Haptic Interface for the Simulation of Endovascular Interventions

Endovascular interventions are minimally invasive surgical procedures that are performed to diagnose and treat vascular diseases. These interventions use a combination of long and flexible instruments known as guidewire and catheter. A popular method of developing the skills required to manipulate the instruments successfully is through the use of virtual reality (VR) simulators. However, the interfaces of current VR simulators have several shortcomings due to limitations in the instrument tracking and haptic feedback systems design. A major challenge of developing physics-based training simulations of endovascular interventional procedures is to unobtrusively access the central, co-axial guidewire for tracking and haptics. This work sets out to explore the state of the art, to identify and develop novel solutions to this concentric occlusion problem, and to perform a validation of a proof of concept prototype. This multi port haptic interface prototype has been integrated with a 3-D virtual environment and features novel instrument tracking and haptic feedback actuation systems. The former involves the use of an optical sensor to detect guidewire movements through a clear catheter, whereas the latter utilises the placement of a customised electromagnetic actuator within the catheter hub. During the proof of concept validation process, both systems received positive reviews. Whilst the haptic interface prototype designed in this work has met the original objectives, there are still important aspects which need to be addressed to improve its content and face validity. With further development, the prototype has the potential to evolve and become a significant improvement over the haptic interfaces that exist today.Open Acces

Rollover warning system for tractor-semitrailer using a modified odenthal rollover index algorithm

Any accident involving a tractor-semitrailer could significantly affect life and component damage as well as the surrounding environment due to the size of the vehicle. One of the main factors that causes tractor-semitrailer accidents is vehicle rollover instability. Therefore, this study aimed to develop a vehicle instability avoidance system for a tractor-semitrailer by implementing it on an accurate tractorsemitrailer model. In developing the model, a new approach was proposed by adopting a virtual Pacejka tire model in modelling the hitch joint of the tractor-semitrailer. The virtual Pacejka tire model has included a 16 degree-of-freedom tractor-semitrailer within MATLAB/Simulink software and later verified using the TruckSim model and validated with published data. It is observed from the verification and validation results, the tractor-semitrailer model using the virtual Pacejka tire model for the hitch joint showed a similar response to the behaviour of the TruckSim model and published data. In terms of vehicle instability avoidance system, the fastest response of the tractor-semitrailer rollover index based on early warning indicator was selected by utilizing several types of rollover index algorithm proposed by the previous researchers. The step steering manoeuvres simulation at a various speed was conducted using MATLAB/Simulink software to obtain the rollover index. It can be observed from the results that the rollover index algorithm proposed by Odenthal provides the fastest index based on the early warning indicator on the tractor unit. In order to optimise the rollover index performance, the Odenthal rollover index algorithm was modified and optimised using Particle Swarm Optimisation (PSO). Finally, the rollover index algorithm was proposed by integrating the modified Odenthal rollover index algorithm with driver steering and vehicle speed inputs instead of lateral acceleration. The modified Odenthal rollover index algorithm performance was evaluated by conducting an experiment involving the step steering manoeuvres, subjected to various vehicle speeds and load conditions through the Hardware-in-the- Loop (HIL) simulation in the TruckSim driving simulator and MATLAB/Simulink software. It was observed from the experimental results that the modified Odenthal rollover index algorithm produced 12.4% faster Time-To-Warn (TTW) than the Odenthal rollover index for the driver. Thus, the modified Odenthal rollover index algorithm demonstrated a better early warning system for the driver to initiate the corrective action

Preparation and characterisation of inexpensive porous kaolin hollow fibre as ceramic membrane supports for gas separation application

Low-cost, porous ceramic kaolin-based hollow fibre membrane support (HFMS) for gas separation application was developed via phase inversion technique. The ceramic suspensions with various ratios of kaolin to polyethersulfone (PESf) binder (5:1 to 9:1) were extruded and then sintered at 1200 to 1500 °C. The HFMSs were characterised by several analyses to investigate the effects of kaolin/PESf ratio and sintering temperature on the sample properties. The results showed that the kaolin/PES ratio and sintering temperature affected the considerable structure and physical properties of the kaolin membrane. It is observed that with increasing sintering temperature, the porosity and gas permeation of the HFMS decreased, while the bending strength and density of the HFMS increased. As a result, a porous HFMS with sufficient mechanical strength and high gas permeation characteristics is achievable if the appropriate kaolin/PESf ratio and sintering temperature are chosen

Novel superhydrophobic and superoleophilic sugarcane green ceramic hollow fibre membrane as hybrid oil sorbent-separator of real oil and water mixture

