Independent Operator Research Articles

Mixed Linear Model of a Safety Dispatch Model in an Active Distribution Network for Source–Grid–Load Interactions

There are a large number of plug-and-play loads in an active distribution network, such as EVs(Electric Vehicles), energy storage, solar power, etc. Due to the lack of security control methods for each terminal node and the lack of distributed power voltage control methods, the large number of loads brings a huge challenge to the security of the distribution network. At present, some regional distribution networks dominated by new energy in China have long-standing problems, such as high voltage impact and frequency flickering, which are extremely harmful to electric equipment, and the resulting load-side accidents have brought huge economic losses. Therefore, research on an optimization model of the source–grid–load interaction in the active distribution network considering the safety characteristics, especially the voltage of the system, will help to improve the quality of the grid dispatch. In this paper, the safety limits of the independent operation of a source network loaded on three sides are used as the operating constraints of the system, and the social welfare of the interaction is maximized as the goal. A joint optimization modeling after the independent solution of the three sides is used as the core means, a heuristic algorithm is used to solve the overall optimization of the whole system, a scheduling optimization model that meets the system security goals is constructed, and this model is used to guide the operation strategy of each node in the system. The Lagrangian relaxation factor is introduced for structural optimization, and finally, the simplified 36-node model of the actual power grid is used for verification. The results show that under the goal of ensuring the economy of the system, the system voltage is controlled within the specified range of the safe operation of the system, which can meet the safety needs of the interaction.

A study on alternative methods of energy hub self-starting generators

Power sources of different forms and capacities are being connected to the grid owing to the rapid increase in the use of renewable energy sources. Korea Gas Corporation is conducting a demonstration project to supply electric power to the microgrid by recycling the pressure energy consumed in the gas static pressure process and by installing a turbo expander generator (TEG) with a capacity of approximately 1.6 [MW] in the pressure reducing valve. The demonstration of the microgrid is being conducted in the southern Gyeongin region of South Korea. In this study, the TEG is replaced with a self-starting generator based on a recovery plan, which is established in the event of a power outage. The TEG is an induction generator, which requires a continuous supply of excitation current from the system to achieve independent operation. This issue is resolved through the charging current provided by the primary restorative transmission line and the TEG is replaced with a self-starting generator. The effect on the system when the TEG is replaced and when it is not replaced, is analyzed statically through the amount of power generated by the swing generator. Consequently, when the self-starting generator is replaced with the TEG, the TEG exhibits the same load level as the self-starting generator when a capacitor with a reactive power as high as 1 [Mvar] is installed in parallel to the TEG-installed busbar.

Production enhancement of long string photovoltaic plants during partial shading through switching capacitor power optimizer circuit

Long series connections are widely preferred by photovoltaic (PV) power plants because they offer advantages such as higher voltage, independent operation of modules at optimal voltage, ease of installation, and lower losses. However, PV power plants are highly susceptible to partial shading and suffer high power losses, resulting in large financial losses. The existing solutions have numerous weaknesses, such as multiple peaks in the characteristic’s curves, erroneous tracking losses, lower power generation and extraction, and limited applications. To overcome the above limitations, a power optimizer based on a switching capacitor circuit has been proposed in this paper to improve the reliability of long strings in power plants under partial shading scenarios. The power optimizer provides higher power output and a single peak in the characteristics curves by minimizing the voltage differences between modules in the string to enable smoother operation of PV systems under partial shading. To evaluate the application and performance of the proposed power optimizer, two PV system sizes are considered and compared with the conventional techniques under static, moving, and progressive partial shading scenarios. From the in-depth analysis, it is found that the power optimizer minimizes the mismatch between modules by reducing the power losses from 70.83 % in the conventional system to 35.13 %. By implementing the power optimizer in the string, a power extraction of up to 68.68 %, generation efficiency of more than 99 %, and power improvement of 54.21 % are achieved along with single-peak characteristics curves.

