Unnamed: 0 int64 0 41k | title stringlengths 4 274 | category stringlengths 5 18 | summary stringlengths 22 3.66k | theme stringclasses 8
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10,000 | A Method to Determine the In-Air Spatial Spread of Clinical Electron Beams | physics.med-ph | We propose and analyze in detail a method to measure the in-air spatial
spread parameter of clinical electron beams. Measurements are performed at the
center of the beam and below the adjustable collimators sited in asymmetrical
configuration in order to avoid the distortions due to the presence of the
applicator. The ... | physics |
10,001 | Assessing the risk from the depleted uranium weapons used in Operation Allied Force | physics.med-ph | The conflict in Yugoslavia has been a source of great concern due to the
radiological and toxic hazard posed by the alleged presence of depleted uranium
in NATO weapons. In the present study some worst-case scenaria are assumed in
order to assess the risk for Yugoslavia and its neighboring countries . The
risk is prove... | physics |
10,002 | The RR interval spectrum, the ECG signal and aliasing | physics.med-ph | A reliable spectral analysis requires sampling rate at least twice as large
as the frequency bound, otherwise the analysis will be unreliable and plagued
with aliasing distortions. The RR samplings do not satisfy the above
requirements and therefore their spectral analysis might be unreliable.
In order to demonstrate... | physics |
10,003 | Generalized Optimal Current Patterns and Electrical Safety in EIT | physics.med-ph | There are a number of constraints which limit the current and voltages which
can be applied on a multiple drive electrical imaging system. One obvious
constraint is to limit the maximum Ohmic power dissipated in the body. Current
patterns optimising distinguishability with respect to this constraint are
singular functi... | physics |
10,004 | Military use of depleted uranium: assessment of prolonged population exposure | physics.med-ph | This work is an exposure assessment for a population living in an area
contaminated by use of depleted uranium (DU) weapons. RESRAD 5.91 code is used
to evaluate the average effective dose delivered from 1, 10, 20 cm depths of
contaminated soil, in a residential farmer scenario. Critical pathway and group
are identifie... | physics |
10,005 | The Uncertainty Relationship In Magnetic Resonance Imaging (MRI) | physics.med-ph | The uncertainty relationship in MRI is shown. The result of uncertainty
relationship is compared with other factors influencing the resolution of MRI.
Our estimations show that the uncertainty relationship is of no significance in
practice. | physics |
10,006 | A comparison of delayed radiobiological effects of depleted-uranium munitions versus fourth-generation nuclear weapons | physics.med-ph | It is shown that the radiological burden due to the battlefield use of circa
400 tons of depleted-uranium munitions in Iraq (and of about 40 tons in
Yugoslavia) is comparable to that arising from the hypothetical battle-field
use of more than 600 kt (respectively 60 kt) of high-explosive equivalent
pure-fusion fourth-g... | physics |
10,007 | Non-linear quantization for arbitrary distributions and applications to Medical Image Processing | physics.med-ph | We report the development of a scalar quantization approach that helps build
tables of decision and reconstruction levels for any probability density
function (pdf). Several example pdf's are used for illustration:
Uniform, Gaussian, Laplace, one-sided Rayleigh, and Gamma (One sided and
double-sided symmetrical). The... | physics |
10,008 | Electron capture decay of indium-111 human carbonic anhydrase I: A time differential K X ray coincidence perturbed angular correlation study | physics.med-ph | The relaxation effects in the perturbed angular correlation spectra of
indium-111 human carbonic anhydrase I (HCA I) are the result of chemical
transmutation and/or the complex Auger cascades that follow the electron
capture decay of indium-111. Time differential K X ray coincidence perturbed
angular correlation (PAC) ... | physics |
10,009 | GPCALMA, a mammographic CAD in a GRID connection | physics.med-ph | Purpose of this work is the development of an automatic system which could be
useful for radiologists in the investigation of breast cancer. A breast
neoplasia is often marked by the presence of microcalcifications and massive
lesions in the mammogram: hence the need for tools able to recognize such
lesions at an early... | physics |
10,010 | A Computer Aided Detection system for mammographic images implemented on a GRID infrastructure | physics.med-ph | The use of an automatic system for the analysis of mammographic images has
proven to be very useful to radiologists in the investigation of breast cancer,
especially in the framework of mammographic-screening programs. A breast
