Difficult Operation Research Articles

Pre-operative factors associated with the development of distal ureteral stump syndrome after upper pole heminephrectomy

For children with duplex systems and severe hydroureteronephrosis of the upper pole, heminephrectomy is one of many suitable treatments, particularly if there is no associated lower pole reflux. Distal ureteral stump syndrome (DSS) is a very difficult complication and manifests as stump empyema, urinary tract infection and/or vulvar discharge and can occur months to years later in 10-20 percent of patients. Secondary distal ureterectomy is an extremely difficult surgery due to inflammation and adhesions. To avoid DSS, distal ureterectomy at the time of heminephrectomy can be performed concurrently but carries a risk of lower pole ureter devascularization and injury. Current literature on DSS has shown associations with subtotal ureterectomy or long ureteral stumps. We hypothesized that there may be preoperative variables prior to heminephrectomy that are associated with the development of DSS. Identify pre-operative risk factors for the development of DSS in pediatric patients who underwent upper pole heminephrectomy for duplex kidneys. Retrospective analysis of pediatric patients who underwent upper pole heminephrectomy at single, academic institution from 1999 to 2021. Pre-operative patient age, gender, history, imaging, and lab results were extracted from patient charts to assess for factors that may predict the development of DSS. Patient groups with and without DSS were compared using Fischer's Exact Test. Five (14%) of 36 patients developed DSS and required secondary distal ureterectomy at a median time of 22 months (IQR 6-27) after heminephrectomy. The presence of ureteral debris (80% of DSS) on preoperative ultrasound (p<0.001), reflux into the upper pole (p=0.005), and mucus discharge (100% of DSS) (p<0.001) prior to surgery were found to be significantly associated with those who developed DSS, compared to those who did not. These three pre-operative factors had high specificity (97-100%) and negative predictive value (94-97%). Substantial experience has shown that less than 20% of patients benefit from distal ureterectomy during upper heminephrectomy. Whether using an open or laparoscopic approach, selection of at-risk patients should lower operative time and avoid injury and devascularization of the lower pole ureter for most patients. The presence or absence of ureteral debris, mucus discharge and/or upper pole reflux prior to heminephrectomy may be useful guides in selecting which patients would benefit from concurrent distal ureterectomy and conversely which patients may safely avoid the additional dissection.

Computational approaches for solving two-echelon vehicle and UAV routing problems for post-disaster humanitarian operations

During and after Hurricane Maria in 2017, the island of Puerto Rico faced an impossible situation: the transportation, power, and communication networks were all damaged, leading to numerous people being trapped. Humanitarian logistics service providers have the responsibility to reach as many affected populations as possible within short periods of time. Their extremely difficult operations are further hindered by these failures in our built environment. Failures in transportation mean that some routes cannot be used by conventional ground vehicles; failures in communication mean that demands are uncertain, and the locations of said demands may be difficult to pinpoint. In this work, we propose a novel two-echelon vehicle routing framework for performing many of the humanitarian logistics operations using aerial uncrewed autonomous vehicles (drones) to address the issues associated with these infrastructure failures. In our proposed framework, we assume that ground vehicles cannot always reach the trapped population directly, but they can transport drones from a depot to some intermediate satellite locations. The drones launched from these locations can serve to both identify demands for medical and other aids (e.g., epi-pens, medical supplies, dry food, water) and make deliveries to satisfy them. Specifically, we present an expert decision support system, in which the resulting optimization problem is formulated as a two-echelon vehicle routing problem with trucks as the first echelon vehicles and drones as the second echelon vehicles. Our framework utilizes two types of drones. Hotspot or communication providing drones have the capability of providing cell phone and internet reception, and hence, are used to capture demands and their locations. Delivery drones are subsequently employed to satisfy these obtained demands. To handle demand uncertainty, we decompose the decision problem into two stages: providing telecommunications capabilities in the first stage, thereby capturing demands precisely, and satisfying the resulting demands in the second stage. To solve the resulting models, we propose a matheuristic computational approach in the form of a decomposition algorithm inspired by column generation to identify optimal drone routes. To showcase the application of our proposed framework, we present results from numerical experiments on datasets created to simulate the demand for medical aid in Puerto Rico after Hurricane Maria.

