Verification of lithium formate monohydrate in 3D-printed container for electron paramagnetic resonance dosimetry in radiotherapy
This study proposes a newly designed pure LFM EPR dosimeter created by inserting LFM into a 3D-printed container. Dosimetric characteristics of the LFM EPR dosimeter and container, such as reproducibility, linearity, energy dependence, and angular dependence, were evaluated and verified through a radiation therapy planning system (RTPS). The LFM EPR dosimeters were irradiated using a clinical linear accelerator. The EPR spectra of the dosimeters were acquired using a Bruker EMX EPR spectrometer. Through this study, it was confirmed that there is no tendency in the EPR response of the container based on irradiation dose or ...
Source: Australasian Physical and Engineering Sciences in Medicine - August 13, 2019 Category: Biomedical Engineering Source Type: research

Optimizing image quality using automatic exposure control based on the signal-difference-to-noise ratio: a phantom study
This study proposes to adjust the sensitivity of automatic exposure control (AEC) for achieving consistent image quality over a range of subject thicknesses in abdominal radiography simulations. The relation between image quality and subject thickness was investigated using a digital radiography system with 10-, 15-, 20-, and 25-cm-thick acrylic phantom. Simple pixel signal-to-noise ratio (SNR) was measured to check the default AEC accuracy for each thickness, and image quality was evaluated using the signal-difference-to-noise ratio (SDNR) with an additional acrylic plate and bone-equivalent material. Based on the figure ...
Source: Australasian Physical and Engineering Sciences in Medicine - August 8, 2019 Category: Biomedical Engineering Source Type: research

An affordable custom phantom for measurement of linac time delay in gated treatments with irregular breathing
In this study we develop and characterise an affordable phantom to be used in routine and patient specific quality assurance (QA) of the Varian Real-Time Position Management ™ (RPM) system. A photodiode has been incorporated into the phantom in order to estimate the time delay. A commercial Quasar phantom was customised to incorporate two stepper motors which independently control an anterior–posterior abdomen/thorax moving plate, and an inferior-superior moving lun g insert. A photodiode placed in the path of the radiation is used to measure when beam on/off occurs. Two Arduino microcontroller boards have been...
Source: Australasian Physical and Engineering Sciences in Medicine - August 8, 2019 Category: Biomedical Engineering Source Type: research

Development of a biological signal-based evaluator for robot-assisted upper-limb rehabilitation: a pilot study
AbstractBio-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, processed surface electromyography (sEMG) signals) are used as the key bio-signal inputs for the evaluator. Accordingly, a robot-based standardized performance testing (SPT) is developed to measure these key bio-signal data. Moreover, fuzzy logic is used to regulate biological signals, and a rules-based sel...
Source: Australasian Physical and Engineering Sciences in Medicine - August 1, 2019 Category: Biomedical Engineering Source Type: research

A new fast algorithm to achieve the dose uniformity around high dose rate brachytherapy stepping source using Tikhonov regularization
AbstractThe dose optimization algorithm based on anatomical points is developed to produce rapidly uniform doses over target distances generated on the target volume edges in high-dose-rate (HDR) brachytherapy stepping source application for a treatment length of 6  cm. Monte Carlo modeling of the60Co HDR brachytherapy source and the surrounding medium were performed using PHITS code. The source dwell times were optimized using Tikhonov regularization in order to obtain uniform dose distribution at the anatomical points located at predefined target distances. The computed dose rates at distances from 0.25 up to 20 &nb...
Source: Australasian Physical and Engineering Sciences in Medicine - July 30, 2019 Category: Biomedical Engineering Source Type: research

EEG power spectrum analysis for schizophrenia during mental activity
The objective of this study is to analyze EEG in patients with schizophrenia using power spectral density during mental activity. The subjects included in this study are 52 schizophrenia subjects and 29 Normal subjects. EEG is recorded under resting condition and during mental activity. Two modified odd ball paradigms are designed to stimulate mental activity and named as stimulus 1 and stimulus 2. EEG signal is filtered using FIR band pass filter to extract delta, theta, alpha, and beta band EEG. This method measures powers of each band using Welch power spectral density method called absolute power. The absolute power of...
Source: Australasian Physical and Engineering Sciences in Medicine - July 30, 2019 Category: Biomedical Engineering Source Type: research

