Adequate Placement Research Articles

Evaluation of Self-vision Assessment Charts in Schools of Eastern Nepal: A Multi Method Study

Introduction: Globally, over two billion people suffer from vision impairment, almost half preventable. In Nepal, the Eastern Regional Eye Care Program introduced self-vision assessment charts in 137 schools for early eye issue detection. This study assessed the charts' use and perceived impact.Methods: A multi-method study was conducted to evaluate the use of self-vision assessment charts in schools in Eastern Nepal. Ethical approval was obtained from Institutional Review Board (Refrence number: 72-079-040). Quantitative data were collected through a questionnaire survey. Quantitative data were analyzed using descriptive statistics, while qualitative data were analyzed using framework analysis. Both methods were integrated to enhance understanding of participants' experiences.Results: In this study, 400 students participated in questionnaire survey, 180 in self vision assessment, and 16 teachers in in-depth interviews. Among the participants, 198 (49.50%) of students used the chart, 125 (65.78%) expressed satisfaction, 241 (60.25%) found it useful, 276 (69%) as beneficial, and 253 (63.25%) stated improved health. There were 93 (23.25%) students who felt knowledgeable about its use, with 18 (10%) using it correctly. In 162 (90%) of schools there were adequate chart placement, 23 (12.77%) provided clear signage for viewing points. Teachers recognized the chart's benefits and encouraged its use, but students lacked awareness. Regular use was viewed as beneficial for early detection of eye issues, though challenges included a need for more awareness among students and teachers and reliance on home remedies.Conclusions: Most students and teachers acknowledged self-vision assessment charts’ benefits but had low utilization and accuracy rates. Strategic interventions such as regular informational sessions, teacher motivation, and engagement with eye health experts are essential.

Event Operation and Management in Risk Assessment for Outdoor Food Bazaar Events

This study evaluates risk management in organizing a food bazaar held in an open field at the Jakarta International Velodrome from May 31 to June 2, 2024. The research methodology includes direct observation, structured interviews with the organizing committee, and document analysis. The assessment results indicate that the event falls into the Very High Risk category for safety aspects, with potential hazards such as smuggling, theft, and fire. Additionally, the cleanliness of the area and healthcare facilities are deemed inadequate, categorized as High Risk. The limitations of hygiene facilities such as toilets and sinks, as well as the risk of dehydration, were also identified. This study recommends enhanced preparation and attention to risk management for similar events in the future to ensure the safety and comfort of visitors. By identifying, analyzing, and evaluating risks more comprehensively, it is hoped that event organizers can minimize potential hazards and improve the quality of future events. The study also emphasizes the importance of collaboration among various stakeholders, including the government, event organizers, security personnel, and healthcare services, to create a safe and comfortable event environment. Measures such as safety training for staff, adequate placement of healthcare facilities, and improved security systems can reduce the risks faced by visitors. Additionally, the study highlights the need for effective communication with the audience regarding safety and health protocols to be followed during the event. The implementation of technology such as crowd monitoring applications and early detection systems can also be a solution in managing risks more effectively.

Staining and Sizing Technique for Human Amniotic Membrane Graft in Refractory Macular Holes.

Purpose: To describe the triple S technique for aiding the visualization (staining), preparation (sizing), and placement (sliding) of human amniotic membrane grafts in cases of refractory macular holes (MHs). Methods: Brilliant blue-green dye was used to stain the graft before insertion for improved visualization and to aid in its orientation. Preoperative optical coherence tomography-based sizing of the graft was performed, and a dermal trephine was used to fashion the graft according to size. Once placed in the eye, the graft was positioned by bimanually sliding it into the MH using a nitinol loop and a Tano brush. Results: Seven eyes of 7 patients had repair of a refractory MH. Anatomic closure was successful in all patients with no postoperative displacement or dislodgement of the graft. The mean logMAR (±SD) visual acuity was 1.80 ± 0.4 preoperatively and 1.27 ± 0.6 at the final follow-up. Conclusions: The triple S technique provided adequate visualization, sizing, and placement of amniotic membrane grafts in cases of refractory MHs. This modification may help reduce the learning curve associated with this technique.