Floating Photovoltaic Systems Coupled with Pumped Hydroplants under Day-Ahead Electricity Market Conditions: Parametric Analysis

The intermittent nature of the solar resource together with the fluctuating energy demand of the day-ahead electricity market requires the use of efficient long-term energy storage systems. The pumped hydroelectric storage (PHS) power plant has demonstrated its technical and commercial viability as a large-scale energy storage technology. The objective of this paper is to analyse the parameters that influence the mode of operation in conjunction with a floating photovoltaic (FPV) power plant under day-ahead electricity market conditions. This work proposes the analysis of two parameters: the size of the FPV power plant and the total process efficiency of the PHS power plant. Five FPV plant sizes are analysed: 50% (S1), 100% (S2), 150% (S3), 350% (S4) and 450% (S5) of the PHS plant. The values of the total process efficiency parameter analysed are as follows: 0.77 for old PHS plants, and 0.85 for more modern plants. The number of daily operating hours of the PHS plant is 4 h. These 4 h of operation correspond to the highest prices on the electricity market. The framework of the study is the Iberian electricity market and the Alto Rabagão dam (Portugal). Different operating scenarios are considered to identify the optimal size of the FPV power plant. Based on the measured data on climatic conditions, an algorithm is designed to estimate the energy production for different sizes of FPV plants. If the total process efficiency is 0.85, the joint operation of both plants with FPV plant sizes S2 and S3 yields a slightly higher economic benefit than the independent mode of operation. If the total process efficiency is 0.77, there is always a higher economic benefit in the independent operation mode, irrespective of the size of the FPV plant. However, the uncertainty of the solar resource estimation can lead to a higher economic benefit in the joint operation mode. Increasing the number of operating hours of the PHS plant above 4 h per day decreases the economic benefit of the joint operation mode, regardless of the total process efficiency parameter and the size of the FPV plant. As the number of operating hours increases, the economic benefit decreases. The results obtained reveal that the coupling of floating photovoltaic systems with pumped hydroelectric storage power plants is a cost-effective and reliable alternative to provide sustainable energy supply security under electricity market conditions. In summary, the purpose of this work is to facilitate decision making on the mode of operation of both power plants under electricity market conditions. The case studies allow to find the optimal answer to the following practical questions: What size does the FPV power plant have to be in order for both plants to be better adapted to the electricity market? What is the appropriate mode of operation of both plants? What is the economic benefit of changing the turbine pump of the PHS power plant? Finally, how does the installation of the FPV power plant affect the water volume of the upper reservoir of the PHS plant? Knowledge of these questions will facilitate the design of FPV power plants and the joint operation of both plants.

In Vitro Evaluation of the Accuracy of Three Electronic Apex Locators Using Different Sodium Hypochlorite Concentrations.

Background and Objectives: The aim of this study was to compare the accuracy of three types of electronic apex locators (EALs) when two different concentrations of NaOCl irrigation solutions are used by two operators. Materials and Methods: After creating the access cavities for 20 single rooted extracted teeth, the actual canal length (ACL) of each canal was determined visually using a #10 file and magnification. The teeth were subsequently inserted in plastic molds filled with alginate. The electronic measurement of root canal length (EWL) was performed using three different electronic apex locators: Root ZX II, Apex ID, and Dual Pex. Two independent operators, an endodontic specialist with 20 years practice and an undergraduate student in the final year of study, performed the irrigation procedures with two different concentrations of NaOCl (2% and 5.25%), and then measured the EWL using each of the EALs. The accuracy of all EALs, was determined in each case by subtracting the EWL from the ACL. Statistical analyses were performed using one-way ANOVA test. Results: In the presence of 2% NaOCl solution, for a margin error of ±0.5 mm, Root ZX II, Apex ID, and Dual Pex presented an accuracy of 90%, 80%, and 85% respectively. The increase in the concentration of the irrigation solution affected the accuracy of Root ZX II and Apex ID for both operators, diminishing it to 75% for the same margin error, but improved Dual Pex's accuracy to 100%. Conclusions: The best accuracy in working length determination was obtained by Root ZX II for 2% NaOCl solution and by Dual Pex for 5.25% NaOCl solution with no significant statistical difference when compared.

