document

Laparoscopic suturing learning curve in an open versus closed box trainer

Rodrigues, S.P. (author), Horeman, T. (author), Blomjous, M.S.H. (author), Hiemstra, E. (author), Van den Dobbelsteen, J.J. (author), Jansen, F.W. (author)

Background The aim of this study was to examine the influence of training under direct vision prior to training with indirect vision on the learning curve of the laparoscopic suture task. Methods Novices were randomized in two groups. Group 1 performed three suturing tasks in a transparent laparoscopic box trainer under direct vision followed by...

journal article 2015

document

Fiber-optic Fabry-Pérot interferometers for force sensing on the tip of a needle

Lembrechts, T.P.A. (author)

Physicians use small variations in the needle insertion force to identify tissue properties and detect membrane punctures during needle insertion. Navigation of a needle towards the target tissue, for example to take a biopsy, is often based on detecting these variations in force. Literature shows that presenting physicians force feedback based...

master thesis 2015

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Statically balanced singular-friction locking

Van der Hoeven, T.R.M. (author)

Locking mechanisms are used in a wide range of applications including energy saving mechanisms in the field of robotics. In this thesis a new class of locking mechanisms is investigated: a combination between a singular- and a friction locking mechanism (singular-friction locker) which is statically balanced with one additional spring. This...

master thesis 2015

document

Stress analysis in atherosclerotic arteries: The influence of heterogeneity

Van Velzen, B. (author)

Atherosclerosis is a progressive arterial disease in which fatty tissue accumulates in the arterial wall. Due to this lipid uptake, the artery thickens and can eventually rupture, causing the lipids to flow into the bloodstream and form blood clots. If this happens in the carotid arteries, which supply the head with oxygenated blood, a stroke...

master thesis 2015

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Optimal CO? pressure for 'stand alone' pneumatic systems

Doedens, D.C. (author)

CO2 powered actuators are a viable alternative in prostheses and robotics. The gas supply is generally limited in such applications, and calls for an optimal system pressure to minimize gas-consumption. Previous work which discusses the optimal pressure was not verifiable, or strictly theoretical. The theoretical work was unintuitive, but did...

master thesis 2015

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Additively Manufactured Open-Cell Porous Biomaterials Made from Six Different Space-Filling Unit Cells: The Mechanical and Morphological Properties

Ahmadi, S.M. (author), Yavari, S.A. (author), Wauthle, R. (author), Pouran, B. (author), Schrooten, J. (author), Weinans, H. (author), Zadpoor, A.A. (author)

It is known that the mechanical properties of bone-mimicking porous biomaterials are a function of the morphological properties of the porous structure, including the configuration and size of the repeating unit cell from which they are made. However, the literature on this topic is limited, primarily because of the challenge in fabricating...

journal article 2015

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Human-Exoskeleton Interaction

Van Dijk, W. (author)

Walking is a very efficient way of getting around and covering large distances. Due to impairments or in extreme conditions, such as carrying a heavy load, one might encounter difficulties while walking. In many cases, wheeled vehicles offer a solution. However, wheeled vehicles are often not suitable for indoor environments or heavy outdoor...

doctoral thesis 2015

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Structural and mechanical characterization of the peri-prosthetic fibrous membrane

Moerman, A.M. (author)

In this pilot study, we obtained the peri-prosthetic fibrous membrane of eleven patients undergoing hip revision surgery due to aseptic loosening. We investigated the molecular content of the tissue by real-time PCR (RT-PCR) and the structural properties by histology and confocal microscopy. Atomic force microscopy (AFM) and nanoindentation were...

master thesis 2015

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Comparing different ultrasound imaging methods for breast cancer detection

Ozmen, N. (author), Dapp, R. (author), Zapf, M. (author), Gemmeke, H. (author), Ruiter, N.V. (author), Van Dongen, K.W.A. (author)

Ultrasound is frequently used to evaluate suspicious masses in breasts. These evaluations could be improved by taking advantage of advanced imaging algorithms, which become feasible for low frequencies if accurate knowledge about the phase and amplitude of the wave field illuminating the volume of interest is available. In this study, we compare...

journal article 2015

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Effect of Alkali-Acid-Heat Chemical Surface Treatment on Electron Beam Melted Porous Titanium and Its Apatite Forming Ability

Bsat, S. (author), Yavari, S. (author), Munsch, M. (author), Valstar, E.R. (author), Zadpoor, A.A. (author)

Advanced additive manufacturing techniques such as electron beam melting (EBM), can produce highly porous structures that resemble the mechanical properties and structure of native bone. However, for orthopaedic applications, such as joint prostheses or bone substitution, the surface must also be bio-functionalized to promote bone growth. In the...

journal article 2015

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Needle deflection in tissue

De Jong, T. (author)

