Mohsen Khadem

Mohsen Khadem
The University of Edinburgh | UoE · School of Informatics

MSc, PhD

About

38
Publications
11,529
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399
Citations

Publications

Publications (38)
Article
Full-text available
In this paper, we design and develop a novel robotic bronchoscope for sampling of the distal lung in mechanically-ventilated (MV) patients in critical care units. Despite the high cost and attributable morbidity and mortality of MV patients with pneumonia which approaches 40%, sampling of the distal lung in MV patients suffering from range of lung...
Preprint
Full-text available
The Cosserat rod equations are used to model continuum and soft robots. Solving these equations are computa-tionally expensive, particularly due to mixed boundary values and kinematic constraints. In this paper, we present a novel nonlinear observer that can rapidly estimate the solution of the Cosserat rod equations. We present details of the obse...
Article
Full-text available
This paper presents a medical robotic system for deep orbital interventions, with a focus on Optic Nerve Sheath Fenestration (ONSF). ONSF is a currently invasive ophthalmic surgical approach that can reduce potentially blinding elevated hydrostatic intracranial pressure on the optic disc via an incision on the optic nerve. The prototype is a multi-...
Article
Full-text available
This article presents a model predictive controller (MPC) developed for the autonomous steering of concentric tube robots (CTRs). State-of-the-art CTR control relies on differential kinematics developed by local linearization of the CTRs mechanics model and cannot explicitly handle constraints on robot’s joint limits or unstable configurations comm...
Article
The enhanced dexterity and manipulability offered by master-slave teleoperated surgical systems have significantly improved the performance and safety of minimally invasive surgeries. However, effective manipulation of surgical robots is sometimes limited due to the mismatch between the slave and master robots' kinematics and workspace. The purpose...
Conference Paper
Full-text available
Concentric tube robots (CTR) can traverse tightly curved paths and offer dexterity in constrained environments, making them advantageous for minimally invasive surgical scenarios that experience strict anatomical and surgical constraints. Their shape is controlled via rotation and translation of several concentrically arranged super-elastic precurv...
Poster
Full-text available
While continuum robots have been studied for a variety of surgical applications (e.g., heart, lung, brain, eye, kidney), no existing robotic system can be applied to deep orbital interventions. This work for the first time aims to develop a robotic system designed for deep orbital interventions. A novel fully flexible multi-arm system, based on con...
Article
Haptic-enabled teleoperated surgical systems have the potential to enhance the accuracy and performance of surgical interventions. The user interface of such a system can provide haptic feedback to the surgeon to more intuitively perform surgical tasks. In this paper, we study the added benefits of redundant manipulators as haptic interfaces for te...
Article
Full-text available
In this paper, a 3D automated needle steering system is presented that can enhance the performance of needle-based procedures. The system comprises a nonholonomic needle steering model and a nonlinear controller for 3D needle steering. First, a reduced-order needle steering model is presented. Next, a geometric reduction procedure is carried out to...
Conference Paper
Full-text available
The enhanced dexterity and manipulability offered by continuum manipulators makes them the robots of choice for complex procedures inside the human body. However, without tailored analytical tools to evaluate their manipulability, many capabilities of continuum robots such as safe and effective manipulation will remain largely inaccessible. This pa...
Conference Paper
Full-text available
This paper presents and experimentally evaluates a quasistatic mechanics-based model that describes the shape of concentric tube robotic (CTR) arms when they are eccentrically arranged along an also-flexible backbone. The model can estimate the shape of both the backbone and CTR arms, and can accommodate an arbitrary number of CTR arms arranged in...
Conference Paper
Full-text available
Continuum robots allow accessing surgical targets deep inside the human body by steering along 3D curves in confined spaces. Further, they provide enhanced dexterity compared to traditional instruments [1]. Concentric Tube Robots (CTRs) are representative continuum robots that exhibit shape change by the relative translation and rotation of precurv...
Article
Long flexible needles used in percutaneous procedures such as biopsy and brachytherapy deflect during insertion, thus reducing needle tip placement accuracy. This paper presents a surgeon-in-the-loop system to automatically steer the needle during manual insertion and compensate for needle deflection using an event-triggered controller. A reduced-o...
Conference Paper
Teleoperated surgical robots can significantly improve the performance of minimally invasive surgeries. The performance of a master-slave robotic system depends significantly on the capability of its master device to appropriately interface the user with the slave robot. However, master robots currently used in the clinic present several drawbacks...
Article
Full-text available
Robotic-assisted needle steering can enhance the accuracy of needle-based interventions. Application of current needle steering techniques are restricted by the limited deflection curvature of needles. Here, a novel steerable needle with improved curvature is developed and used with an online motion planner to steer the needle in curved paths insid...
Article
Full-text available
Needle deflection during certain minimally invasive percutaneous procedures, such as prostate biopsy or brachytherapy, is undesired and can be reduced through the use of feedback control. This paper uses a depth-dependent reduced-order 3D nonholonomic model of needle tip motion to propose a needle deflection controller that works in a surgeon-in-th...
Conference Paper
Full-text available
Robotics-assisted needle steering can enhance the performance of needle-based clinical procedures such as biopsy, brachytherapy, and drug delivery. We present an automated needle steering system capable of steering needles in 3D toward targets in tissue while avoiding anatomical obstacles. The system comprises a nonholonomic model of needle steerin...