Adaptive model predictive control for grid‐forming converters to achieve smooth transition from islanded to grid‐connected mode

AbstractOne of the main capabilities of grid‐forming converters is the ability to operate in both islanded and grid‐connected modes. The grid‐forming converters work autonomously and behave as an AC voltage source when they are isolated from the bulk power system. In a grid‐connected mode, it is necessary for them to offer a set of grid‐forming capabilities for enhancing system inertia and strength. A grid‐forming converter may experience significant fluctuations in voltage, current, and frequency when the transition occurs. This paper investigates an improved adaptive model predictive control (AMPC) method for grid‐forming converters to achieve a smooth transition from islanded to grid‐connected mode and balance the contradiction between frequency stability and response speed. The AMPC method uses the angular frequency and phase angle as the performance indicators and introduces the angular frequency variations to adaptively adjust its weight coefficient in the objective function. The implementations and effects of the proposed AMPC method on the grid‐forming converter are theoretically evaluated. Compared to the conventional control, the proposed control scheme can not only suppress voltage, current, and frequency fluctuations, but also achieve a smooth transition. Additionally, the frequency control strategy in the islanded mode is improved for better independent operation. Finally, experiment tests on a controller‐level hardware‐in‐the‐loop simulation platform are carried out to validate the proposed control strategy for achieving a smooth transition.

Prognostic value of subclinical congestion assessed by lung ultrasound in STEMI patients in a short-term follow-up

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): This project received a Scholarship for Training and Research from the Association of Ischemic Heart Disease and Cardiological Critical Care of the Spanish Society of Cardiology and an Original Research Projects Grant from the Catalan Society of Cardiology. Background Heart failure (HF) is an important prognostic factor in ST-segment elevation myocardial infarction (STEMI). Although most STEMI patients are Killip-Kimball class I (KK-I) at admission, there is a risk of developing HF during hospitalization and follow-up. Lung ultrasound (LUS) is an easy, fast, and accurate technique that allows pulmonary congestion to be diagnosed even in pre-clinical stages. Several risk scores have been developed to identify low-risk STEMI patients, nonetheless any of these scores include LUS assessment. Purpose We evaluated the prognostic value of subclinical congestion assessed by LUS at hospital admission in patients with KK-I STEMI. Primary endpoint was a composite of readmission for HF or new acute coronary syndrome or death during 30-day follow-up. Methods This was a multicenter study prospectively enrolling 300 patients admitted for KK-I STEMI. LUS was performed during the first 24 hours after revascularization by and independent operator and B-lines were counted off-line differentiating between patients with wet lung (≥ 3 B-lines in at least one lung field) or dry lung. To assess whether LUS could improve the predictive capacity of current risk scales, a model with categorical result of LUS (dry/wet lung) and categorical result of Zwolle score (low/higher risk) was compared to the isolated result of Zwolle score and net reclassification index (NRI) was calculated. Results Wet lung patients had a higher risk of developing the follow-up composite endpoint (hazard ratio [HR] 10.8, 95% CI 2.6-45.2, p=0.001). After adjusting by a propensity score including age, sex, hypertension, chronic kidney disease (glomerular filtration rate <60ml/min/1,73m2), previous atrial fibrillation/flutter, anterior STEMI, and LVEF, a LUS finding of wet lung remained an independent risk factor for the composite endpoint (adjusted HR 5.4, 95% CI 1.0-28.7, p=0.049). LUS was able to predict de composite endpoint with 62.5% sensitivity, 86.8% specificity, 11.1% positive predictive value and 98.9% negative predictive value. LUS improved the predictive capacity of the Zwolle score (net reclassification improvement = 0.99, 95% CI 0.29-1.69, p=0.006) to predict the composite endpoint. CONCLUSIONS Early subclinical pulmonary congestion identified by LUS in KK-I STEMI patients at hospital admission is a strong predictor of adverse outcomes at 30-day follow-up. Patients without subclinical congestion have a very low risk of adverse outcomes and can potentially benefit from an early discharge. LUS improves the predictive ability of the Zwolle risk score, allowing a more accurate identification of low-risk patients.

Heterogeneously integrated light emitting diodes and photodetectors in the metal-insulator-metal waveguide platform

Abstract We demonstrate heterogeneous integration of active semiconductor materials into the conventional passive metal-insulator-metal (MIM) waveguides to provide compact on-chip light generation and detection capabilities for chip-scale active nanophotonic platforms. Depending on its bias conditions, a metal-semiconductor-metal section can function as either a light emitting diode or a photodetector directly connected to the MIM waveguides. We experimentally verify the independent and combined operations of electrically-driven on-chip light sources and photodetectors.