Conservatism in linear accelerator bunker shielding
AbstractConservatism in the shielding of linear accelerator bunkers is engrained in the methodology of international protocols and guidelines. However, the degree to which this cautious and prudent approach is necessary should be judged against the International Committee of Radiation Protection ’s principles of exposure justification and optimisation. Radiation survey data from 75 concrete barriers was aggregated and compared to exposure predictions from three popular protocols in order to assess any conservatism in factors used to calculate scatter, leakage and beam penetration. These f indings, in addition to a li...
Source: Australasian Physical and Engineering Sciences in Medicine - July 25, 2019 Category: Biomedical Engineering Source Type: research

Modeling scattered radiation from multi-leaf collimators (MLCs) to improve calculation accuracy of in-air output ratio
This study aims to model an extra-focal source for the scattered radiation from multi-leaf collimators (MLCs), namely anMLC scatter source, and to correct in-air output ratio (Sc) calculated using the conventional dual source model (DSM) to achieve better accuracy of point dose calculation. To develop the MLC scatter source, a 6 MV photon beam from a Varian Clinac ® iX linear accelerator with millennium 120 MLCs was used. It was assumed that the position for the MLC scatter source was located at the center of the MLC, consisting of line-based and area-based sources to consider the characteristics of the scattered radia...
Source: Australasian Physical and Engineering Sciences in Medicine - July 22, 2019 Category: Biomedical Engineering Source Type: research

An artificial intelligence-based clinical decision support system for large kidney stone treatment
AbstractA decision support system (DSS) was developed to predict postoperative outcome of a kidney stone treatment procedure, particularly percutaneous nephrolithotomy (PCNL). The system can serve as a promising tool to provide counseling before an operation. The overall procedure includes data collection and prediction model development. Pre/postoperative variables of 254 patients were collected. For feature vector, we used 26 variables from three categories including patient history variables, kidney stone parameters, and laboratory data. The prediction model was developed using machine learning techniques, which include...
Source: Australasian Physical and Engineering Sciences in Medicine - July 22, 2019 Category: Biomedical Engineering Source Type: research

Optimal b-values for diffusion kurtosis imaging in invasive ductal carcinoma versus ductal carcinoma in situ breast lesions
AbstractDiffusion kurtosis imaging (DKI) is a diffusion-weighted MRI technique that probes the non-Gaussian diffusion of water molecules within biological tissues. The purpose of this study was to investigate the DKI model optimal b-values combinations in invasive ductal carcinoma (IDC) versus ductal carcinoma in situ (DCIS) breast lesions. The study included 114 malignant breast lesions (64 IDC and 50 DCIS). Patients underwent a breast MRI examination which included a diffusion-weighted sequence (b  = 0–3000 s/mm2). For each lesion, the b-values were combined among each other (109 combinations) an...
Source: Australasian Physical and Engineering Sciences in Medicine - July 18, 2019 Category: Biomedical Engineering Source Type: research

Lasers in medical diagnosis and therapy by Stephan Wieneke and Christoph Gerhard
(Source: Australasian Physical and Engineering Sciences in Medicine)
Source: Australasian Physical and Engineering Sciences in Medicine - July 18, 2019 Category: Biomedical Engineering Source Type: research

An efficient heart murmur recognition and cardiovascular disorders classification system
AbstractThe problem addressed in this work is the detection of a heart murmur and the classification of the associated cardiovascular disorder based on the heart sound signal. For this purpose, a dataset of Phonocardiogram (PCG) signals is acquired using baseline conditions. The dataset is acquired from 283 volunteers using Littman 3200 electronic stethoscope for a normal and four different types of heart murmurs. The samples are labelled and validated through echocardiography test of each participating volunteer. For feature extraction, normalized average Shannon energy with time-domain characteristics of heart sound sign...
Source: Australasian Physical and Engineering Sciences in Medicine - July 16, 2019 Category: Biomedical Engineering Source Type: research

