Noor Ayuni Che Zakaria

Development of foolproof catheter guide system based on mechatronic design

Minimally invasive surgery (MIS) is a less invasive procedure compared to traditional open surgery. It usually involves laparoscopic devices and remote control manipulation instruments comprising an endoscope for indirect observation of the surgical field. Interventional radiology (IVR) is one of the MIS methodologies. The IVR procedures include diagnosis such as angiograms, and treatment. The IVR procedures use small tubes called catheters, which are inserted through the body cavity or blood vessel to the treatment area. The IVR procedures lead to the risk of X-ray exposure to surgeon since the procedures is using the digital subtraction angiography device to get clear image of the patient blood vessel. Therefore, we have developed a foolproof tele-operated system to guide the catheter. Hence, the reliability in IVR procedure is crucial. The system is based on a mechatronic design methodology characterized by a principle solution specified in CONSENS® (CONceptual design Specification technique for the ENgineering of complex Systems). This principle solution serves as a basis for the first analysis and verification on the system level. Further, the proposed concept of control system can also be re-used in the other foolproof guidance systems.

Spasticity mathematical modelling in compliance with modified ashworth scale and modified tardieu scales

The aim of this work is to formulate a spasticity symptoms-oriented model, in terms of its capability to consistently emulate unidirectional and velocity-dependent spasticity symptoms, based on a Modified Tardieu Scale (MTS). Spasticity stiffness can be simulated using two dynamic equations expressing 1) muscle tone catch during passive stretching at different velocities and 2) resistance through Range Of Motion (ROM). Muscle tone is proportionate to velocity; where muscle resistance is constant until reaching a certain angular velocity. Following different Modified Ashworth Scale (MAS) levels, muscle resistance can occur at varying degrees through the ROM. The simulated spasticity of MAS 1+, based on the developed model, shows a strong positive linear correlation coefficient with average r = 0.7414 for fast forearm extension. The derived model will be used to develop new principles of variable stiffness actuation in an upper limb part-task trainer that is able to emulate upper limb spasticity symptoms.

Emulating Upper Limb Disorder for Therapy Education

Robotics not only contributes to the invention of rehabilitation devices, it can also enhance the quality of medical education. In recent years, the use of patient simulators and part-task trainers in the medical education field has brought meaningful improvements in the training of medical practitioners. Nevertheless, in the context of therapy training for upper limb disorders, trainee therapists still have to engage directly with the patients to gain experience of the rehabilitation of physical diseases. In this work, a high-fidelity part-task trainer that is able to reproduce the stiffness of spasticity and rigidity symptoms of the upper limb, such as those observed in post-stroke patients and Parkinsons disease patients, has been developed. Based on the evaluation carried out by two experienced therapists, the developed part-task trainer is able to simulate different patient cases and help trainee therapists gain pre-clinical experience in a safe and intuitive learning environment.

Mechatronic design for a fail-safe catheter guide system

Interventional Radiology (IVR) is one of the Minimally Invasive Surgery (MIS) methodologies. The operation of the IVR procedures are guided by image guidance Digital Subtraction Angiography (DSA) device which transmits continuous x-rays to detect the position of catheter. Catheter is a small tube inserted in blood vessel or body cavity, used in IVR procedures for diagnosing or treatment purposes. Recently, there has been considerable interest in developing remote-control system for catheter guide to prevent the surgeons from the risk of x-rays exposure. This paper describes the mechatronic design for a fail-safe catheter guide system used in blood circulatory system for IVR procedures. Several aspects of the catheter guide system are described, i.e. requirements, functions, environment, active structure, and behavior. There are close interplay between these aspects. Such a representation forms the basis for the subsequent design concretion. The prototype development of a key module for the catheter guide system, i.e. the slave system, is exemplified.Copyright

Emulation of spasticity symptoms in upper limb part-task trainer for physiotherapist education

The aim of this study is to develop an adequate part-task trainer occupied with varying levels of severity in spasticity symptoms focusing on the upper limb disorder for occupational therapists. Using the developed part-task trainer, the occupational therapists will have opportunities to repetitively engage in training without patient involvement. The part-task trainer is developed following the structure of human arm articulations with the ability to reproduce the spasticity stiffness. The structured interface programming is built providing three levels of spasticity: mild, moderate and severe. The programming was based on the clinical assessment of spasticity, measuring elbow joint angles and forces exerted by the patients. The recreated spasticity stiffness was evaluated by experienced occupational therapists. Therapists provided positive feedback regarding the mild and moderate level of spasticity leaving further improvement needed in order to reproduce the spasticity at the severe level.