Intraoperative Ultrasound in Endoscopic Sagittal Suture Synostosis to Optimize Incision Planning and Avoid Misdiagnosis.

Endoscopy-assisted craniectomy with lateral osteotomies and postoperative helmet molding therapy is a widely used approach in managing sagittal suture craniosynostosis. Generally, the incisions are placed just posterior to the anterior fontanel and just anterior to the posterior fontanel and lambdoid sutures, and accurate incision placement optimizes the safe separation of the superior sagittal sinus. The authors present their 10 year experience with an ultrasound-assisted approach to identify the lambdoid sutures and precisely place the skin incisions. The authors included all patients in care at their institution between 2010 and 2023 who operated for sagittal suture craniosynostosis with endoscopy-assisted craniectomy with lateral osteotomies and postoperative helmet molding therapy. A retrospective review of clinical parameters, surgical data, as well as outcomes, and imaging studies was performed. One hundred patients were operated during the observation period. The mean age was 3.9 ± 3.5 (range: 2.7-6.4) months. Intraoperative ultrasound was documented in 61% of cases (n = 61). In 100% of cases, the incisions were placed behind the anterior and in front of the posterior fontanel, as planned with ultrasound. In 2 additional cases, intraoperative sonography identified a patent sagittal suture in the operating room. A histopathological review showed suture ossification in 100% of operated cases with available reports. Using this technique of ultrasound-guided identification of the lambdoid suture/posterior fontanel, as well as coronal suture/anterior fontanel, may aid in the adequate placement of skin incisions. Patent sutures can be identified in clinically misdiagnosed patients. This study reaffirms the overall utility of ultrasound in pediatric operative neurosurgery.

Use of a new aiming compression device and technique for the repair of navicular bone fractures in horses: A cadaveric study.

To assess the use of a newly developed aiming compression device (ACD) for screw insertion in non-fractured navicular bones (NB) in cadavers. Cadaveric study. A total of 10 cadaveric front limbs of adult horses. Placement of a 3.5 mm cortical screw in non-fractured NB under radiographic guidance was performed in 10 cadaver limbs in a standing position. An ACD was used to stabilize the NB and to guide the drilling process. Preparation and surgical time as well as the number of radiographic images were noted. A postoperative scoring system was used to assess screw placement by cone beam computed tomography (CBCT) and gross examination by two evaluators. The total procedure time was 25-62 min (median 33.5). During the procedure, 11-21 radiographs (median 18.5) were taken. The postoperative gross examination revealed an excellent screw placement in nine NB and poor in one. This could not be reliably assessed with post-procedure CBCT. The described technique achieves an excellent screw placement in 9/10 bones without disrupting the articular or flexural surface of the NB and with no protrusion of the screw head or tip, in a median procedure time of under 35 min. Adequate screw placement is paramount for NB fracture repair. The described approach under radiographic guidance allows adequate screw placement using the ACD to stabilize the NB by lateral to medial compression. This technique facilitates adequate screw placement within the NB without the use of advanced imaging techniques.

Technical Considerations for the Surgical Management of a C2 Spinal Cord Hemangioblastoma and Subjacent Cervical Spondylotic Myelopathy: A 2-Dimensional Operative Video.

