Quality Assurance Tool Research Articles

Lessons From 3 Longitudinal Sensor-Based Human Behavior Assessment Field Studies and an Approach to Support Stakeholder Management: Content Analysis.

Pervasive technologies are used to investigate various phenomena outside the laboratory setting, providing valuable insights into real-world human behavior and interaction with the environment. However, conducting longitudinal field trials in natural settings remains challenging due to factors such as low recruitment success and high dropout rates due to participation burden or data quality issues with wireless sensing in changing environments. This study gathers insights and lessons from 3 real-world longitudinal field studies assessing human behavior and derives factors that impacted their research success. We aim to categorize challenges, observe how they were managed, and offer recommendations for designing and conducting studies involving human participants and pervasive technology in natural settings. We developed a qualitative coding framework to categorize and address the unique challenges encountered in real-life studies related to influential factor identification, stakeholder management, data harvesting and management, and analysis and interpretation. We applied inductive reasoning to identify issues and related mitigation actions in 3 separate field studies carried out between 2018 and 2022. These 3 field studies relied on gathering annotated sensor data. The topics involved stress and environmental assessment in an office and a school, collecting self-reports and wrist device and environmental sensor data from 27 participants for 3.5 to 7 months; work activity recognition at a construction site, collecting observations and wearable sensor data from 15 participants for 3 months; and stress recognition in location-independent knowledge work, collecting self-reports and computer use data from 57 participants for 2 to 5 months. Our key extension for the coding framework used a stakeholder identification method to identify the type and role of the involved stakeholder groups, evaluating the nature and degree of their involvement and influence on the field trial success. Our analysis identifies 17 key lessons related to planning, implementing, and managing a longitudinal, sensor-based field study on human behavior. The findings highlight the importance of recognizing different stakeholder groups, including those not directly involved but whose areas of responsibility are impacted by the study and therefore have the power to influence it. In general, customizing communication strategies to engage stakeholders on their terms and addressing their concerns and expectations is essential, while planning for dropouts, offering incentives for participants, conducting field tests to identify problems, and using tools for quality assurance are relevant for successful outcomes. Our findings suggest that field trial implementation should include additional effort to clarify the expectations of stakeholders and to communicate with them throughout the process. Our framework provides a structured approach that can be adopted by other researchers in the field, facilitating robust and comparable studies across different contexts. Constantly managing the possible challenges will lead to better success in longitudinal field trials and developing future technology-based solutions.

A polymerase chain reaction (PCR) method to detect emerging multidrug-resistant Salmonella Infantis harbouring pESI plasmid in seafood.

Salmonella Infantis is an emerging multidrug-resistant pathogen worldwide due to the acquisition of a megaplasmid pESI (Plasmid of Emerging Salmonella Infantis). Reported initially from poultry, the distribution of pESI-harbouring S. Infantis in other food types, including seafood, is unknown. This study aimed to develop and optimize a PCR assay for detecting pESI plasmid in Salmonella and non-Salmonella Enterobacterales. A duplex PCR targeting the hilA gene and a pESI-associated gene of S. Infantis was designed, and the PCR conditions were optimized. The specificity and sensitivity of the assay were established using 119 Salmonella serovars and 51 non-Salmonella bacterial strains. All Salmonella isolates yielded hilA PCR product, while only pESI S. Infantis was positive for both hilA and pESI genes. No amplification product was obtained with the DNA of 51 non-Salmonella bacterial strains. The detection limit of the duplex PCR was 104 CFU/ml of pure culture of pESI S. Infantis. The sensitivity of detection in artificially spiked shrimp meat was 1 CFU/g after 6 h of enrichment in lactose broth, followed by 12 h of selective enrichment in the Rappaport-Vassiliadis medium. The duplex assay will help screen seafood for Salmonella in general and pESI S. Infantis in particular. Given its high sensitivity, the PCR will be a valuable tool for seafood quality assurance. This approach decreases the typical 3-6 days' identification time of Salmonella to less than 24 hours. S. Infantis carrying the highly transmissible megaplasmid (pESI) is a significant food safety concern. Given its rapid geographical spread and high antimicrobial resistant traits, it is necessary to have a molecular tool that detects pESI-harbouring Salmonella. This study successfully developed a duplex PCR assay that simultaneously detects Salmonella enterica and pESI S. Infantis. This molecular tool will help understand the distribution, sources, and spread of MDR plasmid in the food environment.