Uncrewed surface systems facilitating a new era of global ocean exploration

There is growing recognition that key to addressing critical issues like climate change, global sea level rise and the long-term sustainability of humankind is a more complete understanding of our oceans and processes within them that account for the distribution of global heat, CO2 and provide sustenance to so many. Yet, despite years of effort, less than 25% of the global ocean seafloor has been mapped and less than 5% of the ocean volume explored, likely due to the cost and inefficiency of traditional ocean mapping and exploration techniques using large, very expensive, crewed research vessels. Recent advances in the development of uncrewed surface vessels offer the possibility to reduce costs and increase efficiency of ocean mapping and exploration. Such efficiencies can be gained by using small mother ship-deployed uncrewed vessels acting as relatively inexpensive mapping and sampling force multipliers or the use of small uncrewed vessels launched to from a mother ship to monitor and control autonomous underwater vehicles, allowing multiple operations simultaneously and “verified, directed sampling”, all while freeing the mother ship for independent operations. We are also seeing the development of larger uncrewed vessels launched from shore with long-endurance and range, capable of carrying a full suite of deep ocean mapping and exploration tools. All of these systems and approaches offer great hope but it is very early in our understanding of their full capabilities, costs and limitations and we must be careful not to overpromise, leading to disappointments and early abandonment of a potentially innovative approach, while at the same time maintaining the patience required to continue the research, investment and innovation that will hopefully bring us to a new world of efficient and effective ocean mapping and exploration that will allow us to meet our goal of complete coverage of the ocean.

Semi-device-independent certification of indefinite causal order in a photonic quantum switch

Quantum processes are transformations that act on quantum operations. Their study led to the discovery of the phenomenon of indefinite causal order: some quantum processes, such as the quantum switch, act on independent quantum operations in such a way that the order in which the operations are acted upon not only cannot be determined but is simply undefined. This is the property that we experimentally certify in this work. We report an experimental certification of indefinite causal order that relies only on the characterization of the operations of a single party. We do so in the semi-device-independent scenario with the fewest possible assumptions of characterization of the parties’ local operations in which indefinite causal order can be demonstrated with the quantum switch. To achieve this result, we introduce the concept of semi-device-independent causal inequalities and show that the correlations generated in a photonic quantum switch, in which all parties are able to collect local outcome statistics, achieve a violation of this inequality of 224 standard deviations. This result consists of the experimental demonstration of indefinite causal order with the fewest device-characterization assumptions to date.

Ultrasound-guided fasciotomy for chronic exertional forearm compartment syndrome: a cadaveric feasibility study

ObjectivesChronic exertional forearm compartment syndrome is observed in patients who engage in physical activity requiring repetitive isometric muscular effort of the wrist during prolonged grasping. Open fasciotomy was considered as the gold-standard treatment, for its ability to release all compartments. However, its invasiveness means that high-level athletes have to abstain from competition for a long period of time. For this reason, minimally invasive techniques have been developed, to allow faster recovery.The objective of this cadaveric study was to evaluate the feasibility and reproducibility of ultrasound-guided palmar fasciotomy in the treatment of chronic exertional forearm compartment syndrome. MethodsSurgery consisted in ultrasound-guided palmar fasciotomy of the superficial anterior compartment, using a single minimally invasive approach. Twenty forearms were then dissected by an independent operator, (1) to check complete fasciotomy and (2) to screen for iatrogenic lesions on the tendons, veins and superficial sensory branches. ResultsSixteen fasciotomies were total and 4 partial: i.e., a release rate of 80%. The superficial sensory branches were intact, and notably the branches of the medial cutaneous nerve of the forearm. Mean surgery time was 9 min, progressively decreasing with the repetition of the ultrasound-guided procedure. ConclusionsUltrasound-guided fasciotomy in the management of chronic exertional forearm compartment syndrome appears to be a simple, effective, safe and reproducible technique.

Stochastic planning for low-carbon building integrated energy system considering electric-heat-V2G coupling

The low-carbon building has been proposed to mitigate the climate change caused by environmental problems and realize carbon neutrality in urban areas. In addition, the integrated energy system (IES) has been developed to reduce renewable energy curtailment in the power distribution system and improve energy efficiency due to the independent operation of traditional energy systems. In this paper, we propose a stochastic planning method for low-carbon building IES, in which the Vehicle to Grid (V2G) is also considered to further increase the flexibility of low-carbon buildings. The proposed planning method optimizes the investment and operation costs, and CO2 emission of the building IES, to achieve the maximum benefit of the low-carbon building and help realize carbon neutrality. By considering the uncertainty of distributed renewable energy, multi-energy load fluctuation and the random behavior of EV users, a two-stage stochastic programming model is formulated with chance constraints, in which the heuristic moment matching scenario generation (HMMSG) and sample average approximation (SAA) methods are applied to deal with the uncertainties. In the case study, a real IES office building in Shanghai, where photovoltaic (PV), energy storage system (ESS), fuel cell (FC), EV, etc. are included as planning options, is used as the test system to verify the effectiveness of the proposed planning method, and the functions of the ESS and EV in IES are analyzed in detail in different operation scenarios. The case study results show that the proposed planning scheme can reduce the total cost and carbon emission significantly.© 2017 Elsevier Inc. All rights reserved.

