Surgical Robotics Group

The surgical robotics group aims at developing new robotics-based technologies for robot-assisted surgery and surgery training applications. This includes the design and integration of mechanical and electrical components as well as the development of innovative control structures for these systems. These robotic systems will enhance the safety and efficiency of medical surgeries which leads to more satisfaction in all of the people dealing with the healthcare systems especially the patients, the surgeons, and the residents. This group has enjoyed the collaboration and consultation of several national and international partners in the fields of engineering and medical science.

Current Projects

Surgery Training Haptic Systems

Surgery Training Haptic System

My Ph.D. thesis deals with the control structure design for the eye surgery training haptic system. Due to the interaction between the users in the dual user haptic systems, the decision of each user is affected by the other user. However, most of the related studies use a general tele-operation architecture which is not customized for surgery training. In addition, most of the research reported in the literature are based upon linearity of the system which is an unrealistic assumption. Hence, it is highly beneficial to develop a control architecture based on special requirements of surgery training and analyze its stability as a nonlinear system. This is the objective of my thesis.

Project Manager: Mohammad Motaharifar
Design and implementation of a cooperative adaptive control structure for ARAS haptic eye surgery training system
Project Manager: Arash Iranfar
Design and implementation of a cooperative adaptive control structure for ARAS haptic eye surgery training system

In my thesis design and implementation of a dual user surgery training framework, is discussed. One of the users is a novice surgeon who is learning the procedure by watching and feeling the movements that the other user, which is an expert surgeon, is doing. The training system consists of two identical haptic devices which are connected to each other via a fast and reliable communication channel. The embedded system that is managing the communication can control either of the haptic devices according to a predefined training routine. Three virtual fixture based cooperative control schemes are proposed and compared, and the stability of each is analyzed using passivity and ISS approaches. Moreover, the design and implementation process of the embedded system is discussed and the results for implementing one of the abovementioned approaches are presented.

Eye surgery performance evaluation and improvement using artificial intelligence (AI)
Eye surgery performance evaluation and improvement using artificial intelligence (AI)

Skill assessment and transfer in eye surgery is one of the important considerate goals in surgery training and evaluation. ARAS Haptic System has implemented and developed in Surgical Robotic group of ARAS lab. These haptic devices can measure position and insertion force of tool that can be very useful in practical skill assessment. Based on eye surgery, especially vitrectomy, there are some important and necessary skills for novices like path length, tool’s speed in the entry point, depth perception, motion smoothness, applied forces and etc. I am studying some kinematic and dynamic parameters that can describe the movements well and they were reliable and valid in a practical skills assessment.

Project Managers: Hamed Sadeghi, Parisa Hasani, and Mohammad Javad Ahmadi

Featured Products

 Diamond

The Diamond robot is designed to perform as the slave robot in a robotic-assisted eye telesurgery system. A parallel spherical mechanism is proposed to provide the Remote Center of Motion (RCM) by the mechanical solutions. The proposed parallel mechanism has several advantages over the serial ones owing to the higher structural stiffness and improved position accuracy.

Eagle Eye

Eagle Eye is a novel parallelogram mechanism to provide mechanical Remote Center of Motion (RCM) for robotic-assisted vitreoretinal eye surgery. In the conventional parallelogram mechanism, the two rotational degrees of freedom are provided by a combination of serial and parallel structures. In the Eagle Eye robot, the rotational degrees of freedom are provided by a fully parallel mechanism.

Our Team

The major focus of surgical robotics team is the design and construction of devices to make surgical procedures and surgical training more accurate, effective and less invasive. The current project followed in our team is the design and evaluation of a novel haptic feedback system for facilitating eye surgery training. Undoubtedly, our collaboration with the Farabi Eye Hospital, the Center of Excellence in Ophthalmology, is a valuable and constructive asset for this project. This project involves the design and integration of mechanical and electrical systems and the development of advanced control frameworks for these systems. In addition, the following projects are the most recent projects conducted in our research group:

  • Surgery Training Haptic System
  • Design and implementation of a cooperative adaptive control structure for ARAS haptic eye surgery training system
  • Presentation and implementation of performance evaluation procedure ARAS Haptic System for eye Surgery Training (ARASH: ASiST)
  • Design and implementation of impedance control of the dual-user system for eye surgery training
  • Eye surgery performance evaluation and improvement using artificial intelligence (AI)
  • investigation of the metrics and methods of surgical skill assessment in the Eye Surgery Haptic System
  • Deriving Dynamics of the Eye Surgical Robot for Real-Time Control Purposes
  • Sliding mode impedance control design for teleoperation systems
Collaborators

Prof. Mahdi Tavakoli

Seyed Mahdi Tavakoli Afshari received his BSc and MSc degrees in Electrical Engineering from Ferdowsi University and K.N. Toosi University, Iran, in 1996 and 1999, respectively. He then received his PhD degree in Electrical and Computer Engineering from the University of Western Ontario, London, ON, Canada, in 2005. In 2006, he was a post-doctoral research associate at Canadian Surgical Technologies and Advanced Robotics (CSTAR), London, ON, Canada. In 2007-2008, and prior to joining the Department of Electrical and Computer Engineering at the University of Alberta, Dr. Tavakoli was an NSERC Post-Doctoral Fellow with the BioRobotics Laboratory of the School of Engineering and Applied Sciences at Harvard University, Cambridge, MA, USA. Dr. Tavakoli’s research research focuses on haptics and teleoperation control, medical robotics, surgical robotics and image-guided surgery.

