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Clinical simulator

Anders Fytagoridis, Mattias Åström, Jennifer Samuelsson, Patric Blomstedt
BACKGROUND: The caudal zona incerta (cZi) and posterior subthalamic area (PSA) are an emerging deep brain stimulation (DBS) target for essential tremor (ET). OBJECTIVES: To evaluate the efficacy of tremor control in relation to the anatomical locations of stimulation fields in 50 patients with ET and DBS of the cZi. METHODS: A total of 240 contacts were evaluated separately with monopolar stimulation, and amplitudes were optimized for improvement of tremor and hand function...
October 27, 2016: Stereotactic and Functional Neurosurgery
Mary L Padden-Denmead, Rose M Scaffidi, Regina M Kerley, Amy Lee Farside
BACKGROUND: Simulation and guided reflective journaling have been identified as effective teaching and learning methods to develop critical thinking (CT) and clinical reasoning skills in nursing students. METHOD: A descriptive correlational design was used to determine the relationship between CT and level of reflection using the Holistic Critical Thinking Skills Rubric (HCTSR) and the level of reflection on action assessment (LORAA), respectively, to evaluate 23 baccalaureate student-guided reflective journal entries after a simulation exercise with guided debriefing and after two subsequent clinical experiences...
November 1, 2016: Journal of Nursing Education
Jason Shafrin, Taylor T Schwartz, Darius N Lakdawalla, Felicia M Forma
BACKGROUND: Nonadherence to antipsychotic medication among patients with schizophrenia results in poor symptom management and increased health care and other costs. Despite its health impact, medication adherence remains difficult to accurately assess. New technologies offer the possibility of real-time patient monitoring data on adherence, which may in turn improve clinical decision making. However, the economic benefit of accurate patient drug adherence information (PDAI) has yet to be evaluated...
November 2016: Journal of Managed Care & Specialty Pharmacy
Tao Sun, Jung-Ha Kim, Roger Fulton, Johan Nuyts
PURPOSE: Although current computed tomography (CT) systems can scan the head in a very short time, patient motion sometimes still induces artifacts. If motion occurs, one has to repeat the scan; to avoid motion, sedation or anesthesia is sometimes applied. METHODS: The authors propose a method to iteratively estimate and compensate this motion during the reconstruction. In every iteration, the rigid motion was estimated view-by-view and then used to update the system matrix...
October 2016: Medical Physics
George A Prenosil, Bernd Klaeser, Michael Hentschel, Markus Fürstner, Michael Berndt, Thomas Krause, Thilo Weitzel
PURPOSE: A PET/CT system's imaging capabilities are best described by its point spread function (PSF) in the spatial domain or equivalently by its modulation transfer function (MTF) in the spatial frequency domain. Knowing PSFs or MTFs is a prerequisite for many numerical methods attempting to improve resolution and to reduce the partial volume effect. In PET/CT, the observed PSF is a convolution of the system's intrinsic imaging capabilities including image reconstruction (PSF0) and the positron range function (PRF) of the imaged β(+) emitting isotope...
October 2016: Medical Physics
Qiang Liu, Jian Liang, Carl W Stanhope, Di Yan
PURPOSE: Inaccurate density information may introduce dose calculation errors when inhomogeneity correction is applied. The aim of the present study was to examine the effect of density variation on photon dose calculation accuracy using the convolution/superposition (CS) algorithm with the focus on newer treatment technologies including intensity modulated radiotherapy, volumetric modulated arc radiotherapy, and stereotactic body radiotherapy (SBRT). METHODS: Calculations were first performed using simple inhomogeneity phantoms in order to determine clinically relevant tolerance levels for different tissue types...
October 2016: Medical Physics
G Schooneveldt, H P Kok, E Balidemaj, E D Geijsen, F van Ommen, J Sijbrands, A Bakker, J J M C H de la Rosette, M C C M Hulshof, T M de Reijke, J Crezee
PURPOSE: Hyperthermia is an established (neo)adjuvant treatment modality for a number of pelvic malignancies. Optimal treatment of these tumors requires robust treatment planning, but up until now, the urinary bladder was not modeled accurately, making current simulations less reliable. The authors improved the dielectric and thermophysical model of the urinary bladder in their treatment planning system, and showed the improvements using phantom experiments. METHODS: The authors suspended a porcine bladder in muscle tissue equivalent gel and filled it with 120 ml 0...
