Robotic Surgery / Robot-Assisted Surgery
Marzie Saeidirad; Heidar Ali Talebi; Mohammad Zareinejad; Mohammad Reza Dehghan
Volume 7, Issue 4 , June 2013, , Pages 287-296
Abstract
Computationally fast biomechanical models are required to present the actual behavior of soft tissue in real-time simulation. These models are applied in medical diagnosis, surgical planning and training. One of the challenges in the surgical simulation is soft tissue cutting that requires topology changes ...
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Computationally fast biomechanical models are required to present the actual behavior of soft tissue in real-time simulation. These models are applied in medical diagnosis, surgical planning and training. One of the challenges in the surgical simulation is soft tissue cutting that requires topology changes and elements remeshing in real-time.This paper present a new algorithm for soft tissue cutting using its geometric analysis. This method creates a less number of degrees of freedom and shows a stable simulation that leads in less tissue damage as compared to other methods. According to the simulation results, the proposed algorithm has a relatively high speed. In addition, a mapping method has been proposed that relates physical and visual model and consequently shows a more realistic surgery. In order to achieve a physics based, accurate and reliable force model, Finite Element Method is used. Finally, the proposed algorithm is simulated for three-dimensional soft tissue tumor and evaluated using the SOFA-Framework.
Biomedical Image Processing / Medical Image Processing
Marzie Ershad; Alireza Ahmadian; Houshang Saberi
Volume 7, Issue 2 , June 2013, , Pages 155-162
Abstract
Registration of preoperative images to intra-operative patient space is a crucial step in image guided surgery for tracking surgical tools relative to patient’s anatomy. In image guided spine surgery, due to the difference in patient’s positioning in preoperative imaging, compared with intra-operative ...
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Registration of preoperative images to intra-operative patient space is a crucial step in image guided surgery for tracking surgical tools relative to patient’s anatomy. In image guided spine surgery, due to the difference in patient’s positioning in preoperative imaging, compared with intra-operative situation, there is a difference in spine curvature in these two positioning which means that a single rigid registration is not sufficient for registering the whole spine and it is necessary for each vertebra to be registered separately as a rigid body and with it’s appropriate transformation parameters. The registration was carried out using ICP algorithm. For evaluating the registration, TRE was calculated in the pedicle of the vertebra which is the target in pedicle screw insertion. In order to optimize the TRE this study was focused on the factors affecting TRE including different configuration of landmarks used in registration and the registration algorithm. Optimal configurations for the landmarks used in the registration were proposed and FLE for the point pairs were included in the registration algorithm to increase the registration accuracy. The results indicate a total improvement of 45% in the registration accuracy by optimizing the landmarks’ configuration and the registration algorithm.
Robotic Surgery / Robot-Assisted Surgery
Mohadese Yaryan; Mahyar Naraghi; Seyed Mehdi Rezaei; Mohammad Zareinejad; Hamed Ghafarirad
Volume 6, Issue 4 , June 2012, , Pages 287-297
Abstract
This paper addresses a new control scheme for bilateral telesurgical system with flexible links surgical robot. In this regard, hybrid structure of feedback and feedforward controller is suggested for flexible slave robot. This approach utilizes capability of Input Shaping (IS) as feedforward controller ...
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This paper addresses a new control scheme for bilateral telesurgical system with flexible links surgical robot. In this regard, hybrid structure of feedback and feedforward controller is suggested for flexible slave robot. This approach utilizes capability of Input Shaping (IS) as feedforward controller to reduce vibration at robot’s end tip and the feedback controller based on collocated Proportional-Derivative (PD) for control rigid body motion of the system. Stability of closed loop input shaper for nonlinear systems is discussed for the first time in this article. The stability conditions for overall system with constant communication time delay are derived using lyapunov method. Due to the independence of the system parameters, combination of these controllers results stability robustness to parameter uncertainties. Moreover, It is shown that reshaped master command to slave’s controller improves tracking performance in the presence of robot flexibility. Simulation results are used to verify the main theoretical points of this paper and demonstrate the effectiveness of proposed control framework in terms of input tracking and vibration suppression.