Utilization of registers to create an evidence-based approach in catastrophes and civil defence

Medical data registers are a key instrument of medical care research and a valuable tool for medical quality assurance. The structured plausibility tested documentation of large case numbers on a longitudinally oriented time axis with different points in time of data acquisition enables statements to be made on numerous relevant outcomes, not only the mortality of patients. For incidents outside the daily routine care in trauma surgery, such as natural disasters, accidents with multiple casualties and nonmilitary treatment of the domestic population in defence situations, such registers can provide data-based recommendations for action. These data, mainly obtained from routine traumatological treatment, enable a targeted resource management in the abovenamed incidents, which are associated with mass casualties. Due to the utilization of registers from the military field or from international registers, the perspective is additionally extended with respect to treatment strategies and injury patterns. Whether data can also be generated in a suitable manner for the abovenamed registers in specific disaster situations and can provide a direct gain of knowledge from the incident, must be critically discussed. The maintenance of the register datasets is time-consuming and has been subjected to a more stringent regulation at least since May 2018, when the European Union General Data Protection Regulation (EU-GDPR) came into force. The future Register Act in Germany will hopefully achieve greater simplification in the documentation of routine data.

Adaptive infrared patterns for microscopic surface reconstructions.

Multi-zoom microscopic surface reconstructions of operating sites, especially in ENT surgeries, would allow multimodal image fusion for determining the amount of resected tissue, for recognizing critical structures, and novel tools for intraoperative quality assurance. State-of-the-art three-dimensional model creation of the surgical scene is challenged by the surgical environment, illumination, and the homogeneous structures of skin, muscle, bones, etc., that lack invariant features for stereo reconstruction. An adaptive near-infrared pattern projector illuminates the surgical scene with optimized patterns to yield accurate dense multi-zoom stereoscopic surface reconstructions. The approach does not impact the clinical workflow. The new method is compared to state-of-the-art approaches and is validated by determining its reconstruction errors relative to a high-resolution 3D-reconstruction of CT data. 200 surface reconstructions were generated for 5 zoom levels with 10 reconstructions for each object illumination method (standard operating room light, microscope light, random pattern and adaptive NIR pattern). For the adaptive pattern, the surface reconstruction errors ranged from 0.5 to 0.7 mm, as compared to 1-1.9 mm for the other approaches. The local reconstruction differences are visualized in heat maps. Adaptive near-infrared (NIR) pattern projection in microscopic surgery allows dense and accurate microscopic surface reconstructions for variable zoom levels of small and homogeneous surfaces. This could potentially aid in microscopic interventions at the lateral skull base and potentially open up new possibilities for combining quantitative intraoperative surface reconstructions with preoperative radiologic imagery.

Critical appraisal of Genelyn soft embalming for cadaveric surgical skill training: A systematic review.

Genelyn is a proprietary embalming solution used for preserving cadavers for surgical skill training (SST) and undergraduate teaching. The aim of this review is to examine the Genelyn embalming method critically by analyzing scientific publications that have employed this method for SST and undergraduate education. The systematic review process involved searching for all relevant articles in PubMed, Google Scholar, and Embase using the keywords "Genelyn," Genelyn embalming," "Genelyn embalmed cadaver," and "surgical skill training. All studies on Genelyn embalming published up to August 14, 2024, in the English language were eligible for inclusion. The literature review yielded 92 studies, 43 of which met the inclusion criteria. The Anatomical Quality Assurance (AQUA) tool from the International Evidence-Based Anatomy (iEBA) working group was used to assess and analyze the risk of bias in all the selected full-text articles. The selected studies reported that Genelyn embalming provided life-like joint range of motion, tissue pliability, and color. Cadaveric studies assessing embalming solutions typically had smaller sample sizes, and few of them compared Genelyn embalmed cadavers (GECs) with the other soft embalming solutions. Unlike Theil's embalming, Genelyn embalming is cost-effective, with easy steps for the preparation and storage of the solution and convenient handling of cadavers. Therefore, GECs serve as an efficient tool for SSTs.