Hemangioblastomas are characterized as benign tumors of the central nervous system and are typically associated with von Hippel-Lindau disease in 20% to 30% of patients.1 Spinal hemangioblastomas are rare entities accounting for 2.1% of spinal cord tumors and are most frequently observed in the cervical spinal region.1-4 Treatment interventions include microsurgical resection and stereotactic radiosurgery.5 Understanding the granular detail of surgical management in these complex cases is necessary for optimal clinical outcomes. In this 2-dimensional operative video, we detail the technical nuances for resection of a World Health Organization Grade I hemangioblastoma in the upper cervical spine of a 51-year-old man. The lesion and severe adjacent canal stenosis resulted in extensive spinal cord compression, causing him to experience progressive myelopathic symptoms and neurological deficits. A C1-C7 laminectomy provided exposure of the hemangioblastoma and adequate decompression of the subjacent spondylotic disease. Intraoperative ultrasound was used to localize the tumor and perform a targeted durotomy. The sunburst-colored lesion was eccentric to the left side of C1-C2 and found in the epi-pial region, with pial thickening present in the surrounding area. The feeding vessels and deep draining vein were coagulated and cut. Low-power suction was used for traction/counter-traction dissection of the tumor planes. Owing to a multilevel laminectomy having been performed, hardware placement was performed from C2-T1. Adequate placement of all screws was confirmed with intraoperative 3-dimensional image acquisition. The patient provided informed consent for the operation and for sharing his clinical information, including digital media, for publication; Institutional Review Board not required per institutional policy.

Required volume for color flow injection test to confirm the intravascular placement of a peripheral venous catheter

Background: Confirmation of adequate peripheral intravenous catheter placement is essential before using venous catheters. The color flow injection test has been reported as a method with high sensitivity and specificity for this purpose. The technique involves administrating saline through the peripheral venous route to observe changes in the color flow pattern around the same vein at a more central location. However, the required volume of saline remains uncertain. This study aims to determine the appropriate dosage for conducting the test in pediatric patients and explore any potential correlations between dosage and patient characteristics. Methods: A prospective study was conducted in children under 6 years of age with American Society of Anesthesiologists Physical Status 1–2 presenting for general anesthesia. After an intravenous cannula was placed in the forearm under general anesthesia, normal saline was injected at a speed of approximately 1 mL/s while the axillary artery and vein were observed with color flow Doppler imaging. The volume of normal saline required to induce a change in the color flow pattern around the vessels was measured. Measurements were performed twice and averaged for comparison with patient characteristics and other factors. Results: The study cohort included 30 patients aged from 0.3 to 5.5 (2.6 ± 1.6) years. The change in color flow Doppler imaging was noted in all the patients, and the average volume was 1.40 ± 0.36 mL (95% confidence interval (CI), 1.27–1.54; p < 0.001), which was significantly correlated with age, with a correlation coefficient of 0.435 (95% CI, 0.09–0.69; p = 0.02). Conclusions: The required volume for the color flow injection test is small; therefore, the test is easy to perform and minimally invasive in pediatric patients.

Optimal sizing and placement of battery energy storage system for maximum variable renewable energy penetration considering demand response flexibility: A case in Lombok power system, Indonesia

Indonesia is a tropical climate country with considerable renewable electrical energy source prospects, including photovoltaic (PV) and wind energies. Nevertheless, several variable renewable energy sources (VREs) have exhibited uncertain attributes and substantial reliance on natural conditions, leading to unstable load-related power supply risks. Hence, integrating battery energy storage systems (BESSs) with VRE generators is a dependable approach to bolster renewable energy generator applications on a large-scale grid while providing load demand flexibility. This study determined adequate sizing and placement of the BESS to achieve maximum VRE generator penetration while considering the demand response flexibility. Key indicators, including technical minimum load and system ramp capacity, were identified to achieve maximum penetration of thermal generators. This study also combined a unit commitment procedure with direct current optimal power flow (DC-OPF) as a novel approach to determine the maximum VRE penetration level. An optimization problem model concerning mixed integer linear programming (MILP) was subsequently employed in this study using the CPLEX solver in the general algebraic modeling system (GAMS). The study is based on the IEEE RTS-24 system modified and a real-life case study of the Lombok energy system in Indonesia. Results from the simulated Lombok power system highlighted that optimal sizing and placement of the BESS could lower system costs by 37.66%, 33.63%, and 22.26% compared to the current system conditions during the weekday, weekend, and the lowest day scenarios, respectively. The VRE penetrations of the generators were also higher than the current system conditions by 83%, 51%, and 39% during the weekday, weekend, and the lowest day scenarios, respectively.

