Delivery Errors Research Articles

1011-P: Effect of Fluctuating Temperature on Pump Delivery

Background: Accuracy of continuous subcutaneous insulin infusion (CSII) is essential for glycaemic control. Our study presents results of accuracy assessment of three off-the-shelves CSII under fluctuating temperature at 0,5UI/h. Methods: CSII systems accuracy was assessed by a double measurement approach utilizing a direct mass flow meter and a time-stamped micro-gravimetric test bench combined with a Kalman mathematical filter. CSII was placed inside a chamber of fluctuating temperature: 8h-tests were composed of successions of 1h at 32°C, 1h at 5°C, and compared to 8-hour tests at a 22°C fixed temperature. Accuracy was evaluated using mean of dose error. Mean absolute relative dispersion (MARD) of error was also computed for 15min time-windows. Stroke regularity was assessed in terms of frequency and volume. Tests were conducted both with insulin and medical water. Results: Delivery errors follow temperature profile. MARD of error is significantly higher with fluctuating temperature (85.2%, 44.4%, 20.4% according to each of the 3 CSII pump models) vs. fixed temperature (13.3%, 9.5%, 12.7%). No difference was observed between insulin and medical water. Stroke volume is affected by temperature changes rather than stroke frequency. Conclusion: Temperature and its fluctuations may affect the accuracy and amounts of insulin delivered by CSII. The clinical impact of the difference in insulin intake requires clinical investigations. Disclosure S. Girardot: Employee; Self; Air Liquide. Employee; Spouse/Partner; Air Liquide. P. Jacquemier: Employee; Self; Air Liquide. F. Mousin: Employee; Self; Air Liquide. C. Rendekeu: Employee; Self; Air Liquide. S. Hardy: None. J. Riveline: None.

Vliv regionálních variant španělštiny na kvalitu simultánního tlumočení do češtiny

This paper describes a study conducted as part of the diploma thesis The Impact of Spanish Regional Varieties on the Quality of Simultaneous Interpreting into Czech (2019). The aim of the study was to find whether interpreters make more omissions, additions, semantic errors, and delivery errors when interpreting from Latin American varieties of Spanish than when interpreting from standard European Spanish, as defined by the Royal Spanish Academy (RAE). Another goal was to find whether the expectations of different user groups regarding the quality of simultaneous interpreting differ or not. The theoretical part of this article presents the findings and conclusions of studies published by authors who address the quality of simultaneous interpreting. The research portion of this article describes an experiment conducted at the Institute of Translation Studies, Faculty of Arts, Charles University: five master’s degree students of conference interpreting (Czech A, Spanish C) were asked to simultaneously interpret a speech pronounced by four native speakers – from Argentina, Peru, Mexico and northern Spain. The interpreted versions of the speech were evaluated based on an established quality assessment model. To get another source of data, the interpreters filled out a questionnaire, which included questions about their experience with Spanish regional varieties, as well as a subjective evaluation of the difficulty of the speech, the speakers’ accent, and their own interpreting. Joining the study were ten more participants – five general users and five student-users (3rd year undergraduate students of Spanish for Intercultural Communication), who were asked to assess the renditions in Czech. The last chapter of the article presents the results of the experiment, as well as the results of the questionnaire regarding quality assessment.

Comparison of ICRU 38 rectal reference point dose estimates with measured dose in vivo in cobalt-60 HDR brachytherapy for cervical cancer