Use of 3D biological effective dose (BED) for optimizing multi-target liver cancer treatments
AbstractThe purpose is to calculate the composite 3D biological effective dose (BED) distribution in healthy liver, when multiple lesions are treated concurrently with different hypo-fractionated schemes and stereotactic body radiation therapy, and to investigate the potential of biological based plan optimization. Two patients, each having two tumors that were treated sequentially with different treatment plans, were selected. The treatment information of both treatment plans of the patients was used and their dose matrices were exported to an in-house MATLAB software, which was used to calculate the composite BED distrib...
Source: Australasian Physical and Engineering Sciences in Medicine - July 11, 2019 Category: Biomedical Engineering Source Type: research

Journal name change
(Source: Australasian Physical and Engineering Sciences in Medicine)
Source: Australasian Physical and Engineering Sciences in Medicine - July 10, 2019 Category: Biomedical Engineering Source Type: research

Dose perturbation by metallic biliary stent in external beam radiotherapy of pancreato-biliary cancers
This study aims to investigate dose perturbations caused by a metallic biliary stent (MBS) in patients undergoing external beam radiotherapy for cancers in the pancreato-biliary region. Four MBSs with nitinol mesh were examined in the EasyCube® phantom including a custom stent holder fabricated by a 3D printer. For experimental models, three-dimensional conformal radiotherapy plans using a single anterior –posterior (AP) and four-field box (4FB) as well as volumetric modulated arc therapy (VMAT) plan were prepared to deliver the photon beam of 8 Gy to the stent holder. EBT3 film was used to measure dose dist...
Source: Australasian Physical and Engineering Sciences in Medicine - July 8, 2019 Category: Biomedical Engineering Source Type: research

Measurements of in-air spot size of pencil proton beam for various air gaps in conjunction with a range shifter on a ProteusPLUS PBS dedicated machine and comparison to the proton dose calculation algorithms
In conclusion, spot size increment is dependent on the energy and air gap. The increase in spot size was more pronounced at lower energies ( 
Source: Australasian Physical and Engineering Sciences in Medicine - June 20, 2019 Category: Biomedical Engineering Source Type: research

Applying EMG technology in medial and lateral elbow enthesopathy treatment using Myo motion controller
AbstractElectromyography (EMG) is a diagnostic technique allowing for the detection of signals generated by changes in electrical potentials of striated muscles. The application of this technology is becoming an increasingly popular subject of scientific research. With the appearance of new devices retrieving EMG data, novel methods of its processing for various purposes are being developed. One such device is the Myo movement controller, produced by Thalmic Labs (now North). The device has been used for the analysis of muscle activation levels in patients with"tennis elbow" and"golfer ’s elbow" &...
Source: Australasian Physical and Engineering Sciences in Medicine - June 14, 2019 Category: Biomedical Engineering Source Type: research

Simplifying the human lumbar spine (L3/L4) material in order to create an elemental structure for the future modeling
AbstractThe human lumbar spine incorporates the best joints in nature due to its optimal static and dynamic behavior against the internal and external loads. Developing an elemental structure based on this joint requires simplification in terms of the materials employed by keeping the mechanical and anatomical behaviors of the human lumbar spine. In the present study, the finite element (FE) of two motion segments of the human lumbar spine (L3/L4) was developed based on the CT scan data as the base for vertebrae geometry, verified geometry properties for another part of two motion segments, and combination of materials and...
Source: Australasian Physical and Engineering Sciences in Medicine - June 10, 2019 Category: Biomedical Engineering Source Type: research

Characterisation of out-of-field dose at shallow depths for external beam radiotherapy: implications for eye lens dose
AbstractRe-evaluation of the eye lens radio-sensitivity by the ICRP in 2011 resulted in a significant reduction of the threshold for lens opacities from 8  Gy to 0.5 Gy. This has led to an increase in concern for eye lens doses from treatment sites further from the eye than previously considered. The aim of this study was to examine the out-of-field dose far from the field edge and develop an effective method to accurately characterise the constitue nt components of this dose at varying depths. Dose profile scans using a 0.6 cm3 cylindrical ionisation chamber in a motorised water tank were compared with prev...
Source: Australasian Physical and Engineering Sciences in Medicine - June 10, 2019 Category: Biomedical Engineering Source Type: research