Article
Full-text available
Robotics-assisted needle steering can enhance targeting accuracy in percutaneous interventions. This paper presents a novel dynamical model for robotically controlled needle steering. This is the first model that predicts both needle shape and tip position in soft tissue and accepts needle insertion velocity, needle 180� degree axial rotation, and...
Article
Full-text available
The performance of needle-based interventions depends on the accuracy of needle tip positioning. Here, a novel needle steering strategy is proposed that enhances accuracy of needle steering. In our approach the surgeon is in charge of needle insertion to ensure the safety of operation, while the needle tip bevel location is robotically controlled t...
Conference Paper
Full-text available
Brachytherapy is a widely used treatment for patients with localized cancer where high doses of radiation are administered to cancerous tissue by implanting radioactive seeds into the prostate using long beveled-tip needles. Accurate seed placement is an important factor that influences the outcome of the treatment. In this paper, we present and st...
Article
Full-text available
In percutaneous needle insertions, cutting forces at the needle tip deflect the needle and increases targeting error. Thus, modelling needle-tissue interaction in biological tissue is essential for accurate robotics-assisted needle steering. In this paper, dynamics of needle tip interaction with inhomogeneous biological tissue is described and the...
Conference Paper
Full-text available
Robotics-assisted needle steering can enhance the accuracy of needle-based medical interventions, especially when the designated target locations are obscured by obstacles. However, the steering techniques using standard needles are not capable of achieving high curvatures and cannot follow tightly curved paths inside tissue. In this work, we intro...
Article
Due to the increasing number of people suuering from physical disabilities in the elbow and wrist, developing an assistive wearable robot seems crucial. These disabilities are mostly common in elderly people and people who are suuering from spinal injury or stroke. In this paper, a wearable assistive robot for rehabilitation of the wrist and elbow...
Article
Full-text available
Developing a computational model for studying tribological performance is essential for computing accurate life cycle of various materials. Caused by the existence of complicated and nonlinear interactions between material surfaces, exact modeling of wear behavior is very difficult. Artificial intelligence (AI) can be used in distinguishing similar...
Patent
Full-text available
A tool adapting device attaches to a robotic Surgery arm, and receives a manual Surgical instrument, and translates movement by the robotic Surgery arm into multiple degrees of freedom of the manual Surgical instrument, to interact with a tissue under Surgery.
Article
Full-text available
In needle-based medical procedures, beveled tip flexible needles are steered inside soft tissue to reach the desired target locations. In this paper, we have developed an autonomous image-guided needle steering system that enhances targeting accuracy in needle insertion while minimizing tissue trauma. The system has three main components. First is...
Article
Background: Many deficiencies of minimally invasive robotic surgery systems can be eliminated by using automated laparoscopic tools with force measurement and control capability. Method: A fully modular, automated laparoscopic instrument with a proximal force sensory system was designed and fabricated. The efficacy of the instrument was evaluate...
Article
Full-text available
In this paper we present a model for needle deflection estimation in soft tissue. The needle is modeled as a vibrating compliant cantilever beam that experiences forces applied by the tissue as it is inserted. Each of the assumed vibration modes are associated with a weighting coefficient whose magnitude is calculated using the minimum potential en...
Conference Paper
Full-text available
This paper represents an extension to the kine-matic bicycle model for beveled-tip needle motion in soft tissue, which accounts for non-constant curvature paths for the needle tip. For a tissue that is not stiff relative to the needle, the tissue deformation caused by needle insertion deviates the needle tip position from a constant curvature path....
Conference Paper
Full-text available
In needle-based medical procedures, beveled-tip flexible needles are steered inside soft tissue with the aim of reaching pre-defined target locations. The efficiency of needle-based interventions depends on accurate control of the needle tip. This paper presents a comprehensive mechanics-based model for simulation of planar needle insertion in soft...
Conference Paper
Full-text available
Physical disabilities in elbow and wrist are very common in elderly people or people who are suffering from an injury or a stroke. Therefore, developing an assistive wearable robot seems essential. Herein this paper a simple novel control algorithm is proposed and implemented for controlling the position of a wearable assistive robot. The robot is...
Article
Purpose: Force control of robotic instruments is a difficult task due to the uncertainties causedby changes in the instrument’s geometrical and mechanical characteristics during surgery as well as the nonlinear dynamics of the instrument. A new approach based on an intelligent controller is developed to control the force interactions of a robotic s...
Conference Paper
Laser measuring and control systems are one of the most important practical technologies and have a wide usage in medical, civil, manufacturing and agricultural fields. A wide variety of industrial products are developed for computerized control of earth moving processes. Machines like grader, loader, scraper, and tractor are able to be equipped wi...
Article
Full-text available
Nowadays, a vast range of construction and agricultural machines, such as tractors, graders, scrapers, and back hoes are equipped with computerized control devices for earth moving processes. The main job of these devices consists of the topography surveying, cutting and filling of elevated and spotted low area, and these actions depend on machine...

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