22 research outputs found

    Flexible robotic device for spinal surgery

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    Surgical robots have proliferated in recent years, with well-established benefits including: reduced patient trauma, shortened hospitalisation, and improved diagnostic accuracy and therapeutic outcome. Despite these benefits, many challenges in their development remain, including improved instrument control and ergonomics caused by rigid instrumentation and its associated fulcrum effect. Consequently, it is still extremely challenging to utilise such devices in cases that involve complex anatomical pathways such as the spinal column. The focus of this thesis is the development of a flexible robotic surgical cutting device capable of manoeuvring around the spinal column. The target application of the flexible surgical tool is the removal of cancerous tumours surrounding the spinal column, which cannot be excised completely using the straight surgical tools in use today; anterior and posterior sections of the spine must be accessible for complete tissue removal. A parallel robot platform with six degrees of freedom (6 DoFs) has been designed and fabricated to direct a flexible cutting tool to produce the necessary range of movements to reach anterior and posterior sections of the spinal column. A flexible water jet cutting system and a flexible mechanical drill, which may be assembled interchangeably with the flexible probe, have been developed and successfully tested experimentally. A model predicting the depth of cut by the water jet was developed and experimentally validated. A flexion probe that is able to guide the surgical cutting device around the spinal column has been fabricated and tested with human lumber model. Modelling and simulations show the capacity for the flexible surgical system to enable entering the posterior side of the human lumber model and bend around the vertebral body to reach the anterior side of the spinal column. A computer simulation with a full Graphical User Interface (GUI) was created and used to validate the system of inverse kinematic equations for the robot platform. The constraint controller and the inverse kinematics relations are both incorporated into the overall positional control structure of the robot, and have successfully established a haptic feedback controller for the 6 DoFs surgical probe, and effectively tested in vitro on spinal mock surgery. The flexible surgical system approached the surgery from the posterior side of the human lumber model and bend around the vertebral body to reach the anterior side of the spinal column. The flexible surgical robot removed 82% of mock cancerous tissue compared to 16% of tissue removed by the rigid tool.Open Acces

    Creativity as a Part of the Post-Pandemic Architectural Education: A Brief Discussion

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    The current study discusses the importance of the creativity in architectural education, with a focus on the challenges and their implications on students, educators, and institutions. This study revisits a vision of an educational model for post-pandemic architecture education and discuss the necessary approaches for educators and educational institutions to foster creativity. This study directly reacts to the demand on the pandemic's effect on conventional education by using an instructional approach. This paper contributes to reconceptualizing of a novel approach that is targeted to tackle architectural education challenges in a post pandemic age through foster creativity models. The proposed creativity models are creative and critical thinking, neutral and positive stress, and objective-based creativity. These models are further developed using a thematic analysis process to be integrated in the educational model

    Navigation system for robot-assisted intra-articular lower-limb fracture surgery

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    Purpose In the surgical treatment for lower-leg intra-articular fractures, the fragments have to be positioned and aligned to reconstruct the fractured bone as precisely as possible, to allow the joint to function correctly again. Standard procedures use 2D radiographs to estimate the desired reduction position of bone fragments. However, optimal correction in a 3D space requires 3D imaging. This paper introduces a new navigation system that uses pre-operative planning based on 3D CT data and intra-operative 3D guidance to virtually reduce lower-limb intra-articular fractures. Physical reduction in the fractures is then performed by our robotic system based on the virtual reduction. Methods 3D models of bone fragments are segmented from CT scan. Fragments are pre-operatively visualized on the screen and virtually manipulated by the surgeon through a dedicated GUI to achieve the virtual reduction in the fracture. Intra-operatively, the actual position of the bone fragments is provided by an optical tracker enabling real-time 3D guidance. The motion commands for the robot connected to the bone fragment are generated, and the fracture physically reduced based on the surgeon’s virtual reduction. To test the system, four femur models were fractured to obtain four different distal femur fracture types. Each one of them was subsequently reduced 20 times by a surgeon using our system. Results The navigation system allowed an orthopaedic surgeon to virtually reduce the fracture with a maximum residual positioning error of 0.95±0.3mm (translational) and 1.4∘±0.5∘ (rotational). Correspondent physical reductions resulted in an accuracy of 1.03 ± 0.2 mm and 1.56∘±0.1∘, when the robot reduced the fracture. Conclusions Experimental outcome demonstrates the accuracy and effectiveness of the proposed navigation system, presenting a fracture reduction accuracy of about 1 mm and 1.5∘, and meeting the clinical requirements for distal femur fracture reduction procedures

