下腹部を対象とした極細針によるCTガイド下高正確度穿刺プランニング

早大学位記番号:新8149早稲田大

Assistance strategies for robotized laparoscopy

Robotizing laparoscopic surgery not only allows achieving better accuracy to operate when a scale factor is applied between master and slave or thanks to the use of tools with 3 DoF, which cannot be used in conventional manual surgery, but also due to additional informatic support. Relying on computer assistance different strategies that facilitate the task of the surgeon can be incorporated, either in the form of autonomous navigation or cooperative guidance, providing sensory or visual feedback, or introducing certain limitations of movements. This paper describes different ways of assistance aimed at improving the work capacity of the surgeon and achieving more safety for the patient, and the results obtained with the prototype developed at UPC.Peer ReviewedPostprint (author's final draft

Robot Autonomy for Surgery

Autonomous surgery involves having surgical tasks performed by a robot operating under its own will, with partial or no human involvement. There are several important advantages of automation in surgery, which include increasing precision of care due to sub-millimeter robot control, real-time utilization of biosignals for interventional care, improvements to surgical efficiency and execution, and computer-aided guidance under various medical imaging and sensing modalities. While these methods may displace some tasks of surgical teams and individual surgeons, they also present new capabilities in interventions that are too difficult or go beyond the skills of a human. In this chapter, we provide an overview of robot autonomy in commercial use and in research, and present some of the challenges faced in developing autonomous surgical robots

Optically Sensorized Tendons for Articulate Robotic Needles

This study proposes an optically sensorized tendon composed of a 195 µm diameter, high strength, polarization maintaining (PM) fiber Bragg gratings (FBG) optical fiber which resolves the cross-sensitivity issue of conventional FBGs. The bare fiber tendon is locally reinforced with a 250 µm diameter Kevlar bundle enhancing the level of force transmission and enabling high curvature tendon routing. The performance of the sensorized tendons is explored in terms of strength (higher than 13N for the bare PM-FBG fiber tendon, up to 40N for the Kevlar-reinforced tendon under tensile loading), strain sensitivity (0.127 percent strain per newton for the bare PM-FBG fiber tendon, 0.04 percent strain per newton for the Kevlar-reinforced tendon), temperature stability, and friction-independent sensing behavior. Subsequently, the tendon is instrumented within an 18 Ga articulate NiTi cannula and evaluated under static and dynamic loading conditions, and within phantoms of varying stiffness for tissue-stiffness estimation. The results from this series of experiments serve to validate the effectiveness of the proposed tendon as a bi-modal sensing and actuation component for robot-assisted minimally invasive surgical instruments

Energy shaping control for robotic needle insertion

This work investigates the use of energy shaping control to reduce deflection in slender beams with tip load and actuation at the base. The ultimate goal of this research is a buckling avoidance strategy for robotic-assisted needle insertion. To this end, the rigid-link model of a flexible beam actuated at the base and subject to tip load is proposed, and an energy shaping approach is employed to construct a nonlinear controller that accounts for external forces. A comparative simulation study highlights the benefits of the proposed approach over a linear control baseline and a simplified nonlinear control

Design and performance evaluation of a prototype MRF-based haptic interface for medical applications

This paper describes the construction and stability and transparency evaluation of a prototype two degrees-of-freedom (DoF) haptic interface, which takes ad-vantage of magneto-rheological fluid (MRF)-based clutches for actuation. These small-scale clutches were designed in our lab, and their evaluation were reported previously [1],[2]. MRF-based actuators exhibit superior characteristics,which can significantly contribute to transparency and stability of haptic devices. Based on these actuators, a distributed antagonistic configuration is used to develop the2-DoF haptic interface. This device is incorporated in a master–slave teleoperation setup intended for medical per-cutaneous interventions and soft-tissue palpation. Preliminary studies on the stability and transparency of the haptic interface in this setup using phantom and ex vivo samples show the great potential of MRF-based actuators for integr-tion in haptic devices that require reliable, safe, accurate,highly transparent, and stable force reflection

Robotics-Assisted Needle Steering for Percutaneous Interventions: Modeling and Experiments

