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<jats:title>Abstract</jats:title> <jats:p> <jats:italic>Purpose:</jats:italic> To identify the relative positions of the ultimate RBE, at a LET value of LET<jats:sub>U</jats:sub> (where the LET-RBE turnover point occurs independently of dose), and of the maximum LET (LET<jats:sub>M</jats:sub>) for a range of ions from protons to Iron ions. <jats:italic>Methods:</jats:italic> For a range of relativistic velocities (<jats:italic>β</jats:italic>), the kinetic energies, LET values and ranges for each ion are obtained using SRIM software. For protons and helium ions, the LET changes with <jats:italic>β</jats:italic> are plotted and LET<jats:sub>M</jats:sub> is compared with LET<jats:sub>U.</jats:sub> For all the ions studied the residual ranges of particles at LET<jats:sub>U</jats:sub> and LET<jats:sub>M</jats:sub> are subtracted to provide the physical separation (S) between LET<jats:sub>U</jats:sub> and LET<jats:sub>M</jats:sub>. <jats:italic>Results:</jats:italic> Graphical methods are used to show the above parameters for protons and helium ions. For all the ions studied, LET<jats:sub>U</jats:sub> occurs at kinetic energies which are higher than those at LET<jats:sub>M</jats:sub>, so the ultimate maximal RBE occurs proximal to the Bragg peak for individual particles and not beyond it, as is commonly supposed. The distance S, between LET<jats:sub>U</jats:sub> and LET<jats:sub>M</jats:sub>, appears to increase linearly with the atomic charge value Z. <jats:italic>Conclusions:</jats:italic> For the lighter elements, from protons to carbon ions, S is sufficiently small (less than the tolerance/accuracy of radiation treatments) and so will probably not influence therapeutic decisions or outcomes. For higher Z numbers such as Argon and Iron, larger S values of several centimetres occur, which may have implications not only in any proposed therapeutic beams but also at very low doses encountered in radiation protection where the few cells that are irradiated will typically be traversed by a single particle.</jats:p>

<jats:title>Abstract</jats:title> <jats:p> <jats:italic>Objective:</jats:italic> To investigate the association between subjective pain intensity and objective parameters obtained from two autonomic function tests in a longitudinal study targeting acute pain model in otolaryngology-head and neck region: pupillary light reflex (PLR) and heart rate variability (HRV). <jats:italic>Approach:</jats:italic> We enrolled 35 patients with acute otolaryngology—head and neck region inflammatory disorders at pre-treatment stage. The acute inflammatory disorders were defined as acute tonsillitis, peritonsillar abscess, acute epiglottitis, acute sinusitis, and deep neck space abscess. Patients underwent a numeric rating scale (NRS) to monitor subjective pain intensity, PLR, and HRV as objective tests at 4 time-points during the follow-up term. As main outcome variables, we used 15 analyzable PLR/HRV parameters. To improve robustness of conclusions about the association between NRS and PLR/HRV parameters, we prepared four linear mixed-effects models (LMMs) including predictor variables such as NRS, sociodemographic factors, and individual variability. And then, we selected the better-fit model based on the lowest Akaike’s information criterion. <jats:italic>Main results:</jats:italic> NRS significantly decreased due to treatments. In 14 out of 15 parameters, better-fit models were models including not only sociodemographic factors but also individual variability. We observed significant parameter alterations to one unit change of NRS in five PLR and four HRV parameters. <jats:italic>Significance:</jats:italic> The current study revealed that PLR/HRV parameters can be used as biomarkers reflecting pain relief effects. In addition, the findings suggest the importance of adjusting predictor variables, especially individual variability defined as random effects in LMMs, for obtaining more accurate parameter estimation in the longitudinal study.