Driving the networked Digital OR to perfection

NUCLeUS™ Technology Insight

In 2007, eSATURNUS was the first to offer a Digital Operating Room entirely running on top of the hospital’s IP network: NUCLeUS™ was born.

Since then, eSATURNUS has been working relentlessly to optimize and polish NUCLeUS™. Developers worked in close collaboration with everyone involved in modern hospitals’ workflows and supply chains: distributors, clinicians, OR technicians, IT departments, and hospital management.

Through these experiences, eSATURNUS gained a solid working base, resulting in several features that really matter. Below we highlight a small selection of them.

Unified video capture

OR installation engineers and purchase departments have to face it each time: at install time, the medical equipment to be connected to the digital OR, outputs a different video signal than was originally designed; the purchased digital ¬¬OR components do not fit. More-over, once in use, digital OR configurations and mobile towers are flexibly rearranged to new and shared medical equipment – often a hard puzzle for OR technicians.

NUCLeUS™ eliminates that worry now. All video standards and the whole jungle of custom video modes used by medical equipment: the new Transmitter HD accepts them, and preserves them at their original quality.

Unified form factor

All NUCLeUS™ transmitters and receivers share the same form factor. The compact and completely closed housing has been designed for optimal hygiene and easy cleaning, maintenance-free operation, industrial sturdiness and many mounting options. Compact stocking and easy transport comes as a welcome bonus for distributors and hospital logistics.

Double consolidation

Once connected to NUCLeUS™, the live image of every single piece of medical equipment has become available for real-time display and other media services over the hospital’s Gigabit data network (IP). Modern corporate data networks are often significantly more reliable than traditional video cabling networks. Nevertheless, some people or organizations still have more trust in traditional video cabling.

NUCLeUS™ now makes this discussion unnecessary: in addition to the network stream on the UTP cable, every NUCLeUS™ connected video signal is available over a single coax in HD/3G-SDI.

Both UTP cables and coaxial cables are excellent choices with regard to price, installation comfort and dependability. Their combination is even better.

Powered over Ethernet (PoE)

NUCLeUS™ transmitters and receivers are optionally powered over Ethernet by standards-compliant PoE network switches. This makes safe and cleaner structured cabling possible, and saves valuable

space and energy.

Moreover, your IT department will like the centralized remote control and monitoring possibilities offered by PoE.

Many mounting options

The unified and compact form factor of NUCLeUS™ modules allows a wide range of industrial-strength mounting options: invisible between a monitor and a boom, against a wall, on a table, in an endoscopic tower, in a server rack.

Rapid delivery and set-up

NUCLeUS™ keeps the lead as the most complete platform for digital OR available today: end-user applications, always-on media services, integration APIs, and installed infrastructure. Every part was co-designed with the greatest care to work without a glitch as one product.

Installation profiles have been increasingly standardized: delivery and installation of a NUCLeUS™ digital operating room can now be finished one day after purchase.

Quality and flexibility in video

NUCLeUS™ has been made to fit perfectly within common data networks as found in modern hospitals nowadays: one gigabit per second to the endpoints, and often higher bandwidths for the network backbone.

In this context eSATURNUS has started to offer visually lossless video compression with zero latency for the most-demanding video standards found in the OR today, without quality loss with respect to the established NUCLeUS™-native uncompressed streaming technology. As a result, even with the growing omnipresence of HD equipment in the OR, NUCLeUS™ keeps offering unsurpassed video quality on an affordable network infrastructure, while maintaining the flexibility of all the recording, broadcasting and other media services over the entire hospital.

Visual impact: what you see is what you get

NUCLeUS™ Technology Insight

In a hospital environment, precision is key. In particular, surgeons, working in a microscopy environment, need to get a natural visual feedback. Since procedures in the endoscopic field rely on video, image quality is a central topic in the debate over the use of video in the operating room. Moreover, the digital revolution in endoscopy changes the way surgeons work and communicate, offering great improvement in the service to patients and referring doctors. However, this pay-off requires a significant investment of time and thought on the part of the surgeon. This article deals with some of these issues.

Digitization of video

To create a digital image, a specific device converts the video signal into a digital form. The collected information, which needs to be converted, consist of color models and pixel resolution, both affecting the file size of the image. A few definitions:

• Colordepth: The number of discrete colors available to present an image.

• Pixeldensity: The number of pixels into which an image is divi-ded by the capturing device. The greater the number of pixels/unit area the higher the resolution of the image.

• Filesize: The final size of an uncompressed image is calculated simply by the formula width (in pixels) by height by color depth.

File size affects storage requirements, display delays and transfer times, and so becomes important in the everyday use of the images. An uncompressed high definition image (1920x1080 px) requires 1.4 gigabit/s. Storing one video frame would take 5,9MB, so 1GB takes 5,6 seconds per recorded video. Without compression, this would give an essential ballast to the hospital disk space and more importantly, one video stream would completely saturate a gigabit hospital network.

