Setup Technique Research Articles

MH Setup Technique, A Manually Customized Bracket-Setup, applied in Fully-treated Class II molar-relationship case

The case published in this paper provides a clinical explanation for the importance of MH setup. The casts were cut and teeth were set into wax rims using brackets fit on full engagement archwires. Then another set of brackets was set over the teeth after the necessary adjustments with another full engagement archwires using composite as custom-made bases. The final brackets were transferred to the patient using vacuum-formed indirect transfer trays and the treatment was commenced. The final results were ideal with a total treatment time of one year in an extraction case. The finishing phase was only one month with settling elastics without the need for any brackets modifications despite the class II full unit molar relationship.

Abstract PO5-22-02: Evaluation of a surface-guided and tattoo-less approach to setup for whole breast radiotherapy

Abstract Background: In preparation for adjuvant breast radiation therapy (RT), several small but permanent skin tattoo marks are often placed to assist with surface alignment for treatment setup and delivery. With advancements in surface-guided technologies, it may be possible to achieve setup accuracy with a “tattoo-less” approach, which can improve cosmetic and quality of life outcomes. This study evaluates the feasibility, accuracy, and potential dosimetric implications of a tattoo-less setup technique. Method: A retrospective analysis of 10 patients diagnosed with right-sided breast cancer who received adjuvant whole breast RT using a tattoo-less approach were included in this study. All patients received an initial whole breast dose of 42.56 Gray (Gy) in 16 daily fractions using a tangential three-dimensional conformal planning technique. This was followed by a 10Gy boost to the lumpectomy site delivered in 4 daily fractions. Daily setup for whole breast treatment was performed by aligning each patient to their individual reference breast surface generated from the planning computed tomography (CT) images via the Vision RT system. Bony landmarks were then verified via daily kV imaging, and translational shifts were recorded for each fraction. The kV imaging was performed to confirm the treatment positioning since the tattoo-less approach was new to the department. For 5 patients, dosimetric differences between initial surface alignment and shifts performed based on bony landmarks were evaluated by recalculating the original clinical plan with a new isocenter position using kV image shifts for each of their 16 treatment fractions. A plan sum of the 16 recalculated plans for each patient was used in further dosimetric analysis. Boost fractions were not included in this study, as setup was verified using surgical clips instead of bony anatomy. Results: Translational shifts for 158 fractions were reviewed as no kV imaging was performed for the other 2 fractions. The mean absolute kV imaging shift was 0.29 cm (CI (95%): 0.25, 0.32; range: 0 to 1.25) in the vertical axis, 0.28 cm (0.23, 0.32; 0 to 1.27) in the longitudinal axis, and 0.24 cm (0.20, 0.28; 0 to 1.98) in the lateral axis. Clinical plans for 5 patients were evaluated with a mean absolute kV shift of 0.27 cm (range: 0.15 to 0.39) in the vertical, 0.32 cm (0.13 to 0.77) in the longitudinal, and 0.29 cm (0.18 to 0.38) in the lateral directions. Dosimetric analysis revealed a slight increase in mean heart dose from the original clinical plan, with an average difference of 4.12 cGy (range: 0.7 to 10.5 cGy). The maximum increase in V20Gy of the ipsilateral lung was 2.7%. Less than 1% of change was observed in the maximum plan dose, as well as in the V95% coverage, expect for one patient, whose V95% was decreased from 99.6% to 94.6%. This difference was caused by a large longitudinal shift which could be attributed to possible patient movement. Conclusions: These findings demonstrate the feasibility and accuracy of a tattoo-less treatment approach in a small cohort of breast cancer patients receiving whole breast RT. Further investigation with larger cohorts is warranted. Citation Format: Xinxin Zhang, Swati Mamidanna, Yin Zhang, Xiao Wang, Ning Yue, Shicha Kumar, Lindsay Potdevin, Maria Kowzun, Mridula George, Lara Hathout, Bruce Haffty, Nisha Ohri. Evaluation of a surface-guided and tattoo-less approach to setup for whole breast radiotherapy [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-22-02.

