever-changing terrains, an adaptive mechanism should be included the control system structure. Here, we present a pilot study to illustrate the applicability of a genetic algorithm-based adaptive fuzzy logic control system. The design method could be divided into two stages: initial knowledge base and membership functions for the genetic pool on the basis of the analysis of biological ankle-foot behaviour. Additionally, the construction of genetic optimization mechanism rules and constraints (fitness function, mutation rats, replacement rate, etc.). Takagi-Sugeno-Kang fuzzy (TSK-fuzzy) inference system is selected because the system structure could depict the character of simple impedance control system. The control system and dynamic model were developed using C code and evaluated using MATLAB/Simulink (2019a).
SAGE PUBLICATIONS LTD, 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND, 2020
The conservative techniques of treating knee osteoarthritis (kOA) include wearing orthoses such a... more The conservative techniques of treating knee osteoarthritis (kOA) include wearing orthoses such as knee braces and laterally wedged insoles and applying gait modification techniques such as toe-in gait and toe-out gait. This study aimed at assessing the immediate effects of these techniques in improving physical function of healthy and kOA participants. Five Osteoarthritis Research Society International (OARSI) recommended performance-based tests were randomly applied to measure physical function: (1) 30-second chair stand test (30CST), (2) 40-m (4 x 10) fast-paced walk test (40FPW), (3) stair climb test (SCT), (4) timed up and go test (TUGT) and (5) 6-minute walk test (6MWT) during a single-visit on 20 healthy and 20 kOA patients (age: 59.5 +/- 7.33 and 61.5 +/- 8.63 years, BMI: 69.95 +/- 9.86 and 70.45 +/- 8.80 kg/m(2)). The interventions included natural gait, toe-out gait, toe-in gait, laterally wedged insoles and knee brace. Analysis was performed through repeated-measures ANOVA and independent sample t-test. 30CST and TUGT showed no significant differences for the five test conditions (p > 0.05). Toe-out showed profound effects via pairwise comparison in impairing the physical function while knee brace improved it during 40FPW, SCT and 6MWT. In general, all the tested conservative techniques except laterally wedged insoles had immediate effects on physical performance measures in both healthy and medial knee osteoarthritis participants. The valgus knee brace improved the parameters the most, while toe-out gait impaired them the most. Future studies can develop strategies for improving gait retraining methods on the basis of issues identified by this study.
SAGE PUBLICATIONS LTD, 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND, 2020
Many studies have shown that medical compression products produce different levels of interface p... more Many studies have shown that medical compression products produce different levels of interface pressure during the usage of the products. However, limited studies have explored the pattern of interface pressure exerted by orthotic garments. This case study aimed to investigate the pattern of interface pressure exerted by two types of orthotic garments on a child with cerebral palsy. A 13-year-old child diagnosed with ataxic spastic diplegia cerebral palsy has difficulty to perform sit-to-stand motion even with a walking frame due to his truncal ataxia. A TheraTogs(TM) orthosis and a Dynamic Lycra (R) Fabric Orthosis (DLFO) were prepared for the child. The child's sit-to-stand ability without and with the usage of orthoses was recorded using five sit-to-stand tests. The garments' interface pressure was measured using F-scan (9811E) and F-scan 6.5.1 version software. The pressure was recorded when the child was in sitting position and performing sit-to-stand-to-sit motion. Overall, the child completed the five sit-to-stand test duration within 2.53 +/- 0.04 s and 2.51 +/- 0.09 s with the usage of TheraTogs(TM) orthosis and DLFO, respectively. Higher pressure was exerted by Dynamic Lycra Fabric Orthosis (axillary = 122 mmHg) in contrast to TheraTogs(TM) orthosis (77 mmHg) when the child was in a sitting position. Lower pressure was exerted by DLFO (7 mmHg), over xiphoid level and for TheraTogs(TM)orthosis is 1.2 mmHg over axillary level when the child was performing sit-to-stand motion. The largest range of pressure was exerted by TheraTogs(TM) orthosis with a minimum pressure of 5 mmHg and a maximum pressure of 155 mmHg during sit-to-stand motion. Overall, the DLFO exerted higher mean interface pressure on the child in comparison to TheraTogs(TM) orthosis when the child's body was in a sitting position wearing both upper garment and pants. Both TheraTogs(TM) orthosis and DLFO presented a different range of interface pressure over different body segments and activities.