Surgical anatomy of the cystic artery: A systematic review with meta-analysis

BackgroundThe current evidence-based systematic review with meta-analysis presents a detailed overview of the cystic artery (CA) surgical anatomy, including its origin, number, topography, and morphometry. Moreover, the surgical implications of these variants are further discussed. MethodsAccording to the Evidence-Based Anatomy Workgroup and PRISMA 2020 guidelines, the systematic review was performed using four online databases. The Anatomical Quality Assurance Tool was used to evaluate the risk of bias. Meta-analysis was performed with the R programming software. The pooled prevalence and pooled mean of different CA parameters were calculated. ResultsThe CA most commonly originated from the right hepatic artery (a pooled prevalence of 85.75 %). Other described origins (in order of frequency) were the aberrant right hepatic artery, the common hepatic, the left hepatic, the gastroduodenal, the superior mesenteric, and the middle hepatic arteries. The CA was single in 88.59 %, while it can be identified as double, triple, or absent. Most commonly, it was located inside the cystohepatic triangle in 83.83 %. Most commonly, it was superomedially to the cystic duct (77.80 %) and posteriorly to the common hepatic duct (35.08 %). The CA pooled mean length was 21.34 mm, and its diameter was more commonly over 1 mm. ConclusionThe CA surgical anatomy is paramount when operating on the gallbladder. The CA's altered anatomy and adjacent area could lead to confusion, iatrogenic injury, and prolonged surgical time. The CA depicts high morphological variability; therefore, surgeons should consider the typical anatomy and possible (usual and unusual) variants.

Large-area coverage–transmission near-infrared measurement of dried laver to determine crude protein content

A large-area coverage (LAC)–transmission near-infrared (NIR) measurement scheme was demonstrated to determine the crude protein content of a dried laver sheet. Because dried laver sheets are large (approximately 19 cm × 21 cm) and the algae packing over the sheet is not homogeneous with including numerous void spots, acquisition of sample-representative and reproducible spectra is necessary for reliable quality evaluations. The proposed scheme incorporated a fixed NIR illumination in the y direction and an xz-direction linear motor stage, allowing for a snake scan over an area of 10 cm × 7 cm. This scheme successfully acquired sample-representative and reproducible NIR spectra of nonhomogeneous laver-sheet samples. The predicted crude protein contents of the samples correlated closely with those determined using conventional Kjeldahl analysis, which required destructive sample digestion. The proposed LAC-NIR scheme demonstrated its suitability as a quality assurance tool in real-world field analysis.

A-133 Trusted Test Goes Awry: Investigating Dilution Aberrations for Total Bilirubin

Abstract Background A patient with acute decompensated cirrhosis was hospitalized due to lightheadedness and jaundice, undergoing evaluation for a liver transplant. The attending physician brought to the laboratory’s attention a perplexing pattern in the patient's total bilirubin results. Initially, the patient displayed a consistent trend of elevated total bilirubin levels above the upper limit of linearity, ULOL (> 30 mg/dL), which then plummeted to under the limit of quantification (< 0.1 mg/dL) before surging back to > 30 mg/dL. Methods The total bilirubin in heparinized plasma was measured on the AU5800 by Beckman Coulter. Samples > ULOL are diluted automatically 1:3 utilizing the instrument’s on-board dilution feature. The final test results are reported automatically to an electronic medical record. Following the reported incident, an investigation and troubleshooting plan was developed, encompassing the following steps: Repeat patient testing with total bilirubin concentration > 30 mg/dL and <0.1 mg/dL; Rule out the previously reported potential interferences, including Immunoglobin M and acetaminophen; Conduct a 90-day quality control (QC) review; Perform split test analysis on two instruments within the laboratory and at a reference laboratory; Conduct patient chart reviews to identify discrepancies based on previously reported values; Complete a root cause analysis and develop corrective/preventive action plan. Results Patient sample < 0.1 mg/dL was tested on an alternative instrument, resulting > 30 mg/dL. Patient with normal IgM of 161 mg/dL didn’t reveal any other potential drug interferences in chart review. The 3-month QC review found consistent with peer performance. Split comparison of 6 patients revealed discrepancies for samples > 30 mg/dL on one of the two instrument units. When total bilirubin > 30 mg/dL, the malfunctioning unit erroneously reported values < 0.1 mg/dL after dilution. Review of 34 patient charts showed the impact dates were spanned for 39 days. Since the on-board dilution feature is utilized by 10 other analytes, 892 diluted samples were analyzed for discrepancies. 36 discrepant results were identified among 4 affected assays including total bilirubin, direct bilirubin, creatine kinase, and alanine aminotransferase. These results were corrected, and providers were notified. Conclusions The root cause was traced to a malfunction in one instrument unit, despite no malfunction flags. The laboratory QC concentrations fell within the analytical measurement range, missing the dilution issue during the daily QCs. During an extensive repair period, the on-board dilution was disabled on the affected unit and samples were re-routed to alternative instrument for testing. Policy changes and operator training were initiated for a new result verification process, impacting the laboratory productivity. Autoverification of diluted sample results was disabled for all chemistry analyzers. The vendor identified the issue as sample transfer unit crane misalignment in the up/down direction. It is worth noting that proficiency testing or QCs often do not extend beyond the analytical measurement ranges, leading to undetected incidents. Additional quality measures like periodic patient chart reviews, patient sample comparisons, and other quality assurance tools can aid in on-going dilution performance verification. Open communication between the physicians and laboratories is crucial for prompt issue identification and resolution.