neoplasia is often marked by the presence of microcalcification clusters and
massive lesions... | physics |
10,011 | Diagnostic performance of radiologists with and without different CAD systems for mammography | physics.med-ph | The purpose of this study is the evaluation of the variation of performance
in terms of sensitivity and specificity of two radiologists with different
experience in mammography, with and without the assistance of two different CAD
systems. The CAD considered are SecondLookTM (CADx Medical Systems, Canada),
and CALMA (C... | physics |
10,012 | The CALMA system: an artificial neural network method for detecting masses and microcalcifications in digitized mammograms | physics.med-ph | The CALMA (Computer Assisted Library for MAmmography) project is a five years
plan developed in a physics research frame in collaboration between INFN
(Istituto Nazionale di Fisica Nucleare) and many Italian hospitals. At present
a large database of digitized mammographic images (more than 6000) was
collected and a sof... | physics |
10,013 | Dosimetry for radiocolloid therapy of cystic craniopharyngiomas | physics.med-ph | The dosimetry for radiocolloid therapy of cystic craniopharyngiomas is
investigated. Analytical calculations based on the Loevinger and the Berger
formulae for electrons and photons, respectively, are compared with Monte Carlo
simulations. The role of the material of which the colloid introduced inside
the craniopharyn... | physics |
10,014 | EIT Reconstruction Algorithms: Pitfalls, Challenges and Recent Developments | physics.med-ph | We review developments, issues and challenges in Electrical Impedance
Tomography (EIT), for the 4th Workshop on Biomedical Applications of EIT,
Manchester 2003. We focus on the necessity for three dimensional data
collection and reconstruction, efficient solution of the forward problem and
present and future reconstruc... | physics |
10,015 | Dosimetry characterization of $^{32}$P intravascular brachytherapy source wires using Monte Carlo codes PENELOPE and GEANT4 | physics.med-ph | Monte Carlo calculations using the codes PENELOPE and GEANT4 have been
performed to characterize the dosimetric parameters of the new 20 mm long
catheter based $^{32}$P beta source manufactured by Guidant Corporation. The
dose distribution along the transverse axis and the two dimensional dose rate
table have been calc... | physics |
10,016 | GePEToS : A Geant4 Monte Carlo simulation package for Positron Emission Tomography | physics.med-ph | GePEToS is a simulation framework developed over the last few years for
assessing the instrumental performance of future PET scanners. It is based on
Geant4, written in Object-Oriented C++ and runs on Linux platforms. The
validity of GePEToS has been tested on the well-known Siemens ECAT EXACT HR+
camera. The results o... | physics |
10,017 | Algorithm and performance of a clinical IMRT beam-angle optimization system | physics.med-ph | This paper describes the algorithm and examines the performance of an IMRT
beam-angle optimization (BAO) system. In this algorithm successive sets of beam
angles are selected from a set of predefined directions using a fast simulated
annealing (FSA) algorithm. An IMRT beam-profile optimization is performed on
each gene... | physics |
10,018 | MRI of the lung using hyperpolarized He-3 at very low magnetic field (3 mT) | physics.med-ph | Optical pumping of He-3 produces large (hyper) nuclear-spin polarizations
independent of the magnetic resonance imaging (MRI) field strength. This allows
lung MRI to be performed at reduced fields with many associated benefits, such
as lower tissue susceptibility gradients and decreased power absorption rates.
Here we ... | physics |
10,019 | Stratification of the phase clouds and statistical effects of the non-Markovity in chaotic time series of human gait for healthy people and Parkinson patients | physics.med-ph | In this work we develop a new method of diagnosing the nervous system
diseases and a new approach in studying human gait dynamics with the help of
the theory of discrete non-Markov random processes. The stratification of the
phase clouds and the statistical non-Markov effects in the time series of the
dynamics of human... | physics |
10,020 | The influence of scattered photons on the accurate determination of microcalcification thickness in digital mammography | physics.med-ph | Our interest has been to study the effect that scattered radiation has on
contrast, signal-to-noise ratio and thickness reconstruction in digital
mammographies. Using the GEANT code we have performed Monte-Carlo simulations
of 25 kVp Mo/Mo photons, through a breast phantom which contains a 0.2-1.0 mm
thick microcalcifi... | physics |
10,021 | The impact of field shape optimization: A feasibility study | physics.med-ph | The impact of field shape optimization is studied for prostate type geometry.