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>This work presents a novel architecture, exemplified for electrophysiological applications like ECoG that can be used to detect Epilepsy. The new ECoG is based on a mixed analog-digital architecture (Pulse Amplitude Modulation PAM), that allows the use of thousands of electrodes for recording. Whilst the increased number of electrodes helps to refine the spatial resolution of the medical application, the transmission of the signals from the electrodes to an external analysing device appears to be a bottleneck. To overcoming this, our work presents a hardware architecture and corresponding protocol for a mixed architecture that improves the information density between channels and their signal-to-noise ratio. This is shown by the correlation between the input and the transmitted signals in comparison to a classical digital transmission (Pulse Code Modulation PCM) system. We show in this work that it is possible to transmit the signals of 10 channels with a analog-digital architecture with the same quality of a full digital architecture.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Computed tomography (CT) is the reference method for cardiac imaging, but concerns have been raised regarding the radiation dose of CT examinations. Recently, photon counting detectors (PCDs) and interior tomography, in which the radiation beam is limited to the organ-of-interest, have been suggested for patient dose reduction. In this study, we investigated interior PCD-CT (iPCD-CT) for non-enhanced quantification of coronary artery calcium (CAC) using an anthropomorphic torso phantom and <jats:italic>ex vivo</jats:italic> coronary artery samples. We reconstructed the iPCD-CT measurements with filtered back projection (FBP), iterative total variation (TV) regularization, padded FBP, and adaptively detruncated FBP and adaptively detruncated TV. We compared the organ doses between conventional CT and iPCD-CT geometries, assessed the truncation and cupping artifacts with iPCD-CT, and evaluated the CAC quantification performance of iPCD-CT. With approximately the same effective dose between conventional CT geometry (0.30 mSv) and interior PCD-CT with 10.2 cm field-of-view (0.27 mSv), the organ dose of the heart was increased by 52.3% with interior PCD-CT when compared to CT. Conversely, the organ doses to peripheral and radiosensitive organs, such as the stomach (55.0% reduction), were often reduced with interior PCD-CT. FBP and TV did not sufficiently reduce the truncation artifact, whereas padded FBP and adaptively detruncated FBP and TV yielded satisfactory truncation artifact reduction. Notably, the adaptive detruncation algorithm reduced truncation artifacts effectively when it was combined with reconstruction detrending. With this approach, the CAC quantification accuracy was good, and the coronary artery disease grade reclassification rate was particularly low (5.6%). Thus, our results confirm that CAC quantification can be performed with the interior CT geometry, that the artifacts are effectively reduced with suitable interior reconstruction methods, and that interior tomography provides efficient patient dose reduction.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>It has been reported that when a grounded human is exposed to an electric field at power frequency, a short-circuit current flowing from the feet to the ground is proportional to the square of his or her height. The current, however, should also vary with the body surface area, that is, body shape, even in people with the same height. In the present study, we confirmed this hypothesis using an analytical solution derived from a semi-ellipsoidal model. The short-circuit currents were calculated for various numerical human body models in which the horizontal length of a voxel was varied from 1.8 to 3.0 mm, and the results for different body shapes were compared. Finally, we derived an approximate expression for estimating the short-circuit current from the left-right width (2<jats:italic>b</jats:italic>), frontal thickness (2<jats:italic>c</jats:italic>), and height (<jats:italic>a</jats:italic>) of a human from the analytical solution. The short-circuit currents obtained from the approximate expression are consistent with those obtained from numerical calculations for 48 differently shaped human body models with a correlation coefficient of 0.9942. Hence, we concluded that the short-circuit current can be determined depending on the similarity ratio (<jats:italic>a</jats:italic>/<jats:italic>b</jats:italic>) and the ellipticity ratio (<jats:italic>c</jats:italic>/<jats:italic>b</jats:italic>) of the human body as well as the height. This finding is consistent with the numerical human body models that have been used previously, in which the similarity and ellipticity ratios were very close. Therefore, we can make the limited conclusion that the short-circuit current is proportional only to the square of the height. Additionally, numerical calculations showed that the short-circuit current is the same whether one foot or both feet are grounded.</jats:p>