Cheng Yee Low

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.

Hybrid-Actuated Finger Prosthesis with Tactile Sensing

Finger prostheses are devices developed to emulate the functionality of natural human fingers. On top of their aesthetic appearance in terms of shape, size and colour, such biomimetic devices require a high level of dexterity. They must be capable of gripping an object, and even manipulating it in the hand. This paper presents a biomimetic robotic finger actuated by a hybrid mechanism and integrated with a tactile sensor. The hybrid actuation mechanism comprises a DC micromotor and a Shape Memory Alloy (SMA) wire. A customized test rig has been developed to measure the force and stroke produced by the SMA wire. In parallel with the actuator development, experimental investigations have been conducted on Quantum Tunnelling Composite (QTC) and Pressure Conductive Rubber (PCR) towards the development of a tactile sensor for the finger. The viability of using these materials for tactile sensing has been determined. Such a hybrid actuation approach aided with tactile sensing capability enables a finger design as an integral part of a prosthetic hand for applications up to the transradial amputation level.

Resistivity characteristics of single miniature tactile sensing element based on pressure sensitive conductive rubber sheet

This paper presents the development of a tactile sensor using single miniature sensing element based on pressure sensitive conductive rubber and outlines the resistance measurements performance. This sensor is specially designed for a robotic hand developed at UiTM Faculty of Mechanical Engineering. Nevertheless, the low cost, low density and flexible material is suitable for most robotics hand designs. It exhibits piezoresistive like behavior whose resistance change with force/pressure enables its applications as tactile sensor. The operating principle and hardware architecture of the sensor is explained. It consists of an array of 16 sensing elements in rows and columns for data acquisition. The test results indicate significant drop of resistance with the increase of applied load.

Emulation of muscle tone of upper limb spasticity and rigidity

Stretching the elbow of patients with upper limb disorder elicits diverse muscle tone responses, for instance, in an increased, uniform or jerky manner. This work addresses the emulation of muscle tone of the symptoms of spasticity, lead-pipe rigidity and cogwheel rigidity in the upper limb. A hybrid actuation strategy capable of emulating dynamic muscle tone has been proposed. In such strategy, a Magneto-Rheological brake is used to produce the resistance for a constant stiffness, and supported by a DC servo motor to assist the time delay of the fluid particle settling rate of the magneto-rheological fluid. The outcome is a consistent replication of the motion characteristics where the resistance torque emulated at the elbow joint is in close resemblance with the simulated data of upper limb spasticity and rigidity.

Architecting centralized coordination of soccer robots based on principle solution

Coordination strategy is a relevant topic in multi-robot systems, and robot soccer offers a suitable domain to conduct research in multi-robot coordination. Team strategy collects and uses environmental information to derive optimal team reactions, through cooperation among individual soccer robots. This paper presents a diagrammatic approach to architecting the coordination strategy of robot soccer teams by means of a principle solution. The proposed model focuses on robot soccer leagues that possess a central decision-making system, involving the dynamic selection of the roles and behaviors of the robot soccer players. The work sets out from the conceptual design phase, facilitating cross-domain development efforts, where different layers must be interconnected and coordinated to perform multiple tasks. The principle solution allows for intuitive design and the modeling of team strategies in a highly complex robot soccer environment with changing game conditions. Furthermore, such an approach enables systematic realization of collaborative behaviors among the teammates. Graphical abstract

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.

Hand rehabilitation device system (HRDS) for therapeutic applications

The hand rehabilitation approach for people who are affected by cerebral apoplexy has been a long-standing issue with researchers worldwide. Currently, scientific research has discovered a way to recover the motor function. Moreover, the sensory function can be recovered by neuroplasticity. Previously, the conventional hand rehabilitation approach only focused on the motor function. Therefore, there is a need to develop an effective hand rehabilitation device to recover both the motor and sensory functions. This research embarked on the configuration setup and evaluation of new hand rehabilitation devices using a mechanical stimulation system. The system has directly led to the stimulation of tactile senses, which can later be used to help patients who lack motor and sensory functions. The work was carried out in four stages comprising the development of a programming algorithm, the design and fabrication of the device and finally, an evaluation of the product and its functions. The objective to develop and fabricate a new robust tactile grasping type stimulator for a hand rehabilitation device has been achieved successfully. The preliminary evaluation on a healthy volunteer was carried out to identify the safety factor in the implementation of hardware and software before targeted patients are used.

Strategy planning for collaborative humanoid soccer robots based on principle solution

Collaborative humanoid soccer robots are currently under the lime light in the rapidly advancing research area of multi-robot systems. With new functionalities of software and hardware, they are becoming more versatile, robust and agile in response to the changes in the environment under dynamic conditions. This work focuses on a new approach for strategy planning of humanoid soccer robot teams as in the RoboCup Standard Platform League. The key element of the approach is a holistic system model of the principle solution encompassing various strategies of a soccer robot team. The benefits of the model-based approach are twofold—it enables intuitive behavioral specification of the humanoid soccer robots in line with the team strategies envisaged by the system developers, and it systematizes the realization of their collaborative behaviors based on the principle solution. The principle solution is modeled with the newly developed specification technique CONSENS® for the conceptual design of mechatronic and self-optimizing systems.

Model Based Design of Finger Exoskeleton for Post Stroke Rehabilitation Using a Slotted Link Cam with Lead Screw Mechanism

Post stroke rehabilitation consumes a huge amount of health care resources in terms of costs related to hospital and home assistance. Recently, robot-assisted rehabilitation has been adapted to support physiotherapists in providing high-intensity and repetitive rehabilitation sessions. It has been observed that robotics offers an objective and reliable instrumented tool to monitor patient’s progress and accurately assess their motor function. Each finger is attached to an instrumented mechanism which allowing force control and a mostly linear displacement. This paper presents a novel finger rehabilitation approach for acute paralyzed stroke survivors using a wearable robotic interface for hand motor function recovery. The device designed based on biomechanics measurements, able to assist the subject in opening and closing movements. It capable to adapt with various hand shapes and finger sizes. Main features of the interface include a differential system, and a lead screw mechanism which allows independent movement of the five fingers with actuators. The device is safe, easily transportable, and offers multiple training possibilities. The prototype deployment was carried out to determine the requirements for a finger rehabilitation device, the design and characterization of the complete system. Offering ease of use and affordability, the device has great potential to be deployed for individualized rehabilitation session for patients who have to undergo therapy in their home.

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.