68 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
patient’s 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 fasergeführten
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 langjähriges chirurgisches Training, um die Funktion der angrenzenden Organe zu
sichern und damit die Lebensqualität der Patienten zu erhalten. Die Positionierung des mikroskopis chen Laserapplikators außerhalb des Patienten kann zudem die direkte Sicht auf das Zielgebiet
durch anatomische Variabilität erschweren und den Arbeitsraum einschränken. Weitere klinische
Herausforderungen betreffen die Positionierung des Laserfokus auf der Gewebeoberfläche, die
Bildgebung, die Planung und Ausführung der Laserablation sowie intraoperative Bewegungen
des Zielgebietes. Die vorliegende Dissertation zielt darauf ab, die Limitierungen der TLM durch
robotische Ansätze und intraoperative Assistenz zu adressieren. Obwohl ein Trend zur minimal
invasiven Chirurgie besteht, sind bislang keine hochintegrierten Plattformen für die endoskopische
Applikation fokussierter Laserstrahlung verfügbar. Ebenfalls sind keine Systeme bekannt, die
Szeneninformationen aus der endoskopischen Bildgebung in die Ablationsplanung und -ausführung
einbeziehen. Für eine situsnahe Fokussierung des Laserstrahls wird in dieser Arbeit zunächst
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
längenveränderlichen Kontinuumsmanipulator. Letzterer ermöglicht in Kombination mit einer
mechatronischen Aktuierungseinheit Bewegungen des Endoskopkopfes in fünf Freiheitsgraden.
Die kinematische Modellierung und Regelung des Systems werden in ein modulares Framework
eingebunden und evaluiert. Die Manipulation fokussierter Laserstrahlung erfordert zudem eine
präzise Anpassung der Fokuslage auf das Gewebe. Dafür werden visuelle, haptische und visuell haptische Assistenzfunktionen eingeführt. Diese unterstützen 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 beträgt dabei 0,5 mm. Zur Automatisierung der Ablation
werden abschließend Methoden der bildgestützten Regelung vorgestellt. Experimente bestätigen
einen positiven Effekt der Automationskonzepte für die kontaktfreie Laserchirurgie
肘関節粘弾性特性分析に基づいた可変粘弾性握手マニピュレータの開発
【学位授与の要件】中央大学学位規則第4条第1項【論文審査委員主査】中村 太郎 (中央大学理工学部教授)【論文審査委員副査】平岡 弘之(中央大学理工学部教授)、新妻 実保子(中央大学理工学部准教授)、諸麥 俊司(中央大学理工学部准教授)、万 偉偉(大阪大学准教授)博士(工学)中央大
The 12th Aerospace Mechanisms Symposium
Mechanisms developed for various aerospace applications are discussed. Specific topics covered include: boom release mechanisms, separation on space shuttle orbiter/Boeing 747 aircraft, payload handling, spaceborne platform support, and deployment of spaceborne antennas and telescopes
The design and application of microprocessor based systems for clinical measurement of joint stiffness and grip strength.