    Intra-operative fiducial-based CT/fluoroscope image registration framework for image-guided robot-assisted joint fracture surgery

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    Purpose Joint fractures must be accurately reduced minimising soft tissue damages to avoid negative surgical outcomes. To this regard, we have developed the RAFS surgical system, which allows the percutaneous reduction of intra-articular fractures and provides intra-operative real-time 3D image guidance to the surgeon. Earlier experiments showed the effectiveness of the RAFS system on phantoms, but also key issues which precluded its use in a clinical application. This work proposes a redesign of the RAFS’s navigation system overcoming the earlier version’s issues, aiming to move the RAFS system into a surgical environment. Methods The navigation system is improved through an image registration framework allowing the intra-operative registration between pre-operative CT images and intra-operative fluoroscopic images of a fractured bone using a custom-made fiducial marker. The objective of the registration is to estimate the relative pose between a bone fragment and an orthopaedic manipulation pin inserted into it intra-operatively. The actual pose of the bone fragment can be updated in real time using an optical tracker, enabling the image guidance. Results Experiments on phantom and cadavers demonstrated the accuracy and reliability of the registration framework, showing a reduction accuracy (sTRE) of about 0.88 ±0.2mm (phantom) and 1.15±0.8mm (cadavers). Four distal femur fractures were successfully reduced in cadaveric specimens using the improved navigation system and the RAFS system following the new clinical workflow (reduction error 1.2±0.3mm, 2±1∘). Conclusion Experiments showed the feasibility of the image registration framework. It was successfully integrated into the navigation system, allowing the use of the RAFS system in a realistic surgical application

    Image-Guided Surgical Robotic System for Percutaneous Reduction of Joint Fractures

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    Complex joint fractures often require an open surgical procedure, which is associated with extensive soft tissue damages and longer hospitalization and rehabilitation time. Percutaneous techniques can potentially mitigate these risks but their application to joint fractures is limited by the current sub-optimal 2D intra-operative imaging (fluoroscopy) and by the high forces involved in the fragment manipulation (due to the presence of soft tissue, e.g., muscles) which might result in fracture malreduction. Integration of robotic assistance and 3D image guidance can potentially overcome these issues. The authors propose an image-guided surgical robotic system for the percutaneous treatment of knee joint fractures, i.e., the robot-assisted fracture surgery (RAFS) system. It allows simultaneous manipulation of two bone fragments, safer robot-bone fixation system, and a traction performing robotic manipulator. This system has led to a novel clinical workflow and has been tested both in laboratory and in clinically relevant cadaveric trials. The RAFS system was tested on 9 cadaver specimens and was able to reduce 7 out of 9 distal femur fractures (T- and Y-shape 33-C1) with acceptable accuracy (≈1 mm, ≈5°), demonstrating its applicability to fix knee joint fractures. This study paved the way to develop novel technologies for percutaneous treatment of complex fractures including hip, ankle, and shoulder, thus representing a step toward minimally-invasive fracture surgeries

    A search for resonances decaying into a Higgs boson and a new particle X in the XH→qqbb final state with the ATLAS detector

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    A search for heavy resonances decaying into a Higgs boson (HH) and a new particle (XX) is reported, utilizing 36.1 fb1^{-1} of proton-proton collision data at s=\sqrt{s} = 13 TeV collected during 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. The particle XX is assumed to decay to a pair of light quarks, and the fully hadronic final state XHqqˉbbˉXH \rightarrow q\bar q'b\bar b is analysed. The search considers the regime of high XHXH resonance masses, where the XX and HH bosons are both highly Lorentz-boosted and are each reconstructed using a single jet with large radius parameter. A two-dimensional phase space of XHXH mass versus XX mass is scanned for evidence of a signal, over a range of XHXH resonance mass values between 1 TeV and 4 TeV, and for XX particles with masses from 50 GeV to 1000 GeV. All search results are consistent with the expectations for the background due to Standard Model processes, and 95% CL upper limits are set, as a function of XHXH and XX masses, on the production cross-section of the XHqqˉbbˉXH\rightarrow q\bar q'b\bar b resonance