Opportunities in space life sciences
(Source: Australasian Physical and Engineering Sciences in Medicine)
Source: Australasian Physical and Engineering Sciences in Medicine - June 10, 2019 Category: Biomedical Engineering Source Type: research

Biological surface electromyographic switch and necklace-type button switch control as an augmentative and alternative communication input device: a feasibility study
AbstractAugmentative and alternative communication (AAC) is an approach used to supplement, improve, and support the communication of those with speech or language impairments. We developed an AAC device for diverse approaches, using an electromyographic (EMG) switch and a necklace-type button switch. The EMG switch comprised an EMG signal processor and a switch interface processor. EMG signals were processed using an electrode through the stages of signal acquisition, amplification, filtering, rectification, and smoothing. In the switch interface processor, the microprocessor determined the switch as ON or OFF in response...
Source: Australasian Physical and Engineering Sciences in Medicine - June 3, 2019 Category: Biomedical Engineering Source Type: research

Particle swarm optimization based fusion of ultrasound echographic and elastographic texture features for improved breast cancer detection
AbstractBreast cancer remains the main cause of cancer deaths among women in the world. As per the statistics, it is the most common killer disease of the new era. Since 2008, breast cancer incidences have increased by more than 20%, while mortality has increased by 14%.  The statistics of breast cancer incidences as per GLOBOCAN project for the years 2008 and 2012 show an increase from 22.2 to 27% globally. In India, breast cancer accounts for 25% to 31% of all cancers in women. Mammography and Sonography are the two common imaging techniques used for the diagno sis and detection of breast cancer. Since Mam...
Source: Australasian Physical and Engineering Sciences in Medicine - June 3, 2019 Category: Biomedical Engineering Source Type: research

Comparison of muscle synergies extracted from both legs during cycling at different mechanical conditions
AbstractMuscle synergies are the building blocks for generating movement by the central nervous system (CNS). According to this hypothesis, CNS decreases the complexity of motor control by combination of a small number of muscle synergies. The aim of this work is to investigate similarity of muscle synergies during cycling across various mechanical conditions. Twenty healthy subjects performed three 6- min cycling tasks at over a range of rotational speed (40, 50, and 60  rpm) and resistant torque (3, 5, and 7 N/m). Surface electromyography (sEMG) signals were recorded during pedaling from eight muscles of the ri...
Source: Australasian Physical and Engineering Sciences in Medicine - June 3, 2019 Category: Biomedical Engineering Source Type: research

Winning images from the Photography in Medical Physics (PiMP) competition
(Source: Australasian Physical and Engineering Sciences in Medicine)
Source: Australasian Physical and Engineering Sciences in Medicine - May 28, 2019 Category: Biomedical Engineering Source Type: research

Improving automatic contrast agent extraction system using monochromatic CT number
AbstractIn a previous study, a phantom study of a contrast agent extraction system with computed tomography (CT) number and raw-data-based electron density (ED) was described. The current study improved this system with monochromatic CT (mCT) number and evaluated an anthropomorphic phantom for delineation of the contrast-enhanced region. Dual-energy CT images were scanned with a tissue-equivalent phantom and an anthropomorphic phantom with an iodinated contrast agent (1 –130 mg/mL). The 40, 70, and 130 keV mCT images were reconstructed with 80 and 135 kV CT images. The contrast agent was separated from...
Source: Australasian Physical and Engineering Sciences in Medicine - May 20, 2019 Category: Biomedical Engineering Source Type: research

Artificially enriching the training dataset of statistical shape models via constrained cage-based deformation
AbstractThe construction of a powerful statistical shape model (SSM) requires a rich training dataset that includes the large variety of complex anatomical topologies. The lack of real data causes most SSMs unable to generalize possible unseen instances. Artificial enrichment of training data is one of the methods proposed to address this issue. In this paper, we introduce a novel technique called constrained cage-based deformation (CCBD), which has the ability to produce unlimited artificial data that promises to enrich variability within the training dataset. The proposed method is a two-step algorithm: in the first step...
Source: Australasian Physical and Engineering Sciences in Medicine - May 13, 2019 Category: Biomedical Engineering Source Type: research