Hypoxia is one of the major challenges after scaffold implantation which can lead to cell necrosi... more Hypoxia is one of the major challenges after scaffold implantation which can lead to cell necrosis and bacterial infection. Using of supplemental oxygen can increase the cell proliferation, encourage the cell differentiation and prevent the infections. Developing an engineered scaffold with a sustained oxygen release is an outstanding way for addressing the challenges of oxygen deficiency. In this study, the bioceramic scaffolds were fabricated from biphasic calcium phosphate (BCP) powder with the composition of 60\% hydroxyapatite (HA) and 40\% beta-tricalcium phosphate (beta-TCP). The Robocasting technique was utilised for producing a porous structure comprising interpenetrated ceramic rods in a 3-dimensional tetragonal mesh. The scaffold was modelled by the finite element method (FEM) for computing the stress fields and predicting their mechanical performance. Calcium peroxide (CPO), as an oxygen-producing and antimicrobial biomaterial, was mixed with a polycaprolactone (PCL) solution and was coated on the scaffolds by the dip-coating method. The coating layer possessed three different percentages of CPO (1, 3 and 5 wt\%). The oxygen-releasing profile proved that this design of coating scaffold could be effective as a system of oxygen delivery. According to the antibacterial investigations, releasing of CPO from the scaffolds could inhibit the growth of E. coli and S. aureus. SBF tests confirmed that the coated scaffolds because of CPO particles on their surface presented superior apatite precipitation in comparison with the uncoated one. The differentiated osteoblastic function was monitored by measuring the alkaline phosphatase (ALP) activity. The coated BCP scaffolds with 3\% and 5\% CPO exhibited higher ALP activity compared to the other samples. The results demonstrated that the proposed bioceramic-based scaffolds containing oxygen-generating coating could be optimised to supply an antibacterial performance, ideal mechanical properties, improved ALP activity and higher apatite formation ability. Therefore, these scaffolds can be a promising candidate for applying in bone tissue engineering.
CAMBRIDGE UNIV PRESS, 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA, 2019
Investigating the mechanical properties and dimensional accuracy of 3D printed parts is an import... more Investigating the mechanical properties and dimensional accuracy of 3D printed parts is an important step towards achieving optimum printing conditions. This condition. which leads to the fabrication of parts with appropriate mechanical properties and accuracy, is achieved by studying the effect of different process parameters on the final structure. In this work, Response Surface Methodology (RSM) was employed to design specified experiments to investigate the effects of layer thickness, printing orientation and delay, on the compressive strength and dimensional error of the parts. The results show that an increase in the delay time in X orientation results in better binder spreading and uniformity followed by improvement in the compression strength. Furthermore, more binder spreads in the vertical direction leads to the higher dimensional error in the Z direction. The results proved that the RSM provides a time and cost-efficient design to print the prototypes with optimum strength and dimensional error.
SAGE PUBLICATIONS LTD, 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND, 2019
Transtibial prosthetic sockets can be fabricated either by the conventional way, which involve us... more Transtibial prosthetic sockets can be fabricated either by the conventional way, which involve using plaster of Paris bandages for casting. This will include modifications through hand, scanning and digital imaging of software. The aim of this study is to determine the circumferential profiles and conduct a volumetric analysis of a conventional socket that has fabrication using biosculptor technology. In doing this, a male transtibial amputee, age 28 years old with stable health condition was studied, where circumferential measurements were taken at intervals of 1 cm from the distal end of the residual limb to the medial tibial plateau level. Furthermore, the interior volume of both sockets and residuum were determined directly using water displacement method. A comparative value for the calculation of volume was also carried out using engineering mathematical equations. From these measurements, a total surface bearing transtibial sockets was fabricated to compare the changes of circumferential values of both sockets. The finding shows a percentage of the difference between the volume of the residual limb and conventional sockets to be 6.09\%, whereas the biosculptor fabrication socket was 7.84\% using the water displacement method. A comparison of circumferential profiles and volumetric analysis findings on the contrary showed that socket fabricated using the biosculptor technology is interchangeable with the conventional socket with more advantages, where biosculptor technology produces cheaper sockets and faster process with digital function in the procedure, unlike the conventional manual technique.
