140 research outputs found

    Design of a Hand Held Minimally Invasive Lung Tumour Localization Device

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    Lung cancer is the leading type of cancer that causes death. If diagnosed, the treatment of choice is surgical resection of the tumour. Traditionally, a surgeon feels for the presence of a tumour in open thoracic surgery. However, a minimally invasive approach is desired. A major problem presented by the minimally invasive approach is the localization of the tumour. This project describes the design, analysis, and experimental validation of a novel minimally invasive instrument for lung tumour localization. The instrument end effector is a two degree of freedom lung tissue palpator. It allows for optimal tissue palpation to increase useful sensor feedback by ensuring sensor contact, and prevents tissue damage by uniformly distributing pressure on the tissue with an upper bound force. Finite element analysis was used extensively to guide the design process. The mechanism is actuated using high strength tungsten cables attached to controlled motors. Heat treatment experiments were undertaken with stainless steel alloy 440C for use in the design, achieving a device factor of safety of 4. This factor of safety is based on a 20 N force on the end effector — the approximate weight of a human lung. The design was prototyped and validation experiments were carried out to assess its articulation and its load carrying capacity. Up to 10 N of force was applied to the prototype. Issues to resolve in the current design include cable extension effects and the existence of joint inflection. The end effector was also designed to allow the inclusion of ultrasound, tactile, and kinaesthetic sensors. It is hypothesized that a plurality of sensors will increase the likelihood of positive tumour localization. These sensors, combined with the presented mechanical design, form the basis for research in robotics-assisted palpation. A proof of concept control system is presented for automated palpation

    Design of Novel Sensors and Instruments for Minimally Invasive Lung Tumour Localization via Palpation

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    Minimally Invasive Thoracoscopic Surgery (MITS) has become the treatment of choice for lung cancer. However, MITS prevents the surgeons from using manual palpation, thereby often making it challenging to reliably locate the tumours for resection. This thesis presents the design, analysis and validation of novel tactile sensors, a novel miniature force sensor, a robotic instrument, and a wireless hand-held instrument to address this limitation. The low-cost, disposable tactile sensors have been shown to easily detect a 5 mm tumour located 10 mm deep in soft tissue. The force sensor can measure six degrees of freedom forces and torques with temperature compensation using a single optical fiber. The robotic instrument is compatible with the da Vinci surgical robot and allows the use of tactile sensing, force sensing and ultrasound to localize the tumours. The wireless hand-held instrument allows the use of tactile sensing in procedures where a robot is not available

    Surgical Applications of Compliant Mechanisms:A Review

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    Current surgical devices are mostly rigid and are made of stiff materials, even though their predominant use is on soft and wet tissues. With the emergence of compliant mechanisms (CMs), surgical tools can be designed to be flexible and made using soft materials. CMs offer many advantages such as monolithic fabrication, high precision, no wear, no friction, and no need for lubrication. It is therefore beneficial to consolidate the developments in this field and point to challenges ahead. With this objective, in this article, we review the application of CMs to surgical interventions. The scope of the review covers five aspects that are important in the development of surgical devices: (i) conceptual design and synthesis, (ii) analysis, (iii) materials, (iv) maim facturing, and (v) actuation. Furthermore, the surgical applications of CMs are assessed by classification into five major groups, namely, (i) grasping and cutting, (ii) reachability and steerability, (iii) transmission, (iv) sensing, and (v) implants and deployable devices. The scope and prospects of surgical devices using CMs are also discussed

    Robocatch: Design and Making of a Hand-Held Spillage-Free Specimen Retrieval Robot for Laparoscopic Surgery