Bichromatic tetraphasic full-field optical coherence microscopy.

Full-field optical coherence microscopy (FF-OCM) is a prevalent technique for backscattering and phase imaging with epi-detection. Traditional methods have two limitations: suboptimal utilization of functional information about the sample and complicated optical design with several moving parts for phase contrast. We report an OCM setup capable of generating dynamic intensity, phase, and pseudo-spectroscopic contrast with single-shot full-field video-rate imaging called bichromatic tetraphasic (BiTe) full-field OCM with no moving parts. BiTe OCM resourcefully uses the phase-shifting properties of anti-reflection (AR) coatings outside the rated bandwidths to create four unique phase shifts, which are detected with two emission filters for spectroscopic contrast. BiTe OCM overcomes the disadvantages of previous FF-OCM setup techniques by capturing both the intensity and phase profiles without any artifacts or speckle noise for imaging scattering samples in three-dimensional (3D). BiTe OCM also utilizes the raw data effectively to generate three complementary contrasts: intensity, phase, and color. We demonstrate BiTe OCM to observe cellular dynamics, image live, and moving micro-animals in 3D, capture the spectroscopic hemodynamics of scattering tissues along with dynamic intensity and phase profiles, and image the microstructure of fall foliage with two different colors. BiTe OCM can maximize the information efficiency of FF-OCM while maintaining overall simplicity in design for quantitative, dynamic, and spectroscopic characterization of biological samples.

Feasibility of a Novel Surface-Guided Setup Technique to Reproduce Neck Curvature Using two Regions of Interest.

To improve the setup reproducibility of neck curvature using real-time optical surface imaging (OSI) guidance on 2 regions of interest (ROIs) to infer cervical spine (c-spine) curvature for surface-guided radiotherapy (SGRT) of head-and-neck (HN) and c-spine cancer. A novel SGRT setup approach was designed to reproduce neck curvature with 2 ROIs: upper-chest ROI and open-face ROI. It was hypothesized that the neck curvature could be reproduced if both ROIs were aligned within ±3 mm/2˚ tolerance. This was tested prospectively in 7 volunteers using real-time 3D-OSI guidance and lateral 2D-photography verification after the 3D and 2D references were captured from the initial conventional setup. Real-time SGRT was performed to align chest-ROI and face-ROI, and the longitudinal distance between them was adjustable using a head-support slider. Verification of neck curvature anteriorly and posteriorly was achieved by overlaying edge-extracted lateral pictures. Retrospectively, the relationship between anterior surface and spinal canal alignment was checked in 11 patients using their simulation CT (simCT) and setup cone-beam CT (CBCT). After the anterior surface was rigidly aligned, the spinal canal alignment was checked and quantified using the mean-distance-to-agreement (MDA) and DICE similarity index, and surface-to-spine correlation was calculated. The reproducibility of neck curvatures using the 2xROI SGRT setup is verified and the mean neck-outline-matching difference is within ±2 mm in lateral photographic overlays. The chest-ROI alignment takes 110 ± 58 s and the face-ROI takes 60 ± 35 s. When the anterior body surface is aligned (MDA = 1.1 ± 0.6 mm, DICE = 0.96 ± 0.02,) the internal spinal canal is also aligned (MDA = 1.0 ± 0.3 mm, DICE = 0.84 ± 0.04) in 11 patients. The surface-to-spine correlation is c = 0.90 (MDA) and c = 0.85 (DICE). This study demonstrates the feasibility of the novel 2-ROI SGRT setup technique to achieve reproducible neck and c-spine curvature regardless of neck visibility and availability as ROI. Staff training is needed to adopt this unconventional SGRT technique to improve patient setup.