Needle insertion and guidance plays an important role in medical procedures such as brachytherapy and biopsy. Flexible needles have the potential to facilitate precise targeting and avoid collisions during medical interventions while reducing trauma to the patient and post-puncture issues. Nevertheless, error introduced during guidance degrades the effectiveness of the planned therapy or diagnosis. Although steering using flexible bevel-tip needles provides great mobility and dexterity, a major barrier is the complexity of needle-tissue interaction that does not lend itself to intuitive control. To overcome this problem, a robotic system can be employed to perform trajectory planning and tracking by manipulation of the needle base. This research project focuses on a control-theoretic approach and draws on the rich literature from control and systems theory to model needle-tissue interaction and needle flexion and then design a robotics-based strategy for needle insertion/steering. The resulting solutions will directly benefit a wide range of needle-based interventions. The outcome of this computer-assisted approach will not only enable us to perform efficient preoperative trajectory planning, but will also provide more insight into needle-tissue interaction that will be helpful in developing advanced intraoperative algorithms for needle steering. Experimental validation of the proposed methodologies was carried out on a state of-the-art 5-DOF robotic system designed and constructed in-house primarily for prostate brachytherapy. The system is equipped with a Nano43 6-DOF force/torque sensor (ATI Industrial Automation) to measure forces and torques acting on the needle shaft. In our setup, an Aurora electromagnetic tracker (Northern Digital Inc.) is the sensing device used for measuring needle deflection. A multi-threaded application for control, sensor readings, data logging and communication over the ethernet was developed using Microsoft Visual C 2005, MATLAB 2007 and the QuaRC Toolbox (Quanser Inc.). Various artificial phantoms were developed so as to create a realistic medium in terms of elasticity and insertion force ranges; however, they simulated a uniform environment without exhibiting complexities of organic tissues. Experiments were also conducted on beef liver and fresh chicken breast, beef, and ham, to investigate the behavior of a variety biological tissues

Ilaptic Feedback Device for Needle Insertion

Tele-surgery is one of the emerging fields which combine engineering and medical sciences. Application of tole-surgery can be found in remote communities, war-zones and disasterstricken areas. One of the most complex and tedious issue in tele-surgery is needle insertion. The surgeon relies on haptic feedback during needle insertion. The force exerted on needle during insertion is measured and reproduced at surgeon's end is known as haptic feedback. The realistic force reproduction requires haptic feedback device which should be dynamically identical to needle. The haptic feedback device enables the surgeon to sense the needle insertion remotely. The basic objective of this thesis is to design a device used for needle insertions in soft tissue. The force information from needle insertions is measured by a sensor. The force feedback produced by the device can be used in robot-assisted needle insertion. A device is designed for reality-based data that results in more accurate representation of a needle insertion haptic feedback scenario. The device is modeled dynamically and it is clear from the model that the reactive force is reproduced by the friction forces which is controlled by the motors. The system is sensitive to mass of rollers, mass of the stick and friction between the stick and rollers. The needle insertion force is modeled in three parts; force due to capsule stiffness, friction, and cutting. The force due to capsule stiffness is modeled terms of three components namely diameter of needle, elasticity of tissue and deformation of tissue. The data from model is compared with real time force data. The haptic feedback device input and output forces are compared and the highest correlation factor is 82%. The sensitivity analysis of the device is performed. The capsule stiffness force for 0.9 millimeter diameter needle is 0.98 Newton, the stiffness force for 0.8 millimeter is 0.91 Newton and stiffness force for 0.6 millimeter diameter is 0.41 Newton. The capsule stiffness force for 0.6 millimeter needle is not following the capsule stiffness model. The insertion force data was collected on chicken skin and meat. The device designed in this work is having one degree of freedom; it only produces force feedback for vertical needle insertion. This design is not able to produce the force feedback for angular needle insertion. Graphical User Interface is designed for the visual haptic feedback. The data acquisition is done with the help of a PC sound card. Future work should include the design of a multidegree of freedom haptic feedback device and to advance the GUI for audio feedback that may be extended to accommodate the design of a simulator