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    Specimen retrieval is an important step in laparoscopy, a minimally invasive surgical procedure performed to diagnose and treat a myriad of medical pathologies in fields ranging from gynecology to oncology. Specimen retrieval bags (SRBs) are used to facilitate this task, while minimizing contamination of neighboring tissues and port-sites in the abdominal cavity. This manual surgical procedure requires usage of multiple ports, creating a traffic of simultaneous operations of multiple instruments in a limited shared workspace. The skill-demanding nature of this procedure makes it time-consuming, leading to surgeons’ fatigue and operational inefficiency. This thesis presents the design and making of RoboCatch, a novel hand-held robot that aids a surgeon in performing spillage-free retrieval of operative specimens in laparoscopic surgery. The proposed design significantly modifies and extends conventional instruments that are currently used by surgeons for the retrieval task: The core instrumentation of RoboCatch comprises a webbed three-fingered grasper and atraumatic forceps that are concentrically situated in a folded configuration inside a trocar. The specimen retrieval task is achieved in six stages: 1) The trocar is introduced into the surgical site through an instrument port, 2) the three webbed fingers slide out of the tube and simultaneously unfold in an umbrella like-fashion, 3) the forceps slide toward, and grasp, the excised specimen, 4) the forceps retract the grasped specimen into the center of the surrounding grasper, 5) the grasper closes to achieve a secured containment of the specimen, and 6) the grasper, along with the contained specimen, is manually removed from the abdominal cavity. The resulting reduction in the number of active ports reduces obstruction of the port-site and increases the procedure’s efficiency. The design process was initiated by acquiring crucial parameters from surgeons and creating a design table, which informed the CAD modeling of the robot structure and selection of actuation units and fabrication material. The robot prototype was first examined in CAD simulation and then fabricated using an Objet30 Prime 3D printer. Physical validation experiments were conducted to verify the functionality of different mechanisms of the robot. Further, specimen retrieval experiments were conducted with porcine meat samples to test the feasibility of the proposed design. Experimental results revealed that the robot was capable of retrieving masses of specimen ranging from 1 gram to 50 grams. The making of RoboCatch represents a significant step toward advancing the frontiers of hand-held robots for performing specimen retrieval tasks in minimally invasive surgery

    A Novel Minimally Invasive Tumour Localization Device

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    Lung cancer is one of the leading causes of death, by cancer. The usual treatment is surgical resection of tumours. However, patients who are weak or have poor pulmonary function are deemed unfit for surgery. For these patients, a minimally-invasive approach is desired. A major problem associated with minimally-invasive approaches is tumour localization in real time and accurate measurement of tool--tissue forces. This thesis describes the design, analysis, manufacturing and validation of a minimally-invasive instrument for tumour localization, named Palpatron. The instrument has an end effector that is able to support two previously designed jaws, one containing an ultrasound sensor and the other a tactile sensor. The jaws can move with two degrees of freedom to palpate tissue and rotate about the central axis of the instrument. The Palpatron has uncoupled jaw motion that allows for optimal alignment of sensors to improve data acquisition. The instrument can be easily assembled and disassembled allowing it to be cleaned and sterilized. The mechanism is articulated using push rods, each actuated by a motor. A semi-automatic control system was created for palpation. It is composed of a microcontroller that controls four motors via serial communication. In addition, the Palpatron has the ability to prevent tissue damage by measuring tool--tissue forces. Finite element analysis was used to guide material selection for designed components. Grade 5 titanium was selected for end effector links to provide a factor of safety of 1.2 against yielding under a 10 N point load at the tip of a jaw. The design was fabricated and validated by conducting experiments to test articulation and load carrying capacity. An 8-N force was applied to the instrument, which was successfully supported. The semi-automatic control system was used to perform basic maneuvering tasks to verify jaw motion capabilities. With positive testing results, the Palpatron forms the next step towards a comprehensive robotic-assisted palpation technology

    An Underactuated Flexible Instrument for Single Incision Laparoscopic Surgery

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    More and more patients and surgeons have switched from open surgery to minimally invasive surgery over these years. This exciting advancement has brought massive benefits to patients. Researchers and institutions have proposed robot assisted surgery which combines the advantage of developed robot system and human experience. This thesis reviews state of the art in this area and analyze some advanced surgical instrument for single incision laparoscopic instrument, then propose a design of robotic instrument for single incision laparoscopic surgery which can be integrated with collaborative robot manipulator to construct a surgical robot system.Single-incision laparoscopic surgery (SILS) has its own features and advantages compare to other minimally invasive surgery techniques which also lead to special design requirements for SILS instruments, among which increased flexibility compare to multi-incision surgery instruments is an important part. So we want to design a robotic surgical instrument that has increased flexibility compare to traditional instruments for other MIS techniques. As a laparoscopic robotic instrument compactness and light weight are also our considerations.Single incision laparoscopic surgery (SILS) inserts multiple instruments and laparoscopes through a single trocar which reduces trauma. But this improvement for patients caused difficulty in operation because of instruments triangulation, laparoscope field-of-view, etc. That brings up our challenges in designing a robotic instruments. Designing a highly flexible robotic instrument that provides sufficient workspace and good triangulation in order to relieve the difficulties introduced by narrow instrument trocars.We want to implement a highly recognized surgical instrument with a designed robotic instrument actuation pack. These two parts compose a robotic surgical instrument for single incision laparoscopic surgery. And we want to analyze the performance and viability of our design approach for SILS application