Evaluation of Daily Patient Position Accuracy and Calculation of Setup Errors with Skin Markers and Surface-Guided Radiotherapy (SGRT) in Breast Cancer

This study aims to compare the inter-fractional patient positioning errors between the use of skin markers and SGRT in patients receiving breast radiotherapy. It also includes calculating the inter- and intra-fractional PTV margins required for free breathing (FB) and deep inspiration breath-hold (DIBH) techniques due to setup uncertainties. The treatment data of a total of 2209 fractions from 80 patients who received whole breast or chest wall radiotherapy at an institution between March 2021 and December 2022 were retrospectively analyzed. In the first group of patients, the skin markers placed in the Computed Tomography (CT) scan with the FB technique were aligned and positioned with the room lasers in the Elekta Versa HD, and plan-specific shifts were made. The optical surface scanning procedure was applied to the second group of patients with the Sentinel™ system for FB or DIBH techniques in simulation. Patients were positioned for treatment by matching reference surface images with real-time images from the Catalyst™ HD surface imaging system. Positions of all patients were verified with kilovoltage or cone-beam CT imaging systems, and 3D shift vectors were recorded daily. To compare both setup methods, PTV margins including mean positioning shifts (MPS), the vector length of the shifts and setup errors were calculated from van Herk's formulas. The MPS of all patients using skin markers were 0.20±0.85 cm, 0.32±1.55 cm, and 0.18±0.44 cm in the vertical, longitudinal and lateral directions, respectively. Then, these values given above were found to be 0.12±0.15 cm, 0.06±0.17 cm, 0.07±0.23 cm for FB using Catalyst™ HD, and 0.34±0.30 cm, 0.29±0.26 cm, 0.23±0.30 cm for DIBH. In different setup techniques, no statistically significant difference was found between the 3D shift vectors in any direction with Wilcoxon signed-rank test (p>0.05). The mean standard deviation values in all directions were calculated as 1.22 cm and 0.61 cm, respectively, in patients using skin markers and SGRT. This study indicates a significant difference between the positioning shifts of patients positioned with skin markers and SGRT. The surface imaging system is an advantageous non-invasive method that increases setup accuracy and reproducibility in breast radiotherapy.

A Novel Setup Technique for Radiation Treatment of a Severely Obese Patient With a Primary Brain Tumor.

Modern external beam radiation therapy (EBRT) techniques rely on the accurate positioning of the patient using the treatment couch. These motorized couches have weight limits that have decreased over time and are not able to support severely obese patients requiring EBRT. We aimed to develop a technique to support obese patients who are above their weight tolerance while accurately delivering radiation treatment to a brain tumor. This technique was used on a patient receiving adjuvant radiation for gliosarcoma, a variant of glioblastoma. The patient was CT scanned, and the 3D conformal radiation therapy plan was created. A custom treatment couch was created using a transport stretcher, Styrofoam, a CT couch-top, and an IMRT board, which allowed for a thermoplastic mask to be used for a reproducible setup. AP and lateral portal films were taken prior to each treatment to confirm the accuracy of the manual daily setup of the patient on the custom couch. The patient received 60 Gy in 30 daily fractions of 3DCRT in a reproducible fashion. The average deviation from the isocenter fell within the 10 mm and 8 mm planning margins applied to the clinical target volume (CTV) for the initial and boost fields, respectively. The average daily shifts in the anterior-posterior (AP) direction for the patient were 7.97 (-16.19 to 12.04) mm and 1.98 mm (-1.1 to 4.3) mm for the initial and boost treatments, respectively. The average daily shifts in the superior-inferior (SI) direction were 2.2 (-5.08 to 9.04) mm and 3.88 (-2.9 to 8.0) mm for the initial and boost treatments, respectively. This novel approach allowed treatment at 60 Gy for a gliosarcoma patient who had previously been denied treatment due to his weight. By utilizing readily available materials within the department, our team was able to create a reproducible setup technique to safely treat the patient.