Design and Fabrication of Automatic Weight, Color and Height Based Sorting System

Sorting is a necessary task that is frequently performed in daily life. Manual sorting is an expensive, difficult, and drawn-out operation. Additionally, it slows down manufacturing operations. To solve these issues the sorting system now uses Low-Cost Automation which aims to decrease labor costs, manufacturing times, and processing complexity while also enhancing product quality, boosting output, etc. In this research, an efficient technique for automatically sorting the object based on color, height, and weight has been devised. The objects are recognized, separated, and collected using a collection bin along with a conveyor belt, strain gauge load cell, TCS34725 RGB color sensor, ultrasonic sensor, extra channel path, etc. according to their colors. The Arduino Uno controls the entire operation of this system. Here, three types of products are sorted based on their weight, color, and height. These three colors are red, blue, and green. Firstly, the weight is measured using strain gauge load cells. Then the color of the product has been detected by the color sensor at the same stage, and according to the color collecting bin rotates to the desired angle. Finally, the height is measured by an ultrasonic sensor. An extra channel is used at the end of the conveyor belt. At the end of the channel, a three-portion collecting bin is kept. The bin can be rotated at the desired angle by a servo motor after detecting the specified color object, and objects are being collected from this bin. Thus, the objects are sorted out based on their weight, color, and height. The experimental results show that the system fits the design requirements, is dependable, and has high sorting accuracy.

Reliability analysis of wind power gearbox based on fault tree and monte carlo simulation

The gearbox is an important speed-up component in wind turbine, and the environment in which wind turbine operates is generally harsh. For maintenance and replacement of the gearbox and its difficult operation, it is self-evident that it is important to ensure its reliable operation. Through collecting and analyzing the structural and functional principle of the gearbox and data of common failure modes, the fault tree of the gearbox is established, and failure rate data and corresponding distribution are obtained by manual and data inquiry for each bottom event. Combining Monte Carlo simulation, the reliability curves of each bottom event mode of the gearbox, the gearbox, and important components are solved, and the assumptions of improving the important bottom events are made. By comparing the curves with the previous ones, it is proved that the improvement of important components can effectively improve the system’s reliability.

Laparoscopic cholecystectomy in a resource limited setting: Factors associated with difficult surgeries at the National Referral Hospital, Bhutan

AbstractBackgroundPrediction of difficult laparoscopic cholecystectomy may help in making necessary arrangements for optimal intraoperative requirements and postoperative care. This study was conducted to examine the factors associated with and outcomes of difficult laparoscopic cholecystectomy performed at the Bhutan's largest hospital in 2020.MethodsThis was a cross‐sectional study with a convenience sampling method. Data on clinical features, ultrasonography and intraoperative factors of patients who underwent laparoscopic cholecystectomy were extracted from their medical records, investigation reports and intraoperative surgery note. Difficult laparoscopic cholecystectomy was defined on the basis of the duration of the surgery, injury to bile duct or artery, or conversion to open cholecystectomy. Data were double entered and validated in EpiData 3.1 and analysed in STATA 13.0.ResultsData from 134 patients were extracted. The mean age of the sample was 43 (±SD 13) years. “Difficult laparoscopic cholecystectomy” was reported in 83 patients (62%) and easy laparoscopic cholecystectomy in 51 patients (38%). Those patients having simple adhesions up to the body of the gall bladder were 1.6 times more likely to encounter difficult laparoscopic cholecystectomy (adjusted PR = 1.60, 95% CI 1.04–2.48, p = 0.034). The majority did not have any post‐operative complications (130 cases, 97%). The indications of laparoscopic cholecystectomy were symptomatic gall stone disease (129, 96%), acalculous cholecystitis (2, 1%) and gall bladder polyp (3, 2%).ConclusionsThe proportion of difficult laparoscopic cholecystectomy is high, but the rates of post‐operative complications were minimal with no mortality or injury to bile duct or arteries.