    Cable-driven parallel mechanisms for minimally invasive robotic surgery

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    Minimally invasive surgery (MIS) has revolutionised surgery by providing faster recovery times, less post-operative complications, improved cosmesis and reduced pain for the patient. Surgical robotics are used to further decrease the invasiveness of procedures, by using yet smaller and fewer incisions or using natural orifices as entry point. However, many robotic systems still suffer from technical challenges such as sufficient instrument dexterity and payloads, leading to limited adoption in clinical practice. Cable-driven parallel mechanisms (CDPMs) have unique properties, which can be used to overcome existing challenges in surgical robotics. These beneficial properties include high end-effector payloads, efficient force transmission and a large configurable instrument workspace. However, the use of CDPMs in MIS is largely unexplored. This research presents the first structured exploration of CDPMs for MIS and demonstrates the potential of this type of mechanism through the development of multiple prototypes: the ESD CYCLOPS, CDAQS, SIMPLE, neuroCYCLOPS and microCYCLOPS. One key challenge for MIS is the access method used to introduce CDPMs into the body. Three different access methods are presented by the prototypes. By focusing on the minimally invasive access method in which CDPMs are introduced into the body, the thesis provides a framework, which can be used by researchers, engineers and clinicians to identify future opportunities of CDPMs in MIS. Additionally, through user studies and pre-clinical studies, these prototypes demonstrate that this type of mechanism has several key advantages for surgical applications in which haptic feedback, safe automation or a high payload are required. These advantages, combined with the different access methods, demonstrate that CDPMs can have a key role in the advancement of MIS technology.Open Acces

    Robotic manipulators for single access surgery

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    This thesis explores the development of cooperative robotic manipulators for enhancing surgical precision and patient outcomes in single-access surgery and, specifically, Transanal Endoscopic Microsurgery (TEM). During these procedures, surgeons manipulate a heavy set of instruments via a mechanical clamp inserted in the patient’s body through a surgical port, resulting in imprecise movements, increased patient risks, and increased operating time. Therefore, an articulated robotic manipulator with passive joints is initially introduced, featuring built-in position and force sensors in each joint and electronic joint brakes for instant lock/release capability. The articulated manipulator concept is further improved with motorised joints, evolving into an active tool holder. The joints allow the incorporation of advanced robotic capabilities such as ultra-lightweight gravity compensation and hands-on kinematic reconfiguration, which can optimise the placement of the tool holder in the operating theatre. Due to the enhanced sensing capabilities, the application of the active robotic manipulator was further explored in conjunction with advanced image guidance approaches such as endomicroscopy. Recent advances in probe-based optical imaging such as confocal endomicroscopy is making inroads in clinical uses. However, the challenging manipulation of imaging probes hinders their practical adoption. Therefore, a combination of the fully cooperative robotic manipulator with a high-speed scanning endomicroscopy instrument is presented, simplifying the incorporation of optical biopsy techniques in routine surgical workflows. Finally, another embodiment of a cooperative robotic manipulator is presented as an input interface to control a highly-articulated robotic instrument for TEM. This master-slave interface alleviates the drawbacks of traditional master-slave devices, e.g., using clutching mechanics to compensate for the mismatch between slave and master workspaces, and the lack of intuitive manipulation feedback, e.g. joint limits, to the user. To address those drawbacks a joint-space robotic manipulator is proposed emulating the kinematic structure of the flexible robotic instrument under control.Open Acces
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