Safety Control Architecture for Ventricular Assist Devices

In patients with severe heart disease, the implantation of a ventricular assist device (VAD) may be necessary, especially in patients with an indication for heart transplantation. For this, the Institute Dante Pazzanese of Cardiology (IDPC) has developed an implantable centrifugal blood pump that will be able to help a diseased human heart to maintain physiological blood flow and pressure. This device will be used as a totally or partially implantable VAD. Therefore, performance assurance and correct specification of the VAD are important factors in achieving a safe interaction between the device and the patient’s behavior or condition. Even with reliable devices, some failures may occur if the pumping control does not keep up with changes in the patient’s behavior or condition. If the VAD control system has no fault tolerance and no system dynamic adaptation that occurs according to changes in the patient’s cardiovascular system, a number of limitations can be observed in the results and effectiveness of these devices, especially in patients with acute comorbidities. This work proposes the application of a mechatronic approach to this class of devices based on advanced control, instrumentation, and automation techniques to define a method to develop a hierarchical supervisory control system capable of dynamically, automatically, and safely VAD control. For this methodology, concepts based on Bayesian networks (BN) were used to diagnose the patient’s cardiovascular system conditions, Petri nets (PN) to generate the VAD control algorithm, and safety instrumented systems to ensure the safety of the VAD system.

Management of a Dual-Bus AC+DC Microgrid Based on a Wind Turbine with Double Stator Induction Generator

The topology and management of a sustainable dual-bus, AC and DC, microgrid designed to operate connected to a weak grid is presented. AC+DC hybrid microgrids are a robust and cost-competitive solution for poorly connected areas, as can be found in rural or island electrification. The versatile microgrid proposed in this work is developed around a wind turbine based on a particular induction generator with double stator winding and squirrel cage rotor (DWIG). This singular generator is especially suitable for a combined AC+DC coupled microgrid application. One of its stator windings is coupled to the DC bus via a controlled AC/DC converter. The other is directly connected to the AC bus, only during the periods of abundant wind resource. The DWIG is complemented with photovoltaic panels and a hybrid energy storage system, comprising flow batteries assisted by supercapacitors, which converge to the DC Bus. The DC bus exchanges power with the AC bus through an interlinking inverter. The article describes the topology and details the operation of its Supervisory Control system, which gives rise to the five operating modes of the proposed AC+DC DWIG based microgrid. Its performance under different generation conditions and load regimes is thoroughly assessed by simulation.

Design of Cloud Computing and Microservice-Based Urban Rail Transit Integrated Supervisory Control System Plus

In traditional metro weak current systems, subsystems built by different manufacturers are physically separated, and devices are redundant while data are isolated. This causes low resource use, high maintenance cost, long customization cycles, and high interface complexity. In this paper, based on an analysis of the problems in traditional metro weak current systems, a novel cloud and microservice-based urban rail transit integrated supervisory control system (ISCS) named ISCS Plus is proposed. The integration mode of each subsystem is determined by analyzing safety requirements, real-time performance, and business characteristics. An infrastructure platform is designed to share resources and isolate applications based on cloud computing technology, while traditional subsystems are decomposed as microservices and merged into different applications. Finally, the entire architecture of ISCS Plus is established and its features are discussed. ISCS Plus plays a key role in the systematic, intelligent, and automatic solution for metro weak current systems and supports the development of the world's leading metro weak current systems.