For this study, 76 and 81 Gy plans were generated. Dose distributions for
wedged plans and Intensity Modulated (IM) plans for three and seven fields were
compared for a quadratic cost function. For wedged plans, a Simulated Annealing
Algorith... | physics |
10,022 | A simplified model of the source channel of the Leksell GammaKnife tested with PENELOPE | physics.med-ph | Monte Carlo simulations using the code PENELOPE have been performed to test a
simplified model of the source channel geometry of the Leksell
GammaKnife$^{\circledR}$. The characteristics of the radiation passing through
the treatment helmets are analysed in detail. We have found that only primary
particles emitted from... | physics |
10,023 | Radiostrontium activity concentrations in milk in the Republic of Croatia for 1961 - 2001 and dose assessment | physics.med-ph | Results of systematic measurements of Sr-90 activity concentrations in milk
for the period 1961 - 2001 are summarized. An exponential decline of
radioactivity followed the moratorium on atmospheric nuclear testing. The
highest activity of Sr-90 deposited by fallout, being 1060 Bq/m2, was recorded
in 1963, while the pea... | physics |
10,024 | Quantitative Approach to Intensity-Modulated Radiation Therapy Quality Assurance Based on Film Dosimetry and Optimization | physics.med-ph | To accurately verify the dose of intensity-modulated radiation therapy
(IMRT), we have used a global optimization method to investigate a new
dose-verification algorithm. In practical application of this quality assurance
(QA) procedure, verification of the dose using calculated and measured dose
distributions involves... | physics |
10,025 | A simplified model of the source channel of the Leksell Gamma Knife$^(R)$: testing multisource configurations with PENELOPE | physics.med-ph | A simplification of the source channel geometry of the Leksell Gamma
Knife$^{\circledR}$, recently proposed by the authors and checked for a single
source configuration (Al-Dweri et al 2004), has been used to calculate the dose
distributions along the $x$, $y$ and $z$ axes in a water phantom with a
diameter of 160~mm, ... | physics |
10,026 | Optimization and performance of an optical cardio-magnetometer | physics.med-ph | Cardiomagnetometry is a growing field of noninvasive medical diagnostics that
has triggered a need for affordable high-sensitivity magnetometers. Optical
pumping magnetometers are promising candidates satisfying that need since it
was demonstrated that they can map the heart magnetic field. For the
optimization of such... | physics |
10,027 | CADe tools for early detection of breast cancer | physics.med-ph | A breast neoplasia is often marked by the presence of microcalcifications and
massive lesions in the mammogram: hence the need for tools able to recognize
such lesions at an early stage. Our collaboration, among italian physicists and
radiologists, has built a large distributed database of digitized mammographic
images... | physics |
10,028 | GPCALMA: A Tool For Mammography With A GRID-Connected Distributed Database | physics.med-ph | The GPCALMA (Grid Platform for Computer Assisted Library for MAmmography)
collaboration involves several departments of physics, INFN sections, and
italian hospitals. The aim of this collaboration is developing a tool that can
help radiologists in early detection of breast cancer. GPCALMA has built a
large distributed ... | physics |
10,029 | GPCALMA: a Grid-based tool for Mammographic Screening | physics.med-ph | The next generation of High Energy Physics (HEP) experiments requires a GRID
approach to a distributed computing system and the associated data management:
the key concept is the Virtual Organisation (VO), a group of distributed users
with a common goal and the will to share their resources. A similar approach is
being... | physics |
10,030 | Effect of noise and modeling errors on the reliability of fully 3D Monte Carlo reconstruction in SPECT | physics.med-ph | We recently demonstrated the value of reconstructing SPECT data with fully 3D
Monte Carlo reconstruction (F3DMC), in terms of spatial resolution and
quantification. This was shown on a small cubic phantom (64 projections 10 x
10) in some idealistic configurations. The goals of the present study were to
assess the effec... | physics |
10,031 | The effect of the primary collimator and flattening filter on asymmetric fields for a Siemens PRIMUS linear accelerator | physics.med-ph | Homogeneity for highly asymmetric fields has been studied for a Siemens
PRIMUS linear accelerator. The flattening filter has a radius smaller than the
primary collimator one, creating inhomogeneities that affect large fields in
areas far from the collimator axis, and asymmetric fields with large offset.
Profiles and ab... | physics |
10,032 | Polarized Helium to Image the Lung | physics.med-ph | The main findings of the european PHIL project (Polarised Helium to Image the
Lung) are reported. State of the art optical pumping techniques for polarising
^3He gas are described. MRI methodological improvements allow dynamical
ventilation images with a good resolution, ultimately limited by gas diffusion.
Diffusion i... | physics |
10,033 | Pneumatic capillary gun for ballistic delivery of microparticles | physics.med-ph | A pneumatic gun for ballistic delivery of microparticles to soft targets is
proposed and demonstrated. The particles are accelerated by a high speed flow
of Helium in a capillary tube. Vacuum suction applied to a concentric, larger
diameter tube is used to divert substantially all of the flow of Helium from
the gun noz... | physics |
10,034 | Real time noninvasive cancer diagnostics | physics.med-ph | Laser illumination of tissue results in a characteristic fluorescence
emission spectrum whose features depend on the type of tissue, viz., healthy,
adenoma or malignant. Hence measurement of the fluorescence is potentially a
rapid and reliable diagnostic method. We have applied the technique to thyroid
tissues and foun... | physics |
10,035 | Preliminary study of metabolic radiotherapy with 188Re via small animal imaging | physics.med-ph | 188Re is a beta- (Emax = 2.12 MeV) and gamma (155 keV) emitter. Since its
chemistry is similar to that of the largely employed tracer, 99mTc, molecules
of hyaluronic acid (HA) have been labelled with 188Re to produce a target
specific radiopharmaceutical. The radiolabeled compound, i.v. injected in
healthy mice, is abl... | physics |
10,036 | Performance of three-photon PET imaging: Monte Carlo simulations | physics.med-ph | We have recently introduced the idea of making use of three-photon positron
annihilations in positron emission tomography. In this paper the basic
characteristics of the three-gamma imaging in PET are studied by means of Monte
Carlo simulations and analytical computations. Two typical configurations of
human and small ... | physics |
10,037 | Nuclear Magnetic Resonance with the Distant Dipolar Field | physics.med-ph | Distant dipolar field (DDF)-based nuclear magnetic resonance is an active
research area with many fundamental properties still not well understood.
