Search results for "Medical physics"

Compressive sensing for direct time of flight estimation in ultrasound-based NDT

2017

This paper presents an approach for estimation of ultrasonic time-of-flight (TOF) within a Non Destructive Testing (NDT) and Structural Health Monitoring (SHM) context. The presented method leverages recent advances in the field of Compressive Sensing (CS), which makes use of sparsity in a transform domain of a signal in order to reduce the number of samples required to store it. CS achieves this through a two key ideas: random matrix projections, and l1-penalised linear regression. In this case, sparsity arises from the observation that in a pulse-echo ultrasound test, the number of echoes is relatively small compared to the number of measurement points in a waveform. This sparsity is evid…

Modelling nanoscale fluid dynamics and transport in physiological flows

1996

The concept of nanotechnology is discussed, and its connection with biomedical engineering is elucidated. For the specific field of nanoscale flow and transport problems of physiological relevance, some typical examples are presented, and their interaction is discussed for some classic biomechanical problems like the flow in arteries with blood-wall coupling. Then, existing computational models are presented and classified according to the length scale of interest, with emphasis on particle-fluid problems. Final remarks address the essential unity of biomedical and engineering behaviour and the possible relevance to small-scale industrial research.

Optimization model predictions for postural coordination modes

2003

International audience; This paper examines the ability of the dynamic optimization model to predict changes between in-phase and anti-phase postural modes of coordination and to evaluate influence of two particular environmental and intentional constraints on postural strategy. The task studied was based on an experimental paradigm that consisted in tracking a target motion with the head. An original optimal procedure was developed for cyclic problems to calculate hip and ankle angular trajectories during postural sway with a minimum torque change criterion. Optimization results give a good description of the sudden bifurcation phase between in-phase and anti-phase postural coordination mo…

ImplaVis: A research and educational system for image navigated dental implantology

2005

GEL DOSIMETERS FOR RADIOTHERAPY APPLICATIONS: RESULTS OF A “RESEARCH PROJECT OF NATIONAL INTEREST” (PRIN)

2016

Introduction: Gel dosimeters for three-dimensional mapping of radiotherapy doses were introduced at Yale University in the mid-1980’s. Soon after, research and development in this field also started in Italy. Early work was done at the Istituto Superiore di Sanità and at the Universities of Pisa and Milan. Several institutes now collaborate on this topic with the goal of developing new formulations of hydrogel matrices with improved characteristics of stability, sensitivity and spatial resolution compared to those of earlier Fricke-gel and polymer-gel systems. Materials and methods: Contrary to earlier gels based on natural gelling agents, such as porcine skin gelatin and/or agarose, which …

<title>Pilot clinical evaluation of prototype system for visually reporting the results of ultrasound examination</title>

2000

A dedicated optic-mechanical device, attachable to an ultrasound scanner, has been developed that allows visual documenting of ultrasound examination by recording multiple gray-scale images, i.e. ultrasound tomography (UST), to be performed routinely and at low cost. The device is operated by one hand without interrupting the examination. Each page of UST report is composed by deliberate positioning multiple images within the 2X4 framework and recorded on a 35-mm microfilm. If necessary, graphic reconstructions were composed from standard graphic components and interposed between the original images on the same frame. UST report is communicated to a patient and/or a referring doctor on a co…

Small Bowel Enteroscopy − A Joint Clinical Guideline from the Spanish and Portuguese Small Bowel Study Groups

2020

The present evidence-based guidelines are focused on the use of device-assisted enteroscopy in the management of small-bowel diseases. A panel of experts selected by the Spanish and Portuguese small bowel study groups reviewed the available evidence focusing on the main indications of this technique, its role in the management algorithm of each indication and on its diagnostic and therapeutic yields. A set of recommendations were issued accordingly.Estas recomendações baseadas na evidência detalham o uso da enteroscopia assistida por dispositivo no manejo clínico das doenças do intestino delgado. Um conjunto de Gastrenterologistas diferenciados em patologia do intestino delgado foi selecion…

Current status of double balloon enteroscopy with focus on the Wiesbaden results.

2006

Performing Double-Balloon Enteroscopy: The Utility of the Erlangen EndoTrainer

2008

Double-balloon enteroscopy (DBE) is now an established method for endoscopic visualization of the deep small bowel. DBE is not only a diagnostic tool, but also makes it possible to take biopsy samples and perform endoscopic therapeutic interventions. However, DBE is a complex examination and should therefore only be performed by experienced endoscopists after appropriate training. The best method of teaching DBE and improving the acquisition of competence appears to be through step-by-step training. Lectures and videos are very useful during the initial steps, whereas hands-on training with animal models and demonstration of live DBE procedures are the main components used for providing tra…

Clinical microbeam radiation therapy with a compact source: specifications of the line-focus X-ray tube

2020

Highlights • Line-focus X-ray tubes are suitable for clinical microbeam radiation therapy (MRT). • A modular high-voltage supply safely enables high electron beam powers. • An electron accelerator was designed to generate an eccentric focal spot. • We simulated a peak-to-valley dose ratio above 20 for single-field MRT. • Microbeam arc therapy spares healthy brain tissue compared to single-field MRT.