An Efficient Model for Mitigating Power Transmission Congestion Using Novel Rescheduling Approach

In the electricity business, power evacuation from source to load is a challenging task when there is contingency and agencies have to swirl around for solutions in terms of rescheduling generator dispatch, load slashing, adding of network, etc. The more challenging scenario arises when the independent operator wants to re-dispatch a generator during the contingent situation. So, in this paper, we focus on a new generator rescheduling technique with congestion price and transmission security as an intervention. The significant intention of this paper involves restricting the load thereby dispatching a particular generator or a set of generators with low cost and secure transmission line. In addition to this, the network jamming is unpredictable and does not follow any pattern, but power supply in some zones is disrupted due to hidden reasons. Therefore, a macroscopic or holistic approach is adopted for congestion forecasting through demand schedule, gathering, minimum as well as maximum drawls. Here, two significant factors namely the transmission utilization charges as well as transmission congestion charges for predicting the congestion of a transmission line are evaluated. Finally, the experimental analysis to determine transmission utilization charges, transmission congestion charges, cost function and generation supply as well as demand balance with congestion optimization.

Constructing operator basis in supersymmetry: a Hilbert series approach

In this paper we introduce a Hilbert series approach to build the operator basis for a N = 1 supersymmetry theory with chiral superfields. We give explicitly the form of the corrections that remove redundancies due to the equations of motion and integration by parts. In addition, we derive the maps between the correction spaces. This technique allows us to calculate the number of independent operators involving chiral and antichiral superfields to arbitrarily high mass dimension. Using this method, we give several illustrative examples.

Low-carbon planning for park-level integrated energy system considering optimal construction time sequence and hydrogen energy facility

With the increasing concern about global energy crisis and environmental pollution, the integrated renewable energy system has gradually become one of the most important ways to achieve energy transition. In the context of the rapid development of hydrogen energy industry, the proportion of hydrogen energy in the energy system has gradually increased. The conversion between various energy sources has also become more complicated, which poses challenges to the planning and construction of park-level integrated energy systems (PIES). To solve this problem, we propose a bi-level planning model for an integrated energy system with hydrogen energy, considering multi-stage investment and carbon trading mechanism. First, the mathematical models of each energy source and energy storage in the park are established respectively, and the independent operation of the equipment is analyzed. Second, considering the operation state of multi-energy coordination, a bi-level planning optimization model is established. The upper level is the capacity configuration model considering the variable installation time of energy facilities, while the lower level is the operation optimization model considering several typical daily operations. Third, considering the coupling relationship between upper and lower models, the bi-level model is transformed into a solvable single-level mixed integer linear programming (MILP) model by using Karush–Kuhn–Tucker (KKT) condition and big-M method. Finally, the proposed model and solution methods are verified by comprehensive case studies. Simulation results show that the proposed model can reduce the operational cost and carbon emission of PIES in the planning horizon, and provide insights for the multi-stage investment of PIES.

Probing anomalous ZZγ and Zγγ couplings at the e+e− colliders using optimal observable technique

We study the anomalous ZZγ and Zγγ couplings that can be probed via Zγ production at the e+e− colliders. We take Standard Model Effective Field Theory (SMEFT) approach to examine these anomalous neutral triple gauge couplings in a model independent way. There are four independent dimension-8 operators that generate these gauge interactions, one of them is CP-conserving and rest three are CP-violating. We adopt optimal observable technique to extract the sensitivity at which these anomalous couplings can be probed at future e+e− colliders and then compare the results with the latest experimental limit obtained at the LHC. We also study the impact and advantage of beam polarization in these precision measurements. Statistical limit (95% C.L.) on individual anomalous couplings as well as the correlation between various couplings have been discussed in detail.