Already several intriguing applications have developed, like HOMOGENIZED and
IDEAL spectroscopy, that allow high resolution spectra to be obtained in
inhomogeneous fields, ... | physics |
10,038 | A pixel-based approach to massive lesion detection in X-ray mammography | physics.med-ph | A system for the automated detection of massive lesions in mammograms is
presented. The approach we adopted is a pixel-based and multi-level one. Each
pixel in a mammogram is flagged with the appropriate class membership, e.g.
massive lesions or normal breast tissue. | physics |
10,039 | Pre-processing methods for nodule detection in lung CT | physics.med-ph | The use of automatic systems in the analysis of medical images has proven to
be very useful to radiologists, especially in the framework of screening
programs, in which radiologists make their first diagnosis on the basis of
images only, most of those corresponding to healthy patients, and have to
distinguish pathologi... | physics |
10,040 | Noise-induced first-order transition in anti-tumor immunotherapy | physics.med-ph | We studied the single-variable dynamics model of the tumor growth. A
first-order phase transition induced by an additive noise is shown to reproduce
the main features of tumor growth under immune surveillance. The critical
average cells population has a power-law function relationship with the immune
coefficient. | physics |
10,041 | Effects of bone- and air-tissue inhomogeneities on the dose distributions of the Leksell Gamma Knife$^{\circledR}$ calculated with PENELOPE | physics.med-ph | Monte Carlo simulation with PENELOPE (v.~2003) is applied to calculate
Leksell Gamma Knife$^{\circledR}$ dose distributions for heterogeneous
phantoms. The usual spherical water phantom is modified with a spherical bone
shell simulating the skull and an air-filled cube simulating the frontal or
maxillary sinuses. Diffe... | physics |
10,042 | Fully 3D Monte Carlo image reconstruction in SPECT using functional regions | physics.med-ph | Image reconstruction in Single Photon Emission Computed Tomography (SPECT) is
affected by physical effects such as photon attenuation, Compton scatter and
detector response. These effects can be compensated for by modeling the
corresponding spread of photons in 3D within the system matrix used for
tomographic reconstru... | physics |
10,043 | Experimental study of a liquid Xenon PET prototype module | physics.med-ph | A detector using liquid Xenon in the scintillation mode is studied for
Positron Emission Tomography (PET). The specific design aims at taking full
advantage of the liquid Xenon properties. It does feature a promising
insensitive to any parallax effect. This work reports on the performances of
the first LXe prototype mo... | physics |
10,044 | An Inexpensive Arterial Pressure Wave Sensor and its application in different physiological condition | physics.med-ph | Arterial Blood Pressure wave monitoring is considered to be important in
assessment of cardiovascular system. We developed a novel pulse wave detection
system using low frequency specific piezoelectric material as pressure wave
sensor. The transducer detects the periodic change in the arterial wall
diameter produced by... | physics |
10,045 | Physical basis of SATRO - a new method for analysis of the cardiac muscle depolarisation | physics.med-ph | On the basis of the model of the current flow through a single fibre, changes
in the electric charge density over the myocardium are described. With the use
of relevant analytic formulae, supported with numerical calculations, the
distribution and time dependencies of electric potentials on the surface of the
thorax ha... | physics |
10,046 | Niederhauser's model for epilepsy and wavelet methods | physics.med-ph | Wavelets and wavelet transforms (WT) could be a very useful tool to analyze
electroencephalogram (EEG) signals. To illustrate the WT method we make use of
a simple electric circuit model introduced by Niederhauser, which is used to
produce EEG-like signals, particularly during an epileptic seizure. The
original model i... | physics |
10,047 | Application of Unit Time Block Entropy to Fetal Distress Heart Rate | physics.med-ph | Recently, multiple time scale characteristics of heart dynamics have received
much attention for distinguishing healthy and pathologic cardiac systems.
Despite structural peculiarities of the fetal cardiovascular system, the fetal
heart rate(FHR) displays multiple time scale characteristics similar to the
adult heart r... | physics |
10,048 | Indoor-Atmospheric Radon-Related Radioactivity Affected by a Change of Ventilation Strategy | physics.med-ph | The present author has kept observation for concentrations of atmospheric
radon, radon progeny and thoron progeny for several years at the campus of
Fukushima Medical University. Accidentally, in the midst of an observation
term, i.e., February 2005, the facility management group of the university
changed a strategy fo... | physics |
10,049 | Computer assisted planning and orbital surgery: patient-related prediction of osteotomy size in proptosis reduction | physics.med-ph | BACKGROUND: Proptosis is characterized by a protrusion of the eyeball due to
an increase of the orbital tissue volume. To recover a normal eyeball
positioning, the most frequent surgical technique consists in the osteotomy of
orbital walls combined with the manual loading on the eyeball. Only a rough
clinical rule is c... | physics |
10,050 | Influences of tongue biomechanics on speech movements during the production of velar stop consonants: a modeling study | physics.med-ph | This study explores the following hypothesis: forward looping movements of
the tongue that are observed in VCV sequences are due partly to the anatomical
arrangement of the tongue muscles and how they are used to produce a velar
closure. The study uses an anatomically based 2D biomechanical tongue model.
