51 research outputs found
A continuum robotic platform for endoscopic non-contact laser surgery: design, control, and preclinical evaluation
The application of laser technologies in surgical interventions has been accepted in the clinical
domain due to their atraumatic properties. In addition to manual application of fibre-guided
lasers with tissue contact, non-contact transoral laser microsurgery (TLM) of laryngeal tumours
has been prevailed in ENT surgery. However, TLM requires many years of surgical training
for tumour resection in order to preserve the function of adjacent organs and thus preserve the
patientâs quality of life. The positioning of the microscopic laser applicator outside the patient
can also impede a direct line-of-sight to the target area due to anatomical variability and limit
the working space. Further clinical challenges include positioning the laser focus on the tissue
surface, imaging, planning and performing laser ablation, and motion of the target area during
surgery. This dissertation aims to address the limitations of TLM through robotic approaches and
intraoperative assistance. Although a trend towards minimally invasive surgery is apparent, no
highly integrated platform for endoscopic delivery of focused laser radiation is available to date.
Likewise, there are no known devices that incorporate scene information from endoscopic imaging
into ablation planning and execution. For focusing of the laser beam close to the target tissue, this
work first presents miniaturised focusing optics that can be integrated into endoscopic systems.
Experimental trials characterise the optical properties and the ablation performance. A robotic
platform is realised for manipulation of the focusing optics. This is based on a variable-length
continuum manipulator. The latter enables movements of the endoscopic end effector in five
degrees of freedom with a mechatronic actuation unit. The kinematic modelling and control of the
robot are integrated into a modular framework that is evaluated experimentally. The manipulation
of focused laser radiation also requires precise adjustment of the focal position on the tissue. For
this purpose, visual, haptic and visual-haptic assistance functions are presented. These support
the operator during teleoperation to set an optimal working distance. Advantages of visual-haptic
assistance are demonstrated in a user study. The system performance and usability of the overall
robotic system are assessed in an additional user study. Analogous to a clinical scenario, the
subjects follow predefined target patterns with a laser spot. The mean positioning accuracy of the
spot is 0.5 mm. Finally, methods of image-guided robot control are introduced to automate laser
ablation. Experiments confirm a positive effect of proposed automation concepts on non-contact
laser surgery.Die Anwendung von Lasertechnologien in chirurgischen Interventionen hat sich aufgrund der atraumatischen Eigenschaften in der Klinik etabliert. Neben manueller Applikation von fasergefĂŒhrten
Lasern mit Gewebekontakt hat sich die kontaktfreie transorale Lasermikrochirurgie (TLM) von
Tumoren des Larynx in der HNO-Chirurgie durchgesetzt. Die TLM erfordert zur Tumorresektion
jedoch ein langjÀhriges chirurgisches Training, um die Funktion der angrenzenden Organe zu
sichern und damit die LebensqualitĂ€t der Patienten zu erhalten. Die Positionierung des mikroskopis chen Laserapplikators auĂerhalb des Patienten kann zudem die direkte Sicht auf das Zielgebiet
durch anatomische VariabilitÀt erschweren und den Arbeitsraum einschrÀnken. Weitere klinische
Herausforderungen betreffen die Positionierung des Laserfokus auf der GewebeoberflÀche, die
Bildgebung, die Planung und AusfĂŒhrung der Laserablation sowie intraoperative Bewegungen
des Zielgebietes. Die vorliegende Dissertation zielt darauf ab, die Limitierungen der TLM durch
robotische AnsÀtze und intraoperative Assistenz zu adressieren. Obwohl ein Trend zur minimal
invasiven Chirurgie besteht, sind bislang keine hochintegrierten Plattformen fĂŒr die endoskopische
Applikation fokussierter Laserstrahlung verfĂŒgbar. Ebenfalls sind keine Systeme bekannt, die
Szeneninformationen aus der endoskopischen Bildgebung in die Ablationsplanung und -ausfĂŒhrung
einbeziehen. FĂŒr eine situsnahe Fokussierung des Laserstrahls wird in dieser Arbeit zunĂ€chst
eine miniaturisierte Fokussieroptik zur Integration in endoskopische Systeme vorgestellt. Experimentelle Versuche charakterisieren die optischen Eigenschaften und das Ablationsverhalten. Zur
Manipulation der Fokussieroptik wird eine robotische Plattform realisiert. Diese basiert auf einem
lÀngenverÀnderlichen Kontinuumsmanipulator. Letzterer ermöglicht in Kombination mit einer
mechatronischen Aktuierungseinheit Bewegungen des Endoskopkopfes in fĂŒnf Freiheitsgraden.
