A Simple Method To Repair A Supraglottic Airway Device

Background: During the perioperative period or while in the intensive care unit, the inflation line is often cut accidentally during medical procedures or is damaged. As a result, it is not uncommon for a cuff leak to result in inadequate ventilation for the patient. The risk of using endotracheal tubes (ETTs) for secondary intubation is great, increasing the probability of respiratory tract infection and injury and even causing death in severe cases. The best method is to repair the damaged ETT to avoid secondary intubation and to ensure the safety of patients. Therefore, we recommend a practical and straightforward method to repair damage to the line or valve assembly of an endotracheal tube(ETT) and laryngeal mask airway (LMA).Methods: The distal end of a 22G vein (IV) catheter was inserted into the broken end of the inflation line. After insertion, the internal tube was withdrawn 1 mm to restore the inflation line. After 15 hours, the repaired ETT/LMA devices were tested for air leakage by measuring the pressure and load-bearing tension of the inflation line.Results: There was no difference in ETTs pressure between five intact ETTs and five repaired ETTs (Group A, ETT, mean difference = 0.2 cmH2O; 95% confidence interval 1.78 to 2.12 cmH2O; P = 0.82). When the cuff expanded to 120 cm H2O, there was no air leakage in the five ETTs after repair, and the tensile strength of the inflation line of the repaired ETTs in the experimental group was lower than that in the control group (each n = 5; mean difference = 33.3N; 95% confidence interval, 27.5 to 39.1N; P <0.001). There was no difference in LMAs pressure (Group B, LMAs, mean difference = 0.4 cmH2O; 95% confidence interval: -1.8 to −2.6 cmH2O; P = 0.67). When the cuff was expanded to 120 cmH2O, there was no air leakage from the five repaired LMAs. The tensile strength of the inflation line of the repaired LMAs in the experimental group was lower than that in the control group (n = 5; mean difference = −10; 95% confidence interval: −14 to −5.8 N; P = 0.001).Conclusion: When the ETT, LMA inflation line, or valve assembly is damaged or accidentally broken, an IV catheter can be directly inserted into the inflation line to quickly and effectively repair it. It is a safe and effective emergency remedial measure, which can be widely used in the clinic.

Investigation of a Digital Hydraulic Valve Operated by Servo Motors

This paper describes a new type of digital hydraulic valve run by two servo motors. Digital hydraulics is a cutting-edge technology, which saves more exhausted energy than conventional hydraulic valves. It includes conventional valves, but its working principle is different. Similar or different size valves constitute a digital hydraulic valve assembly. When the assigned valves are opened, a certain amount of flow is obtained from the output of the valve assembly. To control a digital hydraulic valve, Pulse Number Modulation (PNM) Control technique is used for equal valve flow rates, while Pulse Code Modulation (PCM) is used for different valve flow rates. Valves are exerted by independently launched electric coils. Previous studies used controller board and external power booster circuits for coils. In this study, a new type of digital hydraulic valve is designed, manufactured, and tested with the PNM method. The studied valve body has two different valve groups. Every group includes 16 equal valves and 1 camshaft rotated by 1 servo motor. The servo motors are controlled by a PLC. The calculated performance index is found to be 5.1ms which is similar to the results of previous studies. The experimental results showed that the cam and servo motor controlled digital hydraulics is applicable to variable speed control hydraulic systems.

Extending ESP Run Life By Reducing Shutdowns and Improving Restarts Using Novel Pump Protection Technology

Meeting the production demand in today's market without sacrificing performance of the artificial lift method is critical. Aggressive flowback procedures lead to solids production and unplanned electric submersible pump (ESP) shutdowns because of solids overload. A novel pump protection system has been designed, tested, and installed in the field. The system enhances the ESP life, improves restarts, and reduces downhole vibrations and unplanned shutdown by controlling the solids flowback and sending solids-buildup pressure signals. A comparative study on three ESP wells in the Delaware basin (US) demonstrated the efficacy of the system. The system comprises of an intake sand control screen and valve assembly. The novel stainless steel wool screen acts as a three dimensional (3D) filter capable of filtering out particles of 15 to 600 μm, and the valve assembly activated by differential pressure across the screen creates a secondary flow path to allow cyclic cleanup of the screen. Stainless steel wool screen with variable pore sizes is used as the sand control media for its high efficiency in preventing the flow of most of the solid particles. When the solids build up on the screen surface, the valve assembly opens upon reaching a preset differential pressure to enable flow past the screens and into the ESP and allows sands deposited on the screen surface to fall off. The pump protection assembly was tested at surface and installed in three wells along with downhole ESP gauges measuring pressure, temperature and vibrations after pulling out existing ESP completions. Qualification testing confirmed the opening of the valve assembly after solids buildup on the stainless steel wool screen. It also validated that the deposited sand fell-off from the screen surface after flow diverted through the valve assembly and pressure differential across screen dropped. In the field installations, the run life of the ESPs improved by an average of 35%, with comparable production volumes and slow drawdowns. In addition, the number of ESP shutdowns related to sand and solids was reduced by as much as 75%, improving longevity of electrical components. The success rate of ESP startups after planned and unplanned shutdowns also improved by 22%. The increase in inlet pressure captured via the downhole gauges when the valve assembly opened indicated the sand control prevention and mitigation system was bridged, and ESP replacement should be scheduled to minimize deferred production from a solids-induced ESP failure and to minimize surface solids management costs. The vibration signal data obtained from downhole sensors confirmed the reliability of the system. Overall, results demonstrate that the system designed is successful at increasing ESP run life without detriment to well production performance. The new, field-proven pump protection system along with its components and the completion design substantially increase life of ESP by reducing the number of shutdowns related to sand overload, reducing shutdowns, reducing overall vibrations, increasing the probability of successful start after shut-in, and increasing the performance reliability during fracturing of a neighboring well. Consequently, more wells that are looking to increase the ESP life can now benefit from this technology and increase output.