Application of Heat Pumps in New Housing Estates in Cities Suburbs as an Means of Energy Transformation in Poland

This paper presents possible applications of heat pumps in buildings during the energy transformation and decarbonization of a country whose energy sector is highly centralized and based on coal. Contemporary cities are spreading beyond the existing borders and new areas cannot be supplied by the existing centralized district heating system. The only form of energy that is available on the outskirts of cities is electricity, which means that it must be used for all energy needs, including heating. In such a case, the use of heat pumps is perfectly justified in terms of energy, economy and environment, especially when they are coupled with photovoltaic systems. Hypothetical micro housing estate energy systems based on photovoltaics and heat pumps are analyzed in the paper. New options for configuration and operation of the energy systems are considered. Results of a simulation study show that by creating a common local electricity network and a local heating network powered by a central heat pump, the direct use of electricity generated in the local photovoltaic systems increases from 25% to at least 35%, thanks to enabling more even storing and consuming of solar energy during a day, compared to the independent operation of energy systems at individual houses.

Morphology of proximal and distal human semitendinosus compartments and the effects of distal tendon harvesting for anterior cruciate ligament reconstruction.

The human semitendinosus muscle is characterized by a tendinous inscription separating proximal and distal neuromuscular compartments. As each compartment is innervated by separate nerve branches, potential exists for independent operation and control of compartments. However, the morphology and function of each compartment have not been thoroughly examined in an adult human population. Further, the distal semitendinosus tendon is typically harvested for use in anterior cruciate ligament reconstruction surgery, which induces long-term morphological changes to the semitendinosus muscle-tendon unit. It remains unknown if muscle morphological alterations following anterior cruciate ligament reconstruction are uniform between proximal and distal semitendinosus compartments. Here, we performed magnetic resonance imaging on 10 individuals who had undergone anterior cruciate ligament reconstruction involving an ipsilateral distal semitendinosus tendon graft 14 ± 4 months prior, extracting morphological parameters of the whole semitendinosus muscle and each individual compartment from both the (non-injured) contralateral and surgical legs. In the contralateral leg, volume and length of the proximal compartment were smaller than the distal compartment. No between-compartment differences in volume or length were found for anterior cruciate ligament reconstructed legs, likely due to greater shortening of the distal compared to the proximal compartment after anterior cruciate ligament reconstruction. The maximal anatomical cross-sectional area of both compartments was substantially smaller on the anterior cruciate ligament reconstructed leg but did not differ between compartments on either leg. The absolute and relative between-leg differences in proximal compartment morphology on the anterior cruciate ligament reconstructed leg were strongly correlated with the corresponding between-leg differences in distal compartment morphological parameters. Specifically, greater between-leg morphological differences in one compartment were highly correlated with large between-leg differences in the other compartment, and vice versa for smaller differences. These relationships indicate that despite the heterogeneity in compartment length and volume, compartment atrophy is not independent or random. Further, the tendinous inscription endpoints were generally positioned at the same proximodistal level as the compartment maximal anatomical cross-sectional areas, providing a wide area over which the tendinous inscription could mechanically interact with compartments. Overall, results suggest the two human semitendinosus compartments are not mechanically independent.

A percutaneous ultrasound-guided iliotibial band release technique reduces surgical time and costs compared to an endoscopic technique.

External snapping hip is caused by the iliotibial band snapping from the greater trochanter during hip movement. The aim of this study was to compare a technique of ultrasound-guided iliotibial band release versus a similar endoscopic technique. An anatomical study was performed on 10 cadavers i.e. 20 hips. The same operator performed ultrasound-guided and endoscopic iliotibial band release on either side of each specimen. An independent operator performed an open control to verify the outcome measures. The primary outcome was iliotibial cutting percentage, defined as the ratio of the transversal cut distance and the width of the iliotibial at the most prominent portion of the great trochanter. Secondary outcomes included nerve injuries. The surgical time was assessed and disposable medical supplies costs were estimated. The average cutting percentage was 95% ± 8 by ultrasound, compared with 91% ± 11 by endoscopy (n.s.). No iatrogenic lesions were found, particularly nerve damage. The average duration of the ultrasound procedure was 12.3 minutes ± 6 compared to 21 minutes ± 10.7 for endoscopy (p=0.04), with a 3-fold decrease between the first and last procedure, regardless of the technique. The ultrasound procedure was 3 times less expensive in terms of disposable medical supplies (120.5€ versus 353.5€). This technique of ultrasound-guided iliotibial band release appears to be as effective and safe as a similar endoscopic technique. The surgical time is reasonable for a surgeon trained in ultrasound, with lower disposable supplies costs. A comparative clinical study is further needed to assess the actual benefits of each technique.