Dr. Seyed-Farzad Mohammadi

Seyed Farzad Mohammadi received the Fellowship degree in anterior segment of the eye from the Tehran University of Medical Sciences, Tehran, Iran, in 2007. He is currently an Associate Professor of ophthalmology with Translational Ophthalmology Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences. His current research interests include bench-to-bedside researches and ophthalmic epidemiology. He is board-certified in ophthalmology and a fellow of the International Council of Ophthalmology, and he is currently involved in Ophthalmic Epidemiology & Public Health Ophthalmology initiatives; Anterior Segment, Cornea & Refractive Surgery clinical research; Anterior Segment Regenerative Ophthalmology (Corneal Endothelial Cell Therapy); Robotics in Ophthalmic Surgery Education; Natural Lens Biomechanics; & Corneal Imaging (non-optical).

Prof. Keyvan Hashtrudi-Zaad

Keyvan Hashtrudi-Zaad received the Ph.D. degree in electrical and computer engineering from the University of British Columbia, Vancouver, BC, Canada, in 2000. He then held a consulting position with Motion Metrics International Corporation, Vancouver, where he was involved in the development of a dynamic payload monitoring system for heavy duty hydraulic machines. In 2001, he joined the Department of Electrical and Computer Engineering, Queens University, Kingston, ON, Canada, where he is currently a Professor and the Co-Director of the BioRobotics Research Laboratory. His current research interests include telerobotics, haptics, telerehabilitation, autonomous driving, and control systems. Dr. Hashtrudi-Zaad served as an Associate Editor for the IEEE TRANSACTIONS ON HAPTICS and on the organization committees of a number of IEEE-sponsored conferences.

Dr. Alireza Lashay

Dr. Alireza Lashay obtained his PhD in vetreo retinal surgery from Tehran University of Medical Sciences,iran in the year 1993. He holds a Master Degree (MSc) in Opthalmology from Tehran University of Medical Sciences, Iran in the year 1988, followed by a Bachelor’s Degree in general medicine from Tehran University of Medical Sciences,Iran in the year 1981. He is now working as a Professor in Opthalmology in Tehran University of Medical Sciences.

Prof. Ghasem Fakhraee

Dr. Ghasem Fakhraei has awarded his Fellow in Glaucoma, Wills Eye Institute, Thomas Jefferson University, Philadelphia, USA, in January 2009, and Fellow in Glaucoma, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran, January 2008. He is now working as an accociate Professor in opthalmology, Glaucoma Service, in tehran university of medical sciences.

Dr. Hamid Riazi

Dr. Hamid Riazi currently works at Farabi eye hospital as a assistant professor of ophthalmology. Hamid does research in Ophthalmology. Their most recent publication is ‘Successful treatment of tubercular multifocal serpiginous-like choroiditis without use of anti-inflammatory drugs: A case report with multimodal imaging’.

Dr. Mohammad Motaharifar

Dr. Mohammad Motaharifar received the B.Sc. degree in electrical engineering from the Iran University of Science and Technology, Tehran, Iran, in 2009, and the M.Sc. degree in electrical engineering from the Amirkabir University of Technology, Tehran, in 2011. He was a Research Assistant at Real time Systems Laboratory, Electrical Engineering Department, Amirkabir University of Technology from 2011 to 2014. He is currently working toward the Ph.D. degree from the K. N. Toosi University of Technology, Tehran. His research interests include robotics, medical robotics, adaptive control of nonlinear systems, and robust control.

Students

Reza Heidari (Ph.D.)

Reza received his B.Sc. degree in Electrical Engineering from Isfahan University of Technology (IUT) in September 2017. He is currently pursuing his M.Sc. degree in Control Engineering at K.N. Toosi University of Technology, Tehran, Iran. Reza has joined Surgical Robotics group in Advanced Robotics and Automated System (ARAS) Lab. His main research interests are Medical Robotics, including applications in surgical training; Haptics and Teleoperation. He is currently working on design and implementation of impedance control of dual haptic for eye surgery training system.

Hamed Sadeghi (M.Sc.)

Hamed Sadeghi was born in Tehran, Iran in 1996. Hamed finished his B. Sc. in Control engineering at K.N Toosi University of Technology – Tehran in 2018 and started his M. Sc. program in the same major at K.N Toosi University of Technology – Tehran since September 2018 and he joined ARAS group since 2015. His thesis was on focused on Surgical Robotics, mainly design and implement the Electronic hardware of ARASH-ASiST: ARAS Haptic System for EYE Surgery Training and currently He is working as a researcher in the surgical robotics group.

Parisa Hasani (M.Sc.)

Parisa Hasani received the B.Sc. degree in electrical engineering from Shariaty Technical College, Tehran, Iran, in 2018. She is currently pursuing the M.Sc. degree in control engineering from the K. N. Toosi University of Technology, Tehran, Iran. She joined the ARAS laboratory and Surgical Robotics group in October 2018. Her research interests include haptics, medical robotics, master-slave teleoperation, and evaluation in robotic-assisted systems for minimally invasive surgery.

Ali Hassani (M.Sc.)

Ali Hassani was born in Tehran, Iran in 1996. He received his B.Sc degree in Mechanical Engineering from Shahid Chamran University (Jundi Shapur), Ahvaz, Iran in 2018. He is currently a M.Sc student in Mechatronics Engineering at K.N. Toosi University, Tehran, Iran. He joined ARAS group under supervision of Dr. Hamid D. Taghirad since October 2018. His current research interests includes various aspects of Dynamics and Control of Parallel Robots.