SAGE PUBLICATIONS LTD, 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND, 2019
Background: Knee osteoarthritis is a major contributor to the global burden of disease. There is ... more Background: Knee osteoarthritis is a major contributor to the global burden of disease. There is a need of reducing knee joint load and to improve balance and physical function among knee osteoarthritis patients. Objectives: To test the hypothesis that toe-out gait will reduce second peak knee adduction moment further and increase fall risk when combined with knee brace and laterally wedged insole in knee osteoarthritis patients. Study design: Single visit study with repeated measures. Methods: First and second peak knee adduction moments, fall risk and comfort level. First and second peak knee adduction moments were determined from three-dimensional gait analysis, completed under six randomized conditions: (1) natural, (2) knee brace, (3) knee brace + toe-out gait, (4) laterally wedged insole, (5) laterally wedged insole + toe-out gait, and (6) knee brace + laterally wedged insole + toe-out gait. Fall risk was assessed by Biodex Balance System using three randomized stability settings: (1) static, (2) moderate dynamic setting (FR12), and (3) high dynamic setting (FR8). Results: The reduction in first peak knee adduction moment and second peak knee adduction moment was greatest (7.16\% and 25.55\%, respectively) when toe-out gait combine with knee brace and laterally wedged insole. Significant increase in fall risk was observed with knee brace + laterally wedged insole + toe-out gait (42.85\%) at FR12. Similar significant balance reductions were found at FR8 condition for knee brace + toe-out gait (35.71\%), laterally wedged insole + toe-out gait (28.57\%), and knee brace + laterally wedged insole + toe-out gait (50\%) as compared to natural. However, knee brace decreased fall risk at FR12 by 28.57\%. Conclusion: There is a synergistic effect of toe-out when combined with knee brace and laterally wedged insole concurrently in second peak knee adduction moment reduction but with a greater degree of fall risk. Simultaneous use of conservative treatments also decreases comfort level.
MDPI, ST ALBAN-ANLAGE 66, CH-4052 BASEL, SWITZERLAND, 2019
In this paper, a gait patterns classification system is proposed, which is based on Mahalanobis-T... more In this paper, a gait patterns classification system is proposed, which is based on Mahalanobis-Taguchi System (MTS). The classification of gait patterns is necessary in order to ascertain the rehab outcome among anterior cruciate ligament reconstruction (ACLR) patients. (1) Background: One of the most critical discussion about when ACLR patients should return to work (RTW). The objective was to use Mahalanobis distance (MD) to classify between the gait patterns of the control and ACLR groups, while the Taguchi Method (TM) was employed to choose the useful features. Moreover, MD was also utilised to ascertain whether the ACLR group approaching RTW. The combination of these two methods is called as Mahalanobis-Taguchi System (MTS). (2) Methods: This study compared the gait of 15 control subjects to a group of 10 subjects with laboratory. Later, the data were analysed using MTS. The analysis was based on 11 spatiotemporal parameters. (3) Results: The results showed that gait deviations can be identified successfully, while the ACLR can be classified with higher precision by MTS. The MDs of the healthy group ranged from 0.560 to 1.180, while the MDs of the ACLR group ranged from 2.308 to 1509.811. Out of the 11 spatiotemporal parameters analysed, only eight parameters were considered as useful features. (4) Conclusions: These results indicate that MTS can effectively detect the ACLR recovery progress with reduced number of useful features. MTS enabled doctors or physiotherapists to provide a clinical assessment of their patients with more objective way.
SAGE PUBLICATIONS LTD, 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND, 2019
The Cheneau brace has proven its effectiveness in treating the adolescent idiopathic scoliosis pa... more The Cheneau brace has proven its effectiveness in treating the adolescent idiopathic scoliosis patients. However, no studies reported on the analysis of interface pressure in double-curve adolescent idiopathic scoliosis patients. In this study, we evaluated the interface pressure of the Cheneau brace action in double-curve adolescent idiopathic scoliosis patient treatment. A total of 72 (60 girls and 12 boys) patients aged 10 years and above participated in the study. The F-Socket transducers (9811E) were used to evaluate the pressure on the right thoracic and left thoracolumbar curves between normal and maximum strap tension and variation in these interface pressures with other tasks. Each patient was asked to do nine different tasks corresponding to daily activities, and the interface pressures for each activity were recorded for both normal and maximum tension. The resultant mean peak pressure in double-curve adolescent idiopathic scoliosis was higher for right thoracic curves than left thoracolumbar curves in all tasks. The pressure significantly increased at the task of maximal inspiration (p < 0.0001) for both types of curves for normal and maximum tension. The degrees of correction for the thoracic and thoracolumbar curves were 23.2\% and 34.5\%, respectively, after 6 months of brace use (23 h per day). Hence, we could not find any substantial correlation between mean peak pressure in the standing position and degree of scoliosis correction for two curves having r = 0.158, p = 0.356 and r = -0.024, p = 0.889 values.
