Operational Charts Research Articles

A proposal for a new classification of complications in craniosynostosis surgery.

OBJECTIVE Complications have been used extensively to facilitate evaluation of craniosynostosis practice. However, description of complications tends to be nonstandardized, making comparison difficult. The authors propose a new pragmatic classification of complications that relies on prospective data collection, is geared to capture significant morbidity as well as any "near misses" in a systematic fashion, and can be used as a quality improvement tool. METHODS Data on complications for all patients undergoing surgery for nonsyndromic craniosynostosis between 2010 and 2015 were collected from a prospective craniofacial audit database maintained at the authors' institution. Information on comorbidities, details of surgery, and follow-up was extracted from medical records, anesthetic and operation charts, and electronic databases. Complications were defined as any unexpected event that resulted or could have resulted in a temporary or permanent damage to the child. RESULTS A total of 108 operations for the treatment of nonsyndromic craniosynostosis were performed in 103 patients during the 5-year study period. Complications were divided into 6 types: 0) perioperative occurrences; 1) inpatient complications; 2) outpatient complications not requiring readmission; 3) complications requiring readmission; 4) unexpected long-term deficit; and 5) mortality. These types were further subdivided according to the length of stay and time after discharge. The overall complication rate was found to be 35.9%. CONCLUSIONS The proportion of children with some sort of complication using the proposed definition was much higher than commonly reported, predominantly due to the inclusion of problems often dismissed as minor. The authors believe that these complications should be included in determining complication rates, as they will cause distress to families and may point to potential areas for improving a surgical service.

Magnetic Resonance (MR) Imaging Assessment for Glossopharyngeal Neuralgia: Value of Three-Dimensional T2-Reversed MR Imaging (3D-T2R) in Conjunction with Other Modes of 3D MR Imaging.

SummaryBackgroundTo retrospectively examine the usefulness of gray-scale reversal imaging of T2-weighted images (3D-T2R) in conjunction with other modes of 3D MRI for preoperative assessments in patients with glossopharyngeal neuralgia (GPN) due to neurovascular compression.Material/MethodsImaging findings on 3D-T2R, constructive interference in steady state (CISS), and MRA were analyzed with reference to operative charts in 10 patients with GPN.ResultsOffending vessels were associated with the posterior inferior cerebellar artery (PICA) in 9 of 10 patients (90%). Eight of the 10 patients (80%) had offending vessels located at the supraolivary fossette. Of those eight patients, six (75%) had a shift of the ipsilateral vertebral artery to the affected side. Five (42%) and seven (48%) contact points were associated with the root entry/exit zone and the peripheral nerve system segment, respectively. In six of nine contact points (67%), 3D-T2R demonstrated the pathomorphological features at the contact points better than CISS.ConclusionsThe offending vessels were mostly associated with posterior inferior cerebellar arteries, were frequently located at the supraolivary fossette, and had attachments at the root entry/exit zone and at the peripheral segment of the glossopharyngeal nerve, which was well demonstrated on 3D-T2R.

Research and application of key technologies in drawing energy storage operation chart by discriminant coefficient method

Discriminant coefficient method (DCM) is a traditional method in guiding the cascade reservoirs joint operation, but it cannot be well used directly in the practical application. This paper combined DCM with the cascade reservoirs energy storage operation chart (CRESOC) and proposed a new DCM based drawing model. In addition, three key technologies in the drawing process and one key technology in the practical application were studied emphatically, which can realize the combined utilization of DCM and CRESOC perfectly. In the case study, we took the cascade reservoirs of Li Xianjiang River in southwest China as an instance to study the CRESOC by the proposed drawing model. Compared with the existing single reservoir operation charts, the simulation results show that the CRESOC presents better performance in terms of power generation and assurance rate, especially on the latter, which has a growth of 6.8%. Moreover, in order to eliminate the insufficient of DCM in practical application, the boundary control curves of each reservoir for water storage and water supply were optimized by the proposed optimization technique, and the simulation results show that there is no water abandonment in all the 43 dry seasons after the optimization.