The objective of this study was to compare the ICRU 38 calculated rectal dose with in vivo dosimetry measured doses in cobalt-60 HDR brachytherapy for cervical cancer. A total of 48 brachytherapy insertions done on 15 patients treated from January to March 2017 at our institution were included in this prospective cross-sectional study. The results demonstrated no significant difference between the computed ICRU rectal point dose and in vivo maximum measured rectal dose ((r) 0.6208, p < 0.0001 [S]; t test p = 0.1578 [NS] 95% CI − 0.78 to 0.46), but a significant difference between ICRU rectal point and in vivo mean measured rectal dose ((r) 0.6033, p < 0.0001 [S]; t test p < 0.0001 [S] 95% CI − 0.81 to 0.35). These findings were seen even when sub-analyzed for the two used fraction sizes of 7 Gy and 8 Gy. The results also showed no significant differences in the maximum ((r) 0.9029, p < 0.0001 [S]; t test p = 0.2576 [NS], 95% CI − 0.21 to 0.06) and mean ((r) 0.9766, p < 0.0001 [S]; t test p = 0.2786 [NS], 95% CI − 0.93 to 0.03) doses taken from treatment planning system assigned dose points coinciding with the imaged probes of the in vivo dosimeter. Overall, this study was able to provide additional evidence that in vivo dosimetry can be validly used in the clinical setting to estimate the dose to the rectum during Co-60 HDR brachytherapy. Use of this technique allows for an additional quality assurance method that can contribute to reductions of errors in dose delivery.

Single-Isocenter Volumetric Modulated Arc Therapy vs. CyberKnife M6 for the Stereotactic Radiosurgery of Multiple Brain Metastases.

Introduction: Stereotactic radiosurgery (SRS) is becoming more frequently used for patients with multiple brain metastases (BMs). Single-isocenter volumetric modulated arc therapy (SI-VMAT) is an emerging alternative to dedicated systems such as CyberKnife (CK). We present a dosimetric comparison between CyberKnife M6 and SI-VMAT, planned at RayStation V8B, for the simultaneous SRS of five or more BM.Patients and Methods: Twenty treatment plans of CK-based single-session SRS to ≥5 brain metastases were replanned using SI-VMAT for delivery at an Elekta VersaHD linear accelerator. Prescription dose was 20 or 18 Gy, conformally enclosing at least 98% of the total planning target volume (PTV), with PTV margin-width adapted to the respective SRS technique. Comparatively analyzed quality metrics included dose distribution to the healthy brain (HB), including different isodose volumes, conformity, and gradient indices. Estimated treatment time was also compared.Results: Median HB isodose volumes for 3, 5, 8, 10, and 12 Gy were consistently smaller for CK-SRS compared to SI-VMAT (p < 0.001). Dose falloff outside the target volume, as expressed by the gradient indices GI_high and GI_low, was consistently steeper for CK-SRS compared to SI-VMAT (p < 0.001). CK-SRS achieved a median GI_high of 3.1 [interquartile range (IQR), 2.9–1.3] vs. 5.0 (IQR 4.3–5.5) for SI-VMAT (p < 0.001). For GI_low, the results were 3.0 (IQR, 2.9–3.1) for CK-SRS vs. 5.6 (IQR, 4.3–5.5) for SI-VMAT (p < 0.001). The median conformity index (CI) was 1.2 (IQR, 1.1–1.2) for CK-SRS vs. 1.5 (IQR, 1.4–1.7) for SI-VMAT (p < 0.001). Estimated treatment time was shorter for SI-VMAT, yielding a median of 13.7 min (IQR, 13.5–14.0) compared to 130 min (IQR, 114.5–154.5) for CK-SRS (p < 0.001).Conclusion: SI-VMAT offers enhanced treatment efficiency in cases with multiple BM, as compared to CyberKnife, but requires compromise regarding conformity and integral dose to the healthy brain. Additionally, delivery at a conventional linear accelerator (linac) may require a larger PTV margin to account for delivery and setup errors. Further evaluations are warranted to determine whether the detected dosimetric differences are clinically relevant. SI-VMAT could be a reasonable alternative to a dedicated radiosurgery system for selected patients with multiple BM.