A phase field finite element study and evaluation of sulfide stress cracking in DCB specimen testing

The challenges presented by sour environments rich in hydrogen sulfide (H2S) underscore the necessity for a comprehensive understanding of material behavior under such conditions. The cracking susceptibility of metals and alloys used for subsurface equipment in downhole oil and gas exploration operations is particularly concerning. The NACE Double Cantilever Beam (DCB) test has emerged as a widely used quality assurance tool in the petroleum industry, leveraging fracture mechanics principles to assess the environment-assisted cracking (EAC) resistance of metals and alloys. The DCB test evaluates the fracture toughness KISSC of materials in H2S-containing environments via assessment of the crack arrest, which serves as a vital parameter in structural integrity assessments to mitigate the risk of service-related failures from sulfide stress cracking (SSC). However, various studies suggest that different test parameters, such as arm displacement and initial notch, significantly influence KISSC. This work presents a detailed numerical investigation on a comprehensive simulation of the DCB test, examining the effects of different test parameters on KISSC prediction. A coupled deformation-diffusion phase field framework is adopted to simulate SSC in DCB specimens arising from a complex interplay between material deformation, hydrogen diffusion, and fracture. The numerical results show good agreement with experimental results reported in the literature and provide deeper insights into the factors affecting crack growth and arrest in DCB testing.

The correlation of the modulation complexity score (MCS) with the number of segments and local gamma passing rate for the Intensity Modulated Radiation Therapy (IMRT) treatment planning delivery.

To compare the modulation complexity scores across treatment sites, and to examine their connection with monitor unit, segment number and global and local gamma passing percentage. The cross-sectional study was conducted at the Baghdad Centre for Radiation Therapy and Nuclear Medicine, Baghdad Medical City, Baghdad, Iraq, from May 2021 to February 2022. Included were 34 patients, with the age range between 20 - 50 years, subjected to intensity-modulated radiation therapy for head and neck tumours in group A or pelvic tumours in group B. Treatment planning was done using Monaco 5.1, and radiotherapy was done using Synergy linear accelerator. Modulation complexity scores were calculated using MATLAB 2019a. Data was analysed using SPSS 24. Of the 34 patients, 22(64.7%) were in group A; 12(54.5%) males and 10(45.5%) females. There were 12(35.3%) patients in group B; 8(66.7%) females and 4(33.3%) males. The number of segments was greater in group B than group A. A modest positive linear association was seen in group A, demonstrating that an increase in segment numbers resulted in a rise in modulation complexity score (R2=0.0244). Group B tumours had inverse negative linear correlation (R2=0.0189). As the complexity of plans increased in group A, local gamma passing percentage decreased (R2=0.0452). Group B showed a slight negative connection with modulation complexity score (R2=0.0622). The modulation complexity score may be used to provide a simple prediction for pre-treatment verification, and it may also serve as a simple quality assurance tool for intensity-modulated radiation therapy plans.

