We presents a 5-DOF manipulator which consists of three parts, 1-DOF translational joint, a bendable skeleton (2-DOF for Omni-directional bending motion), and a rotatable forceps gripper (1-DOF for rotation, 1-DOF for opening/closing). The bendable segment in the manipulator achieves two orthogonal bending DOFs by pulling or pushing three parallel universal-joint-based shaft chains. Forward and inverse kinematics of the bendable skeleton is analyzed. The workspace calculation illustrates that the structure of the three parallel shaft chains can reach a bending angle of 90 degree in arbitrarily direction. The reachability of the manipulator is simulated in Adams. According to the surgical requirements, the manipulator is actuated to draw circle during the tests while the end effector is kept bending at 60 degree. The results show that the end effector can precisely track the planning trajectory (precision within 1 mm).
Q. Liu; J. CHEN; S. Shen; B. Zhang; M. G. Fujie; C. M. Lim & H. REN Design, Kinematics, Simulation of Omni-directional Bending Reachability for a Parallel Structure Forceps Manipulator BioRob2016, 6th IEEE RAS/EMBS International Conference on Biomedical Robotics and Biomechatronics, June 26-29, 2016, Singapore, 201
We present a novel flexible endoscope (FE) which is well suited to minimally invasive cardiac surgery (MICS). It is named the cardioscope. The cardioscope is composed of a handle, a rigid shaft, a steerable flexible section, and the imaging system. The flexible section is composed of an elastic tube, a number of spacing disks, a constraint tube, and four wires. It employs the constrained wire-driven flexible mechanism (CWFM) with a continuum backbone, which enables the control of both the angulation and the length of the flexible section. Compared to other endoscopes, e.g., rigid endoscope (RE) and fixed-length FE, the cardioscope is much more dexterous. The cardioscope can bend over 180 deg in all directions, and the bending is decoupled from the distal tip position. Ex vivo tests show that the cardioscope is well suited to MICS. It provides much wider scope of vision than REs and provides good manipulation inside confined environments. In our tests, the cardioscope successfully explored the full heart through a single hole, which shows that the design is promising. Despite being designed for MICS, the cardioscope can also be applied to other minimally invasive surgeries (MISs), such as laparoscopy, neurosurgery, transnasal surgery, and transoral surgery.
Z. Li; M. Zin Oo; V. Nalam; V. Duc Thang; H. Ren; T. Kofidis & H. Yu Design of a Novel Flexible Endoscope- Cardioscope Journal of Mechanisms and Robotics, ASME, 2016, 8, 051014-051014
Z. Li; M. Z. Oo; V. D. Thang; V. Nalam; T. Kofidis; H. Yu & H. Ren Design of a Novel Flexible Endoscope – Cardioscope 2015 IDETC: ASME 2015 International Design Engineering Technical Conferences , 2015