Feasibility of 3D tracking and adaptation of VMAT based on VMAT-CT

BackgroundLocal computed tomography (CT) reconstruction is achievable with portal images acquired during volumetric-modulated arc therapy (VMAT) delivery and was named as VMAT-CT. However, the application of VMAT-CT is limited because it has limited field of view and no density information. In addition, the new generation of multi-leaf collimator with faster speed and various collimator angles used in patients’ plans could cause more artifacts in VMAT-CT. The goal of this study was to extend VMAT-CT concept, generate complete three-dimensional (3D) CT images, calculate new 3D dose, track and adapt VMAT plan based on updated images and dose. Materials and methodsVMAT-CT and planning CT of phantoms were fused by rigid or deformable registration to create VMAT-CT+ images. Trackings based on planning CT, VMAT-CT+, and cone beam CT (CBCT) were compared. When prescription dose was not met for planning target volume (PTV), re-planning was demonstrated on an in-house deformable phantom. Possible uncertainties were also evaluated. ResultsTracking based on VMAT-CT+ was accurate and superior to those based on planning CT and CBCT since VMAT-CT+ can detect changes during treatment. PTV coverage in the deformable phantom decreased after deformations but went up and met the prescription goal after re-planning. The impact of uncertainties on dose was minimal. Conclusion3D tracking and adaptation of VMAT based on VMAT-CT are feasible. Our study has the potential to increase the confidence of beam delivery, catch and remedy errors during VMAT.

Average Age of Information in Update Systems With Active Sources and Packet Delivery Errors

This letter studies the “age of information” (AoI) in a multi-source status update system where N active sources each send updates of their time-varying process to a monitor through a server with packet delivery errors. We analyze the average AoI for stationary randomized and round-robin scheduling policies. For both of these scheduling policies, we further analyze the effect of packet retransmission policies, i.e., retransmission without resampling, retransmission with resampling, or no retransmission, when errors occur. Expressions for the average AoI are derived for each case. It is shown that the round-robin schedule policy in conjunction with retransmission with resampling when errors occur achieves the lowest average AoI among the considered cases. For stationary randomized schedules with equiprobable source selection, it is further shown that the average AoI gap to round-robin schedules with the same packet management policy scales as O(N ). Finally, for stationary randomized policies, the optimal source selection probabilities that minimize a weighted sum average AoI metric are derived.

A Deep Learning-based correction to EPID dosimetry for attenuation and scatter in the Unity MR-Linac system

PurposeEPID dosimetry in the Unity MR-Linac system allows for reconstruction of absolute dose distributions within the patient geometry. Dose reconstruction is accurate for the parts of the beam arriving at the EPID through the MRI central unattenuated region, free of gradient coils, resulting in a maximum field size of ~10 × 22 cm2 at isocentre. The purpose of this study is to develop a Deep Learning-based method to improve the accuracy of 2D EPID reconstructed dose distributions outside this central region, accounting for the effects of the extra attenuation and scatter. MethodsA U-Net was trained to correct EPID dose images calculated at the isocenter inside a cylindrical phantom using the corresponding TPS dose images as ground truth for training. The model was evaluated using a 5-fold cross validation procedure. The clinical validity of the U-Net corrected dose images (the so-called DEEPID dose images) was assessed with in vivo verification data of 45 large rectum IMRT fields. The sensitivity of DEEPID to leaf bank position errors (±1.5 mm) and ±5% MU delivery errors was also tested. ResultsCompared to the TPS, in vivo 2D DEEPID dose images showed an average γ-pass rate of 90.2% (72.6%–99.4%) outside the central unattenuated region. Without DEEPID correction, this number was 44.5% (4.0%–78.4%). DEEPID correctly detected the introduced delivery errors. ConclusionsDEEPID allows for accurate dose reconstruction using the entire EPID image, thus enabling dosimetric verification for field sizes up to ~19 × 22 cm2 at isocentre. The method can be used to detect clinically relevant errors.

Abstract No. 583 Augmented fluoroscopy-guided endobronchial and transbronchial biopsy using endovascular steerable guiding sheaths in swine

