Author: jeya

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In this paper the displacement analysis of an under-constrained parallel robot supported by flexible shafts is addressed. The problem consists of identifying the equilibrium poses of a moving platform when the shaft lengths are changed. Similar to under-constrained cable-driven parallel robots, the moving platform preserves some freedoms once shaft lengths are fixed. Thus, kinematics and statics must be taken into account simultaneously. However in contrast to cables, shafts may also impose torsional resistance on the moving platform which is considered in this study. To investigate the effect of this torsional resistance the pose of the moving platform with respect to the changes of length of shafts is investigated and compared to the pose of moving platform driven by cables

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Robotic assistance in Minimally Invasive Surgery
(MIS) have extended the capabilities of surgeons via improved
precision dexterity and computer assistance. By tapping on
the capabilities of MIS, this paper aims to design a new
tendon Fixation mechanism which utilizes springs to actuate
surgical tools for the removal of osseous giant cell tumor.
We presents our preliminary design conceptualization and
prototype development using spring backbone and tendon-
driven mechanism. By investigating different tendon routing
mechanisms, for the first time this study shows that it is
potentially feasible to accomplish needle-size (outer diameter
of 1 mm) to catheter-size (outer diameter of 2-3 mm) single-
channel surgical instruments for minimally invasive surgery.
Through this mechanism, it is expected that our surgical robot
can provide completeness of tumor removal through a minimal
incision without compromising oncological principles

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Intravascular ultrasound (IVUS) imaging provides two-dimensional (2D) real-time luminal and transmural cross-sectional images of intravascular vessels with detailed pathological information. It has offered significant advantages in terms of diagnosis and guidance and has been increasingly introduced from coronary interventions into more generalized endovascular surgery. However, IVUS itself does not provide spatial pose information for its generated images, making it difficult to construct a 3D intravascular visualization. To address this limitation, IVUS imaging-driven 3D intravascular reconstruction techniques have been developed. These techniques enable accurate diagnosis and quantitative measurements of intravascular diseases to facilitate optimal treatment determination. Such reconstruction extends the IVUS imaging modality from pure diagnostic assistance to intraoperative navigation and guidance and supports both therapeutic options and interventional operations. This paper presents a comprehensive survey of technological advances and recent progress on IVUS imaging-based 3D intravascular reconstruction and its state-of-the-art applications. Limitations of existing technologies and prospects of new technologies are also discussed.

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Purpose: Origami-based biomedical device design is an emerging technology due to its ability to be deployed from a minimal foldable pattern to a larger volume. This paper aims to review state-of-the-art origami structures applied in the medical device field. Methods: Publications and reports of origami structure related to medical device design from the past 10 years are reviewed and categorized according to engineering specifications, including the application field, fabrication material, size/volume, deployment method, manufacturability, and advantages. Results: This paper presents an overview of the biomedical applications of devices based on origami structures, including disposable sterilization covers, cardiac catheterization, stent grafts, encapsulation and microsurgery, gastrointestinal microsurgery, laparoscopic surgical grippers, microgrippers, microfluidic devices, and drug delivery. Challenges in terms of materials and fabrication, assembly, modeling and computation design, and clinical adoptability are discussed at the end of this paper to provide guidance for future origami-based design in the medical device field. Conclusion: Concepts from origami can be used to design and develop novel medical devices. Origami-based medical device design is currently progressing, with researchers improving design methods, materials, fabrication techniques, and folding efficiency.

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To realize the stability of the passive magnetic robotic system, a novel combination of permanent magnets is proposed. As we know, a single passive magnetic levitation is impossible to suspend all degrees of freedom of a rigid body; this article researches the combination of multiple passive magnetic bearings by the finite element method (FEM) simulation. Through changing the magnetization direction of permanent magnets, the radial force and axial force can be changed correspondingly. Various magnetization angles of permanent magnets are analysed, and the relationships are analysed among radial force, axial force, and axial displacement. Finally, the optimized magnetization angle of the permanent magnets and their arrangements are proposed. According to the analytic results, it is feasible to realize the stability using the proposed configuration.

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Robot manipulators are increasingly used in minimally invasive surgery (MIS). They are required to have small size, wide workspace, adequate dexterity and payload ability when operating in confined surgical cavity. Snake-like flexible manipulators are well suited to these applications. However, conventional fully actuated snake-like flexible manipulators are difficult to miniaturize and even after miniaturization the payload is very limited. The alternative is to use underactuated snake-like flexible manipulators. Three prevailing designs are tendon-driven continuum manipulators (TCM), tendon-driven serpentine manipulators (TSM) and concentric tube manipulators (CTM). In this paper, the three designs are compared at the mechanism level from the kinematics point of view. The workspace and distal end dexterity are compared for TCM, TSM and CTM with one, two and three sections, respectively. Other aspects of these designs are also discussed, including sweeping motion, scaling, force sensing, stiffness control, etc. From the results, the tendon-driven designs and concentric tube design complement each other in terms of their workspace, which is influenced by the number of sections as well as the length distribution among sections. The tendon-driven designs entail better distal end dexterity while generate larger sweeping motion in positions close to the shaft.

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This paper presents a hybrid tele-manipulation system, comprising of a sensorized 3D-printed soft robotic gripper and a soft fabric-based haptic glove, that aim at improving grasping manipulation and providing sensing feedback to the operators. The flexible 3D-printed soft robotic gripper broadens what a robotic gripper can do, especially for grasping tasks where delicate objects such as glassware are involved. It consists of four pneumatic finger actuators, casings with through hole for housing the actuators, and adjustable base. The grasping length and width can be configured easily to suit a variety of objects. The soft haptic glove is equipped with flex sensors and soft pneumatic haptic actuator, which enables the users to control the grasping, to determine whether the grasp is successful and to identify the grasped object shape. The fabric-based soft pneumatic haptic actuator can simulate haptic perception by producing force feedback to the users. Both the soft pneumatic finger actuator and haptic actuator involve simple fabrication technique, namely 3D-printed approach and fabric-based approach respectively, which reduce fabrication complexity as compared to the steps involved in traditional silicone-based approach. The sensorized soft robotic gripper is capable of picking up and holding a wide variety of objects in this study, ranging from lightweight delicate object weighing less than 50 g to objects weighing 1100 g. The soft haptic actuator can produce forces of up to 2.1 N, which is more than the minimum force of 1.5 N needed to stimulate haptic perception. The subjects are able to differentiate the two objects with significant shape differences in the pilot test. Compared to the existing soft grippers, this is the first soft sensorized 3D-printed gripper, coupled with a soft fabric-based haptic glove, that has the potential to improve the robotic grasping manipulation by introducing haptic feedback to the users.

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