Magnetic fluid hyperthermia controlled by frequency counter and colorimetric program systems based on magnetic nanoparticles

Magnetic nanoparticles (MNP) are anticipated to perform better in terms of thermal conductivity when exposed to alternating magnetic fields (AMF). Herein, key parameters for efficient heating are examined in an AMF that is organized and managed by a zero voltage switching (ZVS) and frequency counter system, which has shown great potential for hyperthermia (HT). The present study investigates the set-up of a matched coil coupled with direct current (DC) power and a frequency counter. The set-up technique for inducing HT in magnetic fluid NPs used in in vitro experiments and magnetic fluid calorimetric applications is advanced. Superparamagnetic iron oxide nanoparticles Fe3O4 (SPIONs) was prepared by the sonochemical method and coated with polyethylene glycol (Fe3O4@PEG). Our sample Fe3O4@PEG crystallized nano-size with an average particle size of 14 nm, and high magnetic saturation (MS) about 49 emu/g. The MNPs exposed to AMF at 300 kHz exhibited the highest thermal values (42–45 °C). The specific absorption rate values of 188, 217, and 234 W/g for the NP concentrations of 5, 10, and 20 mg/ml, respectively reveal the improvement of our set-up to enhance the SPIONs as a thermal agent.

Generating missing patient anatomy from partially acquired cone-beam computed tomography images using deep learning: a proof of concept

The patient setup technique currently in practice in most radiotherapy departments utilises on-couch cone-beam computed tomography (CBCT) imaging. Patients are positioned on the treatment couch using visual markers, followed by fine adjustments to the treatment couch position depending on the shift observed between the computed tomography (CT) image acquired for treatment planning and the CBCT image acquired immediately before commencing treatment. The field of view of CBCT images is limited to the size of the kV imager which leads to the acquisition of partial CBCT scans for lateralised tumors. The cone-beam geometry results in high amounts of streaking artifacts and in conjunction with limited anatomical information reduces the registration accuracy between planning CT and the CBCT image. This study proposes a methodology that can improve radiotherapy patient setup CBCT images by removing streaking artifacts and generating the missing patient anatomy with patient-specific precision. This research was split into two separate studies. In Study A, synthetic CBCT (sCBCT) data was created and used to train two machine learning models, one for removing streaking artifacts and the other for generating the missing patient anatomy. In Study B, planning CT and on-couch CBCT data from several patients was used to train a base model, from which a transfer of learning was performed using imagery from a single patient, producing a patient-specific model. The models developed for Study A performed well at removing streaking artifacts and generating the missing anatomy. The outputs yielded in Study B show that the model understands the individual patient and can generate the missing anatomy from partial CBCT datasets. The outputs generated demonstrate that there is utility in the proposed methodology which could improve the patient setup and ultimately lead to improving overall treatment quality.

CELL IMMOBILIZATION FOR CYCLODEXTRIN PRODUCTION: MINI REVIEW

Cell immobilization has been applied in various industries, including chemical manufacturing, food, pharmaceutical, and textile. Recently, innovations in cell immobilization techniques and support materials have been put forward for application in high value-added chemical biosynthesis, such as cyclodextrin (CD). The techniques, support materials, and process parameters of cell immobilization play important roles in achieving high CD yield. This review should help one choose the correct cell immobilization technique and support for a CD biosynthesis setup. Previously, CD biosynthesis utilized free cells, even though they present difficulties such as the low product yield, cell lysis, unstable plasmid, and non-reusable cells. This review highlights how the problems that arise from free-cell bioreactors could be mitigated by cell immobilization. The process conditions of cell immobilization for CD production are also presented.

Accuracy and Efficiency of Patient Setup Using Surface Imaging versus Skin Tattoos for Accelerated Partial Breast Irradiation

