Minilaparotomy Cholecystectomy: A Forgotten Art in Laparoscopic Cholecystectomy Era (Our Experience from a Peripheral Hospital in North India)

Background: This study aimed to report the experience of performing minilaparotomy cholecystectomy in a peripheral hospital by a single surgeon. Methods: Data collected from 50 consecutive patients undergoing minilaparotomy cholecystectomy by a single surgeon over 18 months at a peripheral hospital were reviewed and studied. The recorded data encompassed demographics, operating time, incision size, conversion rate to open cholecystectomy, perioperative complications, and hospital stay duration. Results: Fifty consecutive patients, who underwent minilaparotomy cholecystectomy for symptomatic cholelithiasis, were studied, among whom 48 patients were females. The participants’ mean age was 45 years. The length of the surgical incision was 4.5 - 6 cm, and only three patients required conversion to open cholecystectomy. The average operating time was 60 minutes; and the average postoperative hospital stay was 2.14 days. Conclusions: Minilaparotomy cholecystectomy is comparable with laparoscopic cholecystectomy in terms of postoperative morbidity, and it is ideal for peripheral hospitals lacking laparoscopic facilities.

Outcome of Pertrochanteric Femur Fractures with Proximal Femur Locking Compression Plate

Background: Fractures of the proximal femur, including fractures affecting the pertrochanteric region, have become a public health problem. Owing to aging of the population, we have to operate on even more elderly patients who sometimes present with significant co-morbidities. Although conventional implants have given good results in stable peritrochanteric fractures, proximal femur locking compression plate (PFLCP) which has been recently introduced is better suited for comminuted, unstable pertrochanteric fractures and osteoporotic bones. In PF-LCP, bone-implantconstruct so formed is mechanically stable and fixation failure due to screw loosening in osteoporotic bone can be reduced. Materials &Methods: This prospective study was conducted in our institute and was approved by local ethical committee. Twenty-five consecutive patients of either sex with age more than 60 years (range, 60-84) having pertrochanteric fractures were operated upon with PFLCP. A.O classification was followed in the study and Singh’s index for osteoporosis was calculated. Operating time, blood loss and any technical difficulty with the implant were recorded. Patients were followed clinically and radiologically for union at fracture site and implant-related complications for a period of 24 months. The Harris Hip Score was used to document hip functions at final follow-up. Observations: Amongst the 25 patients, the average operation time in our study was 66.60±10.57 minutes. The average radiological union was 3.40±0.63 months (13.6 weeks). Average time for full weight bearing was 13.12±1.90 weeks. There were two cases of wound infection, one case of coxa vara and one case of a proximal screw back-out. There was no case of plate lift or screw breakage. There was no case of non-union. Conclusion: The PFLCP can be a feasible alternative to the treatment of peritrochanteric fractures. Treatment with PFLCP can provide good-to-excellent healing in osteoporotic bones having comminuted and unstable peritrochanteric fractures, with a limited occurrence of complications.

Deep Learning Prediction for Rotational Speed of Turbine in Oscillating Water Column-Type Wave Energy Converter

This study uses deep learning algorithms to predict the rotational speed of the turbine generator in an oscillating water column-type wave energy converter (OWC-WEC). The effective control and operation of OWC-WECs remain a challenge due to the variation in the input wave energy and the significantly high peak-to-average power ratio. Therefore, the rated power control of OWC-WECs is essential for increasing the operating time and power output. The existing rated power control method is based on the instantaneous rotational speed of the turbine generator. However, due to physical limitations, such as the valve operating time, a more refined rated power control method is required. Therefore, we propose a method that applies a deep learning algorithm. Our method predicts the instantaneous rotational speed of the turbine generator and the rated power control is performed based on the prediction. This enables precise control through the operation of the high-speed safety valve before the energy input exceeds the rated value. The prediction performances for various algorithms, such as a multi-layer perceptron (MLP), recurrent neural network (RNN), long short-term memory (LSTM), and convolutional neural network (CNN), are compared. In addition, the prediction performance of each algorithm as a function of the input datasets is investigated using various error evaluation methods. For the training datasets, the operation data from an OWC-WEC west of Jeju in South Korea is used. The analysis demonstrates that LSTM exhibits the most accurate prediction of the instantaneous rotational speed of a turbine generator and CNN has visible advantages when the data correlation is low.