    Study of the material of the ATLAS inner detector for Run 2 of the LHC

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    Instituto de Física La Plat

    ULOGA GRADITELJSKOG NASLEDJA U PLANIRANJU I RAZVOJU EVROCENTRIČNIH URBANIH PODRUČJA U 20. VEKU

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    The present study is concerned with assessing the currently used methods for improving the skills of continued education in the architectural engineering departments as well as the architectural market in Egypt. The main hypothesis of this study is that: the concept of continued-education in architecture is absent in Egypt, the current mechanisms of supporting continued-education are neither active nor effective, and the architectural education is not enough alone to build a professional architectural character.Survey forms have been distributed for practitioners, and interviews have been conducted with stakeholders for the sake of assessing the role of the universities in Egypt in supporting the graduates’ skills development. The study compared the collected data about these universities through three main points: continued-education, graduates’ follow-up and environment & community services.At the end, this study suggests some mechanisms based on the data analysis of the collected information. These mechanisms will help improving the practice of architecture in Egypt. In addition, the study proposed some recommendations regarding practicing architecture in Egypt for architecture’s practitioners, Egyptian Engineering Syndicate, and Egyptian executive entities such as ministry of higher education & prime minister office. These recommendations will be delivered as well as a copy of this research to all stakeholders in order to be taken into considerations.Ova studija se bavi procenom trenutno korišćenih metoda za poboljšanje veština kontinuiranog obrazovanja na odsecima za arhitektonski inženjering, kao i na arhitektonskom tržištu u Egiptu. Glavna hipoteza ove studije je da: koncept kontinuiranog obrazovanja u arhitekturi nije prisutan u Egiptu, trenutni mehanizmi podrške kontinuiranom obrazovanju nisu ni aktivni ni efikasni, a arhitektonsko obrazovanje nije samo dovoljno za izgradnju profesionalnog arhitektonskog karaktera .Obrasci ankete su distribuirani inženjerima iz prakse, a obavljeni su i intervjui sa zainteresovanim stranama radi procene uloge univerziteta u Egiptu u podršci razvoju veština diplomaca. Studija je uporedila prikupljene podatke o ovim univerzitetima kroz tri glavne tačke: kontinuirano obrazovanje, praćenje diplomaca i usluge zaštite životne sredine i zajednice.Na kraju, ova studija predlaže neke mehanizme zasnovane na analizi podataka prikupljenih informacija. Ovi mehanizmi će pomoći u poboljšanju prakse arhitekture u Egiptu. Pored toga, studija je predložila neke preporuke u vezi sa praktikovanjem arhitekture u Egiptu inženjera arhitekture, Egipatskog inženjerskog sindikata i egipatske izvršne vlasti kao što su Ministarstvo visokog obrazovanja i kancelarija premijera. Ove preporuke će biti dostavljene kao i kopija ovog istraživanja svim zainteresovanim stranama kako bi se uzele u obzir.

    Experimental and computational models show the influence of flow rate and orifice size and geometry on the shape of the jet flow.

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    <p>(a) For any given orifice, there was a perfect linear correlation between flow rate, and wavelength, , with excellent agreement between the experimental and CFD analysis as shown for an orifice with cross sectional area and of and respectively. The relationship between flow rate and wavelength was also estimated using the method of Rayleigh which assumes small amplitude perturbations from a cylindrical jet in contrast to the current CFD analysis. For large amplitude oscillations which occur when aspect ratios , the Rayleigh method significantly under estimated the wavelength. (b) The dilation parameter, , is dependent on the cross sectional area and the aspect ratio () and therefore may be used to describe urethral/meatal opening. Comparisons between the CFD and experimental data for a range of orifice shapes show an excellent agreement in the values of .</p
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