Evaluation of the Effect of Hyaluronic Acid Injection on the Reconstruction of Reduced Interdental Papillae in Patients Referred to Shiraz School of Dentistry.

The occurrence of papillary defects adjacent to teeth or dental implants causes both the dental staff and the patients to be concerned about the esthetic issues. Interdental papilla reconstruction surgery is one of the most difficult and unpredictable mucogingival surgeries. The present study aimed to investigate the efficacy of hyaluronic acid injection in the reconstruction of the interdental papilla. This clinical trial study was conducted on four patients with 20 deficient interdental papillae who met the inclusion criteria. At first, local anesthesia was applied. Afterward, 0.2 mL of 1.6% hyaluronic acid (HA) gel was injected (at the tip of the papilla and 2-3 mm below the tip of the papilla) three times every two weeks. At baseline, three, and six months later, clinical photography was taken under standard conditions. The papilla height (the distance between the interdental papilla tip and the basis), black triangle area, and the distance between the interdental papilla tip and contact point of adjacent teeth were all measured using Image J software. The effectiveness of using HA gel in reducing the black triangle area was 85.06%. Furthermore, the papilla length increased by 70.256% while contact to papilla distance decreased by 83.026%. At different times, the values of the studied variables in the three levels were significantly different (p< 0.05). Injection of HA with 1.6% concentration at two points of the interdental papilla was effective in interdental papilla reconstruction at the aesthetic zone, especially in long-term, follow-ups (especially 6 months).

Exploring the Funding Challenges Faced by Small NGOs: Perspectives from an Organization with Practical Experience of Working in Rural Malawi.

Malawi is a small landlocked country in Southern Africa, which faces a number of development challenges. It is one of the world's poorest nations and over 70% of the population live below the International Poverty Line of $2.15 per day. Health inequalities are a well-documented problem and those most affected are women and children. Non-governmental organizations (NGOs) play a vital role in supplementing government efforts to provide health services to vulnerable people in areas that are difficult to reach. The World Medical Fund (WMF) is a small medical charity that operates in the central, rural, Nkhotakota region of Malawi where many children lack access to even basic health services. To date, WMF has successfully provided free care and treatment for over 400,000 sick children, but its initiatives, such as mobile clinics, rely entirely on external donations. Since 2000, the funding resources available to small NGOs have declined and efforts to attract funding have become increasingly competitive. Frequently, the criteria used for funding decisions are too rigid, and do not reflect the difficult operating conditions on the ground in rural Africa. As one of the world's most highly resource constrained healthcare environments, Malawi illustrates the need for more flexible funding criteria from donors so that NGOs can carry out their work to save children's lives.

Разработка контроллера электромеханического датчика положения

Electromechanical position sensors, including sine-cosine rotary transformers, compared to sensors based on other physical principles, have greater reliability, a simple design and resistance to difficult operating conditions. This makes them attractive for use in various motion control systems that require measurement of the position of the actuator axis. However, the use of such sensors requires special hardware and software devices – controllers that ensure their operation. This article is devoted to the development of such a controller, which generates, captures, and processes signals of the sine-cosine rotary transformer. When developing the controller of the sine-cosine rotary transformer, methods of system analysis of electrical, electromagnetic and information processes and means of their implementation, methods of software development, as well as methods of experimental research were applied. A description of the controller of a sine-cosine rotary transformer in phase mode is given, taking into account the hardware and computing resources of the microcontroller which implements it. At the same time, physical processes are correlated with information processes associated with the generation, capture and procession of signals. The reasons for the decrease in the position measurement accuracy are revealed. Various technical solutions have been applied to take into account and eliminate them. Among them are the coordination of physical and information processes, taking into account the execution time of calculations by the microcontroller, analysis of the correctness of the position measurement results and their smoothing according to moving average method. The controller software has been developed, which can serve as a typical element for microprocessor-based control systems. Experimental results are obtained, illustrating the achievement of the development result. Application of various technical solutions has made it possible to ensure the accuracy of position measurement up to a tenth of a degree with a high intensity of information updating. As a result of the study, a detailed and comprehensive solution of the developing a controller for a sine-cosine rotating transformer problem is given, which is the scientific and practical value of the materials presented in the article. The results obtained can be applied in various motion control systems and serve as the basis for the development of controllers for various electromechanical position sensors.