The frequent oil spill accidents in nowadays has aroused great attention all over the world. Superhydrophobic and superoleophilic grafted on various substrates have attracted much attention to treat oil and water mixture because of their unique performance that can effectively separate oil and water mixture. At the same time, ceramic membrane also shows potential substrates to be used in treating oil and water mixture. However, conventional ceramic membrane that made from alumina show drawbacks in term of its high cost production. Herein, we report a new ceramic membrane that derived from agricultural-sugarcane bagasse waste and modified into superhydrophobic and superoleophilic to act as hybrid oil sorbent and separator. In this study, we successfully treat three types of real oil and water mixture from palm oil mill effluent (POME), restaurant and car wash with oil rejection and flux up to 99% and 134 L/m2h, respectively. In summary, this work demonstrates a facile, economic and effective method to fabricate superhydrophobic and superoleophilic substrates for oil and water separation

The pedagogical affordances of e-portfolio in learning how to teach: A systematic review

The advances in technology have paved the way for student centred learning environment which allows for higher students’ engagement, active participation, deep meaningful learning, and critical thinking. One of the technology applications which have gained popularity at the beginning of the 1990s is the use of e-portfolio. Studies in many professional fields have shown exceptional findings on the adoption of e-portfolio. Nonetheless, the development of e-portfolio affordances over a period of time has yet to be explored to ascertain its usefulness particularly in the area of teacher education. This article presents the process of systematic literature on the e-portfolio pedagogical affordances in teacher education programs and issues to be addressed for successful implementation. Using the content analysis method, 28 articles which focused on e-portfolio, teacher education, English as a second language, scientific research, and secondary school were reviewed. The findings of the review have mainly shed positive lights on its use in documenting student teachers’ learning experiences particularly on assisting and assessing student teachers learning how to teach. This article implicates the relevance of having a holistic view and understanding of the e-portfolio pedagogical affordances and the need to recognize issues to be addressed prior to its implementation in a teacher education program. With this understanding, the university and teacher education institutions can have a well-defined policy on the adoption of e-portfolio into their teacher education programs.

Development of a haptic feedback actuator for an endovascular interventions simulator interface

Endovascular interventions are minimally invasive surgical procedures that are performed to diagnose and treat vascular diseases using flexible instruments known as guidewire and catheter. A popular method of developing the skills required to manipulate the instruments successfully is through the use of virtual reality (VR) simulators. However, the interfaces of current VR simulators have several shortcomings and a major challenge of addressing the shortcomings is to unobtrusively access the central, co-axial guidewire for haptics. This work sets out to explore two different approaches for applying force to the concentric guidewire: direct non-contact electromagnetic force application and a custom actuator designed to be embedded within a catheter hub. An initial implementation of the hub actuator approach was able to produce a suitably strong resistance effect when the guidewire is advanced, but further work is needed to reduce the actuator size while maintaining the level of resistance

Evaluating the sintering temperature control towards the adsorptivity of ammonia onto the natural zeolite based hollow fibre ceramic membrane

The disproportionate quantity of ammonia presence in water has led to serious drinkable water scarcity worldwide. The abundant source of mineral and superior cations selectivity has made natural zeolite as a good adsorbent for the ammonia removal. This work aims to fabricate natural zeolite based hollow fibre ceramic membrane (HFCM) via extrusion-based phase inversion and sintering techniques for the ammonia removal in wastewater. The physical properties of the fabricated HFCM were investigated through surface morphologies and pure water permeation. The performance of the HFCM for ammonia removal was studied using synthetic wastewater with HFCM prepared at different sintering temperatures. Of all studied sintering temperatures, it was found that 1050 °C was the best fabrication conditions. The membrane also revealed acceptable morphologies (roughness) and water permeation flux of 249.57 L/m 2 .h to which both contributed to the performance of the HFCM. The ammonia removal using the fabricated HFCM gave an outstanding performance with nearly 90% rejection, which probably is due to the synergistic effect of the two processes in the HFCM system, i.e. adsorption and separation. It was found that natural zeolite based HFCM has a great potential to be developed as a single – step ammonia removal in wastewater treatment

Preparation And Characterization Of Carbon Molecular Sieve Membrane From Polyfurfuryl Alcohol

The application of inorganic membrane would minimize the problems suffered by conventional gas separation technologies such as adsorption, chemical process and polymeric membrane. In this work carbon molecular sieve (CMS) membranes were successfully prepared from polyfurfuryl alcohol (PFA). The CMS membrane substrate was prepared first by coating the dope solution of titania sol onto the titania disk and heated from 300 to 600˚C of sintering temperature. On the other hand, the carbon film was formed by dipping the substrate onto PFA solution followed by carbonization between 400 to 600˚C for 1 to 4 hours of thermal soak times