To assess the feasibility of interventional radiology (IR) methods to perform bronchoscope-free augmented fluoroscopy (AF)-guided endobronchial biopsy using endovascular steerable guiding sheaths compared to interventional pulmonology (IP) methods with a bronchoscope. All animal procedures were approved by the ACUC. Prototype AF guidance software (Philips) based on cone-beam CT (CBCT) and incorporating airway, targets and navigational pathways was used to guide device placement. CBCT was used to evaluate accuracy of first-pass biopsy needle delivery or to updated planning for a second pass. Ex vivo studies were conducted in a fixed swine lung (Nasco). Biopsy needle delivery accuracy with two endobronchial non-steerable precurved guiding sheaths [Edge 90 and Edge 180 (Superdimension, Medtronic)] and two endovascular steerable guiding sheaths [6.5F Destino Twist (DT) (Oscor Inc.) and the 6F Morph (BioCardia) was compared to bronchoscopy. In the in vivo swine study (n = 4), two steerable guiding sheaths were used to deliver a needle (n = 2 swine, 4 biopsies/sheath) or an embolization coil (n = 2 swine, 3-4 coils/sheath). Endpoints in both studies were first-pass and second-pass biopsy needle delivery error defined by the distance between the needle and target center. Ex vivo, first-pass needle delivery error using the bronchoscope was 10.3 ± 4.0 mm. Errors using the precurved Edge 90 and Edge 180 guiding sheaths were 14.3 ± 8.7 mm and 11.4 ± 8.3 mm, respectively. The needle delivery errors for the steerable Morph and DT guiding sheaths were 8.6 ± 2.9 mm and 11.7 ± 2.6 mm, respectively. Second-pass delivery errors were 8.7 ± 0.9 mm (Edge 90), 5.4 ± 1.9 (Edge 180), 5.6 ± 2.4 mm (Morph) and 4.7 ± 1.2 mm (DT), respectively. In vivo, biopsy needle delivery error was 15 ± 7 mm using the Morph and 6 ± 1 mm using the DT. Embolization coil delivery success was 100% successful for both the Morph and DT. Use of steerable guiding sheaths combined with CBCT-based AF image guidance provided the tools for bronchoscope-free endobronchial-guided biopsy is feasible. IR methods in addition to nondiagnostic IP based bronchoscope-guided endobronchial biopsy.

Platform for automatic patient quality assurance via Monte Carlo simulations in proton therapy

For radiation therapy, it is crucial to ensure that the delivered dose matches the planned dose. Errors in the dose calculations done in the treatment planning system (TPS), treatment delivery errors, other software bugs or data corruption during transfer might lead to significant differences between predicted and delivered doses. As such, patient specific quality assurance (QA) of dose distributions, through experimental validation of individual fields, is necessary. These measurement based approaches, however, are performed with 2D detectors, with limited resolution and in a water phantom. Moreover, they are work intensive and often impose a bottleneck to treatment efficiency. In this work, we investigated the potential to replace measurement-based approach with a simulation-based patient specific QA using a Monte Carlo (MC) code as independent dose calculation engine in combination with treatment log files. Our developed QA platform is composed of a web interface, servers and computation scripts, and is capable to autonomously launch simulations, identify and report dosimetric inconsistencies. To validate the beam model of independent MC engine, in-water simulations of mono-energetic layers and 30 SOBP-type dose distributions were performed. Average Gamma passing ratio 99 ± 0.5% for criteria 2%/2 mm was observed. To demonstrate feasibility of the proposed approach, 10 clinical cases such as head and neck, intracranial indications and craniospinal axis, were retrospectively evaluated via the QA platform. The results obtained via QA platform were compared to QA results obtained by measurement-based approach. This comparison demonstrated consistency between the methods, while the proposed approach significantly reduced in-room time required for QA procedures.

Anovel approach to SBRT patient quality assurance using EPID-based real-time transit dosimetry : Astep to QA with in vivo EPID dosimetry.