Performance experiment of ultra high temperature cementing slurry system

Introduction: The escalating pursuit of oil and gas reserves in China has led to increasingly deep and ultra-deep well drilling, encountering extreme temperatures that challenge the heat resistance capabilities of cement slurries. This study addresses the critical need for high-performance cement slurries capable of withstanding ultra-high temperatures during drilling and completion operations.Methods: A novel ultrahigh temperature conventional density (UHTE) cement slurry was formulated by incorporating high-temperature-resistant additives, namely DRF-1S and DRH-2L. An indoor testing framework was established to assess the slurry’s performance across various parameters: Evaluating the slurry’s ability to maintain uniform consistency over time. Measuring the amount of free water separated from the slurry under simulated downhole conditions. Assessing the slurry’s transition from fluid to solid state over time. Determining the compressive strength and other mechanical attributes after curing at elevated temperatures.Results: The experimental findings revealed the following: An optimal silica sand dosage of 50% was found to enhance the overall performance of the UHTE cement slurry. The developed UHTE cement system, fortified with DRF-1S and DRH-2L, demonstrated effective functionality within a temperature range of 180°C to 210°C, representing a significant advancement in high-temperature resistance. The slurry maintained API water loss below 100 mL, ensuring minimal fluid loss during placement. Adjusted thickening time allowed for adequate pumping and placement without premature setting. Settlement stability was maintained below 0.04 g/cm3, indicating excellent homogeneity and stability. Incorporation of the anti-decay material DRB-3S ensured a 28-day compressive strength exceeding 50 MPa at 210°C, signifying robust structural integrity under extreme thermal conditions.Discussion: This research provides a robust foundation for the practical application of UHTE cementing technology in ultra-high temperature environments. The successful development of the UHTE cement slurry system, characterized by its superior temperature resistance, controlled water loss, optimized thickening behavior, and exceptional mechanical properties, paves the way for field trials and further enhancements. Future work will involve testing the effectiveness of the new additive combination under actual downhole conditions and refining the formulation to develop an even more advanced UHTE cementing additive. These advancements will contribute to enhanced wellbore integrity, improved drilling efficiency, and increased safety in deep and ultra-deep oil and gas exploration endeavors in China.

Rescue Lead Implantation After Deep Brain Stimulation for Parkinson's Disease: A Single-Center Experience and Case Series.

Despite the well-established efficacy of deep brain stimulation (DBS) of the subthalamic nucleus (STN) for Parkinson's Disease (PD), there remains a subset of patients with only a moderate improvement in symptoms even with appropriate lead placement and optimal programming. In patients with persistent tremor or dyskinesias, one consideration is the addition of a second "rescue lead" to provide dual stimulation to primary and secondary targets to address the refractory component. This study aimed to assess all "rescue lead" cases from our institution and characterize the patients and their outcomes. Records of all patients with PD treated at our institution between 2005 and 2023 were retrospectively reviewed. Clinical data of all patients treated with a second rescue lead to supplement a positive but inadequate initial DBS response were collected and reviewed. Of 670 patients with PD treated at our institution during the study period, 7 were managed with a rescue lead. All 7 were initially treated with STN DBS with a partial improvement in underlying symptoms, had confirmed appropriate lead placement, and underwent thorough programming. Four patients underwent rescue with a globus pallidus interna lead for persistent dyskinesias, all with subsequent improvement in their dyskinesias. Three patients had persistent tremors that were treated with a rescue ventrointermediate thalamus stimulation with subsequent improvement in tremor scores. There were no operative complications, and all patients tolerated dual stimulation. For a small subset of patients with PD with persistent dyskinesias or tremors after STN DBS despite optimized lead parameters and adequate lead placement, rescue lead placement offers an effective treatment option.

