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<jats:title>Abstract</jats:title> <jats:p>The development of modern micro-processing technology has led to the design and production of sub-millimeter-sized coils. A novel type of micro-magnetic stimulation (<jats:italic>μ</jats:italic>MS) regulatory technology has widely been researched in recent years. This technology has several advantages, including small size, no contact between tissues and the metal coil, and high spatial resolution. Considering some problems with the <jats:italic>μ</jats:italic>MS control technology in practical applications, different kinds of <jats:italic>μ</jats:italic>MS devices have been developed, including an <jats:italic>in vitro</jats:italic> single-point <jats:italic>μ</jats:italic>MS device, an <jats:italic>in vivo</jats:italic> implantable single-point <jats:italic>μ</jats:italic>Ms device, a discrete-array <jats:italic>μ</jats:italic>MS device, and an <jats:italic>in vivo</jats:italic> implantable-array <jats:italic>μ</jats:italic>Ms device. Given the problems that currently exist in the design and implementation of this device, such as the key problems of structural design, implantation method, experimental safety, and reliability of the device, we review the development process in detail. We also discuss the precise targeting advantage of this device, which is likely to be of great significance for wide-ranging applications of magnetic stimulation technology.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>In optimizing the imaging conditions, changes in image quality due to scattered radiation are important evaluation targets. This study focuses on the evaluation of the image quality improvement characteristics obtained using anti-scatter grids in digital x-ray imaging, and proposes a frequency-dependent modulation transfer function (MTF) improvement factor, <jats:inline-formula> <jats:tex-math> <?CDATA $MI{F}_{G}(u),$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>M</mml:mi> <mml:mi>I</mml:mi> <mml:msub> <mml:mrow> <mml:mi>F</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>G</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:mi>u</mml:mi> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> <mml:mo>,</mml:mo> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bpexabfc2fieqn1.gif" xlink:type="simple" /> </jats:inline-formula> as a new evaluation index. Accordingly, the purpose of this study is to clarify the validity and the usefulness of this proposed index in the performance evaluation of grids. The proposed <jats:inline-formula> <jats:tex-math> <?CDATA $MI{F}_{G}(u)$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>M</mml:mi> <mml:mi>I</mml:mi> <mml:msub> <mml:mrow> <mml:mi>F</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>G</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:mi>u</mml:mi> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bpexabfc2fieqn2.gif" xlink:type="simple" /> </jats:inline-formula> method is applied to evaluate several types of grids with different grid densities and ratios, and the characteristics of grids exhibiting different performances are examined. The proposed index is calculated based on the MTF measurement by using an edge test device. The results show that <jats:inline-formula> <jats:tex-math> <?CDATA $MI{F}_{G}(u)$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>M</mml:mi> <mml:mi>I</mml:mi> <mml:msub> <mml:mrow> <mml:mi>F</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>G</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:mi>u</mml:mi> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bpexabfc2fieqn3.gif" xlink:type="simple" /> </jats:inline-formula> changed according to grid type and scatter conditions. In particular, a remarkable difference was observed in the high scatter condition compared with the low condition. <jats:inline-formula> <jats:tex-math> <?CDATA $MI{F}_{G}(u)$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>M</mml:mi> <mml:mi>I</mml:mi> <mml:msub> <mml:mrow> <mml:mi>F</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>G</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:mi>u</mml:mi> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bpexabfc2fieqn4.gif" xlink:type="simple" /> </jats:inline-formula> in the vertical direction with regards to the absorbing strips shows a peak at 0.2–0.5 cycles/mm and be a constant value from approximately 1 cycle/mm; while <jats:inline-formula> <jats:tex-math> <?CDATA $MI{F}_{G}(u)$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>M</mml:mi> <mml:mi>I</mml:mi> <mml:msub> <mml:mrow> <mml:mi>F</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>G</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:mi>u</mml:mi> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bpexabfc2fieqn5.gif" xlink:type="simple" /> </jats:inline-formula> in