MP48-20 MENTAL WORKLOADS OF SURGEONS IN UROLOGY: A PROSPECTIVE OBSERVATIONAL STUDY

You have accessJournal of UrologyCME1 Apr 2023MP48-20 MENTAL WORKLOADS OF SURGEONS IN UROLOGY: A PROSPECTIVE OBSERVATIONAL STUDY Shigeru Harada, Takashige Abe, Jun Furumido, Keita Takahashi, Kanta Hori, Noriyuki Abe, Masafumi Kon, Sachiyo Murai, Haruka Miyata, Hiroshi Kikuchi, Ryuji Matsumoto, Takahiro Osawa, and Nobuo Shinohara Shigeru HaradaShigeru Harada More articles by this author , Takashige AbeTakashige Abe More articles by this author , Jun FurumidoJun Furumido More articles by this author , Keita TakahashiKeita Takahashi More articles by this author , Kanta HoriKanta Hori More articles by this author , Noriyuki AbeNoriyuki Abe More articles by this author , Masafumi KonMasafumi Kon More articles by this author , Sachiyo MuraiSachiyo Murai More articles by this author , Haruka MiyataHaruka Miyata More articles by this author , Hiroshi KikuchiHiroshi Kikuchi More articles by this author , Ryuji MatsumotoRyuji Matsumoto More articles by this author , Takahiro OsawaTakahiro Osawa More articles by this author , and Nobuo ShinoharaNobuo Shinohara More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003294.20AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: In urology, new technologies such as laparoscopic and robotic surgery are spreading, and physicians manage to catch up with novel methods. While professional burnout is recently emphasized, the mental and physical costs during surgery are not well understood. Our aim was to clarify the mental workloads (MWLs) of urologists during surgery and predictive factors. METHODS: Urologists in Hokkaido, Japan, joined this study. Between December 2020 and December 2021, after each surgical case, they reported patients’ backgrounds, their role (independent operator, operator under supervision, instructor, 1st, 2nd assistant), surgical outcomes (procedure, operative time, blood loss, complications, near-miss incidents etc.), subjective procedure difficulty, and MWLs, which was assessed by National Aeronautics and Space Administration-Task Load Index (NASA-TLX), via SurveyMonkey®. A multiple linear mixed-effects model was utilized to analyze the factors associated with NASA-TLX. RESULTS: 65 urologists (5 women) joined the study, and 2159 data were collected in 7 days after surgeries (open=250, laparoscopy=315, robotics=407, transurethral surgeries=743, and others=444). A multiple linear mixed-effects model revealed that female surgeons (estimate: +13.90, p=0.035), laparoscopic surgery [+2.54 (reference: transurethral surgery), p=0.035], intraoperative complications (+7.83, p<0.001), near-miss incidents (+3.34, p<0.001), longer operative time (continuous, +0.06, p<0.001), and higher blood loss (continuous, +0.001, p=0.01) were associated with higher MWLs. Operator under supervision (+17.42, p<0.001), independent operator (+8.86, p<0.001), instructor (+4.46, p=0.003), and 1st assistant (+3.90, p=0.01) also showed higher MWLs than 2nd assistant (reference). MWLs correlated with subjective surgical difficulty, with higher scores (+8.05, p<0.001) when the procedure was more difficult, and lower scores (-8.05, p<0.001) when it was less difficult than expected. MWLs was lower as the number of previous surgeries increased (-1.90, p<0.001). CONCLUSIONS: Surgeon MWLs were influenced by multiple factors. Regarding the role of surgery, operators showed higher MWLs, especially under supervision. Instructors should be aware of the high MWLs of operators under their supervision and devise instructional interventions. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e663 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Shigeru Harada More articles by this author Takashige Abe More articles by this author Jun Furumido More articles by this author Keita Takahashi More articles by this author Kanta Hori More articles by this author Noriyuki Abe More articles by this author Masafumi Kon More articles by this author Sachiyo Murai More articles by this author Haruka Miyata More articles by this author Hiroshi Kikuchi More articles by this author Ryuji Matsumoto More articles by this author Takahiro Osawa More articles by this author Nobuo Shinohara More articles by this author Expand All Advertisement PDF downloadLoading ...