Design and analysis of a novel long-distance double tendon-sheath transmission device for breast intervention robots under MRI field

Cancer represents a major threat to human health. Magnetic resonance imaging (MRI) provides superior performance to other imaging-based examination methods in the detection of tumors and offers distinct advantages in biopsy and seed implantation. However, because of the MRI environment, the material requirements for actuating devices for the medical robots used in MRI are incredibly demanding. This paper describes a novel double tendon-sheath transmission device for use in MRI applications. LeBus grooves are used in the original transmission wheels, thus enabling the system to realize long-distance and large-stroke transmission with improved accuracy. The friction model of the transmission system and the transmission characteristics model of the novel tendon-sheath structure are then established. To address the problem that tension sensors cannot be installed in large-stroke transmission systems, a three-point force measurement method is used to measure and set an appropriate preload in the novel tendon-sheath transmission system. Additionally, experiments are conducted to verify the accuracy of the theoretical model and multiple groups of tests are performed to explore the transmission characteristics. Finally, the novel tendon-sheath transmission system is compensated to improve its accuracy and the experimental results acquired after compensation show that the system satisfies the design requirements

Needle and Biopsy Robots: a Review

Purpose of the review Robotics is a rapidly advancing field, and its introduction in healthcare can have a multitude of benefits for clinical practice. Especially, applications depending on the radiologist\u2019s accuracy and precision, such as percutaneous interventions, may profit. This paper provides an overview of recent robot-assisted percutaneous solutions. Recent findings Percutaneous interventions are relatively simple and the quality of the procedure increases a lot by introducing robotics due to the improved accuracy and precision. The success of the procedure is heavily dependent on the ability to merge pre- and intraoperative images, as an accurate estimation of the current target location allows to exploit the robot\u2019s capabilities. Summary Despite much research, the application of robotics in some branches of healthcare is not commonplace yet. Recent advances in percutaneous robotic solutions and imaging are highlighted, as they will pave the way to more widespread implementation of robotics in clinical practic

Neurological Disease Diagnosis and Treatment via Precise Robotic Intervention

This work focuses on the development and application of mechatronic systems for measurement, diagnosis and treatment of acute and chronic neurological conditions. The development of an automated tendon reflex stimulation device, as well as analysis and classification methods for both automated and manual stimulus delivery will provide the groundwork for improvements to both diagnosis and treatment of neurological injuries. In a similar vein, development of a variable resonance actuator for Magnetic Resonance Elastography imaging enables tissue property measurement of the intervertebral discs, hopefully providing an early marker and better understanding of degeneration. In addition to MRI based spinal tissue property measurements, an MRI guided high precision robot is developed for direct injection into the spinal cord, along with an accompanying image guided control scheme. The novel parallel plane mechanism enables control of 4 degrees of freedom, while the linear piezoelectric actuators in a direct drive configuration enables superior accuracy. Taken together, these robotic device developments constitute contributions to the field of precision medical robotics with applications to physiological understanding of the human body.Ph.D

DESIGN, DEVELOPMENT, AND EVALUATION OF A MRI-GUIDED NEUROSURGICAL INTRACRANIAL ROBOT

Brain tumors are among the most feared complications of cancer. Their treatment is challenging because of the lack of good imaging modality and the inability to remove the complete tumor. To overcome this limitation, we propose to develop a Magnetic Resonance Imaging (MRI)-compatible neurosurgical robot. The robot can be operated under continuous MRI, and the Magnetic Resonance (MR) images can be used to supplement physicians' visual capabilities, resulting in precise tumor removal. We have developed two prototypes of the Minimally Invasive Neurosurgical Intracranial Robot (MINIR) using MRI compatible materials and shape memory alloy (SMA) actuators. The major difference between the two robots is that one uses SMA wire actuators and the other uses SMA spring actuators combined with the tendon-sheath mechanism. Due to space limitation inside the robot body and the strong magnetic field in the MRI scanner, most sensors cannot be used inside the robot body. Hence, one possible approach is to rely on image feedback to control the motion of the robot. In this research, as a preliminary approach, we have relied on image feedback from a camera to control the motion of the robot. Since the image tracking algorithm may fail in some situations, we also developed a temperature feedback control scheme which served as a backup controller for the robot. Experimental results demonstrated that both image feedback and temperature feedback can be used reliably to control the joint motion of the robots. A series of MRI compatibility tests were performed to evaluate the MRI compatibility of the robots and to assess the degradation in image quality. The experimental results demonstrated that the robots are MRI compatible and created no significant image distortion in the MR images during actuation. The accomplishments presented in this dissertation represent a significant development of using SMA actuators to actuate MRI-compatible robots. It is anticipated that, in the future, continuous MR imaging would be used reliably to control the motion of the robot. It is aspired that the robot design and the control methods of SMA actuators developed in this research can be utilized in practical applications

Surgical Applications of Compliant Mechanisms:A Review

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

Medical robots for MRI guided diagnosis and therapy

Magnetic Resonance Imaging (MRI) provides the capability of imaging tissue with fine resolution and superior soft tissue contrast, when compared with conventional ultrasound and CT imaging, which makes it an important tool for clinicians to perform more accurate diagnosis and image guided therapy. Medical robotic devices combining the high resolution anatomical images with real-time navigation, are ideal for precise and repeatable interventions. Despite these advantages, the MR environment imposes constraints on mechatronic devices operating within it. This thesis presents a study on the design and development of robotic systems for particular MR interventions, in which the issue of testing the MR compatibility of mechatronic components, actuation control, kinematics and workspace analysis, and mechanical and electrical design of the robot have been investigated. Two types of robotic systems have therefore been developed and evaluated along the above aspects. (i) A device for MR guided transrectal prostate biopsy: The system was designed from components which are proven to be MR compatible, actuated by pneumatic motors and ultrasonic motors, and tracked by optical position sensors and ducial markers. Clinical trials have been performed with the device on three patients, and the results reported have demonstrated its capability to perform needle positioning under MR guidance, with a procedure time of around 40mins and with no compromised image quality, which achieved our system speci cations. (ii) Limb positioning devices to facilitate the magic angle effect for diagnosis of tendinous injuries: Two systems were designed particularly for lower and upper limb positioning, which are actuated and tracked by the similar methods as the first device. A group of volunteers were recruited to conduct tests to verify the functionality of the systems. The results demonstrate the clear enhancement of the image quality with an increase in signal intensity up to 24 times in the tendon tissue caused by the magic angle effect, showing the feasibility of the proposed devices to be applied in clinical diagnosis

From Concept to Market: Surgical Robot Development

Surgical robotics and supporting technologies have really become a prime example of modern applied information technology infiltrating our everyday lives. The development of these systems spans across four decades, and only the last few years brought the market value and saw the rising customer base imagined already by the early developers. This chapter guides through the historical development of the most important systems, and provide references and lessons learnt for current engineers facing similar challenges. A special emphasis is put on system validation, assessment and clearance, as the most commonly cited barrier hindering the wider deployment of a system