Assessment of the accuracy of truebeam intrafraction motion review (IMR) system for prostate treatment guidance
AbstractIntrafraction motion review (IMR), a real-time 2D, motion management feature of the Varian Truebeam ™ incorporates triggered imaging, automatic fiducial marker detection and automatic beam hold. With the increasing adoption of high dose per fraction stereotactic body radiotherapy (SBRT) this system provides a potential means to ensure treatment accuracy. The goal of this study was therefore to i nvestigate and quantify key performance characteristics of IMR for prostate treatment guidance. Phantom experiments were performed with a custom Computerized Imaging Reference Systems, Inc (CIRS) pelvis phantom with i...
Source: Australasian Physical and Engineering Sciences in Medicine - May 13, 2019 Category: Biomedical Engineering Source Type: research

Dosimetric validation of the Theragenics AgX-100 ® I-125 seed for ROPES eye plaque brachytherapy
AbstractWith the discontinued distribution of the I-125 Oncura Onco seed (model 6711), the Theragenics AgX100 ® I-125 seeds were considered as a suitable alternative for eye plaque brachytherapy as their physical properties matched the requirements for use with the ROPES eye plaques. The purpose of this study aims at validating the dosimetry of the AgX-100 loaded ROPES plaques (11 mm diameter, 15 mm diam eter with flange, 15 mm diameter with notch, 18 mm diameter) and assess the differences with the discontinued I-125 6711 model. To independently verify the plaque dosimetry, the brachytherapy module...
Source: Australasian Physical and Engineering Sciences in Medicine - May 13, 2019 Category: Biomedical Engineering Source Type: research

The power of sample size through a multi-scanner approach in MR neuroimaging regression analysis: evidence from Alzheimer ’s disease with and without depression
AbstractThe inconsistency of volumetric results often seen in MR neuroimaging studies can be partially attributed to small sample sizes and variable data analysis approaches. Increased sample size through multi-scanner studies can tackle the former, but combining data across different scanner platforms and field-strengths may introduce a variability factor capable of masking subtle statistical differences. To investigate the sample size effect on regression analysis between depressive symptoms and grey matter volume (GMV) loss in Alzheimer ’s disease (AD), a retrospective multi-scanner investigation was conducted. A ...
Source: Australasian Physical and Engineering Sciences in Medicine - May 3, 2019 Category: Biomedical Engineering Source Type: research

Leonardo DaVinci ’s contributions to medical physics and biomedical engineering: celebrating the life of a ‘Polymath’
(Source: Australasian Physical and Engineering Sciences in Medicine)
Source: Australasian Physical and Engineering Sciences in Medicine - May 2, 2019 Category: Biomedical Engineering Source Type: research

Dose verification for liver target volumes undergoing respiratory motion
This study aims to evaluate the accuracy of dose delivered to superior liver tumours using passive respiratory monitoring, in the absence of gating technology, for a range of treatment techniques. An in-house respiratory phantom was designed and constructed to simulate the lung a nd liver anatomy. The phantom consisted of adjacent slabs of lung and liver equivalent materials and a cam drive system to emulate respiratory motion. A CC04 ionisation chamber and Gafchromic EBT3 film were used to perform point dose and dose plane measurements respectively. Plans were calculated us ing an Elekta Monaco treatment planning system (...
Source: Australasian Physical and Engineering Sciences in Medicine - May 2, 2019 Category: Biomedical Engineering Source Type: research

A computationally bio-inspired framework of brain activities based on cognitive processes for estimating the depth of anesthesia
AbstractThis paper develops a computationally bio-inspired framework of brain activities based on concepts, such as sensory register (SR), encoding, emotion, short-term memory (STM), selective attention, working memory (WM), forgetting, long-term memory (LTM), sustained memory (SM), and response selection for estimating the depth of anesthesia (DOA) using electroencephalogram (EEG) signals. Different brain regions, such as the thalamus, cortex, neocortex, amygdala, striatum, basal ganglia, cerebellum, and hippocampus, are considered for developing a cognitive architecture and a computationally bio-inspired framework. A cli...
Source: Australasian Physical and Engineering Sciences in Medicine - April 23, 2019 Category: Biomedical Engineering Source Type: research