130 Using Abdominal Fat Ratio to predict difficult laparoscopy – a potential indicator for Robotics/TaTME?

Abstract Introduction Minimally-invasive surgery has revolutionised colorectal cancer surgery. Intra-abdominal/visceral adiposity increases the chance of conversion to open surgery. Abdominal fat ratio (AFR) has been identified as predictive for this. New techniques, such as robotic platforms and Trans-anal Total Mesorectal Excision (TaTME), are generally less susceptible to visceral obesity. We hypothesise that AFR can predict difficult laparoscopic surgery and promote selective use of alternative surgical techniques. Methods Hospital coding data identified 117 anterior resection and abdominoperineal excision of the rectum procedures between April 2017 and March 2020. Planned/actual procedure and histological factors were recorded. AFR was calculated using the method from Scott et al (Ann R Coll Surg Engl 2017). Mann-Whitney U testing and binomial logistic regression were used to compare AFR between laparoscopic completed (LC) and conversion to open (CtO) groups. Results 73 cases were completed laparoscopically, 35 converted to open. 9 cases were planned open. AFR between LC and CtO groups was comparable (Median LC = 3.94; CtO = 3.64; U = 1220, p=0.71). Binomial logistic regression showed no relationship between AFR and conversion to open surgery (OR 1.11 95% confidence interval 0.92-1.36, p=0.27). Conclusion No statistically significant differences were found. This may result from the small numbers included but may also reflect the multifactorial nature of intra-operative decision-making. Post-chemoradiotherapy effects and difficulties obtaining safe views through inadequate small bowel retraction or bulky mesentery were cited more often in the conversion group than problematic visceral obesity. Other recognised factors should be considered in future, larger series analysis.

Effect of thoracoscopic and thoracotomy on postoperative wound complications in patients with lung cancer: A meta-analysis.

Because of the difficult surgical procedures, patients with lung cancer who have received thoracic surgery tend to have postoperative complications. It may lead to postoperative complications like wound infection, wound haematoma and pneumothorax. A lot of research has assessed the effect of various surgery methods on postoperative complications in pulmonary cancer. The purpose of this meta-analysis is to establish if thoracoscopic is superior to that of thoracotomy in the rate of post-operative complications. From the beginning to the end of June 2023, we performed an exhaustive search on four main databases for key words. The Hazard of Bias in Non-Randomized Interventional Studies (ROBINS-I) was evaluated in the literature. In the end, 13 trials that fulfilled the eligibility criteria underwent further statistical analyses. The results showed that thoracoscopic intervention decreased the risk of post operative wound infection (dominant ratio [OR], 3.00; 95% confidence margin [CI], 1.98, 4.55; p < 0.00001) and air-leakage after operation (OR, 1.30; 95% CI, 1.04, 1.63; p = 0.02). There was no statistically significant difference between the two groups in terms of the rate of haemorrhage after operation (OR, 0.10; 95% CI, 0.73, 1.66; p = 0.63). Our findings indicate that thoracoscopic is less likely to cause post operative infection and gas leakage than thoracotomy, and it does not decrease the risk of postoperative haemorrhage. As some of the chosen trials are too small to conduct meta-analyses, care must be taken when handling the data. In the future, a large number of randomized, controlled trials will be required to provide additional evidence for this research.