MDPI, ST ALBAN-ANLAGE 66, CH-4052 BASEL, SWITZERLAND, 2019
Gait analysis is recognized as a method used in quantifying gait disorders and in clinical evalua... more Gait analysis is recognized as a method used in quantifying gait disorders and in clinical evaluations of patients. However, the current guidelines for the evaluation of post anterior cruciate ligament reconstruction (ACLR) patient outcomes are primarily based on qualitative assessments. This study aims to apply gait analyses and mathematical, index-based health management, using the Mahalanobis Taguchi System (MTS) and the Kanri Distance Calculator (KDC) to diagnose the level of the gait abnormality and to identify its contributing factors following ACLR. It is hypothesized that (1) the method is able to discriminate the gait patterns between a healthy group (HG) and patients with ACLR (PG), and (2) several contributing factors may affect ACLR patients' rehabilitation performance. This study compared the gait of 10 subjects in the PG group with 15 subjects in the HG. The analysis was based on 11 spatiotemporal parameters. Gait data of all subjects were collected in a motion analysis laboratory. The data were then analyzed using MTS and KDC. In this study, two significant groups were recognized: the HG, who achieved results which were within the Mahalanobis space (MS), and (ii) the PG who achieved results above the MS. The results may be seen as being on-target and off-target, respectively. Based on the analysis, three variables (i.e., step width, single support time, and double support time) affected patient performance and resulted in an average mark of above 1.5 Mahalanobis distance (MD). The results indicated that by focusing on the contributing factors that affect the rehabilitation performance of the patients, it is possible to provide individualized and need-based treatment.
ROYAL SOC CHEMISTRY, THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND, 2016
Iron (Fe)-induced hydroxyapatite (HA) layered double hydroxides (LDH) with different concentratio... more Iron (Fe)-induced hydroxyapatite (HA) layered double hydroxides (LDH) with different concentrations of Fe (FH95 and FH85) were prepared by a novel in situ coprecipitation method. For the first time, LDH is intercalated with calcium cations (Ca-I(2+)) by producing Frenkel defects. The LDH structure was precisely characterized by thermogravimetric analysis and X-ray diffraction study. The exfoliation in the basal planes was also confirmed by high resolution transmission electron microscopy. Hydrophilicity and change in mass in vitro swelling in phosphate buffered saline (PBS) medium were characterized to check the wettability of the pellet samples in aqueous media. The morphological and elemental study of the carriers was done before and after aceclofenac (AF) drug loading by a field emission electron microscope. Interactions of AF with LDH drug carriers (FH85 and FH95) were studied by Fourier transforms infrared spectroscopy. The AF drug-release mechanism of these novel LDH carriers was diffusion. The AF drug loading efficiency and releasing criteria were found to be better in FH95 than the carrier FH85. The FH95 LDH carrier can store the AF drug and can release the drug in a controlled manner in aqueous medium of PBS under simulated body conditions. Furthermore, the newly developed LDH material is highly biocompatible as well as a potential drug carrier. Therefore, the developed LDH drug carrier could be a potential drug scavenger for non-steroidal anti-inflammatory drugs such as AF.
SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS, 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA, 2016
Fourier transform infrared (FTIR) spectroscopy technique can detect the abnormality of a cervical... more Fourier transform infrared (FTIR) spectroscopy technique can detect the abnormality of a cervical cell that occurs before the morphological change could be observed under the light microscope as employed in conventional techniques. This paper presents developed features extraction for an automated screening system for cervical precancerous cell based on the FTIR spectroscopy as a second opinion to pathologists. The automated system generally consists of the developed features extraction and classification stages. Signal processing techniques are used in the features extraction stage. Then, discriminant analysis and principal component analysis are employed to select dominant features for the classification process. The datasets of the cervical precancerous cells obtained from the feature selection process are classified using a hybrid multilayered perceptron network. The proposed system achieved 92\% accuracy. (C) The Authors. Published by SPIE
SAGE PUBLICATIONS LTD, 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND, 2016
Background: This article describes a total surface bearing prosthetic socket for a patient (25-ye... more Background: This article describes a total surface bearing prosthetic socket for a patient (25-year-old female) with a bulbous stump. Case Description and Methods: The subject had unstable excessive soft tissue at the distal end of the residuum. After 2years of prosthetic use, she experienced several problems, including pain in the residual limb and knee joint. Pressure distribution was evaluated during ambulation. We also designed a total surface bearing socket with Velcro as suspension system to distribute the load evenly on the residual limb, and to facilitate donning procedure. Findings and Outcomes: The main site of weight bearing in the old prosthesis (patellar tendon bearing) was anterior proximal region of the residual limb, especially the patellar tendon. The pressure was almost 10 times higher than the distal region during level walking. Pressures were distributed more evenly with the total surface bearing socket design, and the donning was much easier. Conclusion: Pressure distribution within the socket could be affected by socket design and suspension system. Using the total surface bearing socket and Velcro as suspension system might facilitate donning of prosthesis and reduce traction at the end of residual limb during the swing phase of gait. Clinical relevance Proper socket design and suspension system based on the amputees' need can facilitate rehabilitation process and lead to the amputee's satisfaction. The pressure is distributed more uniformly over the residual limb by the total surface bearing socket compared to the patellar tendon bearing socket for lower limb amputees with unusual stump shape.
MDPI, ST ALBAN-ANLAGE 66, CH-4052 BASEL, SWITZERLAND, 2016
Since humidity sensors have been widely used in many sectors, a suitable humidity sensing materia... more Since humidity sensors have been widely used in many sectors, a suitable humidity sensing material with improved sensitivity, faster response and recovery times, better stability and low hysteresis is necessary to be developed. Here, we fabricate a uniformly porous humidity sensor using Ca, Ti substituted Mg ferrites with chemical formula of CaMgFe1.33Ti3O12 as humidity sensing materials by solid-sate step-sintering technique. This synthesis technique is useful to control the grain size with increased porosity to enhance the hydrophilic characteristics of the CaMgFe1.33Ti3O12 nanoceramic based sintered electro-ceramic nanocomposites. The highest porosity, lowest density and excellent surface-hydrophilicity properties were obtained at 1050 degrees C sintered ceramic. The performance of this impedance type humidity sensor was evaluated by electrical characterizations using alternating current (AC) in the 33\%-95\% relative humidity (RH) range at 25 degrees C. Compared with existing conventional resistive humidity sensors, the present sintered electro-ceramic nanocomposite based humidity sensor showed faster response time (20 s) and recovery time (40 s). This newly developed sensor showed extremely high sensitivity (\%S) and small hysteresis of <3.4\%. Long-term stability of the sensor had been determined by testing for 30 consecutive days. Therefore, the high performance sensing behavior of the present electro-ceramic nanocomposites would be suitable for a potential use in advanced humidity sensors.
Balance control plays an important role in maintaining daily activity. However, studies on postur... more Balance control plays an important role in maintaining daily activity. However, studies on postural control among middle-aged adults are scarce. This study aims (i) to examine directional control (DCL) and electromyography activity (EMG) for different stability levels, and (ii) to determine left-right asymmetry for DCL and muscle activity among sedentary middle-aged adults. Twenty healthy, middleaged adults (10 males, 10 females; age= 50.0 +/- 7.5 yrs; body height: 1.61 +/- 0.10 m; body mass: 70.0 +/- 14.5 kg) participated in the study. EMG for left and right side of rectus femoris (RF), biceps femoris (BF), and medial gastrocnemius (MG) were recorded. Two-way repeated measures analysis of variance was used to assess the effect of dynamic level on DCL and EMG, whereas independent sample t-test was conducted to analyse the asymmetries of DCL and EMG for the left and right leg. When the dynamic tilt surface increased, DCL scores significantly decreased (except forward, forward-rightward, and backward -leftward direction) and only RF muscle indicated significant differences. Left-right asymmetry was found in BF and MG muscles. No significant gender difference was observed in DCL and EMG. These data demonstrated that increased dynamic tilt surface may increase the displacement of center of pressure of certain directions, and stimulate RF activity in dynamic stance among sedentary middle-aged adults. Further studies should be conducted to examine the dynamic stance and muscle activity of the lower limb in age-matched patient groups with balance abnormalities. (C) 2016 Elsevier Ltd. All rights reserved.