Mohammad Javad Ahmadi (M.Sc.)

Mohammad Javad Ahmadi was born in Dec. 1996 in Sari in northern IRAN near the beautiful Caspian Sea. In 2011 he was accepted into the NODET (National Organization for Developement of Exceptional Talent) and spent four years in Shahid Beheshti high school and graduated with Diploma GPA of 4/4. In 2015 he entered Amirkabir University of Technology (Polytechnic of Tehran), Tehran, Iran and received his B.Sc. degree in Electrical and Control Engineering with a GPA of 4/4. Currently, He is a graduate student in Control Engineering at K. N. Toosi University of Technology, Tehran, Iran and he has joined the surgical robotics group in Advanced Robotics and Automated System (ARAS) Lab under the supervision of Prof. Hamid D. Taghirad. His main research interest includes medical robots, surgical robots, mobile robots, flying robots, etc. He is also interested in doing research in Control theory, Artificial intelligence & Neural network, IIoT & IoT, and Multi-agent system & Consensus algorithm.

Ashkan Rashvand (M.Sc.)

Ashkan Rashvand was born in 26 June 1997 in Qazvin. He graduated from Shahid Babaii NODET (National Organization for Developement of Exceptional Talent) high school. He finished his B.Sc. in controls engineering at Imam Khomeini International University in 2019 with 3.78/4 total GPA. He has always believed that the most important factors to a person’s success in a specific field are their motivation and interest in that field. Believing this idea helped him to be ranked one of the top student during his bachelor position. He started his M. Sc. program in the same major at K.N Toosi University of Technology under supervision of Prof. Taghirad . Now he is a member of ARAS group. His main research interests is robotics (Robots motion planning ,Robots-Assisted Therapy) and Artificial Life.

Alumni
  • Sara AbkhoftePedram Agand, Mohammad Savadzadeh, Rashid Mokhtari, Bita Fallahi, Omid Gerami, Maryam Salimifar, Samim Khosravi, Soheil Gholami, Zahra Marvi, Kamran Taran, Maryam Moafi Madani, Bahareh Sabouri, Ali Alipour, Farbid Farshidian.

Related Publications

TitleAbstractYearTypePDFResearch Group
Applications of Haptic Technology, Virtual Reality, and Artificial Intelligence in Medical Training During the COVID-19 Pandemic
Mohammad Motaharifar, Alireza Norouzzadeh, Parisa Abdi, Arash Iranfar, Faraz Lotfi, Behzad Moshiri, Alireza Lashay, Seyed Farzad Mohammadi, Hamid D Taghirad
Abstract:

This paper examines how haptic technology, virtual reality, and artificial intelligence reduce the physical contact in medical training during the COVID-19 Pandemic. Notably, any mistake made by the trainees during the education stages might lead to undesired complications for the patient. Therefore, training of the medical skills to the trainees have always been a challenging issue for the expert surgeons, and this is even more challenging in pandemics. The current method of surgery training needs the novice surgeons to attend some courses, watch some procedure, and conduct their initial operations under the direct supervision of an expert surgeon. Owing to the requirement of physical contact in this method of medical training, the involved people including the novice and expert surgeons confront a potential risk of infection to the virus. This survey paper reviews novel recent breakthroughs along with new areas in which assistive technologies might provide a viable solution to reduce the physical contact in the medical institutes during the COVID-19 pandemic and similar crises.

2021JournalPDFSurgical Robotics
Kinematic and Dynamic Analysis of ARASH ASiST: Toward Micro Positioning
A Hassani, MR Dindarloo, R Khorambakht, A Bataleblu, H Sadeghi, R Heidari, A Iranfar, P Hasani, NS Hojati, A Khorasani, N KhajeAhmadi, M Motaharifar, H Riazi-Esfahani, A Lashay, SF Mohammadi, HD Taghirad
Abstract:

This article elaborate on the kinematic and dynamic analysis of ARASH:ASiST, "ARAS Haptic System for Eye Surgery Training", which is developed for vitrectomy eye surgery training. The mechanism selection of this system is reviewed first, in order to assist such a precise intraocular eye surgery training. Then the kinematics and dynamics analysis of the proposed haptic system is investigated. To verify the reported result, a prototype of ARASH:ASiST is modeled in MSC-ADAMS ® , and the results of the dynamic formulation are validated. Finally, a common model-based controller is implemented on the real prototype, and it is verified that with such controller a suitable accuracy of 200 μm is attainable for the surgical instrument.