(1920x1080) x 3 1024x1024

5,9Mbyte

bit -> byte

30/s x 8 x (1920x1080) x 3 1024x1024x1024

1,4 Gb/s

Frames ps

RGBresolution

1 frame

Uncompressed video needs min. 1,4 Gb/s network

What detail is needed?

In some clinical situations resolution is not important, e.g. a large mass may be easily identified at low resolution. On the other hand, subtle findings such as the disruption of the vascular pattern may require a higher pixel ratio. To show the image on a computer screen, the resolution of the screen determines the optimal resolu-tion, but for printing e.g. for a journal manuscript, more pixels per inch are needed.

File compression

For practical purposes, uncompressed images are almost theoretical relics of the past. With the increasing utility of network-based and internet-based computer applications, the need for smaller files is indisputable. Moreover, because of the possibility to use efficient file

compressions, high data rates are no longer acceptable in a modern hospital environment.

File compression is a computational processing technique that effec-tively reduces the size of a file by removing redundancies in large binary data sets. Full motion video requires a minimal display rate of 30 frames/s. As demonstrated earlier, with uncompressed sources, disk storage would be rapidly exceeded and image transmission even on high-speed networks would be slow. Compression is measured as a ratio of the size of the original data divided by the compressed data.

There are two general categories of compression techniques: lossless and lossy:

• Lossycompression implies that some information is lost in the compression/decompression process, but algorithms can be designed to minimize the effect of data loss on the diagnostic features of the images. In order to achieve practical archival storage and transmission of medical images, lossy compression techniques are commonly employed.

• Losslesscompression techniques preserve all the information in the compression/decompression process. When images are used as a means of primary diagnosis, they require lossless compression, storage and transmission. However, in most cases, this technique also results in dedicated high-speed network requirements and high-end hardware infrastructure.

RtoR™ visually lossless compression

NUCLeUS™ video encoding and decoding is based on RtoR™ visually lossless compression. Technically, the original resolution of 1920x1080 pixels, the frame rate and the color space remain the same in the beginning and the end of the chain. Visual artifacts are being eliminated without having any form of delay on a standard IP network, due to the patented RtoR™ technology. In short, the user will not notice the difference between a visually lossless compres-sion and an uncompressed image.

Also, depending on the surgeons’ preference, photographic standards can be either lossless or lossy implemented. The patented RtoR™ image compression provides many advantages over other uncompressed, lossless or lossy image streams.

Perfect image quality with lots of flexibility

Via NUCLeUS™, the users get a unique feature. The software is designed keeping in mind that everybody needs high quality images for presentations. On the other hand, surgeons need to shoot entire interventions for documentation. Often, this is an unmanageable compromise.

In NUCLeUS™, a surgeon does not have to choose between high or low quality. He can record multiple sources in different qualities at the same time. This also postpones the real-time quality choice, which can be a stressful and additional decision during surgeries.

A choice of quality

In conclusion, NUCLeUS™ provides a surgeon real-time imaging without any compromise in quality. The recording of images can be initiated without any preparatory steps from the surgeon. He can follow his intuition to record the images in any quality he prefers. This makes NUCLeUS™ the ultimate platform in- and outside the operating suite.

Real to Real (RtoR™) patented technology

NUCLeUS™ Technology Insight

All surgical procedures require an extremely accurate and efficient eye-hand coordination. Many of these procedures and those invol-ving endoscopy in particular, rely on video systems to provide visual feedback to the clinician.

Understanding video latency

Each video system consists of at least a camera, a display and appro-priate cabling between the two devices. There is a tiny lag between the occurrence of a movement in the visual scene and the time when that same movement can actually be displayed on the screen. This time lag is called latency.

The delay is primarily caused by the image processing hardware in the camera and in the display.

Latency in the operating room

Think of how much more snappy, light, accurate and controlled a sports car can feel. Compare this with family cars made for the mass market. Most of this feeling is realized by keeping the time between the steering action and the consequent movement of the vehicle low at all times.

In very much the same way, clinicians in the operating room are very dependent on a highly responsive visual feedback for the accuracy and efficiency of their actions and decisions. Psycho-visual studies point out that a latency of 100 milliseconds is the perceptual limit: below that, it is not felt by humans. Above that point, some people will start noticing. A delay of 150 milliseconds is perceived by everyone.

Latency of video cabling

In its most basic form, traditional video cabling adds almost no latency to the unavoidable intrinsic system latency of 40 to 60 milli-seconds. However, in practice, due to the demand for more flexible video routing and switching in the operating room, the initial setup grows. Over time, the video system explodes into a hybrid clutter of video switches, video signal converters and other related equipment. These intermediary boxes can easily each add up to 60 milliseconds of latency to the video systems chain. And from there to a point where it will be noticed by clinical end-users.

Latency of video over IP

Video for home or office applications is often routed over IP networks. Their video compression techniques generate conside-rable latencies that range from 60 milliseconds to even 150 millise-conds.