An efficient medical image encryption algorithm for telemedicine applications

Applications for healthcare execute computations that support various patient diagnostics and save private user data on cloud servers. User data is being held at ransom as a result of increasing cyberattacks on medical systems. Additionally, unreliable external parties who sell private data for profit can access mathematical calculations on data stored in the cloud. In this research, we suggest an efficient Homomorphic medical image encryption algorithm protecting medical plaintext data against unauthorised access via homomorphic encryption. To increase the security level Paillier's encryption scheme (PES) is utilized to select the optimal key. Homomorphic encryption is a method of authentication which helps one to perform observes of the encrypted information through decrypting it. Secret sharing splits up computations among a number of edge virtual nodes and hides all arithmetic operations, preventing unreliable cloud servers from figuring out what was done with the encrypted patient data. Cloud computing resources help virtual edge nodes perform computationally difficult mathematical operations and lower latency in device-edge node data transmission. During the experimental study, different factors including execution time, encryption time, and decryption time are used to evaluate the performance of the suggested approach. The proposed technique's execution time is 2% faster than the currently used HE method and 4% faster than the ECC algorithm.

Exploring New Horizons: Surgical Robots Supported by Artificial Intelligence

Artificial intelligence-assisted surgical robots combine the agility and accuracy of robotic systems with the cutting-edge capabilities of AI technology. These advanced surgical robots are made to help surgeons carry out difficult surgical procedures more precisely and effectively. Surgical robots with AI algorithms built in can analyse enormous volumes of patient data, make choices in real-time, and adjust to changing circumstances. The surgical process and patient safety could both be considerably improved by this technology. Several important advantages of surgical robots powered by AI include Enhanced Accuracy Surgical robots can make extremely precise motions with little error because of the capabilities of robotics and AI, leading to more accurate surgical procedures. During an operation, real-time decision-making AI algorithms can evaluate data from a variety of sources, including patient vitals, medical imaging, and surgical history, to give surgeons on-the-spot recommendations and insights. Artificial intelligence-driven surgical robots can automate tedious and repetitive activities, freeing surgeons to concentrate on more important choices and increasing operating room productivity. By analysing patient data and delivering individualized insights, AI can help surgeons with preoperative planning, resulting in better surgical approaches and outcomes. AI technology's sophisticated skills can assist in identifying potential dangers and difficulties during surgery, allowing surgeons to proactively address them and reduce unfavourable events.

A Novel Analytical Model for Mutual Inductance Calculations Between Two Nonidentical N-Sided Polygonal Planar Coils Arbitrarily Positioned in 3-D Space for Wireless Power Transfer

Mutual inductance (MI) calculation is of great importance, because there are many systems that operate on the principle of inductive coupling. This paper presents a novel analytical model that calculates the MI between two non-identical n-sided polygonal planar coils located in arbitrary position in 3D space. The model depends upon misalignment of both the primary and the secondary coils of a wireless power transfer (WPT) system operating based on inductive coupling. The polygonal coils used in this model may differ from each other in terms of size, shape and turns number. The misalignment cases considered in the proposed model include lateral, angular, lateral-angular and vertical distance variation between the primary and secondary coils. Based on Stokes Theorem, instead of using the magnetic flux density vector, the magnetic vector potential (MVP) is used to reach the required magnetic flux in the calculation of the MI. A single analytical solution function that can calculate the MI between two planar polygonal coils of any shape in a simple manner and short time duration is obtained by performing difficult mathematical operations through MVP. Results obtained from the developed new model are compared with finite element analysis (FEA), experimental and other studies in the literature. The good agreement of the results of this study with the other results has proved the accuracy and validity of the proposed new analytical model.