Management Information Systems for Tree Fruit–2: Design of a Mango Harvest Forecast Engine

Spatially enabled yield forecasting is a key component of farm Management Information Systems (MISs) for broadacre grain production, enabling management decisions such as variable rate fertilization. However, such a capability has been lacking for soft (fleshy)-tree-fruit harvest load, with relevant tools for automated assessment having been developed only recently. Such tools include improved estimates of the heat units required for fruit maturation and in-field machine vision for flower and fruit count and fruit sizing. Feedback on the need for and issues in forecasting were documented. A mango ‘harvest forecast engine’ was designed for the forecasting of harvest timing and fruit load, to aid harvest management. Inputs include 15 min interval temperature data per orchard block, weekly manual or machine-vision-derived estimates of flowering, and preharvest manual or machine-vision-derived estimates of fruit load on an orchard block level across the farm. Outputs include predicted optimal harvest time and fruit load, on a per block and per week basis, to inform harvest scheduling. Use cases are provided, including forecast of the order of harvest of blocks within the orchard, management of harvest windows to match harvesting resources such as staff availability, and within block spatial allocation of resources, such as adequate placement of harvest field bin and frost fans. Design requirements for an effective harvest MIS software artefact incorporating the forecast engine are documented, including an integrated database supporting spatial query, data analysis, processing and mapping, an integrated geospatial database for managing of large spatial–temporal datasets, and use of dynamic web map services to enable rapid visualization of large datasets.

Applying earth system justice to phase out fossil fuels: learning from the injustice of adopting 1.5 °C over 1 °C

The Paris Agreement has seen the adoption of a 1.5° to 2 °C climate target, based on the belief that climate change becomes ‘dangerous’ above this level. Since then, the scientific community and the countries most affected by global warming have reiterated that the maximum limit to be reached should be 1.5 °C. This paper goes one step further by questioning the reasoning behind the adoption of these targets, arguing that the fossil fuel-dependent political context in which they were adopted has undermined justice concerns. We highlight the political influence of the fossil fuels industry within target-setting negotiations, analyzing the evolution of climate targets and fossil fuel lobbying. We then harness published scientific evidence and the Earth System Justice framework to analyze the impacts of the 1.5 °C target, and the injustices that have so far been implicitly deemed acceptable. We argue that 1 °C would have been a far more just target and was undermined by vested interests and status quo maintenance. Finally, we propose just supply-side policies to ensure an adequate placement of responsibility on the fossil fuel industry. This way we (a) identify political influences and scientific blind spots that have and could continue to hinder climate action, (b) reveal how these influences delayed more ambitious climate objectives, contributing to the adoption of an unjust climate target, and (c) promote a focus on supply-side measures and polluting industries in order to break free from the impasse in the energy transition and foster more just outcomes.

Using central venous pressure waveform to confirm the placement of an internal jugular central venous catheter in the intensive care unit

BackgroundA mobile chest X-ray is traditionally performed to confirm the position of an internal jugular central venous catheter (CVC) after placement in the intensive care unit (ICU). Using chest radiography to confirm CVC position often results in delays in authorising the use of the CVC, requires the deployment of additional human resources, and is costly. ObjectiveThis study aimed to determine the feasibility and accuracy of using the central venous pressure (CVP) waveform to confirm the placement of internal jugular CVCs. MethodsThis retrospective study was conducted in a single quaternary ICU over a 6-month period. We included adult patients who had internal jugular CVC inserted and CVP transduced as part of their routine care in the ICU. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CVP waveform analysis in confirming the position of internal jugular CVC relative to chest radiography were calculated. ResultsA total of 241 internal jugular CVCs were inserted (in 219 patients, 35.6% female), and the CVP waveform was assessed. In 231 cases, this suggested adequate placement in a central vein, which corresponded with a correct position on subsequent chest X-ray. On six occasions, the CVP waveforms were interpreted as suboptimal; however, on chest X-rays, the CVCs were noted to be in a suitable position (sensitivity: 97.5%). Four suboptimal CVP waveforms were obtained, and they correctly identified CVC malposition on subsequent chest X-ray (specificity: 100%). The average time from CVC insertion to radiological completion was 118 minutes. ConclusionCVP waveform analysis provides a feasible and reliable method for confirming adequate internal jugular CVC position. The use of chest radiography can be limited to cases where suboptimal CVP waveforms are obtained.