Lumbar microendoscopic discectomy: surgical technique and nuances.

Lumbar microendoscopic discectomy (MED) is a minimally invasive transmuscular approach that combines standard lumbar microsurgical techniques with endoscopy. MED advantages include reduced tissue trauma, direct visualization of the nerve root and disc disease, and allowing bony decompression in cases with spinal or lateral recess stenosis. Operative charts and videos of patients undergoing MED were retrieved from our database and reviewed. A description of the surgical technique was then formulated. The surgical technique of MED is described and is essentially similar to conventional microdiscectomy. Some modifications are, however, necessary owing to the difference between microscopic and endoscopic views.

Laparoscopic resection of paraaortic/paracaval neurogenic tumors: surgical outcomes and technical tips.

Due to variations in location and size, laparoscopic surgery for paraaortic or paracaval neurogenic tumors is challenging. We evaluated the surgical outcomes, as well as surgical tips and tricks. Between 2000 and 2015, 25 procedures were performed in 24 patients. One patient underwent second surgery due to the recurrence of paraganglioma. Data were collected on the tumor diameter, tumor location, perioperative outcomes, pathology, and last-known disease status. Regarding the operative procedures, we reviewed the operative charts or videos to identify surgical tips and tricks. The median tumor diameter was 5.0cm (range 1.5-10). The tumor location was suprahilar in 10, hilar in 6, and infrahilar in 9 cases. Regarding the approach, a transperitoneal approach was selected in 24 cases and retroperitoneal approach in 1. The median operative time and blood loss were 208min (range 73-513) and 10mL (range 0-1020), respectively. No patient required blood transfusion or conversion to open surgery. Pathological examination revealed paraganglioma in 12, ganglioneuroma in 7, and schwannoma in 6 cases. At the last follow-up, 23 patients were free of disease, while one patient developed metastatic multiple recurrence of paraganglioma 54months after the second laparoscopic surgery. A review of the surgical records revealed several tips and tricks, including taping the vena cava/renal vein (n=2) being helpful for detaching a retrocaval tumor from these great vessels, or rotating the kidney to provide a favorable operative view of tumors behind the renal hilum (n=2). In recent cases, 3D-CT was helpful for preoperative planning. Laparoscopic resection of paraaortic or paracaval neurogenic tumors is feasible in experienced hands. Surgeons should be familiar with detaching maneuvers around great vessels and the mobilization of adjacent organs. Careful preoperative planning is mandatory.

High arterial ligation and risk of anastomotic leakage in anterior resection for rectal cancer in patients with increased cardiovascular risk.

Controversy still exists as to whether division of the inferior mesenteric artery close to the aorta influences the risk of anastomotic leakage after anterior resection for rectal cancer. This population-based study was carried out to evaluate the independent association between high arterial ligation and anastomotic leakage in patients with increased cardiovascular risk. All 2673 cases of registered anterior resection for rectal cancer from 2007 to 2010 were identified from the Swedish Colorectal Cancer Registry and cross-referenced with the Prescribed Drugs Registry, rendering a cohort of all patients with increased cardiovascular risk. Operative charts and registered data were reviewed for 722 patients. The association between high tie and anastomotic leakage, as quantified by ORs and 95% CIs, was evaluated in a logistic regression model, with adjustment for confounding, including assessment of interaction. Symptomatic anastomotic leakage occurred in 12.3% (41/334) of patients in the high tie group and in 10.6% (41/388) in the low tie group. The use of high tie was not independently associated with a higher risk of anastomotic leakage (OR = 1.05; 95% CI: 0.61-1.84). In a post-hoc analysis, patients with a history of manifest cardiovascular disease and American Society of Anesthesiologists (ASA) score III-IV seemed to be at greater risk (OR = 3.66; 95% CI: 1.04-12.85). In the present population-based, observational setting, high tie was not independently associated with an increased risk of symptomatic anastomotic leakage after anterior resection for rectal cancer. However, this conclusion may not hold for patients with severe cardiovascular disease.