Structural Analysis of URL For Malicious URL Detection Using Machine Learning

Malicious websites are intentionally created websites that aid online criminals in carrying out illicit actions. They commit crimes like installing malware on the victim's computer, stealing private data from the victim's system, and exposing the victim online. Malicious codes can also be found on legitimate websites. Therefore, locating such a website in cyberspace is a difficult operation that demands the utilization of an automated detection tool. Currently, machine learning/deep learning technologies are employed to detect such malicious websites. However, the problem persists since the attack vector is constantly changing. Most research solutions use a limited number of URL lexical features, DNS information, global ranking information, and webpage content features. Combining several derived features involves computation time and security risk. Additionally, the dataset's minimal features don't maximize its potential. This paper exclusively uses URLs to address this problem and blends linguistic and vectorized URL features. Complete potential of the URL is utilized through vectorization. Six machine learning algorithms are examined. The results indicate that the proposed approach performs better for the count vectorizer with random forest algorithm

Total thyroidectomy: reduction in postoperative hypoparathyroidism.

Total thyroidectomy is associated with a high risk of postoperative hypoparathyroidism, mainly due to the unintended surgical damage to the parathyroid glands or their blood supply. It is possible that surgeons who also perform parathyroid surgery see lower rates of postoperative hypoparathyroidism. In a single institution, we investigated the effects of restricting total thyroidectomy operations for Graves' disease to two surgeons who performed both thyroid and parathyroid surgeries. We aimed to evaluate the rates of postoperative hypoparathyroidism in a 10-year period with primary attention toward patients with Graves' disease. Retrospective cohort study from a single institution. We defined the rate of permanent hypoparathyroidism after total thyroidectomy as the need for active vitamin D 6 months postoperatively. Between 2012 and 2016, seven surgeons performed all thyroidectomies. From January 2017, only surgeons also performing parathyroid surgery carried out thyroidectomies for Graves' disease. We performed total thyroidectomy in 543 patients. The rate of permanent hypoparathyroidism decreased from 28% in 2012-2014 to 6% in 2020-2021. For patients with Graves' disease, the rate of permanent hypoparathyroidism decreased from 36% (13 out of 36) in 2015-2016 to 2% (1 out of 56) in 2020-2021. In cancer patients, the rate of permanent hypoparathyroidism decreased from 30% (14 out of 46) in 2012-2014 to 10% (10 out of 51) in 2020-2021. Restricting thyroidectomy to surgeons who also performed parathyroid operations reduced postoperative hypoparathyroidism markedly. Accordingly, we recommend centralisation of the most difficult thyroid operations to centres and surgeons with extensive experience in parathyroid surgery. Thyroid surgery is performed by many different surgeons with marked differences in outcome. Indeed, the risk of postoperative permanent hypoparathyroidism may be very high in low-volume centres. This serious condition affects the quality of life and increases long-term morbidity and the patients develop a life-long dependency of medical treatments. We encountered a high risk of hypoparathyroidism after the operation for Graves' disease and restricted the number of surgeons to two for these operations. Further, these surgeons were experienced in both thyroid and parathyroid surgeries. We show a dramatic reduction in postoperative hypoparathyroidism after this change. Accordingly, we recommend centralisation of total thyroidectomy to surgeons with experience in both thyroid and parathyroid procedures.

A uniportal video assisted thoracic surgery approach for lung cancer with silicosis and highly inflammatory lymph nodes

While uniportal video-assisted thoracic surgery (U-VATS) is a viable minimally invasive surgical approach, it may restrict the control of surgical instruments. Furthermore, whether or not U-VATS is well-indicated for lung cancer with silicosis and inflammatory lymph nodes is unclear. We herein report a case of resection performed by U-VATS for lung cancer with silicosis and highly inflammatory lymph nodes and describe the procedures and techniques used. The vessels and bronchus cannot be dissected easily in the hilum due to the presence of several extremely inflamed lymph nodes, and these structures had to be exposed while avoiding inflammatory lymph nodes #10 and #12u in this case. Curved instruments and hooked electrocautery proved useful for these procedures. In addition, the grasping technique using the curved forceps was useful for achieving sufficient tension to expose the vessels. Bulk dissection of the pulmonary artery and bronchus with a stapler may be useful when these structures cannot be isolated, such as with B1 and A2a in the present case. The postoperative course was good, and the patient was discharged on postoperative day 6. Substantial experience and knowledge as well as proficiency with the associated techniques will make difficult surgeries such as this case possible by U-VATS.