Tissue elastic... | physics |
10,051 | Orbital and Maxillofacial Computer Aided Surgery: Patient-Specific Finite Element Models To Predict Surgical Outcomes | physics.med-ph | This paper addresses an important issue raised for the clinical relevance of
Computer-Assisted Surgical applications, namely the methodology used to
automatically build patient-specific Finite Element (FE) models of anatomical
structures. From this perspective, a method is proposed, based on a technique
called the Mesh... | physics |
10,052 | Prediction of tissue decompression in orbital surgery | physics.med-ph | Objective: A method to predict the relationships between decompressed volume
of orbital soft tissues, backward displacement of globe after osteotomy, and
force exerted by the surgeon, was proposed to improve surgery planning in
exophthalmia reduction. Design: A geometric model and a poroelastic finite
element model wer... | physics |
10,053 | Biomechanical models to simulate consequences of maxillofacial surgery | physics.med-ph | This paper presents the biomechanical finite element models that have been
developed in the framework of the computer-assisted maxillofacial surgery.
After a brief overview of the continuous elastic modelling method, two models
are introduced and their use for computer-assisted applications discussed. The
first model d... | physics |
10,054 | Computer-aided hepatic tumour ablation : requirements and preliminary results | physics.med-ph | Surgical resection of hepatic tumours is not always possible, since it
depends on different factors, among which their location inside the liver
functional segments. Alternative techniques consist in local use of chemical or
physical agents to destroy the tumour. Radio frequency and cryosurgical
ablations are examples ... | physics |
10,055 | A 3D dynamical biomechanical tongue model to study speech motor control | physics.med-ph | A 3D biomechanical dynamical model of human tongue is presented, that is
elaborated in the aim to test hypotheses about speech motor control. Tissue
elastic properties are accounted for in Finite Element Modeling (FEM). The FEM
mesh was designed in order to facilitate the implementation of muscle
arrangement within the... | physics |
10,056 | A simulator for maxillo-facial surgery integrating cephalometry and orthodontia | physics.med-ph | Objectives : This paper presents a new simulator for maxillo-facial surgery,
that gathers the dental and the maxillo-facial analyses together into a single
computer-assisted procedure. The idea is first to propose a repositioning of
the maxilla, via the introduction of a 3D cephalometry, applied to a 3D virtual
model o... | physics |
10,057 | Computer-aided hepatic tumour ablation | physics.med-ph | Surgical resection of hepatic tumours is not always possible. Alternative
techniques consist in locally using chemical or physical agents to destroy the
tumour and this may be performed percutaneously. It requires a precise
localisation of the tumour placement during ablation. Computer-assisted surgery
tools may be use... | physics |
10,058 | A finite element study of the influence of the osteotomy surface on the backward displacement during exophthalmia reduction | physics.med-ph | Exophthalmia is characterized by a protrusion of the eyeball. The most
frequent surgery consists in an osteotomy of the orbit walls to increase the
orbital volume and to retrieve a normal eye position. Only a few clinical
obser-vations have estimated the relationship between the eyeball backward
dis-placement and the d... | physics |
10,059 | Comparison of linear and non-linear soft tissue models with post-operative CT scan in maxillofacial surgery | physics.med-ph | A Finite Element model of the face soft tissue is proposed to simulate the
morphological outcomes of maxillofacial surgery. Three modelling options are
implemented: a linear elastic model with small and large deformation
hypothesis, and an hyperelastic Mooney-Rivlin model. An evaluation procedure
based on a qualitative... | physics |
10,060 | Physical modelling of the airflow-walls interactions to understand the sleep apnea syndrome | physics.med-ph | Sleep Apnea Syndrome (SAS) is defined as a partial or total closure of the
patient upper airways during sleep. The term "collapsus" (or collapse) is used
to describe this closure. From a fluid mechanical point of view, this collapse
can be understood as a spectacular example of fluid-walls interaction. Indeed,
the uppe... | physics |
10,061 | Models for Planning and Simulation in Computer Assisted Orthognatic Surgery | physics.med-ph | Two aspects required to establish a planning in orthognatic surgery are
addressed in this paper. First, a 3D cephalometric analysis, which is
clini-cally essential for the therapeutic decision. Then, an original method to
build a biomechanical model of patient face soft tissue, which provides
evaluation of the aestheti... | physics |
10,062 | Simulation of the Exophthalmia Reduction using a Finite Element Model of the Orbital Soft Tissues | physics.med-ph | This paper proposes a computer-assisted system for the surgical treatment of
exophthalmia. This treatment is classically characterized by a de-compression
of the orbit, by the mean of an orbital walls osteotomy. The plan-ning of this
osteotomy consists in defining the size and the location of the de-compression
hole. A... | physics |
10,063 | A 3D Finite Element model of the face for simulation in plastic and maxillo-facial surgery | physics.med-ph | This paper introduces a new Finite Element biomechanical model of the human