Intra- and inter-fraction organ motion is amajor concern in stereotactic body radiation therapy (SBRT). It may cause substantial differences between the planned and delivered dose distribution. Such delivery errors may lead to medical harm and reduce life expectancy for patients. The project presented here investigates and improves arapid method to detect such errors by performing online dose verification through the analysis of electronic portal imaging device (EPID) images. To validate the method, arespiratory phantom with inhomogeneous insert was examined under various scenarios: no-error and error-simulated measurements. Simulation of respiratory motions was practiced for target ranges up to 2 cm. Three types of treatment planning technique - 3DCRT (three-dimensional conformal radiation therapy), IMRT (intensity modulated radiation therapy), and VMAT (volumetricmodulated arc therapy - were generated for lung SBRT. Atotal of 54plans were generated to assess the influence of techniques on the performance of portal dose images. Subsequently, EPID images of 52SBRT patients were verified. Both for phantom and patient cases, dose distributions were compared using the gamma index method according to analysis protocols in the target volume. The comparison of error-introduced EPID-measured images to reference images showed no significant differences with 3%/3 mm gamma evaluation, though target coverage was strongly underestimated. Gamma tolerance of 2%/2 mm reported noticeable detection in EPID sensitivity for simulated errors in 3DCRT and IMRT techniques. The passing rates for 3DCRT, IMRT, and VMAT with 1%/1 mm in open field were 84.86%, 92.91%, and 98.75%, and by considering MLC-CIAO + 1 cm (threshold 5%), were 68.25%, 83.19%, and 95.29%, respectively. This study demonstrates the feasibility of EPID for detecting the interplay effects. We recommend using thin computed tomography slices and adding sufficient tumor margin in order to limit the dosimetric organ motion in hypofractionated irradiation with preserved plan quality. In the presence of respiratory and gastrointestinal motion, tighter criteria and consequently using local gamma evaluation should be considered, especially for VMAT. This methodology offers asubstantial step forward in in vivo dosimetry and the potential to distinguish errors depending on the gamma tolerances. Thus, the approach/prototype provides afast and easy quality assurance procedure for treatment delivery verification.

Design of a relief materials delivery system based on UAV

The quality and efficiency of traditional rescue work are seriously affected by the destruction of roads and road traffic. In view of these existing problems, the current work investigates the delivery of relief materials using an unmanned aerial vehicle (UAV). At present, studies investigating the delivery of emergency relief materials are few, the technology is not mature, the disadvantage is bigger. In this paper, the UAV material delivery system can realize the function of automatic navigation and automatic delivery of materials. The experimental results show that, in a large number of delivery tests, 97% of deliveries contained a delivery error within 4 m, 64% of deliveries contained a delivery error within 2 m. The average delivery error was 1.86 m. The results of the experiment show that the accuracy of the UAV material delivery system is high, and the test results can provide reference for the further study of the robot.

Human Factors/Ergonomics (HFE) in Leadership and Management: Organizational Interventions to Reduce Stress in Healthcare Delivery

Clinician Burnout is a personal and public health issue. Most occupational stressors contributing to clinician burnout are systemic. The combination of organizational interventions along with individual interventions is necessary to make significant lasting difference in reducing burnout, improving clinician and patient satisfaction and reducing latent error in healthcare delivery. Application of Human Factors/Ergonomics (HFE) science in healthcare leadership and management is a gap in current training for leaders. HFE uses concepts from organizational, educational and cognitive science, systems science and industrial engineering. HFE application is especially necessary in a fast changing highly stressful healthcare environment which impacts the wellbeing of clinicians and the safety of patients under care. Practical suggestions for working with various healthcare leadership styles and organizational dynamics, while aligning wellness efforts with institutional mission are discussed. Concrete examples of decreasing extraneous mental load on clinicians to preserve their brainpower to achieve quality patient care are illustrated. Organizational interventions in combination with individual interventions to reduce and manage burnout have enormous potential to improve clinician wellbeing and satisfaction in taking care of patients, reduce costs, risk of error and create the safe working environment needed to sustainably give high quality care to patients.

Prediction of VMAT delivery accuracy with textural features calculated from fluence maps