October 2016: Medical Physics
Jennifer Xu, Alejandro Sisniega, Wojciech Zbijewski, Hao Dang, J Webster Stayman, Michael Mow, Xiaohui Wang, David H Foos, Vassillis E Koliatsos, Nafi Aygun, Jeffrey H Siewerdsen
PURPOSE: A cone-beam CT scanner has been developed for detection and monitoring of traumatic brain injury and acute intracranial hemorrhage (ICH) at the point of care. This work presents a technical assessment of imaging performance and dose for the scanner in phantom and cadaver studies as a prerequisite to clinical translation. METHODS: The scanner incorporates a compact, rotating-anode x-ray source and a flat-panel detector (43 × 43 cm(2)) on a mobile U-arm gantry with source-axis distance = 550 mm and source-detector distance = 1000 mm...
October 2016: Medical Physics
Bradley M Dickson, Parker W de Waal, Zachary H Ramjan, H Eric Xu, Scott B Rothbart
In this communication we introduce an efficient implementation of adaptive biasing that greatly improves the speed of free energy computation in molecular dynamics simulations. We investigated the use of accelerated simulations to inform on compound design using a recently reported and clinically relevant inhibitor of the chromatin regulator BRD4 (bromodomain-containing protein 4). Benchmarking on our local compute cluster, our implementation achieves up to 2.5 times more force calls per day than plumed2. Results of five 1 μs-long simulations are presented, which reveal a conformational switch in the BRD4 inhibitor between a binding competent and incompetent state...
October 21, 2016: Journal of Chemical Physics
D Sharathkumar Sanketh, Samuel Raj Srinivasan, Shankargouda Patil, Kannan Ranganathan
AIM: In the present study, we simulated clinical scenarios by explicitly describing the history and clinical and histological features of hypothetical patients presenting with oral lichen planus (OLP), oral lichenoid lesion, and epithelial dysplasia in a self-designed questionnaire. By doing so, we aimed to elicit a diagnosis from oral pathologists and trainees, analyze their responses, appraise issues, and propose solutions regarding the diagnosis of OLP. METHODS: The questionnaire was distributed to 100 oral pathologists and trainees in South India...
October 26, 2016: Journal of Investigative and Clinical Dentistry
Anh Nguyen Duc, Marcel Wolbers
Composite endpoints are widely used as primary endpoints of randomized controlled trials across clinical disciplines. A common critique of the conventional analysis of composite endpoints is that all disease events are weighted equally, whereas their clinical relevance may differ substantially. We address this by introducing a framework for the weighted analysis of composite endpoints and interpretable test statistics, which are applicable to both binary and time-to-event data. To cope with the difficulty of selecting an exact set of weights, we propose a method for constructing simultaneous confidence intervals and tests that asymptotically preserve the family-wise type I error in the strong sense across families of weights satisfying flexible inequality or order constraints based on the theory of χ¯2-distributions...
October 26, 2016: Statistics in Medicine
Xindi Zhang, Jim Warren, Arden Corter, Felicity Goodyear-Smith
This paper describes development of a prototype data analytics portal for analysis of accumulated screening results from eCHAT (electronic Case-finding and Help Assessment Tool). eCHAT allows individuals to conduct a self-administered lifestyle and mental health screening assessment, with usage to date chiefly in the context of primary care waiting rooms. The intention is for wide roll-out to primary care clinics, including secondary school based clinics, resulting in the accumulation of population-level data...
2016: Studies in Health Technology and Informatics
Paul McKenna, Brent Thoma, Ken Milne, Chris Bond
As part of the Canadian Journal of Emergency Medicine's (CJEM) developing social media strategy, 1 we are collaborating with the Skeptics' Guide to Emergency Medicine (SGEM) to summarize and critically appraise the current emergency medicine (EM) literature using evidence-based medicine principles. In the "Hot Off the Press" series, we select original research manuscripts published in CJEM to be featured on the SGEM website/podcast 2 and discussed by the study authors and the online EM community. A similar collaboration is underway between the SGEM and Academic Emergency Medicine...
October 26, 2016: CJEM
Thomas Peach, Katerina Spranger, Yiannis Ventikos
Bifurcation aneurysms account for a large fraction of cerebral aneurysms and often present morphologies that render traditional endovascular treatments, such as coiling, challenging and problematic. Flow-diverter stents offer a potentially elegant treatment option for such aneurysms, but clinical use of these devices remains controversial. Specifically, the deployment of a flow-diverter device in a bifurcation entails jailing one or more potentially vital vessels with a low-porosity mesh designed to restrict the flow...