ROYAL SOC CHEMISTRY, THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND, 2016
Hydroxyapatite-5 wt\% poly(ethylene glycol) (HA-PEG) core-shell composite nanoparticles (NPs) wer... more Hydroxyapatite-5 wt\% poly(ethylene glycol) (HA-PEG) core-shell composite nanoparticles (NPs) were synthesized using a coprecipitation technique. For the first time, the NPs are characterized for potential drug delivery applications using structural, electrical and in vitro kinetic studies. Phase quantification and the crystal structures of the NPs were analyzed using X-ray diffraction and Fourier transform infrared spectroscopy and the morphology was determined using scanning electron and transmission electron microscopies. Dielectric spectroscopy was used to analyze the polarization behaviour of the HA and HA-PEG core-shell NPs as potential drug carriers by applying an oscillating (100 Hz to 2.5 MHz) electric field. The increased intra-particle interfacial interactions in the HA-PEG NPs confirmed the significant enhancement in interfacial or space charge polarization owing to the reduction in mobility and accumulation of charge-carriers at the interfaces. Thus, HA-PEG showed better aceclofenac drug releasing properties than pristine HA NPs. An in vitro cell study confirmed that the HA and HA-PEG core-shell nanocarriers showed excellent biocompatibility on human dermis fibroblast (HDF) cells. The interaction within the HA-PEG core-shell was stronger than with pristine HA and the biodegradable PEG from the shell-layer neutralized the composite-surroundings path. Hence, it would reduce the direct interaction of aceclofenac drug with the surrounding biomolecules of the delivery paths and enhance the ability for carrying the drug precisely to the target organs.
Background: Today a number of prosthetic suspension systems are available for transtibial amputee... more 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. (C) 2013 Elsevier Ltd. All rights reserved.
Reorganization of movement strategies is crucial in a person with lower-limb amputation to mainta... more Reorganization of movement strategies is crucial in a person with lower-limb amputation to maintain postural balance during upright standing. This study aims to disentangle the contribution of movement strategies in anterior-posterior and medial-lateral directions in predicting the overall postural stability. The overall (OSI),anterior-posterior (APSI) and medial-lateral (MLSI) stability indexes were measured during standing with various sensory conditions by using computerized posturography. Postural stability of amputees was assessed while wearing three types of prosthetic feet: solid ankle cushion heel (SACH), single axis (SA) and energy storage and return (ESAR). We compared the movement strategies of ten unilateral transtibial amputees with nine able-bodied controls using the correlation analysis. The results indicated that amputees exhibited strong to very strong relationship (r= 0.82-0.99)between the OSI and MLSI score in all sensory conditions, in comparison with able-bodied group (r= 0.10-0.90). Meanwhile, amputees showed very weak to very strong relationship (r= 0.15-0.97)between the OSI and APSI score in comparison with able-bodied group (r= 0.96-0.99). This study showed that a consistent strong relationship between OSI-MLSI was found in amputees group as for OSI-APSI in able-bodied group. Thus, movement strategies in below-knee amputees occurred most in medial-lateral direction compared to anterior-posterior direction in able-bodied group.
Proprioception of lower extremity plays an important role in detecting changes of foot orientatio... more Proprioception of lower extremity plays an important role in detecting changes of foot orientation, pain, and temperature perception. The loss of foot sensation may result increased of difficulty in our daily activities, and affected quality of life. This study aimed to investigate the association between postural stability and foot vibration sensation. Ten transtibial amputees participated in this study. The postural stability test for the Biodex Balance System was used to measure the postural performance for dynamic standing condition. A 128Hz tuning fork used to measure the vibration sensation at the sole of the foot. The current findings revealed that traumatic amputee have significance higher foot vibration sensitivity than diabetes dysvascular amputee. A weak correlation was found between postural activity and vibration sensation at first metatarsal head. The findings may provide a basic knowledge for the contribution of vibration sensation to the postural balance for future studies.