Comprehensive Analysis of Impurity Detection in Linear Alkyl Benzene–Based Liquid Scintillators Using Infrared Spectroscopy for Enhanced Neutrino Detection

Abstract We present a comprehensive analysis of infrared (IR) spectra for linear alkyl benzene (LAB)-based scintillation solutions, focusing on the detection and identification of impurities. Previous research primarily utilized ultraviolet-visible spectroscopy to investigate electronic structures and transitions, whereas our approach emphasizes vibrational transitions and IR spectral characteristics. We specifically examined the presence of common impurities, such as acetone, water, and three impurity compounds (IMP1, IMP2, and IMP3) identified by the JUNO Collaboration. Acetone, a common contaminant from cleaning procedures, was detected by its characteristic absorption peaks at 1200, 1360, and 1700 $\rm {cm}^{-1}$. Water, an inevitable by-product of Gd-loaded LAB using a neutralization reaction process, was identified through distinct O-H stretching and H-O-H bending vibrations at 3200–3600 $\rm {cm}^{-1}$ and 1600 $\rm {cm}^{-1}$, respectively. The IR spectra of IMP1, IMP2, and IMP3 were theoretically calculated, revealing unique absorption bands for key functional groups, including carbonyl (C=O), amide (C-N), sulfoxide (S=O), aryl chloride (Ar-Cl), azo (N=N), and ether (C-O-C) groups. The findings confirm the absence of these impurities in the LAB (+ 2,5-Diphenyloxazole [PPO] + 1,4-Bis(2-methylstyryl)benzene [bis-MSB]) sample, ensuring the high performance and accuracy of neutrino detectors. This study demonstrates the effectiveness of IR spectroscopy as a powerful analytical tool for quality assurance in liquid scintillation solutions, providing a robust framework for enhancing the reliability and precision of neutrino detection experiments.

Deep learning methods for 2D in-vivo dose reconstruction with EPID detector

Over the past two decades, radiotherapy has seen a steep increase in technological complexity of treatment preparation and treatment execution, calling for the development of more and better quality assurance tools and procedures. In-vivo dosimetry has emerged as a very powerful tool for treatment verification in conjunction with Electronic Portal Imaging Devices (EPIDs). However, EPIDs present several drawbacks like non-water equivalence and cumbersome calibration procedures. Artificial intelligence, specifically Deep Learning (DL), plays a crucial role in this context. A critical step is modeling the EPID response to estimate 2D dose distributions (Portal Dose, PD). This work introduces a DL-based methodology aimed at converting EPID responses into PD images. The proposed procedure is fully data driven, being based on advanced DL methods. This approach will allow bypassing the complex calibration steps needed to overcome the non-water equivalent panel.

Constricting Gaps: Protocol development, implementation challenges and lessons learned for the reality map of unmet needs for Palliative Care Interventions in advanced cancer patients study in Romania and Switzerland

BackgroundPatients with advanced cancer experience many symptoms and needs requiring a Palliative Care Intervention (PCI). Identifying gaps between needs for PCIs and experienced delivery may improve health care, furthermore the association of gaps with quality indicators (QI). The multicentre Romanian (RO)-Swiss (CH) reality map study implemented a novel protocol based on needs concepts and culturally adapted quality indicators (QI). MethodsAn interactive mapping guide measuring unmet needs for PCIs monthly over six months, patient characteristics (cognition, EAPC basic data set, Cofactors) and QI (Inappropriate Anticancer Treatment, High Symptom Burden [IPOS, EQ5D], Repeated ER Admissions, Aggressive End-of-Life Care, and Quality of Death-and-Dying) were developed, applying swiss standards for quality assurance. A composite endpoint (QI, cofactors) was planned. Finally, local solutions responding to gaps were piloted. ResultsFrom 308 patients (RO: 262, CH: 46, age 62j [mean], 74 % ECOG PS 1&2, 81 % current anticancer treatment) baseline and first follow-up data revealed main gaps (symptom management, spiritual needs, family support), country differences (e.g. illness understanding, spiritual needs) and a significant association of the number of gaps with depression. Later data become less, and data quality on QI variable, revealing gaps in research conduct competences, resources, and applicability of over-sophisticated quality assurance tools. Nevertheless, the unmet needs data promoted local initiatives, 81 patients participated in feasibility studies. Finally, the joint experience stimulated academic developments and national integration of palliative care into oncology. ConclusionsPairing motivation and enthusiasm with more modest aims, feasibility testing of all outcomes and investment in research competences may disperse gaps.

