Algorithms for Automated Pointing of Cardiac Imaging Catheters

This paper presents a modified controller and expanded algorithms for automatically positioning cardiac ultrasound imaging catheters within the heart to improve treatment of cardiac arrhythmias such as atrial fibrillation. Presented here are a new method for controlling the position and orientation of a catheter, smoother and more accurate automated catheter motion, and initial results of image processing into clinically useful displays. Ultrasound imaging (intracardiac echo, or ICE) catheters are steered by four actuated degrees of freedom (DOF) to produce bi-directional bending in combination with handle rotation and translation. Closed form solutions for forward and inverse kinematics enable position control of the catheter tip. Additional kinematic calculations enable 1-DOF angular control of the imaging plane. The combination of positioning with imager rotation enables a wide range of visualization capabilities, such as recording a sequence of ultrasound images and reconstructing them into 3D or 4D volumes for diagnosis and treatment. The algorithms were validated with a robotic test bed and the resulting images were reconstructed into 3D volumes. This capability may improve the efficiency and effectiveness of intracardiac catheter interventions by allowing visualization of soft tissues or working instruments. The methods described here are applicable to any long thin tendon-driven tool (with single or bi-directional bending) requiring accurate tip position and orientation control.Engineering and Applied Science

From open radical hysterectomy to robot-assisted laparoscopic radical hysterectomy for early stage cervical cancer: aspects of a single institution learning curve

We analysed the introduction of the robot-assisted laparoscopic radical hysterectomy in patients with early-stage cervical cancer with respect to patient benefits and surgeon-related aspects of a surgical learning curve. A retrospective review of the first 14 robot-assisted laparoscopic radical hysterectomies and the last 14 open radical hysterectomies in a similar clinical setting with the same surgical team was conducted. Patients were candidates for a laparoscopic sentinel node procedure, pelvic lymph node dissection and open radical hysterectomy (RH) before August 2006 and were candidates for a laparoscopic sentinel node procedure, pelvic lymph node dissection and robot-assisted laparoscopic radical hysterectomy (RALRH) after August 2006. Overall, blood loss in the open cases was significantly more compared with the robot cases. Median hospital stay after RALRH was 5 days less than after RH. The median theatre time in the learning period for the robot procedure was reduced from 9 h to less that 4 h and compared well to the 3 h and 45 min for an open procedure. Three complications occurred in the open group and one in the robot group. RALRH is feasible and of benefit to the patient with early stage cervical cancer by a reduction of blood loss and reduced hospital stay. Introduction of this new technique requires a learning curve of less than 15 cases that will reduce the operating time to a level comparable to open surgery

Design, fabrication and control of soft robots

Conventionally, engineers have employed rigid materials to fabricate precise, predictable robotic systems, which are easily modelled as rigid members connected at discrete joints. Natural systems, however, often match or exceed the performance of robotic systems with deformable bodies. Cephalopods, for example, achieve amazing feats of manipulation and locomotion without a skeleton; even vertebrates such as humans achieve dynamic gaits by storing elastic energy in their compliant bones and soft tissues. Inspired by nature, engineers have begun to explore the design and control of soft-bodied robots composed of compliant materials. This Review discusses recent developments in the emerging field of soft robotics.National Science Foundation (U.S.) (Grant IIS-1226883

A Closed Loop Shape Control for Bio-inspired Soft Arms

We present a model-based approach for the control of the shape of a tendon-driven soft arm. The soft robotic structure, which is inspired by an octopus arm, has variable section that allows to obtain variable curvature when actuated. The main goal of our control system is to obtain a target curvature at a desired section of the arm. The controller combines input shaping and feedback integral control in order to overcome modeling errors and constant disturbances. Simulations show the coupling between the control loop and a dynamic model of the arm

Soft particles for granular jamming

© Springer Nature Switzerland AG 2019. In the last decade, soft robots demonstrated their distinctive advantages compared to 'hard' robots. Soft structures can achieve high dexterity and compliance. However, only low forces can be exerted, and more complicated control strategies are needed. Variable stiffness robots offer an alternative solution to compensate for the downsides of flexible robots. One of the most common approach in the development of variable stiffness robots is the use of granular jamming. In this paper a variable stiffness manipulator based on granular jamming is studied. Here, we propose the use of soft and deformable spherical particles instead of commonly used rigid particles. Further on, we evaluate the performance of the soft particles under vacuum. In addition, a comparison between our approach and the standard approach to granular jamming is presented. The proposed soft particles show good performance in terms of their capability of compacting and squeezing against each other to achieve a high-stiffness robot arm