BackgroundComprehensively textural feature performance test from volumetric modulated arc therapy (VMAT) fluences to predict plan delivery accuracy.MethodsA total of 240 VMAT plans for various treatment sites were analyzed, with Trilogy and TrueBeam STx systems. Fluence maps superposed fluences at each control point per plan. The textural features were the angular second moment (ASM), inverse difference moment (IDM), contrast, variance, correlation, and entropy, calculated from fluence maps using three displacement distances. Correlation analysis of textural feature performance as predictors of VMAT delivery accuracy used global gamma passing rates with MapCHECK2 and ArcCHECK dosimeters, and mechanical delivery errors calculated from machine log files.ResultsSpearman’s rank correlation coefficients (r) of the ASM (d = 10) to the gamma passing rates with 1%/2 mm using the MapCHECK2 were 0.358 and 0.519, respectively (p < 0.001). For the ArcCHECK, they were 0.273 (p = 0.001) and 0.259 (p = 0.009), respectively. The r-values of the ASM (d = 10) to the Trilogy and TrueBeam STx MLC errors were − 0.843 and − 0.859, respectively (p < 0.001), and those to the MU delivery errors were − 0.482 and − 0.589, respectively (p < 0.001). The ASM (d = 10) showed better performance in predicting VMAT delivery accuracy.ConclusionsThe ASM (d = 10) calculated from VMAT plan fluence maps were strongly correlated with global gamma passing rates and MLC delivery errors, and can predict VMAT delivery accuracy.

Evaluation and improvement the safety of total marrow irradiation with helical tomotherapy using repeat failure mode and effects analysis

Background & purposeHelical tomotherapy has been applied to total marrow irradiation (HT-TMI). Our objective was to apply failure mode and effects analysis (FMEA) two times separated by 1 year to evaluate and improve the safety of HT-TMI.Materials and methodsA multidisciplinary team was created. FMEA consists of 4 main steps: (1) Creation of a process map; (2) Identification of all potential failure mode (FM) in the process; (3) Evaluation of the occurrence (O), detectability (D) and severity of impact (S) of each FM according to a scoring criteria (1–10), with the subsequent calculation of the risk priority number (RPN=O*D*S) and (4) Identification of the feasible and effective quality control (QC) methods for the highest risks. A second FMEA was performed for the high-risk FMs based on the same risk analysis team in 1 year later.ResultsA total of 39 subprocesses and 122 FMs were derived. First time RPN ranged from 3 to 264.3. Twenty-five FMs were defined as being high-risk, with the top 5 FMs (first RPN/ second RPN): (1) treatment couch movement failure (264.3/102.8); (2) section plan dose junction error in delivery (236.7/110.4); (3) setup check by megavoltage computed tomography (MVCT) failure (216.8/94.6); (4) patient immobilization error (212.5/90.2) and (5) treatment interruption (204.8/134.2). A total of 20 staff members participated in the study. The second RPN value of the top 5 high-risk FMs were all decreased.ConclusionQC interventions were implemented based on the FMEA results. HT-TMI specific treatment couch tests; the arms immobilization methods and strategy of section plan dose junction in delivery were proved to be effective in the improvement of the safety.

Application effect of logistics robot in the distribution management of consumables and materials in Operating Room

Objective To analyze the application effect of logistics robot in the distribution management of consumables and materials in Operating Room and to explore its application value. Methods From December 1st to 11th in 2018, the intraoperative distribution of consumables and materials in Operating Room of Sun Yat-sen Unviersity Cancer Hospital was divided into the robot distribution group (logistic robot was used in distribution) and manual distribution group (manual power was used in distribution) based on rooms. The service time, number of service of the logistic robots and manual delivery were recorded and the incidence of logistic robots' collision was counted. Every delivery time, the error rate of the delivered goods, number and time of operation suspension for waiting for the goods in both of the two groups were counted separately and the differences between the two groups in delivery time, delivery error rate, number of times and time of operation suspension for goods waiting were compared, and the satisfaction of medical staff to the distribution of the two groups were compared. Results Robot distribution group delivered 1 295 trips in total, with an average of 3.8 rooms per trip, and no collisions happened. In the robot distribution group, time required for each delivery (72.62±7.8) s, the error rate of delivery (0.13%) , number of waiting during operation (93 times) and waiting time during operation (25.58±3.8) s were all lower than those in the manual distribution group[ (160.50±20.2) s, 0.76%, 157 times, (43.75±6.8) s], with statistically significant differences (P<0.01) . The satisfaction of medical staff in the robot distribution group was higher than that in the manual distribution group, and the difference was statistically significant (χ2=7.103, P=0.029) . Conclusions The application of logistic robots to distribute consumables and materials in the Operating Room can partly reduce the workload of the scout nurses, reduce the waiting time in the operation, achieve swiftness and accuracy, realize intelligent management of high-value consumables, and improve the working efficiency and management quality in the Operation Room. Key words: Operating Room; Logistics robot; Consumables management; Intellectualization; Informationization

Optical imaging provides rapid verification of static small beams, radiosurgery, and VMAT plans with millimeter resolution.

