Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study

BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P < 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P < 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223

Hybrid Model Based Control of a Mechatronics Line Served by Mobile Robot with Manipulator

International audienceThis paper presents the model and control structure of an assembly/disassembly mechatronics line (A/DML) served by a wheeled mobile robot (WMR) equipped with robotic manipulator (RM). The model is a hybrid type, where A/DML is the discrete part and WMR with RM is the continuous part. Moreover, the model operates as a synchronized with signals from sensors. Thus, using Petri Nets (PN) in modeling, get a Synchronized Hybrid Petri Nets (SHPN). The disassembly process starts after the assembly process and final piece fails the quality test, in order to recover the components. The WMR equipped with RM is used only in disassembling process, in order to transport the components from the disassembling locations to the storage locations. Thus, the A/DML becomes reversible. Using a LabView platform and SHPN model, a real-time control structure is implemented

Hybrid Model Based Control of a Mechatronics Line Served by Mobile Robot with Manipulator

International audienceThis paper presents the model and control structure of an assembly/disassembly mechatronics line (A/DML) served by a wheeled mobile robot (WMR) equipped with robotic manipulator (RM). The model is a hybrid type, where A/DML is the discrete part and WMR with RM is the continuous part. Moreover, the model operates as a synchronized with signals from sensors. Thus, using Petri Nets (PN) in modeling, get a Synchronized Hybrid Petri Nets (SHPN). The disassembly process starts after the assembly process and final piece fails the quality test, in order to recover the components. The WMR equipped with RM is used only in disassembling process, in order to transport the components from the disassembling locations to the storage locations. Thus, the A/DML becomes reversible. Using a LabView platform and SHPN model, a real-time control structure is implemented

A Theoretical Approach of the Generalized Hybrid Model Based Control of Repetitive Processes

International audienceA generalized Synchronized Hybrid Petri Nets (SHPN) model based control of a hybrid repetitive processes is presented in this paper. The whole process has two components: one discrete and one continuous. Its evolution can be described by a set of repetitive tasks. The generalized SHPN model is associated to this hybrid system with N repetitive tasks. The generalized SHPN model is customized to an assembly/disassembly mechatronics line (A/DML), served by a wheeled mobile robot (WMR) equipped with robotic manipulator (RM). The behavior as a hybrid system appears during disassembly, when WMR with RM is used to transport the work parts from the disassembly locations to the storage location in order to be reused in assembly. The assembly can be modeled as discrete system events (DES). This hybrid system takes into consideration the distribution of the necessary tasks to perform the hybrid disassembly of the work parts, by synchronization between WMR equipped with RM and A/DML. An optimization approach of the cycle time, associated to the control of repetitive processes is also presented

Task Planning Algorithm in Hybrid Assembly/Disassembly Process

6 pagesInternational audienceA model of a mechatronic assembly/disassembly line served by a robotic manipulator mounted on mobile platform, in order to perform disassembly, is proposed in this paper. The model is a hybrid one in which the mechatroninc line is the discrete system and the wheeled mobile robot (WMR) together with the robotic manipulator (RM) is considered the continuous system. The mobile platform is used only in disassembling operations in order to transport the components from the disassembling locations to the storage locations. The cycle performed by the WMR equipped with RM is the continuous part of the hybrid system. Therefore, a Hybrid Petri Net (HPN) is used in modeling and control. This hybrid system takes into consideration the distribution of the necessary tasks to perform the hybrid disassembly of a component, using robot synchronization with flexible line process. The ultimate goal is to make completely reversible the assembly line, that is to execute full disassembly

Discrete-time sliding-mode control of four driving-steering wheels autonomous vehicle

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Laser-based Obstacle Avoidance Algorithm for Four Driving/Steering Wheels Autonomous Vehicle

International audienceIn this paper an algorithm for trajectory-tracking with obstacle avoidance for autonomous vehicles is presented. The algorithm tracks a trajectory composed of an intended global trajectory that was previously generated and local obstacle avoidance trajectories that are created when an obstacle is detected by the laser. A discrete-time sliding-mode controller is used by the autonomous vehicle to follow the global trajectory and the local obstacle avoidance trajectories. Quintic equations are used to generate the paths used by the vehicle to avoid the obstacles. The velocity, acceleration, angular velocity and angular acceleration profiles are calculated for the generated paths and fed to the sliding-mode controller

Event-Based PID Control of a Flexible Manufacturing Process

In most cases, the system control is made in a sampled manner, measuring the controlled value at a predefined frequency given by the sampling time. However, not all processes provide relevant information at regular intervals, especially in manufacturing. To reduce the costs and complexity of systems, event-based measuring is necessary. To control this kind of process, an event-based controller is needed. This poses some challenges, especially between the event-triggered measurement, as the process runs in an open loop. In the literature, most event-based controllers are based on the comparison of the error value with a predefined value and activate the controller if this value is crossed. However, in this type of controller, the measured value is measured at a predefine interval and is not suited for most event-based processes. In manufacturing systems, the most usual event-based process is represented by the conveyor transportation system. In this process, the product position is measured only in key locations on the conveyor. For the optimal operation of a flexible manufacturing system, the presence of a product in a key location at predetermined intervals is necessary. For this purpose, this article presents an event-based PID controller implemented on a conveyor transportation system