Mise en place d’une activité de reconstruction microchirurgicale du sein par tissus autologues. Évolution sur 20 ans et revue de 1138 cas

The authors conducted a retrospective study of breast reconstruction with DIEP free flap between 1994 and 2014 by a single team. A retrospective analysis of all operative charts and hospitalization was conducted for the period from 1994 to 2014. The number of cases per year, the complication rate of the donor site and recipient site, and surgery time were recorded. Sequence analysis was conducted to determine the elements that have enabled to implement this technique reliably and effects of the learning curve. The series was split into two periods (1994/2011 and 2012/2014) corresponding to two different hospitals with the same team. The total number of shreds of 1138 between November 1994 and December 2014 respectively with 477 and 661 the period 1994/2011 to 2012/2014 period. The failure rate increased from 8% to 2.2%. The establishment of units mainly dedicated to microsurgical reconstruction can offer the DIEP technique reliably and reproducibly.

Microbial analysis and parametric optimization of activated sludge process in paper and pulp mill effluent plant: a case study

Environmental factors affecting the degradation efficiency of paper and pulp mill wastewater were identified and optimized in this study. An attempt has been made to design the thickening area of the secondary clarifier for paper and pulp mill wastewater to ensure critical loading condition by considering the initial concentration of mixed liquor suspended solids, recycling ratio, desired underflow concentration, and mean cell residence time. Natural coagulants, coagulant dose, and coagulant aid dose used in the coagulation_flocculation process were optimized using the design of experiment approach for turbidity and chemical oxygen demand reduction. Operational charts were developed for parameter adjustments in steady state process control.

Acute penile trauma and associated morbidity: 9-year experience at a tertiary care center.

Penile fracture is an uncommon urologic emergency, defined as traumatic rupture of the tunica albuginea of the corpus cavernosum. It occurs mainly in young adults during sexual activity. In the United States, urethral injury is associated with 10-38% of all penile fractures. Diagnosis can be made clinically with the classic triad of an audible crack, detumescence, and appearance of hematoma. We sought to identify characteristics associated with true penile fracture vs. other diagnoses, and determine associated morbidity and risk factors for complications. Retrospective operative chart review identified 39 patients (mean age 39.4 years) with clinical features of penile fracture presenting to Boston Medical Center from June 2004 to May 2013. Average time from injury to presentation was 76 h (range 0.5 h-9 days) and the mechanism of injury was coital in 32 (82%) patients. Thirty-two patients (82%) had confirmed penile fracture, 7 (18%) had isolated vascular injury. Of confirmed fractures, 4 (13%) had bilateral corporal injury and associated urethral injury. Imaging was utilized in a total of 21 cases, penoscrotal ultrasound (US) in 17 cases, retrograde urethrogram (RUG) in 3 cases, and magnetic resonance imaging (MRI) in 1 case. Penile exploration was carried out via degloving (n = 5, 13%) or penoscrotal (n = 34, 87%) incisions. At follow-up, six patients (15%) had complications: 2 wound infections, 2 new-onset erectile dysfunction (ED), 1 urethral stricture, 1 fistula and 1 wound dehiscence. Urethral injury increased the risk of post-operative complications (p = 0.015). Penile fracture is primarily a clinical diagnosis, however imaging may be helpful if diagnosis is uncertain. Urethral injury should be suspected in cases of bilateral corporal injury and may be associated with increased morbidity. Surgical approach does not affect morbidity, but may facilitate surgical repair.

Study on Cascade Energy Storage Operation Chart Optimization of Li Xianjiang Basin Based on Progressive Optimal Algorithm

Based on the cascade reservoirs of Li Xianjiang basin, the study of cascade energy storage operation chart was carried out in this paper. Combining the commonly used discriminant method in joint dispatching of cascade reservoirs, the drawing method of energy storage scheduling figure was described detailedly, especially the calculation process of deriving the typical runoff that corresponds to the up and down basic scheduling lines. Considering the power generation reliability was enhanced when implementing the joint operation for cascade reservoirs, the maximum power generation model based on energy storage operation chart was proposed in this paper, and the progressive search method is used in the solving process of the model in a certain range of guaranteed output. In addition, result of the model was further optimized by using Progressive Optimal Algorithm, and comparing the optimized result with the conventional dispatching scheme under the unchanged guaranteed output, the power generation has increased 0.04 million kWh and assurance rate increased 9%.