Not with the video over IP solution of NUCLeUS™. The patented RtoR™ technique effectively adds no latency to the end-to-end visualisation chain and keeps electrical latency around 5

milliseconds.

NUCLeUS™ incorporates proprietary and patented RtoR™, based on a simultaneous encoding and decoding of video slices. The monitor will display them with no supplementary latency.

This eliminates the ever-growing need for auxiliary video routing and processing equipment. Therefore it also eliminates the risk, proper to traditional cabling, that extending the video system increases latency in an uncontrolled way.

RtoR™ ensures the snappy feeling from basic traditional video cabling, while still preserving the easiness of use of video over IP. On average, there is an electrical data delay of 5 milliseconds. RtoR™ adds no delay to this. So NUCLeUS™ can match comparison with any cabled system but it beats both Video over IP and cable networks when multiple operating rooms need to be integrated. Therefore NUCLeUS™ is a fast and future proof piece of equipment for you as a medical professional.

VIDE

O O

VER

IPTM

Camera Image

Monitor Image

Monitor Image

Camera Image

Encoding and decoding of the enti re image

RtoR™ encoding

RtoR™ decoding

Guaranteed safety in a secure environment

NUCLeUS™ Technology Insight

High quality images and real-time video have become indispensable in the modern operating theatre. Images from the operating room are available throughout the hospital in a superb quality and without any latency. Obviously, all this would lose its value if uptime of the system could not be guaranteed at all times. NUCLeUS™ assures physicians of a constant availability of their video sources by taking intelligent and preventive measures.

NUCLeUS™ preventive maintenance

A NUCLeUS™ integration is always done in close cooperation with the hospital. It is of vital importance that all individual IT-pieces are tuned to each other. eSATURNUS will always analyze the existing IT-infrastructure, suggest where to improve and validate the result prior to installation. These steps are compulsory in order to fulfill the essential quality requirements and guarantee a smooth installation.

After installation, the eSATURNUS support team remotely monitors the health of the installation. Any performance deterioration is dealt with before it becomes noticeable by the end-user. Preventive maintenance and monitoring keep NUCLeUS™ uptime to a maxi-mum.

Server redundancy

NUCLeUS™ allows all servers to be placed in the hospital’s data center. The mere fact that they are located in an air-conditioned and dust-free environment will already boost their availability.

NUCLeUS™ servers can be classified in two categories: those executing management and supervisory tasks and those providing mere compute power.

• Servervirtualization:Obviously, machines running supervisory tasks may never fail. Supervisory machines are for this reason virtualized. Virtualization platforms are capable of guaranteeing extreme levels of availability. Hardware for the host system can be implemented redundantly, as are the hard-disks and data stores, network interfaces etc. Moreover, redundant hardware can be placed in different data-rooms to safeguard against fire or power outage. Virtual machines migrate automatically to a redundant server in case of hardware failure.

• Hotfailovers:A second class of servers in a NUCLeUS™ installation only provides compute power to the system. These machines are implemented as a pool of low-cost physical servers. If one server in the pool fails, another one will immediately take over. Smart dimensioning the pool with only one server guarantees 100% percent availability.

Network redundancy

The NUCLeUS™ digital operating room concept is based on the correct functioning of the hospital network. It uses the underlying, redundant network architecture and assumes sufficient bandwidth between the OR and the datacenter.

Obviously, a transparent communication between the hospital and the integrator, is the foundation of a smooth installation, since the NUCLeUS™ image streams are transported over channels that are extrinsic of NUCLeUS™. Therefore certain agreements need to be

concluded. All of this is described in an accurate installation guide. By following this manual, NUCLeUS™ can be implemented to fit the costumer needs.

Graceful degradation

In the rare case of network or server failure, NUCLeUS™ degrades gracefully from a digital operating room to a traditional (regular) operating room.

The primary cable provides a direct video-link between the equip-ment that does not have its own visualization means and one or more surgical monitors. The sources that are directly wired are typically endoscopic cameras.

Whenever a primary wired video source is visualized, NUCLeUS™ instructs the surgical monitor to switch its input to the primary cable. From now on, network or server problems may compromise digital OR functionality (recording, videoconferencing etc.) but the basic functioning of the operating room is never jeopardized.

As an additional safety measure, NUCLeUS™ will also instruct every surgical monitor to switch its input to the primary cable upon the detection of network or server malfunction.

As a last resort, the surgical monitors can always be switched manually to the primary wire.

A safe choice

The NUCLeUS™ concept is more fault-tolerant than any other solution and inherently safe. Compared to classic AV systems, it uses significantly less cabling and scales much better. Compared to other video-over-IP providers, it is safer because of the intelligent use of server and network power. On top of that, the primary wiring guarantees visualization of predefined sources, so an ongoing opera-tion will never be stopped. NUCLeUS™ provides the best of both the AV and Video-over-IP worlds.

* All NUCLeUS™ installations proceed following the requirements described in the network and server dimensioning guide. Don’t forget to ask for them.