Introduction: One of the factors that contribute to the total needle-targeting error in medical procedures is needle deflection, which can lead to e.g. hemorrhage, prolonged intervention time and decreased treatment efficiency. This deflection can be defined as the deviation of the needle from its suspected straight insertion path. In this study...

master thesis 2015

document

Early Detection of Rheumatoid Arthritis using extremity MRI: Quantification of Bone Marrow Edema in the Carpal bones

Roex, E.A.H. (author)

Visual scoring of magnetic resonance images for the early detection of rheumatoid arthritis is prone to human subjectivity and lacks sensitivity. In a bid to develop an objective and quantitative alternative using digital image processing, this thesis proposes automatic segmentation of the carpal bones, followed by the quantification of bone...

master thesis 2015

document

Predicting Object Size from Hand Kinematics: A Temporal Perspective

Ansuini, C. (author), Cavallo, A. (author), Koul, A. (author), Jacono, M. (author), Yang, Y. (author), Becchio, C. (author)

Research on reach-to-grasp movements generally concentrates on kinematics values that are expression of maxima, in particular the maximum aperture of the hand and the peak of wrist velocity. These parameters provide a snapshot description of movement kinematics at a specific time point during reach, i.e., the maximum within a set of value, but...

journal article 2015

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Multimodal Joint Visual Attention Model for Natural Human-Robot Interaction in Domestic Environments

Domhof, J.F.M. (author)

Due to population ageing, the cost of health care will raise in the coming years. One way to help humans, and especially elderly people, is the introduction of domestic robots that can assist people in daily life such that they are less dependent on home care. Joint visual attention models can be used for natural robot-human interaction. Joint...

master thesis 2015

document

Comprehensive neuromechanical assessment in stroke patients: Reliability and responsiveness of a protocol to measure neural and non-neural wrist properties

Van der Krogt, H. (author), Klomp, A. (author), De Groot, J.H. (author), De Vlugt, E. (author), Van der Helm, F.C.T. (author), Meskers, C.G.M. (author), Arendzen, J.H. (author)

Background: Understanding movement disorder after stroke and providing targeted treatment for post stroke patients requires valid and reliable identification of biomechanical (passive) and neural (active and reflexive) contributors. Aim of this study was to assess test-retest reliability of passive, active and reflexive parameters and to...

journal article 2015

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Early motor learning changes in upper-limb dynamics and shoulder complex loading during handrim wheelchair propulsion

Vegter, R.J.K. (author), Hartog, J. (author), De Groot, S. (author), Lamoth, C.J. (author), Bekker, M.J. (author), Van der Scheer, J.W. (author), Van der Woude, L.H.V. (author), Veeger, H.E.J. (author)

Background To propel in an energy-efficient manner, handrim wheelchair users must learn to control the bimanually applied forces onto the rims, preserving both speed and direction of locomotion. Previous studies have found an increase in mechanical efficiency due to motor learning associated with changes in propulsion technique, but it is...

journal article 2015

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Full regeneration of segmental bone defects using porous titanium implants loaded with BMP-2 containing fibrin gels

Van der Stok, J. (author), Koolen, M.K.E. (author), De Maat, M.P.M. (author), Amin Yavari, S. (author), Alblas, J. (author), Patka, P. (author), Verhaar, J.A.N. (author), Van Lieshout, E.E.M. (author), Zadpoor, A.A. (author), Weinans, H.H. (author), Jahr, H. (author)

Regeneration of load-bearing segmental bone defects is a major challenge in trauma and orthopaedic surgery. The ideal bone graft substitute is a biomaterial that provides immediate mechanical stability, while stimulating bone regeneration to completely bridge defects over a short period. Therefore, selective laser melted porous titanium,...

journal article 2015

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Catheter for use in endovascular intervention

Dobbelsteen, J.J. (author), Clogenson, H.C. (author)

patent 2015

document

Early subsidence of shape-closed hip arthroplasty stems is associated with late revision

Van der Voort, P. (author), Pijls, B.G. (author), Nieuwenhuijse, M.J. (author), Jasper, J. (author), Fiocco, M. (author), Plevier, J.W.M. (author), Middeldorp, S. (author), Valstar, E.R. (author), Nelissen, R.G.H.H. (author)

Background and purpose — Few studies have addressed the association between early migration of femoral stems and late aseptic revision in total hip arthroplasty. We performed a meta-regression analysis on 2 parallel systematic reviews and meta-analyses to determine the association between early migration and late aseptic revision of femoral...

journal article 2015

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The design of a new protocol to acccurately estimate the passive and active components of the muscle system

De Jong, I.M. (author)

For this research a new protocol was developed which acquires rich enough data in terms of position, velocity and accelerations such that all the pasive and active parameters of the agonist and antagonist muscle of the wrist in the newest and for this study expended and adapted neuromuscular model can be accurately estimated. Concluded was that...

master thesis 2015