General Electric (France)

International audience

Extreme weather events, which are characterized by high impact and low probability, can disrupt power system components and lead to severe power outages. The increasing adoption of renewable energy resources in the power sector, as part of decarbonization efforts, introduces further system operation challenges because of their fluctuating nature, potentially worsening the impact of these extreme weather events. To address the challenges from these high-impact and low-probability events, the concept of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">resilience</i> has been introduced into the power industry. Considering the potential serious disruptions, the primary goal of resilient power system operation during extreme events is to ensure the continuous supply of critical loads, such as hospitals, police stations, data centers, traffic lights, etc., across various power sectors, which constitutes a system-wide load restoration problem.

Normandy Hadrontherapy (NHa) is developing, in collaboration with Ion Beam Applications (IBA), a full hadrontherapy treatment solution based on a new multiparticle cyclotron. 12C6+ and 4He2+ ions will be accelerated up to 400 MeV/u and (H2)+ up to 260 MeV/u. Three different ion sources will be carried out for each accelerated particle: the mono-charged ion source (H2)+ and low charged ion source He2+ are provided by the Polygon Physics (PP) company. The carbon ion source is under development at NHa in collaboration with IBA and PP. The (H2)+ ion source is an industrial Tubular ECR Source (TES) fitted for the needs of the NHa C400 cyclotron (30 µA of (H2)+). The He2+ ion source is a classic 10 GHz ECR type with a new concept because the complete source is set inside a vacuum chamber and it runs under 10−6 mbar of gas residual pressure. The 12C6+ ion source is also an ECR type ion source operating at 14.5 GHz frequency, its design is under progress to produce a beam providing stability and reproducibility levels compatible with clinical use. The article will present the External Injection System of the NHa C400 cyclotron hence it will focus on the experimental results obtained with the (H2)+ ion source and preliminary outputs from the He2+ ECRIS. A presentation of the multicharged ECRIS design dedicated to the 12C6+ production will be done.

Thanks to their flexibility, modular multilevel converter, also known as MMC, are in the spotlights to help modernize railway infrastructures. To comply with power quality issues in presence of high harmonics components and high-power changes, it's mandatory to provide resilient converters. This article introduces an architecture solution based on MMC converters to provide a 25 kV-50 Hz power supply complying with industry standards. Dynamic performances are analyzed using different kind of load and the back-to-back configuration is validated using averaged sub-modules to ease computation issues.

This paper presents a preliminary study of a 25 kV–50 Hz railway substation power supply system. The control of a back-to-back converter based on modular multilevel converter (MMC) technology was investigated to fit with the power quality requirements of the application. One of the main challenges is the presence of constraining load conditions, under which the train circulation variability, low-frequency harmonics and critical power transients can notably decrease the power quality and lead to instability. In order to address this, cascaded controllers based on resonant controllers are proposed to ensure the desired performance. Furthermore, balancing voltage algorithms are added to avoid stress phenomena and additional losses in the studied power conversion interface. The paper presents the design of the control stages and demonstrates the robust performance of the system using a realistic loading condition of a railway substation.

Endovascular management of spinal dural arteriovenous fistula (DAVF) is arduous because of complex angioarchitecture and motion artifacts and is limited by the two-dimensional (2D) view. However, cone beam computed tomography (CBCT) acquisitions with selective injections allow 3D multiplanar reconstructions contributing to high diagnostic, anatomical and safety value. In this study, we described the use of virtual injection software (VIS) computed from CBCT acquisition and already used for prostatic and cerebral embolization, for the endovascular management of spinal DAVFs (EmboAssist, GE HealthCare, Chicago, USA). The VIS has been designed to facilitate the analysis of the patient's vasculature during the planning of embolization procedures to define the afferent pedicles to the shunt and the incidence of oblique projection, allowing for a better anatomical understanding and helping for the selection of 2D incidence. Combined with 3D roadmapping, VIS allows vessel tracking for selective catheterism and embolization. The VIS is a useful tool for planification and navigation during endovascular treatment of spinal DAVF with a safety value.