Geometric modification and placement of high heat flux ic chips on substrates of different materials for enhanced heat transfer

This article presents the significance of using different sizes and positions of IC (Integrated Circuit) chips that are mounted on substrates of different materials. The ICs are cooled by forced convection in a horizontal wind tunnel. COMSOL Multiphysics 5.4 solve the IC chip cooling problem by selecting a conjugate heat transfer module with laminar flow. FR4, ba-kelite, single and multi-layer copper clad boards are used as substrate materials. Numerical simulations are performed for FR4, bakelite with a constant heat flux of 5000 W/m2, at 2.5 m/s air velocity. In contrast, single and multi-layer copper clad boards are studied for 10000 W/m2 with 1.5 m/s air velocity. The prime objective of this research is to use adequate size and placement of chips generating high heat fluxes for enhanced heat transfer. Results showed that larger chips placed at bottom rows and sequentially decreasing sizes in the subsequent rows for the same overall input for high substrate thermal conductivity give more heat dissipation. Among all configurations A0 – F considered in the study, case E provides minimum tempera-ture using single and multi-layer copper clad boards. In addition to modification of chip sizes, geometric spacing of X1/X2 = 1.8 results in lower maximum temperature.

Embedding Pharmacist Prescribing into Undergraduate Pharmacist Education: A Qualitative Analysis of Student and Stakeholder Perspectives

Abstract Introduction From 2026 onwards, upon passing the registration exam, all pharmacy students will become independent prescribers (IP), with the aim of maximising the diagnostic and therapeutic skillset of all pharmacist graduates. As a result of this, pharmacy undergraduate education requires a shift in curriculum design to align with the change in direction the profession demands. Research is required to ascertain the needs of the local workforce to identify how the Master of Pharmacy (MPharm) course needs to change to future proof the pharmacy workforce and prepare them to independently prescribe. The GPhC new standards for pharmacist prescribing act as a scaffold for the structure of the course, but individual institutions have a level of freedom in curriculum design. Aim To identify the skills, knowledge and best pedagogical approaches required by key stakeholders in the local workforce, to develop an undergraduate prescribing programme for pharmacy students in a North-East England University Pharmacy School. Methods Two focus groups were conducted, one with key educational stakeholders in the North-East of England (Hospital, Primary Care and Academic Leaders in Pharmacy) and one with current MPharm students attending Newcastle University. Participants were selected via convenience sampling. Each group had n=5 participants. Data were recorded and transcribed, then analysed using thematic analysis in NVivo 12 to draw out key themes to consider when redesigning the MPharm curriculum. The project was granted ethical approval by Newcastle University’s Ethics Committee on 27/09/22, Reference 25121/2022. Results Five key themes were derived, with several overlapping across both groups. Themes identified: course content, teaching methods, assessment methods, current level of practice, and barriers to implementation. Within these themes, the key areas where stakeholders and students felt more training was required were identified as; diagnostic skills, mental health, dealing with patients with comprehension difficulties and dealing with complex decisions. The ways in which best to deliver this content were found to be through placement and seminars, also with students notably enjoying problem-based learning (PBL). Issues with hospitals having the capacity to provide adequate placement time for all students was a key concern amongst the stakeholders and was recognised as a key barrier to implementation of enhanced education in the future. Regarding digitalisation of teaching, students expressed a dislike for online delivery of content, but could see the benefits in teaching of emerging technology. However, it was ultimately felt that technology could not replace real-life experience. OSCEs (Objective Structured Clinical Examinations) were recognised as the best way to assess prescribing ability, however further modifications could be made to make them more specific to independent prescribing. Discussion/Conclusion Stakeholders and students felt the current programme should place greater emphasis on diagnostic skills and complex patient scenarios, with specific focus on people with additional needs such as autism. Additional awareness of the diversity of patients and how this affects prescribing decisions also was raised as a pertinent consideration. Limitations of this research include the small sample size of participants, which limits generalisability of opinions contributed. This was due to lack of recruitment time as a result of project time constraints.

