Abstract：
:Regular checks on the performance of radiotherapy treatment units are essential and a variety of protocols has been published. These protocols identify that the determination of isocentre must be accurate and unambiguous since both the localization of a radiation field on a patient and positioning aids are referenced to it. An EPID (BIS 710) with a combined light and radiation scintillation detector screen was used to assess mechanical and radiation isocentres for different collimator and gantry angles. Crosshair positions within light field images were determined from fitted Gaussian intensity profiles and then used to calculate the displacement of the mechanical isocentre. For comparison, the position of the crosshair was also recorded on a graph paper. The radiation field centre was first calculated from the set up geometry for given gantry/collimator angles and then compared with measured values to assess the displacement of the radiation isocentre. The radiation isocentre was also checked by locating a marker, positioned on the couch, on the EPID radiation images for different treatment couch angles. The mechanical and radiation isocentres were determined from the EPID light field and radiation images respectively with an accuracy of 0.3 mm using simple PC based programs. The study has demonstrated the feasibility of using the EPID to assess mechanical and radiation isocentres of a linear accelerator in a quick and efficient way with a higher degree of accuracy achieved as compared to more conventional methods, e.g. the star shot.
journal_name
Australas Phys Eng Sci Medjournal_title
Australasian physical & engineering sciences in medicineauthors
Liu G,van Doorn T,Bezak Edoi
10.1007/BF03178670subject
Has Abstractpub_date
2004-09-01 00:00:00pages
111-7issue
3eissn
0158-9938issn
1879-5447journal_volume
27pub_type
杂志文章abstract：:Bipolar disorder (BD) is a severe psychiatric disorder and has two common types: type I and type II. Early diagnosis of the subtypes is very challenging particularly in adolescence. In this study, 38 adolescents are participated including 18 patients with BD I and 20 patients with BD II. The electroencephalogram signa...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-015-0375-0
更新日期：2015-12-01 00:00:00
abstract：:The purpose of this paper is to describe an outline of a proton therapy system in Nagoya Proton Therapy Center (NPTC). The NPTC has a synchrotron with a linac injector and three treatment rooms: two rooms are equipped with a gantry and the other one is equipped with a fixed horizontal beamline. One gantry treatment ro...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-016-0456-8
更新日期：2016-09-01 00:00:00
abstract：:Cricket bowling generates forces with torques on the upper limb muscles and makes the biceps brachii (BB) muscle vulnerable to overuse injury. The aim of this study was to investigate whether there are differences in the amplitude of the EMG signal of the BB muscle during fast and spin delivery, during the seven phase...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-014-0245-1
更新日期：2014-03-01 00:00:00
abstract：:Properties of a new polymer gel with cross-linked polyvinyl alcohol as a gelatinous matrix were investigated. The new polymer gel dosimeter was named PVABAT. The irradiation was performed using a calibrated 60Co beam. The dose responses of the PVABAT formulations were quantified with MRI transverse relaxation rate (R2...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-017-0573-z
更新日期：2017-09-01 00:00:00
abstract：:Orthovoltage x-ray beams exhibit the characteristic of depth dose buildup which is not well described in the literature. The principal reason for this phenomenon is the increase in dose deposited due to electrons set in motion by secondary (Compton) scattered photons within the phantom, as depth is increased until lon...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：
更新日期：1998-06-01 00:00:00
abstract：:This paper investigates the influence of inhomogeneous head tissue conductivity on EEGs. A head model with inhomogeneity of radial and tangential conductivity is built up. Based on this model the EEG signals are calculated using the finite elements method. The results show that the inhomogeneous radial and tangential ...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/BF03178780
更新日期：2003-09-01 00:00:00
abstract：:Electroencephalographic (EEG) signal records the neuronal activity in the brain and it is used in the diagnosis of epileptic seizure activities. Human inspection of non-stationary EEG signal for diagnosing epilepsy is cumbersome, time-consuming and inaccurate. In this paper an effective automatic approach to detect ep...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-018-0697-9
更新日期：2018-12-01 00:00:00
abstract：:The Australasian College of Physical Scientists and Engineers in Medicine (ACPSEM) radiation oncology specialty group (ROSG) formed a series of working groups in 2011 to develop recommendations for guidance of radiation oncology medical physics practice within the Australasian setting. These recommendations are intend...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章,实务指引
doi：10.1007/s13246-015-0344-7
更新日期：2015-06-01 00:00:00
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journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-012-0165-x
更新日期：2012-12-01 00:00:00
abstract：:Rats are often used in the electromagnetic field (EMF) exposure experiments. In the study for the effect of 900 MHz EMF exposure on learning and memory in SD rats, the specific absorption rate (SAR) and the temperature rise in the rat head are numerically evaluated. The digital anatomical model of a SD rat is reconstr...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-013-0202-4
更新日期：2013-06-01 00:00:00
abstract：:The reliability of the traditional Cobb angle index, which at present exhibits a wide range of reported values, was determined in this study and amounted to a within subject error of +/-4.3 degrees and a between subject error of +/-4.9 degrees. An attempt to pinpoint the source of this variability by investigating the...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：
更新日期：1989-03-01 00:00:00
abstract：:Postural balance requires using joint strategies which may be changed from normal conditions by interfering with the sensory information. The goal of the present study was to quantitatively evaluate the role of the joint mechanisms during perturbed stance. Visual and cognitive interference was imposed to sixteen healt...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-017-0606-7
更新日期：2018-03-01 00:00:00
abstract：:Due to large inter- and intra-patient variabilities of arterial input functions (AIFs), accurately modeling and using patient-specific AIF are very important for quantitative analysis of dynamic contrast enhanced MRI. Computer simulations were performed to evaluate and compare nine population AIF models with the Parke...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-018-0632-0