the parallel direction is a constant value with respect to changes in spatial frequency. It is shown that <jats:inline-formula> <jats:tex-math> <?CDATA $MI{F}_{G}(u)$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>M</mml:mi> <mml:mi>I</mml:mi> <mml:msub> <mml:mrow> <mml:mi>F</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>G</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:mi>u</mml:mi> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bpexabfc2fieqn6.gif" xlink:type="simple" /> </jats:inline-formula> could be used to accurately describe the characteristics of a grid under different imaging conditions. We believe that the use of the proposed index could expand the options for optimizing imaging conditions when using grids.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The potential of naturally occurring substances as a source of biomedical materials is well-recognised and is being increasingly exploited. Silk fibroin membranes derived from <jats:italic>Bombyx mori</jats:italic> silk cocoons exemplify this, for example as substrata for the growth of ocular cells with the aim of generating biomaterial-cell constructs for tissue engineering. This study investigated the transport properties of selected silk fibroin membranes under conditions that allowed equilibrium hydration of the membranes to be maintained. The behaviour of natural fibroin membranes was compared with fibroin membranes that have been chemically modified with poly(ethylene glycol). The permeation of the smaller hydrated sodium ion was higher than that of the hydrated calcium ion for all three ethanol treated membranes investigated. The PEG and HRP-modified C membrane, which had the highest water content at 59.6 ± 1.5% exhibited the highest permeation of the three membranes at 95.7 ± 2.8 × 10<jats:sup>–8</jats:sup> cm<jats:sup>2</jats:sup> s<jats:sup>−1</jats:sup> compared with 17.9 ± 0.9 × 10<jats:sup>–8</jats:sup> cm<jats:sup>2</jats:sup> s<jats:sup>−1</jats:sup> and 8.7 ± 1.7 × 10<jats:sup>–8</jats:sup> cm<jats:sup>2</jats:sup> s<jats:sup>−1</jats:sup> for membranes A and B respectively for the NaCl permeant. Poly(ethylene glycol) was used to increase permeability while exploiting the crosslinking capabilities of horseradish peroxidase to increase the compressive strength of the membrane. Importantly, we have established that the permeation behaviour of water-soluble permeants with hydrated radii in the sub-nanometer range is analogous to that of conventional hydrogel polymers.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Electroencephalogram (EEG) signals recorded from the ambulatory systems are mostly contaminated by various artifacts like, electrooculogram (EOG), motion artifacts (MA) and electrocardiogram (ECG) artifacts. These artifacts limit the accuracy in further analysis of EEG in practise. So far, several existing methods have been proposed with the combination of decomposition techniques and independent component analysis (ICA) to remove single artifacts and only few methods to remove multiple artifacts from the single channel EEG. As improperly denoised EEG signals can result in wrong diagnosis, in this work, Singular Spectrum Analysis (SSA) and ICA are jointly combined with Generalized Moreau Envelope Total Variation (GMETV) technique to simultaneously remove combinations of different artifacts from single channel EEG. In this work, the SSA is used to decompose the contaminated single channel EEG, while the ICA is employed to separate the various hidden sources as independent components (ICs). Although the ICA is adequate in source separation, there is still, some essential EEG signal data appearing as artifact in the IC. Hence, eliminating this would allow EEG signal information to be lost. The GMETV approach is proposed in this paper, to estimate the actual artifacts in order to address these issues. The estimated actual artifacts are subtracted from the artifact ICs providing the residue of wanted component of EEG. This residue is added back to the remaining ICs, to obtain the denoised EEG. Simulation results demonstrated that the proposed technique performs better compared to the existing techniques. The Relative Root Mean Square Error (RRMSE) is reduced by 12.02% and 7.22% compared to SSA-ICA and SSA-ICA-thresholding respectively. Similarly, the Correlation Coefficient (CC) is increased by 21.48% and 8.25% with respect to SSA-ICA and SSA-ICA-thresholding respectively.