Research on Joint Impoundment Dispatching Model for Cascade Reservoir

As more and more large reservoirs been built, competitive impoundment problem of cascade reservoirs becomes a serious matter in the flood recession. Combining the impounding principle with K value discriminant method, a novel impounding strategy of cascade reservoirs is proposed for determining the impoundment sequence and opportunity of each reservoir in premise of the flood control safety. At the same time, the impounding water level control lines of different frequency runoff are drawn according to the flood routing simulation, and then the Impounding Operation Chart (IOC) is manufactured. On this basis, a model of impoundment dispatching in advance based on the IOC is developed. Then the proposed method can be obviously accelerated by using Self-adaptive Electromagnetism-like Mechanism algorithm (SEM). Compared with the original design of impounding scheme, the result indicates that the optimal scheme can improve the fill storage ratio of cascade reservoirs and ease the contradiction between supply and demand of water resources as well with guaranteeing the safety of flood control in the watershed.

Total output operation chart optimization of cascade reservoirs and its application

With the rapid development of cascade hydropower stations in recent decades, the cascade system composed of multiple reservoirs needs unified operation and management. However, the output distribution problem has not yet been solved reasonably when the total output of cascade system obtained, which makes the full utilization of hydropower resources in cascade reservoirs very difficult. Discriminant criterion method is a traditional and common method to solve the output distribution problem at present, but some shortcomings cannot be ignored in the practical application. In response to the above concern, this paper proposes a new total output operation chart optimization model and a new optimal output distribution model, the two models constitute to a double nested model with the goal of maximizing power generation. This paper takes the cascade reservoirs of Li Xianjiang River in China as an instance to obtain the optimal total output operation chart by the proposed double nested model and the 43years historical runoff data, progressive searching method and progressive optimality algorithm are used in solving the model. In order to take the obtained total output operation chart into practical operation, mean value method and stepwise regression method are adopted to extract the output distribution ratios on the basis of the optimal simulation intermediate data. By comparing with discriminant criterion method and conventional method, the combined utilization of total output operation chart and output distribution ratios presents better performance in terms of power generation and assurance rate, which proves it is an effective alternative method to deal with the cascade reservoirs joint operation problem.

Research on Quality Control of Motor Shell Coating Process

SPC method is a process controlling tool with the aid of mathematical method. Define, Measure, Analysis, Improvement and Control is the implementation processes of quality management. Combined with the two methods, the quality fluctuation in the production process could be controlled effectively and qualified products rate could be enhanced excellently. In this paper, the film thickness problem of motor shell coating production line has been studied based on statistical process control and DMAIC processes. The Pareto diagram, cause and effect diagram, operation chart are used to inspect production defects in the process. At same time, the factors leading to product defects are determined. Then, DOE method is applied to find the best parameters of electrophoresis coating process. SPC method is adopted to monitor the improved film thickness. The results show that quality level of coating process has improved greatly.

Arterial ligation in anterior resection for rectal cancer: A validation study of the Swedish Colorectal Cancer Registry

ABSTRACTBackground. The level of arterial ligation has been a variable of the Swedish Colorectal Cancer Registry since 2007. The aim of this study is to evaluate the accuracy of this registry variable in relation to anterior resection for rectal cancer.Methods. The operative charts of all cardiovascularly compromised patients who underwent anterior resection during the period 2007–2010 in Sweden were retrieved and compared to the registry. We selected the study population to reflect the common assumption that these patients would be more sensitive to a compromised visceral blood flow. Levels of vascular ligation were defined, both oncologically and functionally, and their sensitivity, specificity, positive and negative predictive values, level of agreement and Cohen's kappa were calculated.Results. Some 744 (94.5%) patients were eligible for analysis. Functional high tie level showed a sensitivity of 80.2% and a specificity of 90.1%. Positive and negative predictive values were 87.7 and 83.8%, respectively. Level of agreement was 85.5% and Cohen's kappa 0.70. The corresponding calculations for oncologic tie level yielded similar results.Conclusion. The suboptimal validity of the Swedish Colorectal Cancer Registry regarding the level of vascular ligation might be problematic. For analyses with rare positive outcomes, such bowel ischaemia, or with minor expected differences in outcomes, it would be beneficial to collect data directly from the operative charts of the medical records in order to increase the chance of identifying clinically relevant differences.