Factors associated with longer hospital admission in elderly patients with major neurocognitive disorder.

Major neurocognitive disorder presents many challenges to patients, families and healthcare systems, especially when a patient requires admission to a psychiatric hospital. To identify characteristics of older patients with major neurocognitive disorder at risk of prolonged admission in a psychiatric hospital. A tertiary psychiatric hospital in Gauteng province, South Africa. The authors conducted a retrospective review of the hospital database and clinical files. Clinical and demographic data were collected from the files of 50 inpatients, 60 years and older, who were diagnosed with major neurocognitive disorder and admitted between 2015 and 2019. Anonymised data from patient records were captured on an electronic spreadsheet and analysed using T-tests and analysis of variance (ANOVA) to investigate the relationship between patient characteristics and length of hospital admission. The mean duration of admission was 18.29 months. Involuntary admission status (β = 0.239, p = 0.049), level of assistance required (moderate level of assistance [β = 0.378, p = 0.005]; high level of assistance [β = 0.336, p = 0.015]), availability of social support (β = -0.319, p = 0.016) and the presence of behavioural or psychological problems (β = 0.437, p = 0.002) were significantly correlated with longer admission. Using a stepwise regression model, the only significant variable associated with a shorter length of stay was the presence of social support (β = -0.512, p = 0.009). Age, type of major neurocognitive disorder and number of comorbidities were not correlated with the duration of admission (p > 0.005). Social support plays an important role in the management of patients with major neurocognitive disorder. The findings in this study highlight healthcare shortages and a need for adequate placement facilities in South Africa for patients who have no other form of support.

Salience-based VNF placement method for evolving multiple network slices

Network Function Virtualization (NFV) technology enables the deployment of a distinct network slice composed of various virtualized network functions (VNFs) required for offering a communication service. As the user population or network traffic volume fluctuates, the capacity of the network slices must be dynamically adjusted. It is necessary to decide whether to place VNFs in appropriate locations such that the quality of services (QoS) is guaranteed while optimally utilizing the allocated resources. The above challenge can be addressed by solving an optimization problem, such as integer linear programming. However, as solving the optimization problem requires a considerable amount of time, it is not applicable in agile network control mechanisms. In this paper, we propose a network function placement algorithm based on salience, which is one of the characteristic metrics of links in a graph. Our proposal is aimed to provide the adequate placement in short time to achieve the following objectives of keeping the slice reconstruction cost low and avoiding the cases of QoS degradation. The simulation results show that our scheme performs equally well for different sized slices (i.e., the user population). We found that the network reconfiguration costs are low and almost the same for various sized slices when they are reconstructed by the proposed method in a substrate network of 200 nodes. Furthermore, we confirmed that the proposed method keeps the slice reconstruction cost low and avoids blocking of slice reconstruction even in the situations when a resource competition occurs among multiple slices.