Dual-mode optical chemodosimeter for detecting copper ions in the environment, food, and living organisms with smartphone

Techniques for the detection and quantification of active ingredients in plants and foods are of global interest in the field of smart agriculture. The amount of copper ions (Cu2+) in the environment is closely related to water quality, food safety, and biological health. However, the drawbacks of the current copper ions detection techniques include difficult operation and inconvenient field analysis. Due to the reliable analytical parameters, dual-mode optical analysis has become increasingly interesting and popular. Therefore, in this study, a dual-mode optical copper ions detection method was constructed based on a fluorescent chemodosimeter RH-HP. The reaction-based recognition process improves its specificity for copper ion recognition and can be utilized to determine the concentration of copper ions in water samples, agricultural products, cells, and zebrafish. It is worth noting that the analysis and photo function of the smartphone is used to establish the relationship between the change of color RGB values and copper ions concentration. This work offers an economical, portable tool for the in-situ detection of copper ions, demonstrating its potential application for monitoring plant growth processes in future smart agriculture, and provides a reference for the establishment of in-situ portable detection methods for other important substances.

A Novel Model for the Real-Time Evaluation of Hole-Cleaning Conditions with Case Studies

The main challenge in deviated and horizontal well drilling is hole cleaning, which involves the removal of drill cuttings and maintaining a clean borehole. Insufficient hole cleaning can lead to issues such as stuck pipe incidents, lost circulation, slow rate of penetration (ROP), difficult tripping operations, poor cementing, and formation damage. Insufficient advancements in real-time drilling evaluation for complex wells can also lead to drilling troubles and an increase in drilling costs. Therefore, this study aimed to develop a model for the hole-cleaning index (HCI) that could be integrated into drilling operations to provide an automated and real-time evaluation of deviated- and horizontal-drilling hole cleaning based on hydraulic and mechanical drilling parameters and drilling fluid rheological properties. This HCI model was validated and tested in the field in 3 wells, as it was applied when drilling 12.25″ intermediate directional sections and an 8.5″ liner directional section. The integration of the HCI in Well-A and Well-B helped achieve much better well drilling performance (50% ROP enhancement) and mitigate potential problems such as pipe sticking due to hole cleaning and the slower rate of penetration. Moreover, the HCI model was also able to identify hole-cleaning efficiency during a stuck pipe issue in Well-C, which highlights its potential usage as a real-time model for optimizing drilling performance and demonstrates its versatility.

Comparison of methods for monitoring icing of high-voltage power lines and an overview of measuring equipment used to diagnose such lines

The low structural reliability of overhead lines, due to continuous climatic influence, becomes the cause of electrical network accidents and unreliable power supply. Ensuring the trouble-free operation of overhead lines is a complex task, the solution of which is of the utmost importance for the normal functioning of the entire infrastructure. In the autumn-winter period, difficult weather conditions almost completely exclude the quick completion of repair works. A fairly large share of accidents occurs during the formation of icy deposits on wires and lightning protection cables. Today, visual inspections of high-voltage power lines remain the main way of diagnosing icy deposits. In practice, it is necessary to equip overhead lines with ice load telemetry devices, which will allow monitoring the formation of ice deposits on wires in real time. The following diagnostic methods are used in modern ice monitoring devices: strainometric, fiber-optic, aerodynamic, locational, and instrumental-parametric. The tensiometric method of diagnosis is implemented by means of direct measurement of the icy load on the wire with subsequent comparison of the measured values with predetermined values of the threshold loads. To implement this diagnostic method, magnetoelastic force measuring sensors are used. Such a sensor is connected between the traverse of the U-shaped support and the upper end of the corresponding garland of insulators with a phase wire. Ice, wind and ice-wind loads are measured separately. This method has a limited scope of application, namely for diagnosing the formation of ice on the phase wires of intermediate spans of single-circuit lines with two-post U-shaped resistances. The fiber-optic method of strain gauge measurements is implemented in object control systems under difficult operating conditions, at nuclear power plants. The mechanical effort sensor (fiber-optic strain sensor) implements the fiber-optic method of strain measurement. Fiber-optic strain sensors are characterized by high accuracy due to resistance to interference and complexity of execution.