face, which has been developed to be integrated into a simulator for plastic
and maxillo-facial surgery. The idea is to be able to predict, from an
aesthetic and functional point of view, the deformations of a patient face,
resulting from repos... | physics |
10,064 | The mesh-matching algorithm: an automatic 3D mesh generator for Finite element structures | physics.med-ph | Several authors have employed Finite Element Analysis (FEA) for stress and
strain analysis in orthopaedic biomechanics. Unfortunately, the use of
three-dimensional models is time consuming and consequently the number of
analysis to be performed is limited. The authors have investigated a new method
allowing automatical... | physics |
10,065 | The geometric calibration of cone-beam imaging and delivery systems in radiation therapy | physics.med-ph | We propose a method to achieve the geometric calibration of cone-beam imaging
and delivery systems in radiation therapy; our approach applies to devices
where an X-ray source and a flat-panel detector, facing each other, move in
circular orbits around the irradiated object. In order to extract the
parameters of the geo... | physics |
10,066 | The dual-gain mode: a way to enhance the dynamic range of X-ray detectors | physics.med-ph | Varian Medical Systems has manufactured and recently put into operation a
clinically-applicable solution for image-guided radiation therapy. Cone-beam CT
imaging, one of the operation modes of the imaging unit of this device, aims at
high-quality volumetric reconstruction. To boost the image quality, the
dual-gain mode... | physics |
10,067 | The dual-dose imaging technique: a way to enhance the dynamic range of X-ray detectors | physics.med-ph | We describe a method aiming at increasing the dynamic range of X-ray
detectors. Two X-ray exposures of an object are acquired at different dose
levels and constitute the only input data. The values of the parameters which
are needed to process these images are determined from information contained in
the images themsel... | physics |
10,068 | Distributions of positron-emitting nuclei in proton and carbon-ion therapy studied with GEANT4 | physics.med-ph | Depth distributions of positron-emitting nuclei in PMMA phantoms are
calculated within a Monte Carlo model for Heavy-Ion Therapy (MCHIT) based on
the GEANT4 toolkit (version 8.0). The calculated total production rates of
$^{11}$C, $^{10}$C and $^{15}$O nuclei are compared with experimental data and
with corresponding r... | physics |
10,069 | Growth Laws in Cancer: Implications for Radiotherapy | physics.med-ph | Comparing both, the more conventional Gompertz tumor growth law (GL) and the
``Universal'' law (UL), recently proposed and applied to cancer,we have
investigated the growth law's implications on various radiotherapy regimen.
According to GL, the surviving tumor cell fraction could be reduced 'ad
libidum', independent... | physics |
10,070 | Improving human ankle joint position sense using an artificial tongue-placed tactile biofeedback | physics.med-ph | Proprioception is comprised of sensory input from several sources including
muscle spindles, joint capsule, ligaments and skin. The purpose of the present
experiment was to investigate whether the central nervous system was able to
integrate an artificial biofeedback delivered through electrotactile
stimulation of the ... | physics |
10,071 | Morphological Instability and Cancer Invasion: A 'Splashing Water Drop' Analogy | physics.med-ph | We present an analogy between two unrelated instabilities. One is caused by
the impact of a drop of water on a solid surface while the other one concerns a
tumor that develops invasive cellular branches into the surrounding host
tissue. In spite of the apparent abstractness of the idea, it yields a very
practical resul... | physics |
10,072 | Modeling the production of VCV sequences via the inversion of a biomechanical model of the tongue | physics.med-ph | A control model of the production of VCV sequences is presented, which
consists in three main parts: a static forward model of the relations between
motor commands and acoustic properties; the specification of targets in the
perceptual space; a planning procedure based on optimization principles.
Examples of simulation... | physics |
10,073 | Multimodal registration of the face for computer-aided maxillofacial surgery | physics.med-ph | This paper introduces a multimodal elastic registration algorithm applied to
match a generic Finite Element model of the face to several patients
morphologies. The method is automatic and appears to be accurate and robust.
The computing time is compatible with clinical practice constraints. | physics |
10,074 | A stiffness sensor to help in the diagnosis and the surgery of orbital pathologies | physics.med-ph | Proptosis is characterized by a protrusion of the eyeball due to an increase
of the orbital tissue volume. To recover a normal eyeball positioning, the most
frequent surgical technique (BROD technique) consists in the osteotomy of
orbital walls combined with a loading on the eyeball to initiate tissue
decompression. In... | physics |
10,075 | Computer-aided planning for zygomatic bone reconstruction in maxillofacial traumatology | physics.med-ph | An optimal planning procedure has been proposed to define the target position
of the zygomatic bone following a fracture of the mid-face skeleton. The
protocol has been successfully tested on healthy subjects, and ensures the
global symmetry of the face could be obtained after the reconstruction surgery.