Fourier Transform Infrared (FTIR) spectroscopy technology has been currently used to study the st... more Fourier Transform Infrared (FTIR) spectroscopy technology has been currently used to study the structural changes of cells at the molecular level in a cervical cancer. However, in the FTIR data acquisition process, it has undergone twice noise degradations. In this study, to apply the FTIR spectra for input data into classification tools, the FTIR spectra need to be smoothed before feature extraction process. A smoothing technique namely Quadratic of Half Ellipse (QHE) filter was proposed for smoothing the cervical cells FTIR spectra. The QHE filter was tested using 850 cervical cells FTIR spectra. The cervical cells FTIR spectra were corrupted by 20, 25, 30, 25, 40, 45 dB of S/N. The proposed filter achieved good performance for smoothing the corrupted cervical cells FTIR spectra. (C) 2015 The Authors. Published by Elsevier B.V.
With the rapid development of IoT devices, the information from the environment now can easily be... more With the rapid development of IoT devices, the information from the environment now can easily be collected and accumulated to provide useful services to the end users. In traditional transit system, the passenger waits for the arrival of the bus, but there is no assurance of seat. Sometimes, the bus is full of passengers, and the passenger needs to travel standing. If the travel time is higher, then the passenger's comfort is jeopardized during the travel from the source location to the destination. Alternatively, the passenger cannot know on the fly whether a little more waiting may ensure a seat in the next available transport. So, an efficient method is needed to ensure the seat in a transport facility along the passenger's trip. This paper introduces a transit matching method that finds transport with a consideration of the passenger's satisfaction.
Background: Knee osteoarthritis (kOA), the most commonly occurring type of osteoarthritis in the ... more Background: Knee osteoarthritis (kOA), the most commonly occurring type of osteoarthritis in the world and one of the key contributors to global burden of disease significantly affects the physical functionality of the patient. The two conservative techniques of kOA include orthoses (knee braces and wedged insoles) and gait modification techniques (toe-in and toe-out gait). Previous studies assessing these two types of techniques do not present a comparison between their effects on physical functionality of the patient. Methods: Five OARSI (Osteoarthritis Research Society International) recommended performance-based tests to measure physical function of kOA patients: (1) 30s chair stand test (2) 40m fast-paced walk test (3) stair climb test (4) timed up and go (TUG) test (5) 6min walk test were applied on a total of 5 kOA patients randomly (Age: 59.2 +/- 11.09 years, BMI: 25.94 +/- 3.77 kg/m2, Kellgren-Lawrence Grades 1,2 and 4). The test conditions included normal gait, toe-out gait, toe-in gait, use of laterally wedged insoles and use of knee brace. The study was a single visit study assessing immediate effects, however, patients were given enough time and training to get used to the interventions. Data from the tests were analyzed using Repeated-Measures ANOVA. Results: No significant differences were observed among the five test conditions for 30sec chair stand test, 40m fast-paced walk test, TUG test and 6min walk test (p > 0.05). Pairwise comparison showed that toe-out differed significantly from toe-in (p = 0.042), insoles (p = 0.037), and brace (p = 0.011) while toe-in differed significantly from toe-out (p = 0.042), insoles (p = 0.035) and brace (p = 0.012). Conclusions: In general, orthoses and gait modifications seemed to have similar physical performance measures for kOA patients. The results however, indicated that gait modifications are affecting stair ascent of the kOA patients differently as compared to orthoses. Larger sample size may reveal a more accurate influence of the test conditions used in this study.
Knee flexion contracture on a stump side is a phenomenon in which the stump cannot move in normal... more Knee flexion contracture on a stump side is a phenomenon in which the stump cannot move in normal range of motion (ROM) or cannot be fully extended. This study has been carried out by using Biodex Stability System (BSS) in order to investigate the effect of stump flexion contracture towards the postural stability among the transtibial prosthesis users with the intervention of alignment accommodation. The BSS provides the reading of anterior-posterior stability index (APSI), medial-lateral stability index (MLSI), and overall stability index (OSI). Higher reading of the index indicates lesser stability. Each of the subjects had been tested in three different sessions that were Visit 1 (before contracture improvement), Visit 2 (after contracture improvement without alignment readjustment), and Visit 3 (after contracture improvement with alignment readjustment). The APSI reading was significantly higher during Visit 2 compared to Visit 1 and Visit 3. The OSI during Visit 2 was also found significantly higher compared to Visit 3. In Visit 2, the degree of contracture was significantly improved with 44.1\% less than Visit 1. The stability index in anterior-posterior aspect (APSI) was proven to be lower as the prosthetic alignment was adjusted according to the ROM of knee. This finding explained that the alignment set up based on the adaptation with the stump's ROM can contribute positively in maintaining postural stability.
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Papers by Noor Azuan Abu Osman