#6634 PATIENTS' PERSPECTIVES ON HAEMODIALYSIS ACCESS: A QUALITATIVE STUDY

Abstract Background and Aims There is high quality evidence that favours the use of arteriovenous fistulas (AVFs) over central venous catheters (CVCs) for haemodialysis access, based on the association with lowest mortality and fewest complications [1]. However, less is known regarding patient and nurse preferences concerning access choices and the drivers underlying these preferences. One previous study [2] identified physical concerns regarding fistulas as the predominant barrier preventing patients with a CVC from switching to an AVF. Here we provide an expansion on these barriers, alongside novel exploration of nursing opinion on access choice. Methods Data was collected through individually administered patient surveys across 4 regional dialysis sites in East Anglia (n = 380), and anonymised online survey requests to nursing staff at the sites. Deductive and inductive strategies were employed for analysis of the qualitative data. The aim of the thematic analysis of the data was to determine the preferred access modality of patients and nurses, and the drivers for the preferences. Results 63% (n = 238) of patients responded to the questionnaire. Patient responses fell into one of four categories; drivers toward, or barriers against AVFs or CVCs. The largest of these categories was the barriers for AVFs, within which four main themes were identified: ‘Fear’, ‘difficult AVF surgery’, ‘patient preference for lines’ or ‘patients awaiting AVF surgery or transplant’. A smaller theme of ‘insufficient information’ regarding access choice was also identified. ‘Fear’ was the largest theme, within which five subthemes were identified: fear of needles, pain, bleeding, fistula appearance, or fear of complications heard from other patients on the dialysis unit. ‘Difficult AVF surgery’ encompassed two subthemes; those who have had previous failed traumatic attempts or those whose current vascular architecture was not amenable to fistula surgery. The other three categories received far fewer responses. The AVF driver category focussed on fistulas being preferred medically with reduced infection risk, whilst drivers for lines included it being ‘comfortable’ and patients saying that the line works for them. The one comment in the CVC barrier category cited difficulties experienced with lines like blockages and infections. 13 responses were received from dialysis nurses. All respondents were aware of the medical preference for patients to have a fistula, and the reasons why. Nurses themselves also preferred their patients to have fistulas, referencing the same reasons. However, most nurses thought patients preferred CVCs, and were able to cite the same reasons as the patients themselves. Lastly, nurses reported that they convey the benefits and risks of different access types correctly when asked by patients at the dialysis units. Conclusion These findings highlight that, whilst doctors and nurses focus on long-term health benefits of AVF when discussing vascular access choices, patients are focussed on the immediate potential risks of an AVF. We hypothesise that, whilst dialysing, patients share stories of fistula-related complications that drive short-term fear of AVFs, with such impact that the messages conveyed by health professionals are often negated. This difference in agendas is essential to acknowledge. The relationship between clinician, nurse and patient in the haemodialysis setting is unique given its longevity, frequency of contact, and holistic nature. Implementing a strategy to bridge this agenda gap could strengthen this relationship and provide a basis for optimum, evidence-based treatment. We therefore suggest the use of positive patient AVF experiences, delivered via peer education sessions, as a tool to introduce drivers for, and uptake of, AVF for dialysis patients in the future.