2021ConferencePDFSurgical Robotics
A Review on Applications of Haptic Systems, Virtual Reality, and Artificial Intelligence in Medical Training in COVID-19 Pandemic
R Heidari, M Motaharifar, H Taghirad, SF Mohammadi, A Lashay
Journal of Control
Abstract:

This paper presents a survey on haptic technology, virtual reality, and artificial intelligence applications in medical training during the COVID-19 pandemic. Over the last few decades, there has been a great deal of interest in using new technologies to establish capable approaches for medical training purposes. These methods are intended to minimize surgerychr('39')s adverse effects, mostly when done by an inexperienced surgeon

2021JournalPDFSurgical Robotics
A Review on Applications of Haptic Systems, Virtual Reality, and Artificial Intelligence in Medical Training in COVID-19 Pandemic
R Heidari, M Motaharifar, H Taghirad, SF Mohammadi, A Lashay
Journal of Control
Abstract:

This paper presents a survey on haptic technology, virtual reality, and artificial intelligence applications in medical training during the COVID-19 pandemic. Over the last few decades, there has been a great deal of interest in using new technologies to establish capable approaches for medical training purposes. These methods are intended to minimize surgerychr('39')s adverse effects, mostly when done by an inexperienced surgeon

2021JournalPDFSurgical Robotics
Applications of Haptic Technology, Virtual Reality, and Artificial Intelligence in Medical Training During the COVID-19 Pandemic
Mohammad Motaharifar, Alireza Norouzzadeh, Parisa Abdi, Arash Iranfar, Faraz Lotfi, Behzad Moshiri, Alireza Lashay, Seyed Farzad Mohammadi, Hamid D Taghirad
Abstract:

This paper examines how haptic technology, virtual reality, and artificial intelligence help to reduce the physical contact in medical training during the COVID-19 Pandemic. Notably, any mistake made by the trainees during the education process might lead to undesired complications for the patient. Therefore, training of the medical skills to the trainees have always been a challenging issue for the expert surgeons, and this is even more challenging in pandemics. The current method of surgery training needs the novice surgeons to attend some courses, watch some procedure, and conduct their initial operations under the direct supervision of an expert surgeon. Owing to the requirement of physical contact in this method of medical training, the involved people including the novice and expert surgeons confront a potential risk of infection to the virus. This survey paper reviews recent technological breakthroughs along with new areas in which assistive technologies might provide a viable solution to reduce the physical contact in the medical institutes during the COVID-19 pandemic and similar crises.

2021JournalPDFSurgical Robotics
Applications of Haptic Technology, Virtual Reality, and Artificial Intelligence in Medical Training During the COVID-19 Pandemic
Mohammad Motaharifar, Alireza Norouzzadeh, Parisa Abdi, Arash Iranfar, Faraz Lotfi, Behzad Moshiri, Alireza Lashay, Seyed Farzad Mohammadi, Hamid D Taghirad
Abstract:

This paper examines how haptic technology, virtual reality, and artificial intelligence help to reduce the physical contact in medical training during the COVID-19 Pandemic. Notably, any mistake made by the trainees during the education process might lead to undesired complications for the patient. Therefore, training of the medical skills to the trainees have always been a challenging issue for the expert surgeons, and this is even more challenging in pandemics. The current method of surgery training needs the novice surgeons to attend some courses, watch some procedure, and conduct their initial operations under the direct supervision of an expert surgeon. Owing to the requirement of physical contact in this method of medical training, the involved people including the novice and expert surgeons confront a potential risk of infection to the virus. This survey paper reviews recent technological breakthroughs along with new areas in which assistive technologies might provide a viable solution to reduce the physical contact in the medical institutes during the COVID-19 pandemic and similar crises.

2021JournalPDFSurgical Robotics
A force reflection robust control scheme with online authority
adjustment for dual user haptic system

Mohammad Motaharifar, Hamid D. Taghirad
Mechanical Systems and Signal Processing
Abstract:

This article aims at developing a control structure with online authority adjustment for a
dual-user haptic training system. In the considered system, the trainer and the trainee
are given the facility to cooperatively conduct the surgical operation. The task dominance
is automatically adjusted based on the task performance of the trainee with respect to the trainer. To that effect, the average norm of position error between the trainer and the trainee is calculated in a sliding window and the relative task dominance is assigned to the operators accordingly. Moreover, a robust controller is developed to satisfy the require-
ment of position tracking. The stability analysis based on the input-to-state stability (ISS) methodology is reported. Experimental results demonstrate the effectiveness of the
proposed control approach.

2020JournalPDFSurgical Robotics
Surgical Instrument Tracking for Vitreo-retinal Eye Surgical Procedures Using ARAS-EYE Dataset
F Lotfi, P Hasani, F Faraji, M Motaharifar, HD Taghirad, SF Mohammadi
28th Iranian Conference on Electrical Engineering (ICEE)
Abstract:

Real-time instrument tracking is an essential element of minimally invasive surgery and has several applications in computer-assisted analysis and interventions. However, the instrument tracking is very challenging in the vitreo-retinal eye surgical procedures owing to the limited workspace of surgery, illumination variation, flexibility of the instruments, etc. In this article, as a powerful technique to detect and track surgical instruments, it is suggested to employ a convolutional neural network (CNN) alongside a newly produced ARAS-EYE dataset and OpenCV trackers. To clarify, firstly you only look once (YOLOv3) CNN is employed to detect the instruments. Thereafter, the Median-flow OpenCV tracker is utilized to track the determined objects. To modify the tracker, every “ n” frames, the CNN runs over the image and the tracker is updated. Moreover, the dataset consists of 594 images in which four “shaft”, “center”, “laser”, and “gripper” labels are considered. Utilizing the trained CNN, experiments are conducted to verify the applicability of the proposed approach. Finally, the outcomes are discussed and a conclusion is presented. Results indicate the effectiveness of the proposed approach in detection and tracking of surgical instruments which may be used for several applications.