This paper proposes a robust longitudinal registration method for Contrast Enhanced Spectral Mammography in monitoring neoadjuvant chemotherapy. Because breast texture intensity changes with the treatment, a non-rigid registration procedure with local intensity compensations is developed. The approach allows registering the low energy images of the exams acquired before and after the chemotherapy. The measured motion is then applied to the corresponding recombined images. The difference of registered images, called residual, makes vanishing the breast texture that did not changed between the two exams. Consequently, this registered residual allows identifying local density and iodine changes, especially in the lesion area. The method is validated with a synthetic NAC case where ground truths are available. Then the procedure is applied to 51 patients with 208 CESM image pairs acquired before and after the chemotherapy treatment. The proposed registration converged in all 208 cases. The intensity-compensated registration approach is evaluated with different mathematical metrics and through the repositioning of clinical landmarks (RMSE: 5.9 mm) and outperforms state-of-the-art registration techniques.

Modern fluoroscopes used for image guidance have become quite complex. Adding to this complexity are the many regulatory and accreditation requirements that must be fulfilled during acceptance testing of a new unit. Further, some of these acceptance tests have pass/fail criteria, whereas others do not, making acceptance testing a subjective and time-consuming task. The AAPM Task Group 272 Report spells out the details of tests that are required and gives visibility to some of the tests that while not yet required are recommended as good practice. The organization of the report begins with the most complicated fluoroscopes used in interventional radiology or cardiology and continues with general fluoroscopy and mobile C-arms. Finally, the appendices of the report provide useful information, an example report form and topics that needed their own section due to the level of detail.

Objective. This paper proposes a 4D dynamic tomography framework that allows a moving sample to be imaged in a tomograph as well as the associated space-time kinematics to be measured with nothing more than a single conventional x-ray scan. Approach. The method exploits the consistency of the projection/reconstruction operations through a multi-scale procedure. The procedure is composed of two main parts solved alternatively: a motion-compensated reconstruction algorithm and a projection-based measurement procedure that estimates the displacement field directly on each projection. Main results. The method is applied to two studies: a numerical simulation of breathing from chest computed tomography (4D-CT) and a clinical cone-beam CT of a breathing patient acquired for image guidance of radiotherapy. The reconstructed volume, initially blurred by the motion, is cleaned from motion artifacts. Significance. Applying the proposed approach results in an improved reconstruction quality showing sharper edges and finer details.

US and MRI are two validated techniques in fetal brain expertise. Fusion imaging (FI) allows to obtain an image combining the advantages of both methods and provide an image with more clinical information. The objective is to evaluate the clinical use of the off-line US-MRI FI in the fetal brain development. It was a prospective study in Necker Hospital (NCT04142606) conducted from January to June 2021. We included normal singleton pregnancies between 20 and 36 WG. Each patient underwent an ultrasound scan with volume acquisitions in the 3 planes, followed by a fetal brain T2w MRI (1.5 T) the same day. The US and MRI images were merged using 4 precise landmarks with the 4D view fusion software (GE Healthcare) We have developed a standardised method based on 29 anatomical structures to perform a complete neurosonogram by an expert. A total of 85 patients were included (8 patients per 2 WG). We obtained 31 US and MRI volumes allowing the FI. The FI results in more predefined anatomical landmarks in the neurosonogram than each modality separately. Indeed, for advanced gestational terms the shadowing of the fetal skull, fetal position and attenuation complicate the interpretation of cerebral brain development such as basal ganglia, trigone, Sylvius Acqueduc or cerebellar foliation; whereas on the same slice, MRI gave access to the full brain gyration, brain stem or peri-cerebellar spaces Moreover, Doppler US can provide information on vascularisation in the MR image. This is a promising off-line US-MRI FI tool allowing to navigate within two merged volumes acquired the same day. The interest could be major for educational purpose, brain development follow-up and in case of fetal pathologies at high risk of brain damages such as CMV or TTTS. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.