Exploring the use of portable infrared spectroscopy as a quality assurance tool for the Australian Native/Traditional food industry: a case study on finger lime (Citrus australasica)

SummaryFinger limes (Citrus australasica) are an Australian native and traditional food that are known for their caviar‐like pearls often referred to as “Citrus Caviar”. This study aimed to spectrally characterise finger lime varieties sourced across South‐East Queensland and Northern New South Wales. The varieties investigated demonstrated a wide diversity in their phenotypic appearance; however, their infrared spectra were similar. The NIR spectra of the samples were collected using a portable instrument and the data analysed using principal component analysis (PCA) and partial least squares (PLS) regression. Differences in the PCA score plot were observed associated with the different varieties analysed. The cross‐validation statistics obtained for the prediction of adulteration of finger with Tahitian lime were R2CV and SECV 0.96% and 7%, respectively (using 8 PLS factors), using PLS regression. This study demonstrated that a portable handheld NIR instrument is able to identify finger lime varieties using both whole fruits and the corresponding peel samples. This study also showed that NIR was able to identify the level of adulteration of finger lime with Tahitian lime.

System Tools for Quality Assurance for Electric Vehicle Design

System Tools for Quality Assurance for Electric Vehicle Design

Development and Validation of an ICH-Compliant Optimized RP-HPLC Method for Quantitative Analysis of Favipiravir

Favipiravir (FAV) has emerged as a promising antiviral agent. It is particularly effective against influenza and other RNA virus infections. The aim and objective of the present study was developing and optimizing chromatographic conditions for faster analysis of FAV and demonstrating its applicability for tablet assay. The chromatographic separation was obtained using mobile phase with 90:10 % v/v ratio of ammonium acetate buffer (pH 4.5) and methanol on a Waters C18 column (250 x 4.6 mm, 5 µ). A flow rate of 1.4 mL/min was optimized. Chromatographic detection was perform at a wavelength of 323 nm. The FAV retention time was 6.46 min, indicating the efficiency and speed of the method. The developed method was rigorously validated according to ICH guidelines. A strong linear correlation (r2 = 0.9995) was established in the 5–60 μg/mL range, indicating adequacy for quantitative analysis. The method demonstrated high accuracy, with FAV recovery ranging from 98.77 % to 100.89 %. The % RSD results of less than 2% for intermediate precision and repeatability showed that the method exhibited high precision. The developed HPLC method reduces the Rt. Notably, this method complies with regulatory standards, establishing it as a valuable tool for quality assurance, pharmacological evaluation, and clinical monitoring of FAV. Thus, this validated RP-HPLC method provides a robust and sensitive method for routine FAV quantification, with high accuracy, precision, and compliance results, supporting its potential use in the clinical pharmaceutical industry.

Faculty perspectives on accreditation, academic freedom and quality learning in private higher education institutes: empirical evidence

Purpose This study aims to investigate the effects of standardization, accreditation process on academic freedom and quality learning in higher education institutes (HEIs). In addition, this study explores the mediating effects of academic freedom between standardization, accreditation and learning. Design/methodology/approach To attain the objective, the study uses the theory of self-determination as its theoretical underpinning. The smart PLS-SEM technique is applied for analyzing data. Findings The results indicate that the accreditation process has a significant negative influence on faculty academic freedom and quality of learning in the sampled HEIs. There is also a significant mediating effect of academic freedom. Research limitations/implications There are a few limitations in this study. First, the study considers the faculty members only as respondents. Second, this study only considers the faculty members of private universities as respondents. In the future, public HEIs could also be included in similar studies. Finally, this research has been done in the context of a developing country. Practical implications The findings of the study have pervasive implications for the authorities in HEIs. The authorities of HEIs might capitalize on this evidence in formulating the appropriate policy for their HEIs. Social implications As the accreditation process weakens academic freedom and quality learning, accreditation should not be viewed as an institutional development and quality assurance tool. Rather, accreditation ought to allow for amplifying faculty voices, empowering faculty and protecting their rights. Originality/value Quantitative analysis on the subject addressed in the current study is scarce. Therefore, this research can be considered valuable for stakeholders of HEIs.

Analysis of the gamma index using an indigenously developed anthropomorphic heterogeneous female pelvis (AHFP) phantom.