Now that the p... | physics |
10,076 | Automatic finite elements mesh generation from planar contours of the brain: an image driven 'blobby' approach | physics.med-ph | In this paper, we address the problem of automatic mesh generation for finite
elements modeling of anatomical organs for which a volumetric data set is
available. In the first step a set of characteristic outlines of the organ is
defined manually or automatically within the volume. The outlines define the
"key frames" ... | physics |
10,077 | Biomechanics applied to computer-aided diagnosis: examples of orbital and maxillofacial surgeries | physics.med-ph | This paper introduces the methodology proposed by our group to model the
biological soft tissues deformations and to couple these models with
Computer-Assisted Surgical (CAS) applications. After designing CAS protocols
that mainly focused on bony structures, the Computer Aided Medical Imaging
group of Laboratory TIMC (... | physics |
10,078 | A New Health Strategy to Prevent Pressure Ulcer Formation in Paraplegics using Computer and Sensory Substitution via the Tongue | physics.med-ph | Pressure ulcers are recognized as a major health issue in individuals with
spinal cord injuries and new approaches to prevent this pathology are
necessary. An innovative health strategy is being developed through the use of
computer and sensory substitution via the tongue in order to compensate for the
sensory loss in ... | physics |
10,079 | Framework and Bio-Mechanical Model for a Per-Operative Image-Guided Neuronavigator Including 'Brain-Shift' Compensation | physics.med-ph | In this paper we present a methodology to adress the problem of brain tissue
deformation referred to as "brainshift". This deformation occurs throughout a
neurosurgery intervention and strongly alters the accuracy of the
neuronavigation systems used to date in clinical routine which rely solely on
preoperative patient ... | physics |
10,080 | Modéliser le physique pour comprendre le contrôle : le cas de l'anticipation en production de parole | physics.med-ph | This chapter introduces numerical simulations provided by a 2D biomechanical
model of the tongue. These simulations help in understanding the influence of
the lingual mechanical characteristics onto the anticipation phenomena that are
measured on acoustic and articulatory speech data. | physics |
10,081 | Evaluating soft tissue simulation in maxillofacial surgery using pre and post-operative CT scan | physics.med-ph | One of the most important issue in soft tissue modeling is to assess the
quality of the simulations. A validation protocol is presented based on two CT
scans of the patient acquired before and after cranio-maxillofacial surgery.
The actual bones repositioning realized during the intervention are accurately
measured and... | physics |
10,082 | Reproduction of hypopnea phenomenon using a physical and numerical model | physics.med-ph | Obstructive sleep apnea syndrome is now considered as a major health care
topic. An in-vitro setup which reproduces and simplifies upper airway geometry
has been the basis to study the fluid/walls interaction that leads to an apnea.
It consists of a rigid pipe (the pharynx) in contact with a deformable latex
cylinder f... | physics |
10,083 | Modélisation biomécanique tri-dimensionnelle de l'articulateur lingual pour étudier le contrôle de la parole | physics.med-ph | A 3D biomechanical dynamical model of human tongue is presented, which is
elaborated to test in the future hypotheses about speech motor control. Tissue
elastic properties are accounted for in Finite Element Modelling (FEM). The FEM
mesh was designed in order to facilitate implementation of muscle arrangement
in the to... | physics |
10,084 | Evaluation of a lingual interface as a passive surgical guiding system | physics.med-ph | Under conventional "open-" surgery, the physician has to take care of the
patient, interact with other clinicians and check several monitoring devices.
Nowadays, the Computer Assisted Surgery proposes to integrate 3D cameras in the
operating theatre in order to assist the surgeon in performing minimal-invasive
surgical... | physics |
10,085 | Maxillofacial computer aided surgery: a 5 years experience and future | physics.med-ph | This paper gives a review of the experience provided by our group in terms of
computer aided maxillo-facial surgery. | physics |
10,086 | A 3D Finite Element evaluation of the exophthalmia reduction | physics.med-ph | This paper presents a first evaluation of the feasibility of Finite Element
modelling of the orbital decompression, in the context of exophthalmia. First
simulations are carried out with data extracted from a patient TDM exam.