Skin tattoos represent the standard approach for surface alignment and setup of breast cancer radiation therapy, yet permanent skin markings contribute to adverse cosmesis and patient dissatisfaction. With the advent of contemporary surface-imaging technology, we evaluated setup accuracy and timing between "tattoo-less" and traditional tattoo-based setup techniques. Patients receiving accelerated partial breast irradiation (APBI) underwent traditional tattoo-based setup (TTB), alternating daily with a tattoo-less setup via surface imaging using AlignRT (ART). Following initial setup, position was verified via daily kV imaging, with matching on surgical clips representing ground truth. Translational shifts (TS) and rotational shifts (RS) were ascertained, as were setup time and total in-room time. Statistical analyses used the Wilcoxon signed rank test and Pitman-Morgan variance test. A total of 43 patients receiving APBI and 356 treatment fractions were analyzed (174 TTB fractions and 182 using ART). For tattoo-less setup via ART, the median absolute TS were 0.31 cm in the vertical (range, 0.08-0.82), 0.23 cm in the lateral (0.05-0.86), and 0.26 cm in the longitudinal (0.02-0.72) axes. For TTB setup, the corresponding median TS were 0.34 cm (0.05-1.98), 0.31 cm (0.09-1.84), and 0.34 cm (0.08-1.25), respectively. The median magnitude shifts were 0.59 (0.30-1.31) for ART and 0.80 (0.27-2.13) for TTB. ART was not statistically distinguishable from TTB in terms of TS, except in the longitudinal direction (P=.154, .059, and .021, respectively), and was superior to TTB for magnitude shift (P < .001). The variance of each TS variable was significantly narrower for ART compared with TTB (P ≤ .001 vertical, P=.001 lateral, P=.005 longitudinal). The median absolute RS for ART was 0.64° rotation (range, 0.00-1.90), 0.65° roll (0.05-2.90), and 0.30° pitch (0.00-1.50). The corresponding median RS for TTB were 0.80° (0.00-2.50), 0.64° (0.00-3.00), and 0.46° (0.00-2.90), respectively. ART setup was not statistically different from TTB in terms of RS (P=.868, .236, and .079, respectively). ART showed lower variance than TTB in terms of pitch (P=.009). The median total in-room time was shorter for ART than TTB (15.42 vs 17.25 minutes; P=.008), as was the median setup time (11.12 vs 13.00 minutes; P=.001). Moreover, ART had a narrower distribution of setup time with fewer lengthy outliers versus TTB. These findings suggest that a tattoo-less setup approach with AlignRT may be sufficiently accurate and expeditious to supplant surface tattoos for patients receiving APBI. Further analyses with larger cohorts will determine whether tattoo-based approaches can be replaced by noninvasive surface imaging.

Current Trends in the Use of Postless Hip Arthroscopy: A Survey of the International Society for Hip Arthroscopy Membership.

Previous studies have demonstrated the risks of pudendal nerve and/or soft tissue complications due to the use of a perineal post during hip arthroscopy. Recently, various postless hip arthroscopy techniques have been described in the literature. To assess the current international trends in the use of postless hip arthroscopy among hip preservation specialists. Cross-sectional study. An anonymous 11-item survey was sent by email to all members of the International Society for Hip Arthroscopy (ISHA) in January 2022. Surgeons were asked various questions regarding their current use of post-assisted or postless hip arthroscopy, if they had changed their setup technique during their career and the reason for that change, and their perceived rate of pudendal nerve and/or perineal soft tissue injuries using their current technique. Descriptive statistics were used to report the results of each question. The Student t test was used to compare the number of years in practice between post-assisted and postless users. Fisher exact tests were performed to compare categorical rates of pudendal nerve and soft tissue complications between post-assisted and postless users. A total of 126 surveys were completed from 431 ISHA members (29.2%). Sixty-one percent of the surgeons currently use a perineal post, while 33% use a postless technique. Seventy-five percent of the perineal post users and 98% of the postless users self-reported a rate of pudendal nerve and/or soft tissue injury of <1% (P = .015). Among 41 respondents who indicated changing their technique at some point, 59% reported doing so because of pudendal nerve and/or soft tissue complications. Among surgeons who switched from a perineal post to a postless setup, 71% indicated they have noticed a decrease in the rate of pudendal nerve and/or soft tissue complications. Although use of a perineal post is still a more common setup technique among hip arthroscopists, approximately one-third of surgeons use a postless technique. Surgeons who have switched to a postless technique often did so because of perineal complications, with the majority noticing a subjective decrease in these complications with the use of postless hip arthroscopy.