October 25, 2016: Proceedings of the Institution of Mechanical Engineers. Part H, Journal of Engineering in Medicine
Karin Törne, Andreas Örnberg, Jonas Weissenrieder
: During implantation load-bearing devices experience stress that may influence its mechanical and corrosion profile and potentially lead to premature rupture. The susceptibility to stress corrosion cracking (SCC) of the Mg-Al alloy AZ61 and Zn was studied in simulated body fluid (m-SBF) and whole blood by slow strain rate (SSR) testing in combination with electrochemical impedance spectroscopy (EIS) and further ex-situ analysis including scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy...
October 22, 2016: Acta Biomaterialia
Simone Savastano, Vincenzo Vanni, Roman Burkart, Maurizio Raimondi, Fabrizio Canevari, Simone Molinari, Enrico Baldi, Aurora I Danza, Maria Luce Caputo, Romano Mauri, Francois Regoli, Giulio Conte, Claudio Benvenuti, Angelo Auricchio
PURPOSE: Early and good quality cardiopulmonary resuscitation (CPR) and the use of automated external defibrillators (AEDs) are key factors to improve the outcome in patients with cardiac arrest. However, AED peri- and post-shock ECG analysis pauses may prolong hands-off time and reduce CPR effectiveness. METHODS: This study consisted of 2 independent parts. In the first part, the time performance of 12 different commercially available AEDs were tested in a manikin based scenario; in the second one, the AEDs recordings following the clinical use (same manufacturers as in the benchmark testing) in 2 different regions (Pavia, Italy, and Ticino, Switzerland) were retrieved and analyzed to evaluate the analysis time and post-shock time...
October 22, 2016: Resuscitation
Alessandro Esposito, Taxiarchis Sakellaris, Patrícia Limede, Filipa Costa, Luis T Cunha, Anabela Gregório Dias, Joana Lencart, Sandra Sarmento, Carla Carmelo Rosa
PURPOSE: To study the impact of shielding elements in the proximity of Intra-Operative Radiation Therapy (IORT) irradiation fields, and to generate graphical and quantitative information to assist radiation oncologists in the design of optimal shielding during pelvic and abdominal IORT. METHOD: An IORT system was modeled with BEAMnrc and EGS++ Monte Carlo codes. The model was validated in reference conditions by gamma index analysis against an experimental data set of different beam energies, applicator diameters, and bevel angles...
October 22, 2016: Physica Medica: PM
Palena A Pinto, Guillaume Colas, Tobin Filleter, Grace M De Souza
Yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP) is a ceramic material used in indirect dental restorations. However, phase transformation at body temperature may compromise the material's mechanical properties, affecting the clinical performance of the restoration. The effect of mastication on 3Y-TZP aging has not been investigated. 3Y-TZP specimens (IPS E-max ZirCAD and Z5) were aged in three different modes (n=13): no aging (control), hydrothermal aging (HA), or chewing simulation (CS). Mechanical properties and surface topography were analyzed...
October 26, 2016: Microscopy and Microanalysis
Ryan A Devenyi, Francis A Ortega, Willemijn Groenendaal, Trine Krogh-Madsen, David J Christini, Eric A Sobie
Imbalances of ionic currents can destabilize the cardiac action potential and potentially trigger lethal cardiac arrhythmias. Here we combined mathematical modeling with information-rich dynamic-clamp experiments to elucidate regulation of action potential morphology in guinea pig ventricular myocytes. Parameter sensitivity analysis was used to predict how changes in ionic currents alter action potential duration, and these were tested experimentally using dynamic clamp, a technique that allows for multiple perturbations to be tested in each cell...
October 24, 2016: Journal of Physiology
Arthur Lalonde, Hugo Bouchard
To develop a general method for human tissue characterization with dual- and multi-energy CT and evaluate its performance in determining elemental compositions and quantities relevant to radiotherapy Monte Carlo dose calculation. Ideal materials to describe human tissue are obtained applying principal component analysis on elemental weight and density data available in literature. The theory is adapted to elemental composition for solving tissue information from CT data. A novel stoichiometric calibration method is integrated to the technique to make it suitable for a clinical environment...
November 21, 2016: Physics in Medicine and Biology
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