Federated Online Learning Aided Multi-Objective Proactive Caching in Heterogeneous Edge Networks

To address the drastic increase in multimedia traffic volume, mobile edge caching (MEC) has been exploited to reduce redundant data transmissions by equipping computation and storage capacity at the edge network. Previous works on learning-based caching problems often only concern pre-storing popular contents to satisfy users’ demands. In this work, we investigate the cache strategy design problem with two possibly conflicting objectives, namely, cache hit and cache profit, in heterogeneous multi-MEC server networks when content profiles are unknown. We then formulate this multi-objective caching problem as a Multi-agent Multi-objective Combinatorial Multi-Armed bandit (MMC-MAB) problem and propose a two-step caching framework that estimates content properties first and then optimizes cache placement. Specifically, to accommodate the system heterogeneity in estimation, we utilize an adaptive federated learning-based estimation to approach the unknown content popularity and profit profiles, which wisely use both local and external observations by adjusting the mixing factors. To address the multiple objective optimizations, we propose two effective methods, based on individual dominance and combinatorial dominance, to achieve adequate Pareto-optimal cache placement. Both theoretical results and comprehensive experiments clearly validate the effectiveness and efficiency of our proposed approaches.

An autonomous X-ray image acquisition and interpretation system for assisting percutaneous pelvic fracture fixation.

Percutaneous fracture fixation involves multiple X-ray acquisitions to determine adequate tool trajectories in bony anatomy. In order to reduce time spent adjusting the X-ray imager's gantry, avoid excess acquisitions, and anticipate inadequate trajectories before penetrating bone, we propose an autonomous system for intra-operative feedback that combines robotic X-ray imaging and machine learning for automated image acquisition and interpretation, respectively. Our approach reconstructs an appropriate trajectory in a two-image sequence, where the optimal second viewpoint is determined based on analysis of the first image. A deep neural network is responsible for detecting the tool and corridor, here a K-wire and the superior pubic ramus, respectively, in these radiographs. The reconstructed corridor and K-wire pose are compared to determine likelihood of cortical breach, and both are visualized for the clinician in a mixed reality environment that is spatially registered to the patient and delivered by an optical see-through head-mounted display. We assess the upper bounds on system performance through in silico evaluation across 11 CTs with fractures present, in which the corridor and K-wire are adequately reconstructed. In post hoc analysis of radiographs across 3 cadaveric specimens, our system determines the appropriate trajectory to within 2.8 ± 1.3mm and 2.7 ± 1.8[Formula: see text]. An expert user study with an anthropomorphic phantom demonstrates how our autonomous, integrated system requires fewer images and lower movement to guide and confirm adequate placement compared to current clinical practice. Code and data are available.

V-002 Robotic suprapubic eTEP retrorectus repair for incisional hernia

Abstract Aim A retrorectus mesh position is often considered the most suitable for the repair of a midline incisional hernia. The minimal invasive extraperitoneal approach is gaining popularity. Material & Methods A 56-year-old female patient, who had a laparoscopic deroofing of a bile cyst in her history, presented with an incisional midline hernia (EHS M2-M3, width 6.6 cm). Preoperative optimization via dietary instructions reduced her BMI from 40 kg/m2 to a BMI of 35 kg/m2. Results A robotic extraperitoneal approach via suprapubic docking was performed. The patient is positioned supine and flexed for 15° at the level of the spina iliaca. An intraperitoneal trocar is placed to explore the abdomen for adhesions. Three trocars are placed in the suprapubic position in the extraperitoneal plane whereafter the robot is docked. A dissection in the cranial direction is performed in the retrorectus plane by incising both posterior rectus fascia in a symmetric way. A preperitoneal plane behind the linea alba is created. At the level of the hernia defect the hernia sac is opened, and adhesions are freed. Once the retrorectus space is dissected up to the xyphoid, the linea alba is reconstructed with a barbed suture size 0. A self-fixating mesh is placed in the retrorectus position. The posterior layer of the peritoneum is closed. The postoperative course was uneventful. Conclusions We present an extraperitoneal minimal invasive approach to the retrorectus plane allowing for an adequate retrorectus dissection and mesh placement like in a classical Rives-Stoppa repair.