Effects of Expansion Size from Gross Tumor Volume to Planning Target Volume on Control Rates and Patterns of Recurrence in Conventionally Fractionated Radiotherapy for WHO Grade I Meningiomas

<h3>Purpose/Objective(s)</h3> In single fraction stereotactic radiosurgery (SRS) for WHO grade I meningiomas, no- or minimal GTV to PTV margin is accepted practice with good outcomes. For complex tumors not eligible for SRS due to size or proximity to critical structures, there has been historical heterogeneity in target volume expansions practices, ranging from margins of a few mm to up to 2 cm. Additional margin is typically added for fractionated treatments to account for setup variability and less precise imaging and setup technique. Larger expansions result in treatment of uninvolved brain parenchyma and organs at risk, which is a concern in patients with expected long survivals. We sought to evaluate whether there is a control difference based on GTV to PTV expansion size in fractionated radiotherapy with either stereotactic or conventional conformal technique. <h3>Materials/Methods</h3> With IRB approval, we identified 87 patients from an institutional database with imaging-defined or WHO grade I meningioma treated with either 3D or IMRT radiation with 5 to 15 mm expansions from GTV (with or without intermediate CTV) or fractionated stereotactic radiotherapy (fSRT) using a system with ≤ 3mm GTV to PTV expansions, treated between 1999 and 2018 with at least 2 years of follow-up. All treatments were delivered using 1.8 Gray (Gy) fractions. Kaplan-Meier estimators were used for local failure-free survival (LFFS), marginal-failure free survival (MFFS) and distant failure-free survival (DFFS) analysis, with censoring occurring at failure event or most recent MRI. Local failure was defined as within the treatment field, marginal within 2 cm, and distant as beyond 2 cm. Patient clinical and demographic characteristics analyzed with χ² testing. <h3>Results</h3> With a median follow-up of 9.0 years, 25 patients (29%) received 3D or IMRT and 62 patients (71%) received fSRT. Doses delivered varied from 50.4-54 Gy, with the majority (71%) receiving 54 Gy. Thirty-two (37%) underwent surgery; 24 were sub-total resections. Total events were low, with 4 local failures (5%), 1 marginal failure (1%) and 1 distant failure (1%). The fSRT and 3D/IMRT groups each had two local failures; 3/4 local failures occurred in areas near critical organs at risk (two in suprasellar region, one in cavernous sinus). Extent of surgical resection was not correlated with risk for local failure. For 3D/IMRT vs fSRT, 5- and 10-year LFFS were 100% vs 98% (p=0.46) and 94% vs 96% (p=0.34), 5- and 10-year MFFS were 100% vs 100% and 100% vs 92% (p=0.004), and 5- and 10-year DFFS were 100% vs 98% at both time points (p=0.65 and p=0.67, respectively). <h3>Conclusion</h3> In this patient cohort, there was no local control benefit to larger GTV to PTV expansions. For patients with tumors not eligible for SRS, fractionated treatment using a rigorous stereotactic workflow with ≤ 3 mm PTV expansions is an effective approach for WHO grade I meningiomas.