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The present study aimed to dosimetrically evaluate the small-fields of a 6 MV flattening filter-free (FFF) photon beam using different detectors.The 6 MV FFF photon beam was used for measurement of output factor, depth dose, and beam profile of small-fields of sizes 0.6 cm × 0.6 cm to 6.0 cm × 6.0 cm. The five detectors used were SNC125c, PinPoint, EDGE, EBT3, and TLD-100. All measurements were performed as per the International Atomic Energy Agency TRS 483 protocol. Output factors measured using different detectors as direct reading ratios showed significant variation for the smallest fields, whereas after correcting them according to TRS 483, all sets of output factors were nearly compatible with each other when measurement uncertainty was also considered. The beam profile measured using SNC125c showed the largest penumbra for all field sizes, whereas the smallest was recorded with EDGE. Compared with that of EBT3, the surface dose was found to be much higher for all the other detectors. PinPoint, EBT3, TLD-100, and EDGE were found to be the detector of choice for small-field output factor measurements; however, PinPoint needs special attention when used for the smallest field size (0.6 cm × 0.6 cm). EDGE and EBT3 are optimal for measuring beam profiles. EBT3, PinPoint, and EDGE can be selected for depth dose measurements, and EBT3 is suitable for surface dose estimation.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We report a methodology to analyze data extracted from infrared images. These pictures show the lower limbs of a cohort of individuals belonging to, (1) voluntary controls and (2) patients diagnosed with diabetes mellitus type II. The analysis is presented in terms of Cross Entropy and temperature distributions; both using the associated thermal histograms. The temperature analysis is placed in terms of comparing the extreme values of <jats:italic>dS</jats:italic>/<jats:italic>dQ</jats:italic>, for controls and patients. In this analysis for the frontal view, the values of specificity and sensitivity calculated were 77.77% and 91.66%, respectively. For the back view, the specificity and sensitivity obtained were 88.8% and 83.3%, respectively. Instead of that, the cross-entropy analysis is placed in the modality of self-referencing. In this part of the study we obtained the coefficient of asymmetry and thermal response (ATR). The values of specificity and sensitivity for the ATR quotient in both cases were 83.3%. The results of both studies have a significant correlation with glucose (<jats:italic>p</jats:italic> &lt; 0.01) and HbA1c (<jats:italic>p</jats:italic> &lt; 0.01). It means that both approaches have statistical correspondence. By means of the Mann-Whitney U test, for independent samples, we get that the characteristic parameters we analyze can be differentiated among the populations of interest with a significance of <jats:italic>p</jats:italic> &lt; 0.05. This suggests that both studies show consistency with the clinical diagnosis; exhibiting clear differences between control and patient groups.</jats:p>

<jats:title>Abstract</jats:title> <jats:p> <jats:italic>Purpose</jats:italic>. The purpose of the current study was to investigate the impact of RayStation analytical pencil beam (APB) and Monte Carlo (MC) algorithms on the interplay effect in pencil beam scanning (PBS) proton-based stereotactic body radiation therapy (SBRT) lung plans. <jats:italic>Methods</jats:italic>. The current <jats:italic>in-silico</jats:italic> planning study was designed for a total dose of 5000 cGy(RBE) with a fractional dose of 1000 cGy(RBE). First, three sets of nominal plans were generated for each patient: (a) APB optimization followed by APB dose calculation (PB‐PB), (b) APB optimization followed by MC dose calculation (PB‐MC), and (c) MC optimization followed by MC dose calculation (MC‐MC). Second, for each patient, two sets of volumetric repainting plans (five repaintings) – PB-MC<jats:sub>VR5</jats:sub> and MC-MC<jats:sub>VR5</jats:sub> were generated based on PB-MC and MC-MC, respectively. Dosimetric differences between APB and MC algorithms were calculated on the nominal and interplay dose-volume-histograms (DVHs). <jats:italic>Results</jats:italic>. Interplay evaluation in non-volumetric repainting plans showed that APB algorithm overestimated the target coverage by up to 8.4% for D<jats:sub>95%</jats:sub> and 10.5% for D<jats:sub>99%</jats:sub>, whereas in volumetric repainting plans, APB algorithm overestimated by up to 5.3% for D<jats:sub>95%</jats:sub> and 7.0% for D<jats:sub>99%</jats:sub>. Interplay results for MC calculations showed a decrease in D<jats:sub>95%</jats:sub> and D<jats:sub>99%</jats:sub> by average differences of 3.5% and 4.7%, respectively, in MC‐MC plans and by 1.8% and 3.0% in MC-MC<jats:sub>VR5</jats:sub> plans. <jats:italic>Conclusion</jats:italic>. In PBS proton-based SBRT lung plans, the combination of APB algorithm and interplay effect reduced the target coverage. This may result in inferior local control. The use of MC algorithm for both optimization and final dose calculations in conjunction with the volumetric repainting technique yielded superior target coverage.