2020ConferencePDFSurgical Robotics
A Robust Controller with Online Authority Transformation for Dual User Haptic Training System
M Motaharifar, H Taghirad, SF Mohammadi
Journal of Control
Abstract:

The design problem for the control a dual-user haptic surgical training system is studied in this article. The system allows the trainee to perform the task on a virtual environment, while the trainer is able to interfere in the operation and correct probable mistakes made by the trainee. The proposed methodology allows the trainer to transfer the task authority to or from the trainee in real time

2020JournalPDFSurgical Robotics
Control Synthesis and ISS Stability Analysis of Dual-User Haptic Training System Based on S-Shaped Function
Mohammad Motaharifar, Hamid D. Taghirad, Keyvan Hashtrudi-Zaad, Seyed Farzad Mohammadi
IEEE/ASME Transactions on Mechatronics
Abstract:

The controller design and stability analysis of dual user training haptic system is studied. Most of the previously proposed control methodologies for this system have not simultaneously considered special requirements of surgery training and stability analysis of the nonlinear closed loop system which is the objective of this paper. In the proposed training approach, the trainee is allowed to freely experience the task and be corrected as needed, while the trainer maintains the task dominance. A special S-shaped function is suggested to generate the corrective force according to the magnitude of motion error between the trainer and the trainee. The closed loop stability of the system is analyzed considering the nonlinearity of the system components using the Input-to-State Stability (ISS) approach. Simulation and experimental results show the effectiveness of the proposed approach.

2019ConferencePDFSurgical Robotics
Control Synthesis and ISS Stability A5Analysis of Dual-User Haptic Training System Based on S-Shaped Function
Mohammad Motaharifar, Hamid D. Taghirad, Keyvan Hashtrudi-Zaad and Seyed Farzad Mohammadi
IEEE/ASME Transactions on Mechatronics
Abstract:

The controller design and stability analysis of dual user training haptic system is studied. Most of the previously proposed control methodologies for this system have not simultaneously considered special requirements of surgery training and stability analysis of the nonlinear closed loop system which is the objective of this paper. In the proposed training approach, the trainee is allowed to freely experience the task and be corrected as needed, while the trainer maintains the task dominance. A special S-shaped function is suggested to generate the corrective force according to the magnitude of motion error between the trainer and the trainee. The closed loop stability of the system is analyzed considering the nonlinearity of the system components using the Input-to-State Stability (ISS) approach. Simulation and experimental results show the effectiveness of the proposed approach.

2019JournalPDFSurgical Robotics
Control Synthesis and ISS Stability Analysis of a Dual-User Haptic Training System Based on S-Shaped Function
Mohammad Motaharifar, Hamid D. Taghirad, Keyvan Hashtrudi-Zaad, and Seyed Farzad Mohammadi
IEEE/ASME Transactions on Mechatronics
Abstract:

The controller design and stability analysis of
a dual user training haptic system is studied. Most of the previously proposed control methodologies for this system
have not simultaneously considered special requirements
of surgery training and stability analysis of the nonlinear
closed-loop system which is the objective of this paper. In the proposed training approach, the trainee is allowed
to freely experience the task and be corrected as needed,
while the trainer maintains the task dominance. A special S-shaped function is suggested to generate the corrective force according to the magnitude of motion error between the trainer and the trainee. The closed-loop stability of the system is analyzed considering the nonlinearity of
the system components using the Input-to-State Stability approach. Simulation and experimental results show the effectiveness of the proposed approach.

2019JournalPDFSurgical Robotics
Control of Dual-User Haptic Training System With Online Authority Adjustment: An Observer-Based Adaptive Robust Scheme
Mohammad Motaharifar, Hamid D. Taghirad, Keyvan Hashtrudi-Zaad and Seyed Farzad Mohammadi
IEEE Transactions on Control Systems Technology
Abstract:

The design problem for the control a dual-user
haptic surgical training system is studied in this article. The
system allows the trainee to perform the task on a virtual environment, while the trainer is able to interfere in the operation and correct probable mistakes made by the trainee. The proposed
methodology allows the trainer to transfer the task authority to or from the trainee in real time. The robust adaptive nature
of the controller ensures position tracking. The stability of the closed-loop system is analyzed using the input-to-output stability approach and the small-gain theorem. Simulation and
experimental results are presented to validate the effectiveness
of the proposed control scheme.

2019JournalPDFSurgical Robotics
A Force Reflection Impedance Control Scheme for Dual User Haptic Training System
M. Motaharifar, A. Iranfar, and H. D. Taghirad 2019 27th Iranian Conference on Electrical Engineering (ICEE)
Abstract:

In this paper, an impedance control based training scheme for a dual user haptic surgery training system is introduced. The training scheme allows the novice surgeon (trainee) to perform a surgery operation while an expert surgeon (trainer) supervises the procedure. Through the proposed impedance control structure, the trainer receives trainee’s position to detect his (her) wrong movements. Besides, a novel force reflection term is proposed in order to efficiently utilize trainer’s skill in the training loop. Indeed, the trainer can interfere into the procedure whenever needed either to guide the trainee or suppress his (her) authority due to his (her) supposedly lack of skill to continue the operation. Each haptic device is stabilized and the closed loop stability of the nonlinear system is investigated. Simulation results show the appropriate performance of the proposed control scheme.