We demonstrate the feasibility of optical imaging as a quality assurance tool for static small beamlets, and pretreatment verification tool for radiosurgery and volumetric-modulated arc therapy (VMAT) plans. Small static beams and clinical VMAT plans were simulated in a treatment planning system (TPS) and delivered to a cylindrical tank filled with water-based liquid scintillator. Emission was imaged using a blue-sensitive, intensified CMOS camera time-gated to the linac pulses. For static beams, percentage depth and cross beam profiles of projected intensity distribution were compared to TPS data. Two-dimensional (2D) gamma analysis was performed on all clinical plans, and the technique was tested for sensitivity against common errors (multileaf collimator position, gantry angle) by inducing deliberate errors in the VMAT plans control points. The technique's detection limits for spatial resolution and the smallest number of control points that could be imaged reliably were also tested. The sensitivity to common delivery errors was also compared against a commercial 2.5D diode array dosimeter. A spatial resolution of 1mm was achieved with our imaging setup. The optical projected percentage depth intensity profiles agreed to within 2% relative to the TPS data for small static square beams (5, 10, and 50mm2 ). For projected cross beam profiles, a gamma pass rate >99% was achieved for a 3%/1mm criteria. All clinical plans passed the 3%/3mm criteria with >95% passing rate. A static 5mm beam with 20 Monitor Units could be measured with an average percent difference of 5.5±3% relative to the TPS. The technique was sensitive to multileaf collimator errors down to 1mm and gantry angle errors of 1°. Optical imaging provides ample spatial resolution for imaging small beams. The ability to faithfully image down to 20MU of 5mm, 6MV beamlets prove the ability to perform quality assurance for each control point within dynamic plans. The technique is sensitive to small offset errors in gantry angles and multileaf collimator (MLC) leaf positions, and at certain scenario, it exhibits higher sensitivity than a commercial 2.5D diode array.

Error detection using an electromagnetic tracking system in multi-catheter breast interstitial brachytherapy

The hybrid treatment delivery system (HTDS) has been proposed as a possible option for a quality assurance in the multi-catheter interstitial brachytherapy for breast cancer patients. The system, which consists out of a prototype afterloader with an integrated electromagnetic tracking (EMT) sensor and an EMT system, allows the automatic measurement of implanted catheters.To test the feasibility of the system for error detection, possible treatment planning errors and treatment delivery errors were simulated. Planning errors such as an incorrect offset value, an incorrect indexer length, tip/connector end swaps, and partial swaps, and; treatment delivery errors such as catheter shifts and catheter connection swaps were manually simulated using phantoms. An in-house Matlab routine was used to assess geometrical deviations between the dwell positions defined based on CT and EMT measurement. Additionally, the influence of implant motion on the detection ability of the system was assessed. An algorithm for the detection and specification of errors based on the error simulation results was developed. At the University Hospital Erlangen, a patient study is ongoing, where errors in patient data were analyzed using the proposed algorithm.All simulated planning errors were detected. Catheter connection swaps can be detected 100% of the time. A shift detection rate of >97% was observed for shifts larger than 1.1 mm, both in the static and the motion measurements. Catheter reconstruction uncertainties and catheter shifts <2 mm were found to be the most common treatment planning and delivery errors in patient data. HTDS proved to be a reliable method for error detection.