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>According to the World Health Organization, 50% of deaths in European Union are caused by Cardiovascular Diseases (CVD), while 80% of premature heart diseases and strokes can be prevented. In this study, a Computer-Aided Diagnostic model for a precise diagnosis of Coronary Artery Disease (CAD) is proposed. The methodology is based on State Space Advanced Fuzzy Cognitive Maps (AFCMs), an evolution of the traditional Fuzzy Cognitive Maps. Also, a rule-based mechanism is incorporated, to further increase the knowledge of the proposed system and the interpretability of the decision mechanism. The proposed method is evaluated utilizing a CAD dataset from the Department of Nuclear Medicine of the University Hospital of Patras, in Greece. Several experiments are conducted to define the optimal parameters of the proposed AFCM. Furthermore, the proposed AFCM is compared with the traditional FCM approach and the literature. The experiments highlight the effectiveness of the AFCM approach, obtaining 85.47% accuracy in CAD diagnosis, showing an improvement of +7% over the traditional approach. It is demonstrated that the AFCM approach in developing Fuzzy Cognitive Maps outperforms the conventional approach, while it constitutes a reliable method for the diagnosis of Coronary Artery Disease.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Segmenting lesion regions of Coronavirus Disease 2019 (COVID-19) from computed tomography (CT) images is a challenge owing to COVID-19 lesions characterized by high variation, low contrast between infection lesions and around normal tissues, and blurred boundaries of infections. Moreover, a shortage of available CT dataset hinders deep learning techniques applying to tackling COVID-19. To address these issues, we propose a deep learning-based approach known as PPM-Unet to segmenting COVID-19 lesions from CT images. Our method improves an Unet by adopting pyramid pooling modules instead of the conventional skip connection and then enhances the representation of the neural network by aiding the global attention mechanism. We first pre-train PPM-Unet on COVID-19 dataset of pseudo labels containing1600 samples producing a coarse model. Then we fine-tune the coarse PPM-Unet on the standard COVID-19 dataset consisting of 100 pairs of samples to achieve a fine PPM-Unet. Qualitative and quantitative results demonstrate that our method can accurately segment COVID-19 infection regions from CT images, and achieve higher performance than other state-of-the-art segmentation models in this study. It offers a promising tool to lay a foundation for quantitatively detecting COVID-19 lesions.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The dosimetry of intraoral radiography procedures is of great interest since dental examinations are among the most numerous radiological procedures. Usually, the surveys are performed using measurements free in air. The entrance surface air kerma (<jats:italic>K</jats:italic> <jats:sub> <jats:italic>e</jats:italic> </jats:sub>) can be estimated from measurements of incident air kerma and the use of backscatter factors (BSF). The purpose of this work is to calculate BSF values suitable for intraoral radiography. In addition to specific intraoral radiography, a comprehensive reassessment of internationally recommended BSF values was performed through Monte Carlo simulations. Moreover, the <jats:italic>K</jats:italic> <jats:sub> <jats:italic>e</jats:italic> </jats:sub> was estimated using the calculated BSF values for a sample of 44 intraoral radiography systems. The interpolation of intraoral radiography BSF values from reference data can lead to an overestimation of up to 10% and 6% in comparison with the values calculated in this work for monoenergetic photons and x-ray spectra, respectively. Such discrepancy may be relevant when defining diagnostic reference levels (DRLs) or performing quality control tests. The calculations for a sample of 44 intraoral radiography systems showed that the majority of the equipment operates with an entrance surface air kerma higher than 3.5 mGy. In the case of adopting a single value to estimate <jats:italic>K</jats:italic> <jats:sub> <jats:italic>e</jats:italic> </jats:sub>, the use of BSF equal to 1.2 results in less dispersion compared to calculated values in this work and the use of 1.1 can underestimate <jats:italic>K</jats:italic> <jats:sub> <jats:italic>e</jats:italic> </jats:sub> values up to 12%.</jats:p>