Die kinematische Modellierung und Regelung des Systems werden in ein modulares Framework
eingebunden und evaluiert. Die Manipulation fokussierter Laserstrahlung erfordert zudem eine
prĂ€zise Anpassung der Fokuslage auf das Gewebe. DafĂŒr werden visuelle, haptische und visuell haptische Assistenzfunktionen eingefĂŒhrt. Diese unterstĂŒtzen den Anwender bei Teleoperation
zur Einstellung eines optimalen Arbeitsabstandes. In einer Anwenderstudie werden Vorteile der
visuell-haptischen Assistenz nachgewiesen. Die Systemperformanz und Gebrauchstauglichkeit
des robotischen Gesamtsystems werden in einer weiteren Anwenderstudie untersucht. Analog zu
einem klinischen Einsatz verfolgen die Probanden mit einem Laserspot vorgegebene Sollpfade. Die
mittlere Positioniergenauigkeit des Spots betrÀgt dabei 0,5 mm. Zur Automatisierung der Ablation
werden abschlieĂend Methoden der bildgestĂŒtzten Regelung vorgestellt. Experimente bestĂ€tigen
einen positiven Effekt der Automationskonzepte fĂŒr die kontaktfreie Laserchirurgie
Proceedings of the NASA Conference on Space Telerobotics, volume 2
These proceedings contain papers presented at the NASA Conference on Space Telerobotics held in Pasadena, January 31 to February 2, 1989. The theme of the Conference was man-machine collaboration in space. The Conference provided a forum for researchers and engineers to exchange ideas on the research and development required for application of telerobotics technology to the space systems planned for the 1990s and beyond. The Conference: (1) provided a view of current NASA telerobotic research and development; (2) stimulated technical exchange on man-machine systems, manipulator control, machine sensing, machine intelligence, concurrent computation, and system architectures; and (3) identified important unsolved problems of current interest which can be dealt with by future research
Data-driven modelling and control of concentric tube robots with application in distal lung sampling
This research aims to explore the use of Concentric Tube Robots (CTRs) as a novel alternative
to needle-based interventions in order to make these procedures more accurate and
repeatable. CTRs due to their small footprint, compliance, and dexterity have been proposed
for several minimally-invasive robotic surgeries. As a novel flexible robot, it has the potential to
reach distal parts of the human lung that are difficult or impossible to reach with conventional
needle-based interventions. There are, however, still significant challenges associated with
the motion and position control of CTRs. Commonly used model-based control approaches
are computationally expensive to solve and often employ simplified geometric/dynamic assumptions,
which could be inaccurate in the presence of unmodelled disturbances and external
interaction forces. Consequently, this work explores different control strategies to overcome
these limitation. This is achieved by first building a simulation environment based on a
computationally improved kinematic model that enables real-time control. Then, data-driven
control approaches are investigated in order to provide accurate position control in the presence
of uncertainties in the system. Finally, a three-phase affordance-aware motion planner
is proposed to demonstrate the feasibility of using CTRs for percutaneous lung biopsy.
According to this, the first part of this work concentrates on computationally efficient real-time
modelling and simulation of CTRs. In order to achieve this, two approaches are taken. The
first one introduces a method that can rapidly estimate the solution of the kinematic model,
while the second approach focuses on implementing the existing model in a computationally
efficient way in Robot Operating System (ROS) using C++.
Second, this work explores data-driven solutions to control the robot without relying on the
kinematic model. Consequently, two data-driven solutions are proposed, namely the Hybrid
Dual Jacobian approach and the Extended Dynamic Mode Decomposition (EDMD) algorithm.
The hybrid controller combines the advantages of model-based and data-driven control approaches,
while the EDMD provides a completely model-free solution to control the robot. Both
controllers are capable of rapidly predicting the robotâs nonlinear dynamics from a limited data
set and offer consistent control under external loading and in the presence of obstacles.