更新日期：2018-06-01 00:00:00
abstract：:The effects of internal and external scatter on surface, build-up and depth dose characteristics simulated by Monte Carlo code EGSnrc for varying field size and SSD for a 10 MeV monoenergetic electron beam with and without an accelerator model are extensively studied in this paper. In particular, sub-millimetre surfac...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/BF03178710
更新日期：2005-09-01 00:00:00
abstract：:Two software packages designed for automatic counting nuclear tracks are tested and compared. The image processing in the first package is divided into three parts segmentation, speckle elimination and removal of ill-formed track holes. The second package is also divided into three parts but the last part is modified ...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：
更新日期：1992-06-01 00:00:00
abstract：:Laparoscopic ultrasound (LUS) has been widely utilized as a surgical aide in general, urological, and gynecological applications. Our study summarizes the clinical applications of laparoscopic ultrasonography in laparoscopic gynecologic surgery. Retrospective analyses were performed on 42 women subjects using laparosc...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-015-0363-4
更新日期：2015-12-01 00:00:00
abstract：:Diamond detectors are particularly well suited for dosimetry applications in radiotherapy for reasons including near-tissue equivalence and high-spatial resolution resulting from small sensitive volumes. However, these detectors have not become commonplace due to high cost and poor availability arising from the need f...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-010-0040-6
更新日期：2010-12-01 00:00:00
abstract：:In recent years, the use of gold nanoparticles in radiation therapy has been introduced as a new approach in radiotherapy. The aim of this study is to investigate the effect of gold nanoparticles (GNPs) in plaque brachytherapy for choroidal melanoma using Monte Carlo (MC) simulation. MCNPX code was used for simulation...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-017-0555-1
更新日期：2017-09-01 00:00:00
abstract：:X-ray transmission tests were performed on a Green-Lite (Infab Corporation) apron/vest combination, and compared to a number of other apron/vest combinations routinely used at Christchurch Hospital as well as a sheet of 0.5 mm lead. The materials were X-rayed using the primary beam of a Philips Optimus 50 X-ray machin...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/BF03178704
更新日期：2005-06-01 00:00:00
abstract：:A set of computer programs to simulate diagnostic x-ray spectra has been developed according to the method of Birch and Marshall, with good agreement to published HPA data. These programs have been extended to simulate spectra generated with capacitor discharge x-ray units. The application of these programs has proved...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：
更新日期：1989-09-01 00:00:00
abstract：:The sample entropy (SampEn) has been widely used to quantify the complexity of RR-interval time series. It is a fact that higher complexity, and hence, entropy is associated with the RR-interval time series of healthy subjects. But, SampEn suffers from the disadvantage that it assigns higher entropy to the randomized ...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-016-0457-7
更新日期：2016-09-01 00:00:00
abstract：:Most of the human head models used in dipole localisation research, which have been reported in the literature to date, assume a simplified cranial structure wherein the head is modelled as a set of distinct homogenous tissue compartments. The inherent inhomogeneity of the tissues has so far been ignored in these mode...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/BF03178283
更新日期：2001-03-01 00:00:00
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journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-014-0294-5
更新日期：2014-12-01 00:00:00
abstract：:The Resonant Recognition Model (rrm) uses digital signal processing methods to investigate protein structure-function; and links the biological function of protein families to unique characteristic frequencies. The rrm originally used a single set of variables: the electron ion interaction potential (EIIP). Here the r...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：
更新日期：1995-12-01 00:00:00
abstract：:Coronary artery disease producing ischemic cardiomyopathy is the most frequent cause of left ventricular systolic dysfunction. Non-ischemic cardiomyopathies can also produce systolic dysfunction; they may be inherited as genetic disorders or occur sporadically. These coronary injuries have repercussions on the left ve...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/BF03178864
更新日期：2005-03-01 00:00:00
abstract：:The study developed two models of an innovative high-speed lancing device and safety lancet, where the specially designed structure causes high-speed motion of the lancet, resulting in only one puncture of the skin. The two experimental models and other lancing devices sold on market were compared in order to: (1) mea...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-016-0490-6
更新日期：2016-12-01 00:00:00
abstract：:Helical tomotherapy (HT) is a novel radiotherapy treatment modality that allows the delivery of intensity modulated radiation in a rotational fashion. Due to the complexity of the treatment approach, it is desirable to have a simple tool for treatment delivery verification. Radiographic film placed under the patient i...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/BF03178723
更新日期：2005-12-01 00:00:00
abstract：:Liver metabolic information is considered as a crucial diagnostic marker for the diagnosis of fever of unknown origin, and liver recognition is the basis of automatic diagnosis of metabolic information extraction. However, the poor quality of PET and CT images is a challenge for information extraction and target recog...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-018-0650-y
更新日期：2018-06-01 00:00:00
abstract：:Bio-signal based assessment for upper-limb functions is an attractive technology for rehabilitation. In this work, an upper-limb function evaluator is developed based on biological signals, which could be used for selecting different robotic training protocols. Interaction force (IF) and participation level (PL, proce...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-019-00783-0
更新日期：2019-09-01 00:00:00
abstract：:This paper proposes a novel approach to detect epilepsy seizures by using Electroencephalography (EEG), which is one of the most common methods for the diagnosis of epilepsy, based on 1-Dimension Local Binary Pattern (1D-LBP) and grey relational analysis (GRA) methods. The main aim of this paper is to evaluate and val...
journal_title：Australasian physical & engineering sciences in medicine
pub_type： 杂志文章
doi：10.1007/s13246-015-0362-5
更新日期：2015-09-01 00:00:00