2019ConferencePDFSurgical Robotics
Implementation of an improved moment-based visual servoing controller on an industrial robot
Parisa Masnadi Khiabani, Javad Ramezanzadeh and Hamid D. Taghirad
International Conference on Robotics and Mechatronics
Abstract:

In this paper, robust nonlinear control of momentbased visual servoing has been proposed. Due to the nonlinear
nature of system, proportional integral sliding mode controller
could improve the performance and robustness of visual servoing.
The proposed method not only increases domain of attraction
even in extraneous image regions, but also it achieves convergence
to the target point despite of uncertainties. The stability of the
controller is analyzed by Lyapunov’s theorem. Furthermore,
Integrated control of 4 DOF camera motions in this work,
drastically improves the accuracy in compare with the kernelbased sliding mode visual servoing. Different experiments are
done to demonstrate considerable performance improvements on
5 DOF industrial robot.

2019ConferencePDFSurgical Robotics
Robust Impedance Control for Dual User Haptic Training System
R. Heidari, M. Motaharifar and H. D. Taghirad
International Conference on Robotics and Mechatronics
In this paper, an impedance controller with switching parameters for a dual-user haptic training system is introduced. The trainer and the trainee are connected through their
haptic consoles, and the trainee performs the surgical procedure
on the environment. The trainer can intervene in the procedure
by pressing a mechanical pedal; thus, the control parameters are
switched to transfer the authority over the task from the trainee
to the trainer. The stability of each subsystem and the closed-loop
stability of the overall system are investigated. The simulation
results verify the performance of the proposed controller.
2019ConferencePDFSurgical Robotics
Skill Assessment Using Kinematic Signatures: Geomagic Touch Haptic Device
N. S. Hojati, M. Motaharifar, H. D. Taghirad, A. Malekzadeh
International Conference on Robotics and Mechatronics
he aim of t his paper is to develop a practical
skill assessment for some designed experimental tasks, retrieved
from Minimally Invasive Surgery. The skill evaluation is very
important in surgery training, especially in MIS. Most of the
previous studies for skill assessment methods are limited in the
Hidden Markov Model and some frequency transforms, such as
Discret e Fourier transform, Discrete Cosine Transform and etc.
In this paper , some features have been ext racted from timefrequency analysis with t he Discret e Wavelet Transform and
t emporal signa l ana lysis of some kinematic metrics whi ch were
compute d from Geom agic Touch kinematic data. In addition,
the k-n earest neighbors classifier are employed to detect skill
level based on ext racted features. Through cross-validation
results, it is demonstrated that t he proposed methodology has
appropriate accuracy in skill level det ection
2019ConferencePDFSurgical Robotics
A Dual-User Teleoperated Surgery Training Scheme Based on Virtual Fixture
A. Iranfar, M. Motaharifar, and H. D. Taghirad
2018 6th RSI International Conference on Robotics and Mechatronics (IcRoM)
Abstract:

The widespread use of minimally invasive surgery (MIS) demands an appropriate framework to train novice surgeons (trainees) to perform MIS. One of the effective ways to establish a cooperative training system is to use virtual fixtures. In this paper, a guiding virtual fixture is proposed to correct the movements of the trainee according to trainer hand motion performing a real MIS surgery. The proposed training framework utilizes the position signals of trainer to modify incorrect movements of the trainee which leads to shaping the trainee's muscle memory. Thus, after enough training sessions the trainee gains sufficient experience to perform the surgical task without any further help from the trainer. The passivity approach is utilized to analyze the stability of system. Simulation results are also presented to demonstrate the effectiveness of the proposed method.

2018ConferencePDFSurgical Robotics
An Observer-Based Force Reflection Robust Control for Dual User Haptic Surgical Training System
M. Motaharifar and H. D. Taghirad
2017 5th RSI International Conference on Robotics and Mechatronics (ICRoM)
Abstract:

This paper investigates the controller design problem for the dual user haptic surgical training system. In this system, the trainer and the trainee are interfaced together through their haptic devices and the surgical operations on the virtual environment is performed by the trainee. The trainer is able to interfere into the procedure in the case that any mistakes is made by the trainee. In the proposed structure, the force of the trainer's hands is reflected to the hands of the trainee to give necessary guidance to the trainee. The force signal is obtained from an unknown input high gain observer. The position of the trainee and the contact force with the environment are sent to the trainer to give him necessary information regarding the status of surgical operations. Stabilizing control laws are also designed for each haptic device and the stability of the closed loop nonlinear system is proven. Simulation results are presented to show the effectiveness of the proposed controller synthesis.

2017ConferencePDFSurgical Robotics
Adaptive Control of Dual User Teleoperation with Time Delay and Dynamic Uncertainty
M. Motaharifar, A. Bataleblu, and H. D. Taghirad
2016 24th Iranian Conference on Electrical Engineering (ICEE)
Abstract:

This technical note aims at proposing an adaptive control scheme for dual-master trilateral teleoperation in the presence of communication delay and dynamic uncertainty in the parameters. The majority of existing control schemes for trilateral teleoperation systems have been developed for linear systems or nonlinear systems without dynamic uncertainty or time delay. However, in the practical teleoperation applications, the dynamics equations are nonlinear and contain uncertain parameters. In addition, the time delay in the communication channel mostly exists in the real applications and can affect the stability of closed loop system. As a result, an adaptive control methodology is proposed in this paper that to guarantee the stability and performance of the system despite nonlinearity, dynamic uncertainties and time delay. Simulation results are presented to show the effectiveness of the proposed adaptive controller methodology.