An Assessment of Sea-Ice Thickness Along the Labrador Coast From AMSR-E and MODIS Data for Operational Data Assimilation

In this paper, sea-ice thickness values are calculated along the Labrador coast using data from two sensors representative of those available for operational data assimilation. Data from the first sensor, the Moderate Resolution Imaging Spectroradiometer (MODIS), are used to calculate the ice thickness using a heat balance equation. Relationships between the MODIS ice thickness and polarization ratio from the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) are used to calculate the thickness of thin ice (less than 0.2 m) from the AMSR-E data. This is done for each frequency on the AMSR-E sensor in the range of 6.9-36.5 GHz. Through comparison with data from ice charts, it is found that the errors are lowest for thickness values calculated from low-frequency AMSR-E data. The accuracies of the ice thickness from MODIS, AMSR-E, operational ice charts, and two moored upward looking sonars are further assessed using the triple collocation method. It is found that the error associated with ice thickness from AMSR-E is the lowest and the error associated with ice thickness from MODIS is the highest. While the MODIS data represent the small-scale variability of the sea-ice thickness better than the AMSR-E data, the MODIS data can produce spurious values of ice thickness due to unmasked clouds. To use ice thickness from MODIS in an automated algorithm, quality control would need to be applied to the MODIS data to remove unmasked clouds which lead to spurious values of thick ice. The errors calculated for the ice thickness from AMSR-E, which are calculated based on a relationship calibrated with MODIS ice thickness from a clear-sky day, indicate that these data would be useful for operational data assimilation.

Modeling and controlling clarifier–thickeners fed by suspensions with time-dependent properties

A one-dimensional model of the process of continuous sedimentation in a clarifier–thickener unit is presented. The governing model is expressed as a system of two nonlinear partial differential equations for the solids volume fraction and the varying settling velocity of the solids as functions of depth and time. This model extends the well-known model for the dynamics of a flocculated suspension in a clarifier–thickener advanced by Bürger et al. (2005). Operating charts are calculated to be used for the control of steady states, in particular, to keep the sediment level and the underflow volume fraction at desired values. A numerical scheme and a simple regulator are proposed and numerical simulations are performed.

COMBINED APPLICATIONS OF LEAN MANUFACTURING AND OSH IN LEATHER MANUFACTURING PROCESSES

Introduction The leather manufacturing process involves intensive manual laboring and there are copious opportunities to apply modern tools such as lean manufacturing for improved productivity and reduced occupational stress. The aim of the work is to assess the feasibility of extending the combined applications of lean manufacturing principles and OSH studies in a leather manufacturing unit in India. Method The lean manufacturing techniques used in this study are time and motion measurements. The ergonomic hazards as a result of work postures were independently assessed and later compared with the time-motion studies. The project involved the collection of videos of the various operations at the leather manufacturing unit. The collected videos were analyzed and the data obtained were compiled in the form of operation charts and time study sheets. Results The time taken for each element has been calculated and a table has been constructed for multiple cycles. The time taken for each operation when all suggestions have been implemented is estimated to give an idea of the time that can be saved. This resulted in a saving of 79.82 secondsand 15% reduction in the total movements throughout the entire process. Based on the sequence of operations followed for the two products produced in the largest quantities (nappa and suede), suggestions for modification of the plant layout have been provided. The proposals aimed at increasing the efficiency of the plant while keeping the costs involved in modification of plant layout to a minimum. An effort has been made to place consecutive operations as close together as possible in order to decrease transportation time and reduce manual labor handling. Conclusion This study has made a number of useful suggestions which if implemented, would result in higher productivity, worker safety, decreased worker fatigue and a more efficient usage of work space. This study can be considered a useful starting point for the modernization of the Indian leather industry as a whole.