Multipurpose Bio-Monitored Integrated Circuit in a Contact Lens Eye-Tracker

We present the design, fabrication, and test of a multipurpose integrated circuit (Application Specific Integrated Circuit) in AMS 0.35 µm Complementary Metal Oxide Semiconductor technology. This circuit is embedded in a scleral contact lens, combined with photodiodes enabling the gaze direction detection when illuminated and wirelessly powered by an eyewear. The gaze direction is determined by means of a centroid computation from the measured photocurrents. The ASIC is used simultaneously to detect specific eye blinking sequences to validate target designations, for instance. Experimental measurements and validation are performed on a scleral contact lens prototype integrating four infrared photodiodes, mounted on a mock-up eyeball, and combined with an artificial eyelid. The eye-tracker has an accuracy of 0.2°, i.e., 2.5 times better than current mobile video-based eye-trackers, and is robust with respect to process variations, operating time, and supply voltage. Variations of the computed gaze direction transmitted to the eyewear, when the eyelid moves, are detected and can be interpreted as commands based on blink duration or using blinks alternation on both eyes.

Comparison of Intestinal Stent Placement Followed By Laparoscopic Surgery and Emergency Surgery in Obstructive Colorectal Cancer: A Retrospective Analysis and Meta-analysis

Background: For patients with colorectal cancer and malignant intestinal obstruction, it is still controversial to perform endoscopic intestinal stent placement followed by laparoscopic surgery. This study compares the endoscopic intestinal stent placement followed by laparoscopic surgery and emergency surgery in patients with colorectal cancer and malignant intestinal obstruction.Method: 11 compliant publications from Pubmed, Cochrane and Embase databases were analyzed using Revies Manager 5.2 software. SPSS 21 was used to retrospectively analyze 99 patients admitted to our center from 2014 to 2019.Results: There were significant differences between the two groups in three of the five criteria. In the SBTS group, the perioperative mortality rate was lower, with an OR of 0.46 (95% CI: 0.22-0.95, P=0.04), the incidence of postoperative wound infection was lower; OR was 0.44 (95% CI: 0.24-0.82, P=0.009); Postoperative hospital stay was shorter, MD was -2.07 (95% CI: -2.55--1.59, P<0.00001).Retrospective analysis of the clinical outcome differences between the SBTS group and ES group in our center: Compared to the ES group, the SBTS group displayed lower infection rate of surgical incision (χ2=3.94,P =0.04) ); no difference in the frequency of occurrence of anastomotic leakage (χ2=0.18,P=0.67), did not reduce perioperative mortality (χ2=0.94,P=0.33);shorter operating time (204.13±37.35 min) (t=5.08,P=0.000), lower intraoperative blood loss (155.65±94.90 ml) (t=3.90,P=0.001); and shorter postoperative hospital stay (12.91±5.47 d) (t=2.64, P=0.01).Conclusion: Compared the emergency surgery group, endoscopic intestinal stent placement followed by the laparoscopic surgery can reduce perioperative mortality, postoperative wound infection, intraoperative blood loss, and the length of postoperative hospital stay. There was no difference between the two methods as far as the incidence of posterior anastomotic leakage and operating time were concerned.

Manufacturing of Bellows Compensator by Pulsed-Magnetic Field Pressure

Bellows are a cylindrical shell with a corrugated part, widely used in aviation engineering as a movable sealing element to balance pressure and temperature differences, which ensure continuous and accurate system operation. The use of bellows expansion joints provides reliable and effective protection of pipelines from static and dynamic loads arising from deformations and vibration. Welded-edge bellows are a popular choice for regulating and controlling fuel supply in aircraft devices. The ability of the compensator to perceive deformations is determined by its assigned operating time, which describes how many cycles, and with what amplitude, the bellows compensator perceives without damage. A method for stamping bellows from tubular billets by using magnetic-pulse field in rigid dies, including sequential shaping of corrugations by distributing the internal magnetic pressure with axial movement of the free end of a tubular billet, characterized in that the material of the tubular billet for shaping corrugations is selected in accordance with its relative elongation.

Power management of variable capacitors in electrical grid systems according to the criterion of mini-mum energy loss

The aim is to manage the transmitted reactive power in electrical grids using variable capacitor batteries according to the criterion of minimum energy loss under different annual reactive load schedules and different numbers of variable capacitor sections. The main theoretical relations were obtained by the methods of mathematical modelling and integral calculus using the theory of optimal control. The influence of the power and number of sections in a capacitor battery on energy losses in the grid was estimated using computational experiments. Dependencies for energy losses in a capacitor battery, as well as for reducing energy losses in the grid, were obtained. These expressions are valid for linearized load schedules. It is shown that the dependences of energy losses in a capacitor battery and the reduction of losses in the grid on the section power have inflection points and pass through a maximum. The presence of inflection points is associated with a change in the number of capacitor sections operating throughout the year. The presence of a maximum is explained by the fact that, with an increase in the power of the capacitor battery, its operating time decreases under the complete number of variable sections. It is established that the batteries of static capacitors with two variable sections can reduce energy losses when transmitting reactive power by over 90%. For three- and four-section static capacitors, the loss reduction is close to 100%. The reduction in energy losses increases when approaching maximal levels of annual reactive load. Energy losses in electrical grid systems can be reduced by capacitor batteries with no more than three or four variable sections. In most cases, this can be achieved by two-section capacitor batteries.