2016ConferencePDFSurgical Robotics
Robust H-Infinity Control of a 2RT Parallel Robot For Eye Surgery
Abbas Bataleblu, Mohammad Motaharifar, Ebrahim Abedlu, Hamid D. Taghirad
2016 4th International Conference on Robotics and Mechatronics (ICROM)
Abstract:

This paper aims at designing a robust controller for a 2RT parallel robot for eye telesurgery. It presents two robust controllers designs and their performance in presence of actuator saturation limits. The nonlinear model of the robot is encapsulated with a linear model and multiplicative uncertainty using linear fractional transformations (LFT). Two different robust control namely, H ? and ?-synthesis are used and implemented. Results reveal that the controllers are capable to stabilize the closed loop system and to reduce the tracking error in the presence of the actuators saturation. Simulation results are presented to show that effectiveness of the controllers compared to that of conventional controller designs. Furthermore, it is observed that ?-synthesis controller has superior robust performance.

2016ConferencePDFSurgical Robotics
Particle Filters for Non-Gaussian Hunt-Crossley Model of Environment in Bilateral Teleoperation
Pedram Agand, Hamid D. Taghirad and Ali Khaki-Sedigh
2016 4th International Conference on Robotics and Mechatronics (ICROM)
Abstract:

Optimal solution for nonlinear identification problem in the presence of non-Gaussian distribution measurement and process noises is generally not analytically tractable. Particle filters, known as sequential Monte Carlo method (SMC), is a suboptimal solution of recursive Bayesian approach which can provide robust unbiased estimation of nonlinear non-Gaussian problem with desire precision. On the other hand, Hunt-Crossley is a widespread nonlinear model for modeling telesurgeries environment. Hence, in this paper, particle filter is proposed to capture most of the nonlinearities in telesergerie environment model. An online Bayesian framework with conventional Monte Carlo method is employed to filter and predict position and force signals of environment at slave side respectively to achieve transparent and stable bilateral teleoperation simultaneously. Simulation results illustrate effectiveness of the algorithm by comparing the estimation and tracking errors of sampling importance resampling (SIR) with extended Kalman filter.

2016ConferencePDFSurgical Robotics
Adaptive Control for Force-Reflecting Dual User Teleoperation Systems
Sara Abkhofte, Mohammad Motaharifar, and Hamid D. Taghirad
2016 4th International Conference on Robotics and Mechatronics (ICROM)
Abstract:

The aim of this paper is to develop an adaptive force reflection control scheme for dual master nonlinear teleoperation systems. Having a sense of contact forces is very important in applications of dual master teleopreation systems such as surgery training. However, most of the previous studies for dual master nonlinear teleoperation systems are limited in the stability analysis of force reflection control schemes. In this paper, it is assumed that the teleopreation system consists of two masters and a single slave manipulator. In addition, all communication channels are subject to unknown time delays. First, adaptive controllers are developed for each manipulator. Next, Input-to-State Stability (ISS) approach is used to analyze the stability of the closed loop system. Through simulation results, it is demonstrated that the proposed methodology is effective in a nonlinear teleopreation system.

2016ConferencePDFSurgical Robotics
An Observer-Based Adaptive Impedance-Control for Robotic Arms: Case Study in SMOS Robot
Soheil Gholami, Arash Arjmandi, and Hamid D. Taghirad
2016 4th International Conference on Robotics and Mechatronics (ICROM)
Abstract:

In this paper an adaptive output-feedback impedance control is proposed to be used in environment-machine interaction applications. The proposed control is designed to achieve a desired robot impedance in the presence of possible dynamical parameter uncertainties. A high-gain observer is utilized in the control structure to achieve this objective by using only position feedback of robot joints, which in turn, reduces implementation costs and eliminates additional sensor requirements. Stability of the overall system is analyzed through input to state stability analysis. Finally, to evaluate the presented structure, computer simulations are provided and the scheme effectiveness is verified.

2016ConferencePDFSurgical Robotics
Kinematic and Workspace Analysis of DIAMOND: An Innovative Eye Surgery Robot
Amir Molaei, Ebrahim Abedloo, Hamid D. Taghirad and Zahra Marvi
2015 23rd Iranian Conference on Electrical Engineering
Abstract:

This paper presents a new robot for eye surgeries, referred to as DIAMOND. It consists of a spherical mechanism that has a remote center of motion (RCM) point and is capable of orienting the surgical instrument about this unique point. Using the RCM as the insertion point of the surgery instruments makes the robot suitable for minimally invasive surgery applications. DIAMOND has two pairs of identical spherical serial limbs that form a closed kinematic chain leading to high stiffness. The spherical structure of the mechanism is compatible with the human head and the robot may perform the surgery upon the head without any collision with the patient. Furthermore, dexterity and having a compact size is taken into account in the mechanical design of the robot. The workspace of the robot is a complete singularity free sphere that covers the region needed for any eye surgeries. In this paper, a comparison between different types of existing eye surgery robots is presented, the structure of the mechanism is described in detail and kinematic analysis of the robot is investigated.

2015ConferencePDFSurgical Robotics
Eye-RHAS Manipulator: From Kinematics to Trajectory Control
Ebrahim Abedloo, Soheil Gholami, and Hamid D. Taghirad
2015 3rd RSI International Conference on Robotics and Mechatronics (ICROM)
Abstract:

One of the challenging issues in the robotic technology is to use robotics arm for surgeries, especially in eye operations. Among the recently developed mechanisms for this purpose, there exists a robot, called Eye-RHAS, that presents sustainable precision in vitreo-retinal eye surgeries. In this work the closed-form dynamical model of this robot has been derived by Gibbs-Appell method. Furthermore, this formulation is verified through SimMechanics Toolbox of MATLAB. Finally, the robot is simulated in a real time trajectory control in a teleoperation scheme. The tracking errors show the effectiveness and applicability of the dynamic formulation to be used in the teleoperation schemes.