Quantitative analysis of effects of the grid specifications on the quality of digital radiography images
In this study, we aimed to analyse the quality of X-ray images acquired using grids with different specifications and proposed standardised criteria for grid use on the basis of our results. We measured modulation transfer function (MTF), normalised noise power spectrum (NNPS) and detective quantum efficiency (DQE) using grids with different ratios (10:1, 12:1 and 15:1) with or without implementing poly methyl methacrylate (PMMA) phantoms (0 –20 cm). Pixel pitch of the detector used in this experiment was 143 μm. Based on this, a grid with a line frequency of 85 line pairs/cm was selected to prevent dist...
Source: Australasian Physical and Engineering Sciences in Medicine - April 15, 2019 Category: Biomedical Engineering Source Type: research

Commissioning and performance characteristics of a pre-clinical image-guided radiotherapy system
AbstractCharacteristics of a small-animal radiotherapy device, the X-RAD SmART, are described following commissioning of the device for pre-clinical radiotherapy research. Performance characteristics were assessed using published standards and compared with previous results published for similar systems. Operational radiation safety was established. Device X-ray beam quality and output dose-rate were found to be consistent with those reported for similar devices. Output steadily declined over 18  months though remained within tolerance levels. There is considerable variation in output factor across the international i...
Source: Australasian Physical and Engineering Sciences in Medicine - April 15, 2019 Category: Biomedical Engineering Source Type: research

A knowledge-based system for brain tumor segmentation using only 3D FLAIR images
This study aims to develop a semi-automatic system for brain tumor segmentation in 3D MR images. For a given image, noise was corrected using SUSAN algorithm  first. A specific region of interest (ROI) that contains tumor was identified and then the intensity non-uniformity in ROI was corrected via the histogram normalization and intensity scaling. Each voxel in ROI was presented using 22 features and then was categorized as tumor or non-tumor by a mul tiple-classifier system. T1- and T2-weighted images and fluid-attenuated inversion recovery (FLAIR) were examined. The system performance in terms of Dice index (D...
Source: Australasian Physical and Engineering Sciences in Medicine - April 8, 2019 Category: Biomedical Engineering Source Type: research

Accurate segmentation of inflammatory and abnormal regions using medical thermal imagery
This study performed temperature emitted inflammatory area segmentation on thermal images of knees and breasts. The proposed segmentation method is of potential value in thermal image processing applications that require expediency and automation. (Source: Australasian Physical and Engineering Sciences in Medicine)
Source: Australasian Physical and Engineering Sciences in Medicine - April 5, 2019 Category: Biomedical Engineering Source Type: research

A review and analysis of stereotactic body radiotherapy and radiosurgery of patients with cardiac implantable electronic devices
AbstractThe implementation of stereotactic body radiation therapy (SBRT) and stereotactic radiosurgery (SRS) has greatly increased due to its convenience and advantages from perspectives ranging from radiobiology to radio physics. Because SBRT/SRS delivers high doses in few fractions, precise dose delivery to target volumes and sufficient sparing of adjacent organs at risk (OARs) are required. Achieving these conflicting objectives is challenging for all patients receiving SBRT/SRS and may be particularly challenging when SBRT/SRS is adopted for treating patients with cardiac implantable electronic devices (CIEDs) because ...
Source: Australasian Physical and Engineering Sciences in Medicine - April 4, 2019 Category: Biomedical Engineering Source Type: research

A review of international and developed practices of medical physics from a legislative and regulatory point of view and its applicability and comparison with Pakistan
The objective of this review is to (i) summarize the international practices for the legislation and regulation of medical physics, (ii) provide a brief overview of the medical physics practices in Pakistan and (iii) discuss the applicability of the IAEA-EC meeting’s recommendations to the case of Pakistan. The review highlights the areas which are addressed in IAEA-EC meeting and could be beneficial to other nations as well, particularly, for low and middle income countries. The review also presents few suggestions how t o progress with the medical physics profession in developing countries in general, and in Pakist...
Source: Australasian Physical and Engineering Sciences in Medicine - April 4, 2019 Category: Biomedical Engineering Source Type: research