Laser-Assisted Method for Cleaning and Analysis of Archaeological Metallic Coins

Metal coins discovered during archaeology have artistic and cultural value. Careful cleaning is required for artifact conservation. Metal artifacts must be cleaned to remove corrosion, which can range from tarnishing to a thick crust, in addition to dust, previous coatings, and burial deposits. Cleaning corrosion is still a challenging conservation process, but the advantages of using traditional cleaning methods outweigh the disadvantages. The current study aimed to evaluate the use of a nanosecond infrared Q-switched Nd: YAG pulsed laser for biodeteriogen elimination by laser cleaning and elemental analysis via LIBS analysis on old, corroded coins. The corroded coins used in this study were found in Egyptian burial dirt. Four different varieties of unknown corroded coins were exposed to laser cleaning testing. Throughout the cleaning process, LIBS diagnostics was used to monitor the laser ablation process as it removed various types of corrosion products. The coins were analyzed with a scanning electron microscope equipped with an energy-dispersive X-ray analyzer before and after the laser cleaning to assess the efficacy of the suggested laser setup technique used in this experiment (SEM-EDX). The results show a reduction in the spectral lines of corroded metals (Cu, Ca, and Mg) in the investigated coins after cleaning when compared to the original analyses. However, the surface morphology of each coin changes somewhat due to the presence of CuOx, which was recognized by increasing the strength of O lines, ensuring the viability of utilizing LIBS to identify the unknown coins tested.

Simulation and compensation of thermal lensing in optical systems.

High-power optical systems are used in a number of industrial applications. One difficulty in designing such systems is that the beam itself is a significant source of heat, which changes the optical properties of the system. To reduce this effect, we propose a new thermal lensing compensation technique based on a detailed analysis of the optical properties of the high-power optical system. To this end, we have developed a new ray tracing simulation technique that accurately models optical propagation through inhomogeneous, anisotropic, and deformed media. This model enables the performance of systems in physically realistic situations to be evaluated efficiently. Experimental comparisons were conducted to validate the simulation. We found excellent agreement between the simulation and the measured data. We have validated the simulation technique for a single lens setup and a complex optical scanner system.

METHODOLOGIES TO PREDICT HYDRODYNAMIC CHARACTERISTICS OF PUSHER AND PULLER PODDED PROPULSORS IN OBLIQUE FLOWS

This paper presents the outcome of a numerical simulation based research program to evaluate the propulsive characteristics of puller and pusher podded propulsors in a straight course and at static azimuthing conditions while operating in open water. Methodologies to predict the propeller thrust and torque, and pod forces and moments in three dimensions using a Reynolds-Averaged Navier Stokes (RANS) solver at multiple azimuthing conditions and pod configurations are presented. To obtain insight into the reliability and accuracy of the results, grid and time step dependency studies are conducted for a podded propulsor in straight-ahead condition. The simulation techniques and results are first validated against measurements of a bare propeller and a podded propulsor in straight ahead condition for multiple loading scenarios and in both puller and pusher configurations. Next, simulations were carried out to model the podded propulsors in the two configurations at multiple loading conditions and at various azimuthing angles from +30° to –30° in 15° increments. The majority of the simulations are carried out using both steady state and unsteady state conditions, primarily to evaluate the effect of setup conditions on the computation time and prediction accuracy. The predicted performance characteristics of the pod unit using the unsteady RANS method were within 1% to 5% of the corresponding experimental measurements for all the loading conditions, azimuthing angles and pod configurations studied. The non-linear behaviour of the performance coefficients of the pod unit are well captured at various loading and azimuthing conditions in the predicted results. This study demonstrates that the RANS solver, with proper meshing arrangement, boundary conditions and setup techniques can predict the performance characteristics of the podded propulsor in multiple azimuthing angles, pod configurations and in the various loading conditions with a same level of accuracy as experimental results. Additionally, the velocity and pressure distributions on and around the pod-strut- propeller bodies are discussed as derived from the RANS predictions.

Improved calibration technique for two-probe setup to enhance its in-circuit impedance measurement accuracy

The in-circuit impedance is a key parameter to evaluate the health and operation of many electrical systems. The two-probe setup (TPS) based on the inductive coupling approach is preferred for in-circuit impedance measurement because it does not require physical electrical contact with the energized system under test. However, the existing calibration technique for the TPS degrades its measurement accuracy at relatively high test frequencies. To enhance the measurement accuracy of the TPS, this paper proposes an improved calibration technique. It considers the frequency-dependent effects of the selected calibration components so that the TPS can maintain good measurement accuracy even at relatively high test frequencies. Using an actual TPS as a test case, experimental results show that the TPS based on the proposed calibration technique maintains good measurement accuracy up to 10 MHz, whereas the same TPS based on the existing calibration technique exhibits significant measurement errors when approaching 10 MHz.