The oncologic radicality of supracricoid partial laryngectomy with cricohyoidopexy in the treatment of advanced N0‐N1 laryngeal squamous cell carcinoma

The aim of the study was to evaluate the oncologic outcome of our series of advanced laryngeal squamous cell carcinomas, primarily treated by supracricoid laryngectomy with cricohyoidopexy or total laryngectomy, to compare the two therapeutic modalities. Retrospective controlled study. We retrospectively reviewed the medical files, operative charts, and pathology reports of 83 patients who underwent total laryngectomy or supracricoid laryngectomy with cricohyoidopexy between February 1999 and March 2009. We only included cases in which both surgical treatments were feasible. Endpoints included local control, locoregional control, overall survival, and disease-specific survival. When we stratified the patients according to T stage, no statistically significant differences emerged in terms of overall and disease-specific survival. When we compared total laryngectomy to cricohyoidopexy in N1 patients, 3-year overall survival and disease-specific survival differences were statistically relevant (P = .022 and P = .030, respectively). Total laryngectomy warranted better results in term of overall and disease-specific survival, although the differences were not statistically significant. Local and locoregional control in the two treatment groups were overlapping, showing that cricohyoidopexy (when technically feasible) could be a valid surgical option in selected advanced laryngeal squamous cell carcinoma.

Two operating modes for turbocharger system

The present paper introduces a turbocharger system that operates in two different modes according to turbocharging requirements. In the first mode, the turbocharger is operating with power assistance at lower engine speeds where the power of the exhaust gases is insufficient. Thereafter, the second mode is switched leading the compressor and the turbine of the turbocharger to rotate separately for best performance. Analysis is presented to find out the parameters affecting the operation of the turbocharger and their values to achieve enhanced turbocharger performance with high efficient impellers. The parameters studied are based on data of the turbocharger operating conditions and the operational requirements of the engine. The analysis considers the turbocharger system, its turbine and its compressor. The operational charts demonstrate the simulated results for two operating modes. This study is helpful as a guide to determine the turbocharger dimensioning and blade profile assignment without using any given blade dimensional value.

基于梯级水库常规调度图的优化绘制

水库调度图作为指导水电站安全高效运行的依据，一直是水库调度研究的热点，然而现有研究大多以单库调度图为对象进行优化，或是基于中长期发电优化调度模型绘制梯级水库调度图。单库优化调度图较难满足梯级调度要求，而后者虽然理论成熟、应用广泛，但存在建模、求解复杂，步骤繁琐，误差较大等的缺点。鉴此，本文提出了一种采用模拟与优化相结合的技术绘制梯级水库优化调度图的实用方法。该法通过直接优化梯级水库常规调度图的调度线，从而获得优化调度图。以乌江流域4座调节性能较好的水库构成的梯级水库为研究对象进行实例分析，模拟调度结果表明较大地提高了梯级长期发电效益，验证了该法的可靠性和有效性，从而为梯级水库优化调度图的绘制提供了新思路。 Reservoir operation chart has been a hot topic of the reservoir operation study as a basis for the guidance of the efficient and safe operation of the hydropower station. However, existing studies are mostly studying on the optimizing drawing of single reservoir, or research on the drawing of cascade reservoirs operation chart using a long-term power optimization scheduling model. Single reservoir optimized operation chart is hard to meet the cascade scheduling requirements, while the latter theory is mature, widely used, but has its flaws. For this, this paper puts forward a drawing way of cascade reservoirs optimal operation charts, using the combination technology of simulation and optimization, through the direct optimization of the cascade reservoirs conventional operation curves. For the cascade hydropower stations on the WujiangRiver, simulation scheduling results show considerably increase on the cascade long-term generation benefit. Thus verify the reliability and validity of the method, so as to provide a new idea to draw the cascade reservoirs operation chart.