The overall aim of the project was to further the research into the objective measurement of the symptoms of arthritic disease. There were three major parts to this study. The first part was to design a measurement system capable of making large scale, objective measurements of the stiffness of the human metacarpophalangeal joint. The second part was to design a new device to measure the grip strength of the human hand objectively. The last part was to use these two measurement systems to conduct research into the clinical manifestations of arthritic disease and study the effects of some therapeutic agents. A new, microcomputer controlled arthrograph system was developed to measure the stiffness of the metacarpophalangeal joint of the index finger. The system proved to be reliable, easy to use and sufficiently accurate to quantify changes in joint stiffness. A new design of grip machine was produced which enabled the forces developed during a power grip to be analysed. Measurement was made of the force contributions of individual digits and the maximum total gripping force. The machine was portable and extremely easy to use. A study of the circadian variation of joint stiffness and grip strength, over a full twenty four hour period, was carried out. Measurements were made every two hour in both healthy and arthritic subjects. A circadian variation of stiffness was observed in the joints of arthritic subjects. Joint stiffness was elevated in the early morning and for some subjects the degree of change was profound. No significant circadian variation was observed in the joint stiffness of healthy subjects. A circadian variation of grip strength was observed in arthritic subjects. Grip strength reached a minimum value between 2.00 and 4.00 a.m. in the majority of subjects. No consistent relationship was found between changes in joint stiffness and changes in grip strength. The effect of several forms of physiotherapy on the joint stiffness of arthritic subjects was studied in both the short and long term. The subjects were measured before, and then immediately after, treatment each time they visited a physiotherapy hand clinic. Only the results of those patients who attended the clinic for a minimum of five weeks were used in any subsequent analysis. Four different treatments were studied: hot wax and ultrasound, hot wax alone, ultrasound alone and exercise. The combination of hot wax baths and ultrasonic therapy effected temporary reductions in all joint stiffness parameters. The reductions in energy dissipation and torque range were highly significant ( p < 0.05 and p < 0.001 respectively ). No significant reductions were found for hot wax, ultrasound alone or exercise. In the long term, no significant change in joint stiffness was found for any of the treatments considered
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Pre-clinical evaluation of the forces during limb lengthening using manual and automated devices
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Limb lengthening procedures use fixation devices to extend the constantly regenerating bone and surrounding soft tissues. Automated devices have been developed that aim to provide a more gradual tissue extension, resulting in better quality of treatment for the patient. Benefits include pain reduction and probable enhanced tissue outcomes. The development of one such new smart lengthening device is described. An integrated numerical model of tissue mechanics during lengthening is presented. It represents the mechanical environment in which the devices extend. The mechanism of the automated device is also modelled using Matlab software and validation was achieved through experimental testing. Validation of the tissue model includes the design of an experimental hydraulic system with the ability to control the peak loads and relaxation over time. A simplified mechanobiological model for the longer term healing effects is proposed. Calibration of the tissue model to clinical data allows for direct comparison of the load and extension of identical tissues, one being lengthened by a traditional device, the other an automated device. This simulation can be extended to include a range of lengthening rates and frequencies of distraction alongside various patient dependent tissue properties. The models also provide the opportunity to assess the effects of iterative changes to the device parameters (such as stiffness) on its performance as well as analyse the effect that these changes have on tissue extension and loading. Use of these models to optimise the device design alongside optimisation of the extension regime can result in improved device design and consequently improved patient outcomes
Proceedings of the ECCOMAS Thematic Conference on Multibody Dynamics 2015
This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat Politècnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: ● Formulations and Numerical Methods ● Efficient Methods and Real-Time Applications ● Flexible Multibody Dynamics ● Contact Dynamics and Constraints ● Multiphysics and Coupled Problems ● Control and Optimization ● Software Development and Computer Technology ● Aerospace and Maritime Applications ● Biomechanics ● Railroad Vehicle Dynamics ● Road Vehicle Dynamics ● Robotics ● Benchmark ProblemsPostprint (published version
Offshore Wind Farms
The coastal zone is the host to many human activities, which have significantly increased in the last decades. However, sea level rise and more frequent storm events severely affect beaches and coastal structures, with negative consequences and dramatic impacts on coastal communities. These aspects add to typical coastal problems, like flooding and beach erosion, which already leading to large economic losses and human fatalities. Modeling is thus fundamental for an exhaustive understanding of the nearshore region in the present and future environment. Innovative tools and technologies may help to better understand coastal processes in terms of hydrodynamics, sediment transport, bed morphology, and their interaction with coastal structures. This book collects several contributions focusing on nearshore dynamics, and span among several time and spatial scales using both physical and numerical approaches. The aim is to describe the most recent advances in coastal dynamics
Technology for large space systems: A bibliography with indexes (supplement 22)
This bibliography lists 1077 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System between July 1, 1989 and December 31, 1989. Its purpose is to provide helpful information to the researcher or manager engaged in the development of technologies related to large space systems. Subject areas include mission and program definition, design techniques, structural and thermal analysis, structural dynamics and control systems, electronics, advanced materials, assembly concepts, and propulsion
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