A comparative study between normal electrocardiogram signal and those of some cardiac arrhythmias based on McSharry mathematical model
AbstractIn this paper, synthetic electrocardiogram signals (SECG) of eight cardiac arrhythmias (sinus bradycardia, junctional bradycardia, tachycardia, flutter, atrial extrasystole, ventricular extrasystole, left branch block and right branch block) are obtained numerically by solving the McSharry mathematical model (2003) based on three coupled ordinary differential equations with the fourth-order Runge –Kutta method. They are compared with normal electrocardiogram signal. Indeed, visual analysis of a section of electrocardiogram (ECG) signals of these arrhythmias was used to suggest suitable values for the paramete...
Source: Australasian Physical and Engineering Sciences in Medicine - April 2, 2019 Category: Biomedical Engineering Source Type: research

Ultrasound shear wave simulation of wave propagation at oblique angles
In this study, the effect of wave propagation at oblique angles on the tissue shear modulus reconstruction was investigated using in silico finite element (FE) simulation. An FE elastic tissue with a hard inclusion model was designed. The shear waves with propagation angles of 0 °, 5°, and 10° were applied to the model. The shear modulus and the percentage error in the model were computed using the AHI equation and the TOF-based algorithm at each propagation angle from 0° to 10°. For the AHI equation, the percentage error was 0% at propagation angles of 0° and 5°, an d 1% at a propagation angle ...
Source: Australasian Physical and Engineering Sciences in Medicine - March 15, 2019 Category: Biomedical Engineering Source Type: research

Development and validation of a measurement system for continuously monitoring postoperative reservoir levels
AbstractFollowing cardiac surgical procedures, multiple drainage systems remain in place inside the patient ’s chest to prevent the development of pericardial effusion or pneumothorax. Therefore, postoperative bleeding must be diligently observed. Currently, observation of the exudate rate is performed through periodical visual inspection of the reservoir. To improve postoperative monitoring, a measurem ent system based on load cells was developed to automatically detect bleeding rates. A reservoir retaining bracket was instrumented with a load cell. The signal was digitized by a microcontroller and then processed an...
Source: Australasian Physical and Engineering Sciences in Medicine - March 13, 2019 Category: Biomedical Engineering Source Type: research

Verification of the Elekta Monaco TPS Monte Carlo in modelling radiation transmission through metals in a water equivalent phantom
This study uses basic shapes providing results that remove the uncertainties in geometry and can therefore be applied to any shape. This will help determine whether errors in dos e calculations are due to the TPS particle transport algorithms or due to other effects, such as inaccurate contouring or incorrect densities. Thus giving the planner an additional degree of freedom in their planning and decision making process. (Source: Australasian Physical and Engineering Sciences in Medicine)
Source: Australasian Physical and Engineering Sciences in Medicine - March 12, 2019 Category: Biomedical Engineering Source Type: research

Application of retrospective data analysis to clinical protocol design: can the potential benefits of breath-hold techniques for breast radiotherapy be assessed without testing on patients?
This study investigated the use of retrospective analysis of past patient treatment plans, as a means to identify the potential for breath-hold techniques to benefit patients. In-house “Treatment and Dose Assessor” code was used to complete a bulk retrospective evaluation of dose-volume metrics for 708 supine and 13 prone breast and chest wall radiotherapy treatments, that were planned using the same clinical protocols, which did not utilise a breath hold technique. For supine patients, results showed statistically significant differences between heart doses from left and right breast treatment plans, in the ab...
Source: Australasian Physical and Engineering Sciences in Medicine - March 8, 2019 Category: Biomedical Engineering Source Type: research

