Zulkifli Ahmad

A Low Cost 3D Foot Scanner for Custom-Made Sports Shoes

Conventional methods to obtain foot anthropometry for custom made sports shoes using anthropometer, callipers and measuring tapes are inaccurate due to the complex anatomy and curvature of the instep, foot arc and related joints. They lead to poor repeatability and large variances, particularly when measurements are taken of different people. Measurements from 3D model have been claimed as a perfect tool to obtain anthropometric data. However a commercial 3D foot scanner to create a 3D foot model can be very costly. In this paper we propose a low cost 3D foot scanner system by integrating available image capture technology such as the Kinect®, appropriate 3D scanning software and a foot scanner rig. An experiment was conducted to compare the anthropometry data taken using conventional method and from the 3D model. The differences recorded for all regions were found to be less than 5%, suggesting that the 3D model produced by this method is accurate. The use of 3D scanner has also decreased the measurement duration, thus increasing the repeatability whilst decreasing human errors that normally occur during the measurement process.

Analysis of an Olympic Scale of a Recurve Bow Riser on the Basis of Malaysian Under 15 and Under 17 Archers

Recurve bow is the only type of bow that used in Olympic Games. To date, none of this bow that suits to Malaysian junior archers. This paper aims to analyze a recurve bow riser on the basis of Malaysian anthropometry. Anthropometric data of Malaysian population was gathered to analyze the loads during drawn bow. A static structural analysis of the Matrix riser was executed on a final design of recurve bow riser. The finding from this study shows that the maximum displacement of recurve riser is correspondence to the established previous study. It can be concluded that the design of recurve bow riser can sustain the force applied by Malaysian junior athletes when they aim the target board at a full drawn bow position. The developed bow riser can be very beneficial for both athletes and coaches during training.

A Comparison of Muscular Activity among European, Korea and Malaysian During Seating Using Musculoskeletal Computational Analysis Method

Sitting is the most common posture in any industry field either in office work, manufacturing or even automotive. Sit for a long time lead to musculoskeletal disorder which causes muscle fatigue. However, different size of people will have a different level of muscle activation. The objective of this paper is to analyse and compare the muscle activation during sitting among European, Korean, and Malaysian. The human size employed for this study is by 95th percentile male. The AnyBody Modelling Software is used to simulate and analyse the human muscle activity of the seating posture of these respective countries. Our finding showed that the trunk of the human body has the highest muscle activity. The Malaysian anthropometry showed the highest muscle activity in sitting posture; followed by Korean and European.

Development of Portable Biofeedback Devices for Sport Applications

The purpose of this project was to propose a portable low-cost ECG and EMG devices that play the role of continuous monitoring of the user heart rate and muscle activity. Collecting and analysis of biological signal like Electrocardiography (ECG) and Electromyography (EMG) are important in the field of healthcare and sports which enable to assess the physiological state and training progress of athlete. Heart rate can reflect individual natural fitness, whereas the EMG signal indicates muscle activation and fatigue level, thus determining the performance. However, most of the EMG and heart rate measuring tools are expensive and large in size. The process of data collection also often confined to hospital or biomechanics laboratory. Therefore, this monitoring system is capable to provide an immediate feedback on physiological data due to the small size and portable for outdoor activities especially for athlete and trainers. The monitoring system is merging together between pulse and muscle sensors which function to measure the heartbeat and muscle activity respectively. Arduino Uno acts as microcontroller to analyze the collected signal and then transmits the data via Bluetooth to Android-based smartphone; laptop through Processing software; or LCD screen. Processing software was used to perform an obtained data in the graphical views.The pulse sensor applies photoplethysmography (PPG) technique to measure the heart rate in beats per minute (bpm). On the other hand, the EMG signal will be collected by passive electrode which allows the monitoring of user muscle stress. In order to validated the result, the pulse sensor result collected via Coolterm application was compared to radial pulse and Treadmill. The result showed that the error rate of the device is negligible and promising.

The kicking performance by different boots material

The purpose of this study was to investigate the kinematics of kicking by experimental and simulation techniques analysis. The differences of material stiffness will affected to the ball velocities. Experimental setup by high speed video camera with 250 frames per second was performed in order to obtain the foot and ball velocities during the kicking process. There are 10 male football players from Majlis Sukan Negeri Terengganu (MSNT) were selected as subjects. Instep kicking with right foot was choosing due to the highest ball velocities can be produced by this technique. Simulation analysis by finite element analysis (FEA) then used to validate the results from experimental work done. Polyethylene material and 2.0mm thickness from boot C was considered as the best boot design compared to the others. It gives the highest maximum stress and the highest force to produce the highest ball velocity. The other variables related to the ball velocity such as coefficient of restitution (COR) and contact time. This study is useful to design the suitable material for each region of boots. It also can help the athletes to identify the characteristics of boot selection for different position on the field.

Effect of chronic obstructive pulmonary disease on airflow motion using computational fluid dynamics analysis

Chronic Obstructive Pulmonary Disease (COPD) ranked as the fifth leading cause of death in 2002 and it is had been predicted to become fourth leading cause of death worldwide by 2030. COPD is a disease that will narrow the airway progressively and it alters the behaviour of normal breathing flow. This study aims to investigate the changes of flow pattern and pressure distribution with respect the presence of COPD on the airways lumen. Four airway models were generated based on the fifth to eighth generations of Weibels lung model. The simulations were carried out using Reynolds number ranging of 200 to 1400, corresponding to an average height man breathing from rest to vigorous state. The three-dimensional (3D) incompressible laminar Navier-Stokes equations are solved using computational fluid dynamics (CFD) solver on unstructured tetrahedral meshes. This method overcomes the problem of the absence of actual images for different COPD locations. The simulation results show that the obstructed airways significantly alter the air flow rate ratio due to the recirculation happens at the obstructed model which prevents air to enter the lower generation. It is found that, as the Reynolds number increases, the pressure drop also increased drastically in obstructed airway.

Detection of cardiac geometry via difference intensity of echocardiogram images.

Echocardiogram is an ultrasound image of the heart that demonstrates the size, motion and composition of cardiac structures and is also used to diagnose various abnormalities of the heart including abnormal chamber size, shape and congenital heart disease. Echocardiography provides important morphological and functional details of the heart. Most of the presented automatic cardiac disease recognition systems that use echocardiograms based on defective anatomical region detection. In this paper we present a simple technique for cardiac geometry detection via echocardiogram images which conquer these borders and exploits cues from cardiac structure. To demonstrate the effectiveness of this technique, we present results for cardiac geometry detection through difference intensity of echocardiogram images. We have developed a simple program code for the prediction of cardiac geometry using difference intensity of echocardiogram images. With this code, users can generate node or point for detection of cardiac geometry as ventricle and atrium in size, shape and location.

Computational Analysis on Performance of Thermal Energy Storage (TES) Diffuser

Application of thermal energy storage (TES) system reduces cost and energy consumption. The performance of the overall operation is affected by diffuser design. In this study, computational analysis is used to determine the thermocline thickness. Three dimensional simulations with different tank height-to-diameter ratio (HD), diffuser opening and the effect of difference number of diffuser holes are investigated. Medium HD tanks simulations with double ring octagonal diffuser show good thermocline behavior and clear distinction between warm and cold water. The result show, the best performance of thermocline thickness during 50% time charging occur in medium tank with height-to-diameter ratio of 4.0 and double ring octagonal diffuser with 48 holes (9mm opening ~ 60%) acceptable compared to diffuser with 6mm ~ 40% and 12mm ~ 80% opening. The conclusion is computational analysis method are very useful in the study on performance of thermal energy storage (TES).