Significance of Postoperative Membranous Urethral Length and Position of Vesico-Urethral Anastomosis for Short Term Continence Recovery Following Robot-Assisted Laparoscopic Radical Prostatectomy

Background We assess whether short term recovery of urinary incontinence following robot-assisted laparoscopic radical prostatectomy (RARP) is associated with preoperative membranous urethral length (MUL) and position of vesico-urethral anastomosis (PVUA). Methods Clinical variables including PVUA and pre- and postoperative MUL were evaluated in 251 patients who underwent RARP from August 2019 to February 2021. Continence recovery was defined as no pad or one security liner per day assessed by patient interview at least 6 months follow-up. Univariate and multivariate logistic regression analyses were used to assess variables associated with continence recovery at 3 months after the operation. Results Continence recovery rates at 3 and 6 months were 75% and 84%, respectively. Lower BMI (<25 kg/m2) (p = 0.040), longer preoperative MUL (≥9.5mm) (p = 0.013), longer postoperative MUL (≥9mm) (p <0.001), higher PVUA (<14.5mm) (p = 0.019) and shorter operating time (<170min) (p = 0.013) were significantly associated with continence recovery at 3 months in univariate analysis. Multivariate analysis revealed that postoperative MUL (OR 3.75, 95% CI 1.90 – 7.40, p <0.001) and higher PVUA (OR 2.02, 95% CI 1.07 – 3.82, p = 0.032) were independent factors for continence recovery. Patients were divided into three groups based on the multivariate analysis, with urinary continence recovery rates found to have increased in turn with rates of 43.7% vs. 68.2% vs. 85.0% (p <0.001) at three months. Conclusions PVUA and postoperative MUL were significant factors for short term continence recovery. Preservation of urethral length might contribute to continence recovery after RARP.

Hybridization of PSO for the Optimal Coordination of Directional Overcurrent Protection Relays

In the electrical power system, the coordination of directional overcurrent protection relays (DOPR) plays a preeminent role in protecting the electrical power system with the help of primary and back up protection to keep the system vigorous and to avoid unnecessary interruption. The coordination between these relays should be pursued at optimal value to minimize the total operating time of all main relays. The coordination of directional overcurrent relay is a highly constrained optimization problem. The DOPR problem has been solved by using a hybridized version of particle swarm optimization (HPSO). The hybridization is achieved by introducing simulated annealing (SA) in original PSO to avoid being trapped in local optima and successfully searching for a global optimum solution. The HPSO has been successfully applied to five case studies. Furthermore, the obtained results outperform the other traditional and state of the art techniques in terms of minimizing the total operating of DOPR and convergence characteristics, and require less computational time to achieve the global optimum solution.

Evaluation of High Penetration Hybrid Laser-GMAW Welding Process Productivity Applied in the Joining of Thick Plates and Pipelines

Welding processes are present in all sectors of the industry, highlighting the manufacturing industry of thick plates and pipelines. In these applications, welding processes have a major influence on costs, schedules, risk analysis and project feasibility. Conventional arc welding processes, such as the gas metal arc welding (GMAW) process, have limitations when applied to high thickness joints due to their maximum achievable penetration depth. On the other hand, the laser beam welding (LBW) welding process, despite reaching high penetration depths, has several limitations mainly regarding the geometric tolerance of the joint. In this regard, the hybrid laser-arc welding (HLAW) process emerges as a promising bonding process, combining the advantages of the GMAW and LBW processes into a single melting pool. Despite the many operational and metallurgical advantages, the HLAW process presents a high complexity due to the high number of parameters involved and the interaction between the laser beam and the electric arc. The present work discusses the challenges involved in the parametrization of the HLAW process applied to the joining of thick plates and pipes, and empirically evaluated a comparison between the HLAW and GMAW processes, showing a reduction of operating time of approximately 40 times, and a reduction of consumption of shielding gas and filler material of approximately 20 times, evidencing the technical and financial contribution of the hybrid process.