Automatic triangulated mesh generation of pulmonary airways from segmented lung 3DCTs for computational fluid dynamics.

Computational fluid dynamics (CFD) of lung airflow during normal and pathophysiological breathing provides insight into regional pulmonary ventilation. By integrating CFD methods with 4D lung imaging workflows, regions of normal pulmonary function can be spared during treatment planning. To facilitate the use of CFD simulations in a clinical setup, a robust, automated, and CFD-compliant airway mesh generation technique is necessary. We define a CFD-compliant airway mesh to be devoid of blockages of airflow and leaks in the airway path, both of which are caused by airway meshing errors that occur when using conventional meshing techniques. We present an algorithm to create a CFD-compliant airway mesh in an automated manner. Beginning with a medial skeleton of the airway segmentation, the branches were tracked, and 3D points at which bifurcations occur were identified. Airway branches and bifurcation features were isolated to allow for automated and careful meshing that considered their anatomical nature. We present the meshing results from three state-of-the-art tools and compare them with the meshes generated by our algorithm. The results show that fully CFD-compliant meshes were automatically generated for an ideal geometry and patient-specific CT scans. Using an open-source smoothed-particle hydrodynamics CFD implementation, we compared the airflow using our approach and conventionally generated airway meshes. Our meshing algorithm was able to successfully generate a CFD-compliant mesh from pre-segmented lung CT scans, providing an automatic meshing approach that enables interventional CFD simulations to guide lung procedures such as radiotherapy or lung volume reduction surgery.

Photochemical and photophysical properties of tetracarboxylic acid phthalocyanines from glycolic and lactic acids in homogeneous and micro heterogeneous media

Glycolic acid and lactic acid substituted zinc phthalocyanines were studied concerning their photophysical and photochemical properties in eight organic solvents (homogeneous medium) and in aqueous media with the presence of CTAB and PVP 360 surfactants. Solvent effects were investigated according to several physical solvent parameters, including studies that used more than one parameter at a time, such as the ET(30) scale and the Lippet-Mataga equation. Computational studies were realized and was found in good agreement with experimental data indicating J-type dimers' formation through hydrogen bonds, which may not affect the spectroscopic properties. Fluorescence lifetimes were recorded using a time-correlated single-photon counting setup (TCSPC) technique. The direct method (analyzing the phosphorescence decay curves of singlet oxygen at 1270 nm) was employed to study singlet oxygen quantum yields. Phthalocyanine macrocycle with lactic acid substituent showed better solvation arrangement than the glycolic derivative, which can be explained based on the presence of the methyl group bonded to the chain. The water solvation of Pc’s in the presence of cationic surfactant (CTAB) and biocompatible polymer PVP 360 increses the importance of this study for appliance in photodynamic therapy (PDT).

Industrial robot performance analysis using low cost set- up

Industrial robot calibration is technique used to increase industrial robot repeatability and accuracy. In our project, we have analyzed various calibration techniques of articulated industrial robots and proposed an original method to analyze Industrial robot performance analysis. The proposed calibration set-up technique is using a mechanical setup of Linear Variable differential Transformer (LVDT) probe and inductive proximity sensor. The Statistical process control (SPC) software is using to monitor the real time data of the process and extracting the data for statistical analysis. The proposed Industrial robot calibration technique is applying at ABB Six Degrees of Freedom industrial robot and analyzing the performance gets affected by various Robot parameter and Internal/External factors. The calibration method is proposed to evaluate the repeatability of an articulated industrial robot using component of a Statistical Analysis course.

Proton beam irradiation of uveal melanoma involving the iris, ciliary body and anterior choroid without surgical localisation (light field)

AimsTo assess treatment outcomes after proton beam irradiation (PBI) without surgical localisation of uveal melanomas involving the iris, ciliary body and anterior choroid.MethodsRetrospective chart review of 125 patients evaluated at...