2015ConferencePDFSurgical Robotics
Vision-Based Kinematic Calibration of Spherical Robots
Pedram Agand, Hamid D. Taghirad and Amir Molaee
2015 3rd RSI International Conference on Robotics and Mechatronics (ICROM)
Abstract:

In this article, a method to obtain spatial coordinate of spherical robot's moving platform using a single camera is proposed, and experimentally verified. The proposed method is an accurate, flexible and low-cost tool for the kinematic calibration of spherical-workspace mechanisms to achieve the desired accuracy in position. The sensitivity and efficiency of the provided method is thus evaluated. Furthermore, optimization of camera location is outlined subject to the prescribed cost functions. Finally, experimental analysis of the proposed calibration method on ARAS Eye surgery Robot (DIAMOND) is presented; In which the accuracy is obtained from three to six times better than the previous calibration.

2015ConferencePDFSurgical Robotics
Sliding Impedance Control for Improving Transparency in Telesurgery
Samim Khosravi, Arash Arjmandi and Hamid D. Taghirad
2014 Second RSI/ISM International Conference on Robotics and Mechatronics (ICRoM)
Abstract:

This paper describes a novel control scheme for teleoperation with constant communication time delay and soft tissue in environment of slave side. This control scheme combine fidelity criteria with sliding impedance. Fidelity is a measure for evaluating telesurgical system when environment at slave side contains soft tissues. Sliding impedance is used to stabilize the teleoperating system with constant time delays and improve tracking performance in the presence of uncertainties in slave dynamics. The control system contains impedance and sliding impedance control in master and slave manipulators, respectively. Parameters of sliding impedance controller are obtained from fidelity optimization problem while parameters of master impedance controller are determined such that to guarantee stability of the entire teleopertaion system. Simulation results demonstrate suitable performance of position and force tracking of the telesurgical system.

2014ConferencePDFSurgical Robotics
Analytical Passivity Analysis for Wave-based Teleoperation with Improved Trajectory Tracking
Bita Fallahi, Hamid D. Taghirad
Canadian Committee for the Theory of Machines and Mechanisms
Abstract:

In wave based teleoperation, although passivity is ensured for any time delay, tracking performance is usually distorted due to the bias term introduced by wave transmission. To improve the position tracking error, one way is to augment the forward wave with a corrective term and achieve pas-sivity by tuning the band width of a low pass filter in the forward path. However, this filter fails to meet the passivity condition in contact to stiff environments, especially at steady state. In this paper a new method is proposed and an analytical solution for passivity at steady state and a semi analytical solution for all other frequencies are represented. This method significantly reduces the complexity of the closed-loop system, ensures passivity in contact to the stiff environments, and improves trajectory tracking. Simulation results are presented to show the effectiveness of the pro-posed method.

2011ConferencePDFSurgical Robotics
Force Control of Intelligent Laparoscopic Forceps
Soheil Kianzad, Soheil O. Karkouti, and Hamid D. Taghirad
Journal of Medical Imaging and Health Informatics
Abstract:

Actuators play an important role at the end-effectors of Minimally Invasive Surgery (MIS) robots. Having local, lightweight and powerful actuators would increase dexterity of surgeons. Shape Memory Alloy (SMA) actuators are considered as good candidates and presented significant behaviors in producing the force needed for grasping. Most of the current MIS systems provide surgeons with visual feedback. However, in many operations this information could not help surgeons to diagnose the manipulated tissue accurately. Therefore, having force and tactile information is also necessary. In order to have this information, local sensors are needed to give force feedback. This would also help to have control over the wire tension and prevent exceeding force causing tissue damages. In this paper a novel design of forceps that uses antagonistic SMA actuators is presented. This configuration helps to increase force and speed and also eliminates the bias spring used in similar works. Moreover, this antagonistic design makes it possible to place the force sensors at the back part of the forceps instead of attaching them to the jaws which results in a smaller forceps design. To control the exerted force, analytical model of system and a force control method are also presented. This enhanced design seems to address some of the existing shortcomings of similar models and remove them effectively.

2011JournalPDFSurgical Robotics
Identification and Robust H-Infinity Control of the Rotational/Translational Actuator System
Mahdi Tavakoli, Hamid D. Taghirad, and Mehdi Abrishamchian
International Journal of Control Automation and Systems
Abstract:

The Rotational/Translational Actuator (RTAC) benchmark problem considers a fourth-order dynamical system involving the nonlinear interaction of a translational oscillator and an eccentric rotational proof mass. This problem has been posed to investigate the utility of a rotational actuator for stabilizing translational motion. In order to experimentally implement any of the model-based controllers proposed in the literature, the values of model parameters are required which are generally difficult to determine rigorously. In this paper, an approach to the least-squares estimation of the parameters of a system is formulated and practically applied to the RTAC system. On the other hand, this paper shows how to model a nonlinear system as a linear uncertain system via nonparametric system identification, in order to provide the information required for linear robust H-Infinity control design. This method is also applied to the RTAC system, which demonstrates severe nonlinearities due to the coupling from the rotational motion to the translational motion. Experimental results confirm that this approach can effectively condense the whole nonlinearities, uncertainties, and disturbances within the system into a favorable perturbation block.

2005JournalPDFSurgical Robotics
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