Results seem to qualitatively validate the feasibility of the simulations, with
a Finite Elem... | physics |
10,087 | Percutaneous renal puncture: requirements and preliminary results | physics.med-ph | This paper introduces the principles of computer assisted percutaneous renal
puncture, that would provide the surgeon with an accurate pre-operative 3D
planning on CT images and, after a rigid registration with space-localized
echographic data, would help him to perform the puncture through an intuitive
2D/3D interface... | physics |
10,088 | Computer aided planning for orthognatic surgery | physics.med-ph | A computer aided maxillofacial sequence is presented, applied to orthognatic
surgery. It consists of 5 main stages: data acquisition and integration,
surgical planning, surgical simulation, and per operative assistance. The
planning and simulation steps are then addressed in a way that is clinically
relevant. First con... | physics |
10,089 | Development and characteristics of the HANARO ex-core neutron irradiation facility for applications in the boron neutron capture therapy field | physics.med-ph | The HANARO ex-core neutron irradiation facility was developed for various
applications in the boron neutron capture therapy (BNCT) field, and its
characteristics have been investigated. In order to obtain a sufficient thermal
neutron flux with a low level contamination of fast neutrons and gamma-rays, a
radiation filte... | physics |
10,090 | Strong Memory in Time Series of Human Magnetoencephalograms Can Identify Photosensitive Epilepsy | physics.med-ph | To discuss the salient role of the statistical memory effects in the human
brain functioning we have analyzed a set of stochastic memory quantifiers that
reflects the dynamical characteristics of neuromagnetic brain responses to a
flickering stimulus of different color combinations from a group of control
subjects whic... | physics |
10,091 | Relaxation and phase space singularities in time series of human magnetoencephalograms as indicator of photosensitive epilepsy | physics.med-ph | To analyze the crucial role of fluctuation and relaxation effects for the
function of the human brain we studied some statistical quantifiers that
support the information characteristics of neuromagnetic brain responses
(magnetoencephalogram, MEG). The signals to a flickering stimulus of different
color combinations ha... | physics |
10,092 | Monte Carlo simulation of the electron transport through thin slabs: A comparative study of PENELOPE, GEANT3, GEANT4, EGSnrc and MCNPX | physics.med-ph | The Monte Carlo simulation of the electron transport through thin slabs is
studied with five general purpose codes: PENELOPE, GEANT3, GEANT4, EGSnrc and
MCNPX. The different material foils analyzed in the old experiments of
Kulchitsky and Latyshev [Phys. Rev. 61 (1942) 254-266] and Hanson et al. [Phys.
Rev. 84 (1951) 6... | physics |
10,093 | Dose distribution in water for monoenergetic photon point sources in the energy range of interest in brachytherapy: Monte Carlo simulations with PENELOPE and GEANT4 | physics.med-ph | Monte Carlo calculations using the codes PENELOPE and GEANT4 have been
performed to characterize the dosimetric properties of monoenergetic photon
point sources in water. The dose rate in water has been calculated for energies
of interest in brachytherapy, ranging between 10 keV and 2 MeV. A comparison of
the results o... | physics |
10,094 | Demonstration of Circadian Rhythm in Heart Rate Turbulence using Novel Application of Correlator Functions | physics.med-ph | Background: It has been difficult to demonstrate circadian rhythm in the two
parameters of heart rate turbulence, turbulence onset (TO) and turbulence slope
(TS).
Objective: To devise a new method for detecting circadian rhythm in noisy
data, and apply it to selected Holter recordings from two post-myocardial
infarct... | physics |
10,095 | A scalable Computer-Aided Detection system for microcalcification cluster identification in a pan-European distributed database of mammograms | physics.med-ph | A computer-aided detection (CADe) system for microcalcification cluster
identification in mammograms has been developed in the framework of the
EU-founded MammoGrid project. The CADe software is mainly based on wavelet
transforms and artificial neural networks. It is able to identify
microcalcifications in different ki... | physics |
10,096 | An Automatic System to Discriminate Malignant from Benign Massive Lesions on Mammograms | physics.med-ph | Mammography is widely recognized as the most reliable technique for early
detection of breast cancers. Automated or semi-automated computerized
classification schemes can be very useful in assisting radiologists with a
second opinion about the visual diagnosis of breast lesions, thus leading to a
reduction in the numbe... | physics |
10,097 | A scalable system for microcalcification cluster automated detection in a distributed mammographic database | physics.med-ph | A computer-aided detection (CADe) system for microcalcification cluster
identification in mammograms has been developed in the framework of the
EU-founded MammoGrid project. The CADe software is mainly based on wavelet
transforms and artificial neural networks. It is able to identify
microcalcifications in different da... | physics |
10,098 | Computer-aided detection of pulmonary nodules in low-dose CT | physics.med-ph | A computer-aided detection (CAD) system for the identification of pulmonary
nodules in low-dose multi-detector helical CT images with 1.25 mm slice
thickness is being developed in the framework of the INFN-supported MAGIC-5
Italian project. The basic modules of our lung-CAD system, a dot enhancement
filter for nodule c... | physics |
10,099 | Lung Nodule Detection in Screening Computed Tomography | physics.med-ph | A computer-aided detection (CAD) system for the identification of pulmonary
nodules in low-dose multi-detector helical Computed Tomography (CT) images with
1.25 mm slice thickness is presented. The basic modules of our lung-CAD system,
a dot-enhancement filter for nodule candidate selection and a neural classifier
for ... | physics |
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