GigE Vision is a natural choice for video transmission in a wide range of medical imaging modalities. The standard allow medical imaging system designers to fully support required point-to-point connections, while gaining the flexibility of video networking, the ability to interwork with a range of computing platforms, and the benefits of lightweight, low-cost cabling or wireless connectivity. In addition, as the standard has gained widespread adoption, a broad selection of off-the-shelf, GigE Visioncompliant products from global vendors helps address interoperability concerns.

GigE Vision in the Networked Operating Room

The wide range of commercially available GigE Vision-compliant video and networking products, including external frame grabbers and embedded hardware, make it relatively straightforward for designers to create a real-time networked operating room without sacrificing investments in existing equipment.

In the example shown in Figure 1, images from an digital X-ray detector in a C-arm are sent over an existing Camera Link or LVDS interface to an external frame grabber, where the images are converted to a GigE Vision-compliant video stream. Alternatively, embedded video interface hardware allows designers to directly integrate GigE Vision-compliant video connectivity into flat panel detectors (FPDs) that can fit into existing systems as replacement for film-based panels.

A second external frame grabber converts images from a camera mounted in the lamp head into the same compliant GigE format. These image feeds are aggregated at an off-the-shelf Ethernet switch and multicast to processing, analysis, display, and recording equipment. Per-frame metadata, such as a precise time-stamp of image acquisition and sensor settings, is transmitted with the images over the Ethernet link for easy integration with DICOM-compliant software and hardware.

The long reach of Ethernet, 100 meters point-to-point over ordinary Cat 5/6 cabling, means processing and analysis equipment can be located outside the sterile environment. This reduces the costs of sterilizing equipment, lowers the risks of patient infection, and allows data to be easily shared across multiple departments. The more flexible cabling also enables a wider degree of movement for robotic applications. With GigE Vision delivered over an 802.11 wireless link, portable X-ray panels can be better positioned to help reduce complexity in the operating room.

At the computer, the video streams in through the Ethernet port, allowing the use of lower cost computing platforms. The video processor highlights areas of interest, including pre-op images, and overlays vital signs information. The composite image is then multicast over the Ethernet network to various displays. In the operating room, an external frame grabber converts the GigE Vision image stream to HDMI/DVI signals for viewing on a high-definition dashboard monitor used by the surgeon to track real-time patient data from different imaging devices and systems.

Expanding the Operating Theatre

One of the key advantages of GigE-based distributed network architectures is the ability to locate intelligent nodes at locations where data collection and control occurs and create video distribution groups with a single server multicasting data to several clients.

Integrating previously isolated image sources and patient data onto a common network and aggregating the information on a single dashboard can increase the situational awareness of operating room staff. In the operating room, for example, the single screen dashboard displays real-time patient data from different imaging devices and systems. The surgeon or operating team members can easily switch between imaging sources, such as white light and fluoroscopic cameras and pre-operative and real-time images, without configuring hardware or software. The image destination can also be easily changed, with real-time video from the operating theatre transmitted to OR scheduling staff, a conference room, multiple departments, or shared with remote specialists.

At the transport layer, the imaging device sends only one copy of the data to a network switch. The Ethernet switch replicates the data for distribution to display panels and processing platforms as required. This ensures video distribution doesn’t impact server performance. Leveraging Ethernet’s inherent multicast capabilities, display and processing functions can be distributed from a single device to multiple devices to help ensure reliability. This also helps GigE Vision cameras to multicast high-quality, uncompressed video to multiple displays and processing nodes simultaneously with the lowest possible latency.

Interfaces based on GigE Vision also speed the design and boost the performance of advanced applications. In full-motion video applications, for example fluoroscopy that uses multiple moving X-ray sources to obtain real-time images of a patient, legacy umbilical interfaces are uneconomical and cumbersome. With 10 GigE interfaces, which support ten times the bandwidth of GigE, multiple image sources can be transmitted simultaneously over a switched Ethernet network to a processor for 3D image generation.

Medical Design Briefs Magazine

This article first appeared in the July, 2014 issue of Medical Design Briefs Magazine.

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