The third part of the thesis explores the use of CTRs in the context of distal lung sampling. This
work demonstrates that CTRs are suitable for Needle-Based Optical Endomicroscopy where
a CTR steers a fluorescent imaging probe with cellular and bacterial imaging capability inside
soft tissue. Then, it is also demonstrated that a CTR can be used as a Steerable Needle to
reach a target deep inside the tissue. To achieve these tasks, a motion planner is essential due
to the fact that a CTR is only capable of reaching specific points in its workspace and there
are a number of configurations where the robot becomes unstable. Based on this, a threeii
phase affordance-aware motion planner algorithm is developed. The motion planner selects
the best entry point for a specific task. Based on the selected entry point it first generates
a stable trajectory from the robotâs initial configuration to the selected entry point. Then, a
feasible trajectory is generated from the entry point to the target. Finally, the proposed datadriven
control algorithm is applied to autonomously steer the robot on the generated trajectory
toward the target region for endomicroscopic imaging
Molecular machinery and manufacturing with applications to computation
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Architecture, 1991.Vita.Includes bibliographical references (p. 469-487).by K. Eric Drexler.Ph.D
Investigating Ultrasound-Guided Autonomous Assistance during Robotic Minimally Invasive Surgery
Despite it being over twenty years since the first introduction of robotic surgical systems in common surgical practice, they are still far from widespread across all healthcare systems, surgical disciplines and procedures. At the same time, the systems that are used act as mere tele-manipulators with motion scaling and have yet to make use of the immense potential of their sensory data in providing autonomous assistance during surgery or perform tasks themselves in a semi-autonomous fashion. Equivalently, the potential of using intracorporeal imaging, particularly Ultrasound (US) during surgery for improved tumour localisation remains largely unused. Aside from the cost factors, this also has to do with the necessity of adequate training for scan interpretation and the difficulty of handling an US probe near the surgical sight. Additionally, the potential for automation that is being explored in extracorporeal US using serial manipulators does not yet translate into ultrasound-enabled autonomous assistance in a surgical robotic setting.
Motivated by this research gap, this work explores means to enable autonomous intracorporeal ultrasound in a surgical robotic setting. Based around the the da Vinci Research Kit (dVRK), it first develops a surgical robotics platform that allows for precise evaluation of the robotâs performance using Infrared (IR) tracking technology. Based on this initial work, it then explores the possibility to provide autonomous ultrasound guidance during surgery. Therefore, it develops and assesses means to improve kinematic accuracy despite manipulator backlash as well as enabling adequate probe position with respect to the tissue surface and anatomy. Founded on the acquired anatomical information, this thesis explores the integration of a second robotic arm and its usage for autonomous assistance. Starting with an autonomously acquired tumor scan, the setup is extended and methods devised to enable the autonomous marking of margined tumor boundaries on the tissue surface both in a phantom as well as in an ex-vivo experiment on porcine liver. Moving towards increased autonomy, a novel minimally invasive High Intensity Focused Ultrasound (HIFUS) transducer is integrated into the robotic setup including a sensorised, water-filled membrane for sensing interaction forces with the tissue surface. For this purpose an extensive material characterisation is caried out, exploring different surface material pairings. Finally, the proposed system, including trajectory planning and a hybrid-force position control scheme are evaluated in a benchtop ultrasound phantom trial
Large space structures and systems in the space station era: A bibliography with indexes
Bibliographies and abstracts are listed for 1372 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1990 and June 30, 1990. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems
NASA SBIR abstracts of 1990 phase 1 projects
The research objectives of the 280 projects placed under contract in the National Aeronautics and Space Administration (NASA) 1990 Small Business Innovation Research (SBIR) Phase 1 program are described. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses in response to NASA's 1990 SBIR Phase 1 Program Solicitation. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 280, in order of its appearance in the body of the report. The document also includes Appendixes to provide additional information about the SBIR program and permit cross-reference in the 1990 Phase 1 projects by company name, location by state, principal investigator, NASA field center responsible for management of each project, and NASA contract number
Technology for large space systems: A bibliography with indexes (supplement 16)
This bibliography lists 673 reports, articles and other documents introduced into the NASA scientific and technical information system between July 1, 1986 and December 31, 1986. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems
- âŠ