Dynamics and Structure of Expert Panel Examinations in Medical Malpractice Cases in the Krasnodar Krai (2010–2018)

Aim. The paper analyses the dynamics and structure of forensic medical examinations conducted by an expert panel in cases involving medical malpractice in the Krasnodar Krai (2010– 2018).Materials and methods. The authors studied the annual reports along with the archived copies of expert panel reports on the cases of medical malpractice submitted in 2010–2018 by the Department for Complex and Expert Panel Examinations (Bureau for Forensic Medical Examination, Krasnodar). The obtained results were processed using Microsoft Excel 2010 and SPSS Statistics Data Editor v.17.0. In this study, the authors employed the following methods: retrospective, comparative and analytical.Results. In 2010–2018, a total of 1,023 expert panel examinations were conducted in cases involving medical malpractice. A steady increase in the number of examinations (from 36 in 2010 to 245 in 2018) is associated with the growing number of citizens complaining about the poor quality of medical care, the interest of judicial and investigation authorities in looking into such offences, etc. A direct cause-and-effect relationship between imperfect and erroneous healthcare delivery and ensuing adverse effects was established in 212 cases, whereas indirect or no relationship was determined in 130 and 644 cases, respectively. The number of examinations pertaining to criminal cases amounted to 29.1%, showing an increase by 3.5 times (from 16 in 2010 to 57 in 2018); while the number of examinations related to civil cases and those conducted during pre-investigation checks came to 18.2% and 52.7%, respectively.Conclusion. The study shows a steady increase in the number of examinations related to medical malpractice (including criminal cases), which reveal a direct cause-and-effect relationship between errors in healthcare delivery and clinical outcomes

CUWSN: energy efficient routing protocol selection for cluster based underwater wireless sensor network

Energy efficient routing protocol selection for Cluster based Underwater Wireless Sensor Network (CUWSN) is aimed to support monitoring and controlling underwater scenarios in the field of Internet of Underwater Things. The crucial requirement of Underwater Wireless Sensor Network (UWSN) is to prolong network lifespan. The aim of this article is to build energy-efficient UWSN that will trim energy expenditure as well as improve performance in the underwater scenario. In the proposed CUWSN, a UWSN architecture is designed, which uses the benefits of cluster head and multi-hop transmission. The proposed CUWSN extends the network lifetime by using multi-hop transmission. The proposed CUWSN model is simulated using QualNet 7.1 simulation tool. In this article, energy consumption, throughput, packet delivery ratio, transmission delay, error signals, and packet loss parameter indicators are considered to investigate the performance of proposed CUWSN. The outcomes of proposed CUWSN exhibit that the AODV routing protocol surpasses the DYMO routing protocol by 80%, the IERP routing protocol by 75%, STAR routing protocol by 47% and ZRP routing protocol by 81% in perspective of energy efficiency. In references to other performance indicators like average path loss and average interference the IERP routing protocol and in case of throughput the ZRP routing protocol performs well among the five routing protocols. Finally, the AODV routing protocol is energy conservative in the proposed CUWSN.

Effect of the firing position on aiming error and probability of hit

This is an extended abstract of a paper to be published in Defence Technology, 2019. Sources of dispersions that contribute to delivery error and reduce the soldier performance in terms of hit probability are numerous. In order to improve the warfighter performance, the source of the errors contributing to the inaccuracy and dispersion of the weapon systems must be understood. They include ammunition dispersion error, gun dispersion, aerodynamic jump and the aiming error. The aiming error or gun pointing error is defined as the angle between the gun muzzle at the instant the trigger is pulled and the line of fire that corresponds to the intendent aim point. This is a round-to-round error. In weapons systems that include the rifle, the ammunition, a sight and a gunner, the aiming error was shown to be the single most important source of dispersion for the regular infantryman. In other words, for the general purpose rifle weapon system, the weak link is often the human. In order to verify and quantify this assertion, an experimental investigation was carried out to determine the aiming error associated with general purpose rifle fired by infantryman. The aiming error was evaluated for various firing positions and scenarios using infantryman for ranges varying between 100 m and 500 m. The results show that the aiming error is the main contributor to dispersion for the general purpose rifle fired by a non-specialized infantryman. The aiming error induced dispersion for unstressed and rested gunners is shown to be at best equivalent to that of the weapon fired from a bench rest by a marksman.