Medical Robotics / Bio-Robotics
Elaheh Kafashi; Mohammad Ali Ahmadi Pajouh; Firooz Bakhtiari Nejad
Volume 14, Issue 4 , February 2021, , Pages 277-290
Abstract
Due to the high number of patients with cerebrovascular disease and stroke, which results in paralysis of organs on one side of the body, including the hand, as well as limitations in traditional rehabilitation methods, it is necessary to build devices to help these people. In this study, initially, ...
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Due to the high number of patients with cerebrovascular disease and stroke, which results in paralysis of organs on one side of the body, including the hand, as well as limitations in traditional rehabilitation methods, it is necessary to build devices to help these people. In this study, initially, given the challenges involved in designing an exoskeleton, the initial design was a mechanism for using it as a continuous passive motion to rehabilitate the fingers. This mechanism is tendon-based and covers both the flexion and extension of the fingers. For this purpose, two active and passive actuators have been used in the exoskeleton, respectively, to flex and extend the fingers. The distinctive feature of this design is its lightness, low volume, adjustability for different hands, compatibility, and comfort for the patient. Also, the kinematics and dynamics relationships modeled on the Lagrange method. The exoskeleton movement simulated in interaction with the finger with MATLAB sim-mechanics software. Finally, using simulation and modeling results, the final design was performed by considering the force of 40 N along the tendon, the exoskeleton made for the index finger. Also, the results of analytical modeling and simulation compared; the error rate of modeling obtained. In the worst case, this value was 15% for the first and second finger joints and 20% for the third joint.
Medical Robotics / Bio-Robotics
Mahya Salem; Saeed Ebrahimi; Mehdi Bamdad
Volume 11, Issue 2 , June 2017, , Pages 111-125
Abstract
In this study, a portable upperlimb exoskeleton is designed for the purpose of rehabilitation and helping the disabled people to do their daily activities. This exoskeleton has two active and one passive degrees of freedom for the shoulder joint. In this system, the idea of cable transmossiom mechanism ...
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In this study, a portable upperlimb exoskeleton is designed for the purpose of rehabilitation and helping the disabled people to do their daily activities. This exoskeleton has two active and one passive degrees of freedom for the shoulder joint. In this system, the idea of cable transmossiom mechanism and guidance pulley with the ability to change the force direction is used. The two active DOFs of the shoulder joint is achived only by pulling one cable for each axis based on the novel design of this mechanism. Each axis of the shoulder is driven independently which implies that a single axis can be installed on the arm. This exoskeleton does not impose any limitation on the vertical motion of the scapula. In addition, it is inexpensive, lightweight and can easily be used. In this paper, after introducing the exoskeleton system, the required motor torques for generating a prescribed task are obtained. In the next step, the kinematic and dynamic equations of this system are derived. By simulating the exoskeleton in CATIA and MATLAB softwares, and presenting the results, the performance of the exoskeleton is evaluated. The results show that this novel exoskeleton system posses an excellent capacity to perform the rehabilitation excersises for shoulder joint.
Medical Robotics / Bio-Robotics
Mojtaba Sharifi; Saeid Behzadipour; Hasan Salarieh; Farzam Farahmand
Volume 9, Issue 1 , April 2015, , Pages 85-98
Abstract
In this paper, a transparent bilateral controller is developed for the control of telesurgery systems that have physical interactions with soft tissue. In this control method, the parameters of a viscoelastic model of the soft tissue are estimated during its interaction with the slave robot using an ...
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In this paper, a transparent bilateral controller is developed for the control of telesurgery systems that have physical interactions with soft tissue. In this control method, the parameters of a viscoelastic model of the soft tissue are estimated during its interaction with the slave robot using an on-line identification method. These estimated parameters are used inanimpedance control of the master robot which is in contact with the surgeon. Also, the slave robot tracks the master robot position using a tracking controller. Accordingly, it is shown that the transparency of the teleoperation system is obtained by estimating and realizing the dynamic parameters of the tissue for the master robot and providing the position tracking performance for the slave robot. The stability, and the position and force tracking performances are proved using the Lyapunov theorem. Moreover, the effectiveness of the proposed transparent bilateral controller is investigated by simulations performed on a piece of beef (as the soft tissue) using a two DOF robot with nonlinear dynamics. The proposed control strategy can be used in telesurgery, telesonography and telerehabilitation systems in which the robot interacts with soft tissues.
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.