It is essential in modern radiotherapy treatment practices to evaluate the quality assurance (QA) of the treatment plan prior to the exclusion of patient from treatment. The typical suitable tools used for patient pretreatment QA are phantoms representing the human anatomy. An anthropomorphic heterogeneous female pelvic (AHFP) phantom has been developed to represent the real female pelvic structure. The objective of the current study is to assess the findings of relative dosimetry carried out utilizing an electronic portal imaging device (EPID) on the AHFP phantom fabricated. The planning target volume (PTV) was created on CT slices of an AHFP phantom to confirm the tool's ability to represent female pelvic anatomy and serve as a QA tool. In order to assess the dose received by healthy organs during radiotherapy, organs at risk such as the bladder and rectum were additionally drawn alongside the PTV. Rapid Arc and Intensity modulated radiation therapy (IMRT) were both used to create the treatment plan on treatment planning system, and the Anisotropic Analytical Algorithm Version 11.0.31 was used to calculate the dose. The results obtained for the average gamma value in RapidArc plans are 0.26, 0.27, and 0.28 (g ≤1) and IMRT plans are 0.39, 0.40, and 0.46 (g ≤1) for target 1, target 2, and target 3, respectively. According to the findings of the current study, the AHFP phantom was used to explore the potential of relative dosimetry using EPID as a QA tool, which was found to be suitable.

An operator-independent quality assurance system for automatically generated structure sets

Objective. This study describes geometry-based and intensity-based tools for quality assurance (QA) of automatically generated structures for online adaptive radiotherapy, and designs an operator-independent traffic light system that identifies erroneous structure sets. Approach. A cohort of eight head and neck (HN) patients with daily CBCTs was selected for test development. Radiotherapy contours were propagated from planning computed tomography (CT) to daily cone beam CT (CBCT) using deformable image registration. These propagated structures were visually verified for acceptability. For each CBCT, several error scenarios were used to generate what were judged unacceptable structures. Ten additional HN patients with daily CBCTs and different error scenarios were selected for validation. A suite of tests based on image intensity, intensity gradient, and structure geometry was developed using acceptable and unacceptable HN planning structures. Combinations of one test applied to one structure, referred to as structure-test combinations, were selected for inclusion in the QA system based on their discriminatory power. A traffic light system was used to aggregate the structure-test combinations, and the system was evaluated on all fractions of the ten validation HN patients. Results. The QA system distinguished between acceptable and unacceptable fractions with high accuracy, labeling 294/324 acceptable fractions as green or yellow and 19/20 unacceptable fractions as yellow or red. Significance. This study demonstrates a system to supplement manual review of radiotherapy planning structures. Automated QA is performed by aggregating results from multiple intensity- and geometry-based tests.

An integrated fuzzy logic and machine learning platform for porosity detection using optical tomography imaging during laser powder bed fusion

Traditional methods such as mechanical testing and x-ray computed tomography (CT), for quality assessment in laser powder-bed fusion (LPBF), a class of additive manufacturing (AM), are resource-intensive and conducted post-production. Recent advancements in in-situ monitoring, particularly using optical tomography (OT) to detect near-infrared light emissions during the process, offer an opportunity for in-situ defect detection. However, interpreting OT datasets remains challenging due to inherent process characteristics and disturbances that may obscure defect identification. This paper introduces a novel machine learning-based approach that integrates a self-organizing map, a fuzzy logic scheme, and a tailored U-Net architecture to enhance defect prediction capabilities during the LPBF process. This model not only predicts common flaws such as lack of fusion and keyhole defects through analysis of in-situ OT data, but also allows quality assurance professionals to apply their expert knowledge through customizable fuzzy rules. This capability facilitates a more nuanced and interpretable model, enhancing the likelihood of accurate defect detection. The efficacy of this system has been validated through experimental analyses across various process parameters, with results validated by subsequent CT scans, exhibiting strong performance with average model scores ranging from 0.375 to 0.819 for lack of fusion defects and from 0.391 to 0.616 for intentional keyhole defects. These findings underscore the model’s reliability and adaptability in predicting defects, highlighting its potential as a transformative tool for in-process quality assurance in AM. A notable benefit of this method is its adaptability, allowing the end-user to adjust the probability threshold for defect detection based on desired quality requirements and custom fuzzy rules.