Effect of computed tomography number-relative electron density conversion curve on the calculation of radiotherapy dose and evaluation of Monaco radiotherapy treatment planning system
This study aims to evaluate the effect of CT-RED curve on the dose calculation by the Monaco radiotherapy TPS. Four CT images of the CIRS phantom were obtained by different CT scanners. The accuracy of the dose calculation in the three algorithms of the Monaco TPS (Monte Carlo, collapse cone, and pencil beam) is also evaluated based on TECDOC 1583. The CT-RED curves from the CT scanners were transferred to the Monaco TPS to audit the different algorithms of the TPS. The dose values were measured with an ionization chamber in the CIRS phantom. Then, the dose values were calculated by the Monaco algorithms in the correspondi...
Source: Australasian Physical and Engineering Sciences in Medicine - March 8, 2019 Category: Biomedical Engineering Source Type: research

Effective temporal resolution and image quality of volume scanning in 320-row detector CT
This study revealed the TSPs and eTRs for non-helical volume scanning in area detector CT. A high eTR resulted in higher image noise. (Source: Australasian Physical and Engineering Sciences in Medicine)
Source: Australasian Physical and Engineering Sciences in Medicine - March 7, 2019 Category: Biomedical Engineering Source Type: research

Effects of spray parameters on skin tumour ablation volume during cryotherapy
AbstractThe main purpose of the study is to establish correlations for the ablation volume and the ice front as a function of the spray parameters. The ablation volume and the ice front depend upon the nozzle diameter, spraying distance and the freeze duration (spray parameters). The estimation of the ablation volume using the spray parameters shall be useful in surgical practice to ablate the different sizes of tumours. Liquid nitrogen spray cooling is carried out with 0.8 mm, 0.6 mm and 0.4 mm nozzle diameters. The spraying distance is maintained at 9 mm, 18 mm and 27 mm. The spray cooling is carried out for a single fre...
Source: Australasian Physical and Engineering Sciences in Medicine - March 5, 2019 Category: Biomedical Engineering Source Type: research

Correction to: Computational study on hemodynamic changes in patient-specific proximal neck angulation of abdominal aortic aneurysm with time-varying velocity
The name of the third author was incorrect in the initial online publication. The original article has been corrected. (Source: Australasian Physical and Engineering Sciences in Medicine)
Source: Australasian Physical and Engineering Sciences in Medicine - March 5, 2019 Category: Biomedical Engineering Source Type: research

Influence of normalization and color features on super-pixel classification: application to cytological image segmentation
AbstractSuper-pixel feature extraction is a key problem to get an acceptable performance in color super-pixel classification. Given a color feature extraction problem, it is necessary to know which is the best approach to solve this problem. In the current work, we ’re interested in the challenge of nucleus and cytoplasm automatic recognition in the cytological image. We propose an automatic process for white blood cells (WBC) segmentation using super-pixel classification. The process is divided into five steps. In first step, the color normalization is calc ulated. The super-pixels generation by Simple Linear Iterat...
Source: Australasian Physical and Engineering Sciences in Medicine - March 4, 2019 Category: Biomedical Engineering Source Type: research

A Monte Carlo study of pinhole collimated Cerenkov luminescence imaging integrated with radionuclide treatment
In this study, we proposed to integrate the CLI technique with the radionuclide treatment as a “see-and-treat” approach, and evaluated the performance of the pinhole collimator-based CLI technique. The detection of Cerenkov luminescence during radionuclide therapy was simulated using the Monte Carlo technique for breast cancer treatment as an example. Our results show that with the pinhol e collimator-based configuration, the location, size and shape of the tumors can be clearly visualized on the Cerenkov luminescence images of the breast phantom. In addition, the CLI of multiple tumors can reflect the relative...
Source: Australasian Physical and Engineering Sciences in Medicine - March 4, 2019 Category: Biomedical Engineering Source Type: research

Feature extraction using traditional image processing and convolutional neural network methods to classify white blood cells: a study
AbstractWhite blood cells play a vital role in monitoring health condition of a person. Change in count and/or appearance of these cells indicate hematological disorders. Manual microscopic evaluation of white blood cells is the gold standard method, but the result depends on skill and experience of the hematologist. In this paper we present a comparative study of feature extraction using two approaches for classification of white blood cells. In the first approach, features were extracted using traditional image processing method and in the second approach we employed AlexNet which is a pre-trained convolutional neural ne...
Source: Australasian Physical and Engineering Sciences in Medicine - March 4, 2019 Category: Biomedical Engineering Source Type: research