Friction Reduction Technology Tailored to Extreme Flow Rates

Non-thru bore drilling tools often feature limited flow range capabilities due to their design complexity. An ever-growing demand in high flow rates required a new technical solution that has the lowest possible pressure drop across the tool. Potential erosion issues as well as consistent functionality of the tool were key design requirements. A new friction reduction technology is presented that addresses the applications with flow rates ranging from low to high. Initial computational fluid dynamics (CFD) analysis suggested the flow split can be executed by restriction at the tail end of the power section. This, however, was challenged by the first test run that took place at 550gpm (5¼-in. tool outside diameter [OD]). While the run objectives were met in its entirety, upon tear down, the early signs of erosion were noticed on the valve assembly. With this evidence on hand, a critical design change was implemented, and as a result, the restriction was moved down the power section to spare the vortex at its tail end. Further improvement was retrofitted to protect the restriction itself with a simple addition of a sleeve. Further field runs were executed with the new tool setup. As the run count progressed, the newly redesigned technology achieved the objectives by delivering effective friction reduction at consistent frequency and pressure drop. It soon became evident that the step change in flow rate did not affect the tool wear and tear. Since its inception the tool has set two field records. The first commercial run marked the fastest curve in the county. As this technology rises to prominence in the US and international markets, more operators are experiencing the savings and lower Authorization For Expenditure (AFEs). The novelty of the design presented in this paper is in the drilling engineer's ability to design and construct wells with increased complexity (high dog leg severity [DLS], directional difficulty index [DDI], extended reach, and multi-lateral) where friction reduction technologies are critical to achieving run objectives. This technology fills a technical gap by meeting the new standards of high torque and flow rates in a compact and robust design. At the time of this writing, no other friction reduction technology meets these tool specifications.

Functional Analysis of a HPHT Subsea Tool Under Thermal Loads

The offshore oil and gas industry continues to develop new tools that are intended to be operated in increasingly harsh environments. Stricter requirements result in more complex assemblies that are composed of multiple closely fitting components. Fluid flows at high temperatures lead to transient and non-uniform temperature distributions in tools. This can affect tool functionality which needs to be assessed with the help of numerical techniques. The objective of this study is to evaluate the effect of thermal loads on the functionality of a valve assembly. A thermal finite element model of the assembly is developed to obtain temperature distribution everywhere in the model in transient and steady states. Temperature profiles are later mapped into structural models to obtain thermal strains at critical regions of the assembly. Thermal deformations are evaluated against internal acceptance criteria for operational functionality of the assembly.

A Vortex Jet Device Applied in the Development of Active Hydro-Pneumatic Dampers Used in Rehabilitation Equipment

The paper overviews and analyses the current status of the development and research of active hydro-pneumatic dampers, which are used in rehabilitation equipment, where vortex jet devices can be applied as control valves. The study focuses on a vortex jet device whose distinctive feature is the absence of mechanically moving parts, describes the principle of its operation, and gives the rationale for using it in the active hydro-pneumatic damper of the knee module prosthesis. From a review of scientific and technical literature, a conclusion is drawn that active hydro-pneumatic dampers are used not only in rehabilitation equipment but also in vehicle shock absorbers. The experience gained in the design and development of active hydro-pneumatic dampers for vehicle shock absorbers was applied in the design and development of an active hydro-pneumatic damper for the knee module. In order to identify the advantages and disadvantages, we examined some designs of active hydro-pneumatic dampers for vehicle shock absorbers. Analysis of technical solutions showed the advantage of vortex jet devices, e.g. high reliability, the ability to work with various working environments, low manufacturing and operating costs; enabled us to recommend a vortex jet device to be used as an actuator, i.e., a vortex valve, in the valve assembly of an active hydro-pneumatic damper. The use of a vortex jet device increases the reliability of the structure and reduces the energy consumption for the control of the structure. The proposed design of the hydro-pneumatic damper allows the use of interactive damping control. The study is the first to introduce the concept and describe the principle of operation of an active hydro-pneumatic damper using a vortex jet device

An analytical model of diesel injector’s needle valve eccentric motion

Past experimental studies have shown that the needle valve of high-pressure diesel injectors undergoes lateral movement and deformation, while the continuous increase in injection pressure enlarges the gap of the needle valve assembly. Two different analytical models, considering or omitting this change are presented here, linking the geometries of the needle valve assembly with the magnitude of needle valve tip lateral movement. It is found that the physical dimensions of the needle valve assembly and the injection pressure have a significant impact on the radial displacement of the needle. For example, for nominal clearances between the needle guidance and the needle valve of about 1–3 μm, the magnitude of the radial movement of the needle tip could reach tens of microns. The model that takes into account the variation of the gap between the needle guide and needle valve is found to give predictions closer to the experimental results.