Siemens (Norway)

Introduction The use of laparoscopic and robotic liver surgery is increasing. However, it presents challenges such as limited field of view and organ deformations. Surgeons rely on laparoscopic ultrasound (LUS) for guidance, but mentally correlating ultrasound images with pre-operative volumes can be difficult. In this direction, surgical navigation systems are being developed to assist with intra-operative understanding. One approach is performing intra-operative ultrasound 3D reconstructions. The accuracy of these reconstructions depends on tracking the LUS probe. Material and methods This study evaluates the accuracy of LUS probe tracking and ultrasound 3D reconstruction using a hybrid tracking approach. The LUS probe is tracked from laparoscope images, while an optical tracker tracks the laparoscope. The accuracy of hybrid tracking is compared to full optical tracking using a dual-modality tool. Ultrasound 3D reconstruction accuracy is assessed on an abdominal phantom with CT transformed into the optical tracker’s coordinate system. Results Hybrid tracking achieves a tracking error < 2 mm within 10 cm between the laparoscope and the LUS probe. The ultrasound reconstruction accuracy is approximately 2 mm. Conclusion Hybrid tracking shows promising results that can meet the required navigation accuracy for laparoscopic liver surgery.

Thermal runaway presents a significant safety risk for any facility or vessel that utilizes battery energy storage. Ensuring that cell temperature remains within a safe and optimal range is crucial to preventing thermal runaway and maximizing the lifespan of battery packs. Liquid cooling systems have been used extensively with success for many years and have proved to be an effective method for maintaining a uniform temperature profile across battery systems. Additionally, with a higher heat capacity relative to ambient air, liquid coolant acts as a thermal obstacle that prevents the spreading of internal faults irrespective of whether it is circulating. Some recent incidents have raised concerns about the potential for thermal runaway in battery packs with liquid coolant systems due to inefficient thermal barriers. This paper discusses how Siemens Energy has addressed this risk through design features that enable effective cooling across the entire cell surface area. Other design considerations for short-circuit and arc prevention are also discussed, along with measures to prevent hazardous gases from entering sensitive zones in the event of an internal fault and/or combustion event.

The voltage droop control concept is the most appropriate strategy to provide primary control in multiterminal VSC-HVDC (MTDC) transmission systems. However, due to voltage drops in the dc lines/cables, the primary power balancing is influenced by the dc grid topology and line resistances. This phenomenon is also evident when determining the secondary control strategy in MTDC systems. In this paper, secondary control in MTDC is derived by analogy to the traditional secondary control in an ac grid system. In doing so, the influences of dc line voltage drops are systematically included in the control strategy to restore power flow to pre-disturbance levels at selected dc terminals. The effectiveness of the strategy is demonstrated with the help of a five terminal VSC-HVDC model in the EMTDC/PSCAD simulation tool.

A solution to the lack of interoperability between the U.S. Department of Defense (DoD) data communications standards and the NATO standards based on the International Organization for Standardization concept for open systems interconnection is presented. The solution is based on conversion between a common subset of the US DoD Transmission Control Protocol and the ISO Class 4 Transport Protocol at the Transport layer, which is the first layer offering any end-to-end service.