The Digital Divide:
Clearing the fog on high-tech camera and video system purchases
by Rick Dana Barlow

Karl Storz

Imagine investing considerable hours in evaluation meetings and then spending tens of thousands of dollars for a high-tech digital camera and video system only to have the surgeon disparagingly remark that the pictures he or she sees don’t look any different than they did with the older equipment.

Frustrating? You bet. Uncommon? Nope. And while you may be quick to blame the tense situation on a defective product or a swarthy vendor sales representative it typically has nothing to do with either. Instead, you most likely have to attribute it to an evaluation process that didn’t go far enough in exploring the details that delineate "a decision from an informed decision" as Marc Shapiro, director of software and integration systems at Olympus America Inc. (Melville, NY) classified it.

Karl Storz Image I

"It’s not a one-size-fits-all situation," Shapiro said, "which is why our company tries to deliver customized solutions based on a facility’s needs. You have to define your requirements up front. If a surgeon says that we spent all this money on a new system but he doesn’t like the image what have you really accomplished? Image is everything. If you have a lousy image from the video scope or the camera you’ll have a lousy image on the monitor."

Simply put, you have to filter out the marketing hype, closely scrutinize label claims and pay particular attention to the fine print, recognize and understand how the new digital devices will work with your existing equipment, and above all else know what you want the camera and video system to do and why you want that outcome.

"In most cases it seems to be that a majority of people purchasing digital cameras and video systems are not fully aware of the overall cost associated with integrating a ‘truly’ digital system," said Chris Irwin, video integration specialist at Skytron Corp. (Grand Rapids, MI). "There are a lot of variables to consider, such as the intended application, equipment selection, future capabilities and expansion. If one were to plan on integrating a completely digital system they should plan on investing the dollars to do it correctly. Otherwise it is money wasted."

ConMed Linvatec digital camera system

It’s extremely easy to be seduced by the glamour and glitz of anything called digital. In the broadcast, consumer and now healthcare markets, digital is one of the hottest buzzwords driving buying patterns, but it’s the clinicians and medical facilities that seem to be getting burned more frequently.

"The biggest reason why customers want digital equipment is because they perceive digital as state-of-the-art," said Tom Deppmeier, director of marketing for ConMed Linvatec Imaging (Santa Barbara, CA). "When they think digital they think it must be better and that may or may not be true."

ConMed Linvatec digital camera system

Certainly, digital cameras and video equipment offer significant benefits over traditional and less expensive analog equipment, in terms of image quality, such as color and resolution; faster image development and processing, including recording, editing and archiving; integration simplicity with operating room devices and equipment; and a more efficient exchange of data over fewer lines and longer distances with potentially less electronic interference.

"Digital cameras offer a very high fidelity transmission, and the output signals are not affected by noise in the signal as is a common drawback to analog cameras," Irwin said. "One of the biggest advantages offered by digital cameras is they are not susceptible to generation loss like analog camera signals. In other words, if you were to copy an analog signal to a VHS tape and use the copy to create yet another copy you would find the quality of the last-recorded copy to be very poor. And depending on the ‘noise’ or interference in the original signal the recording may not be viewable at all. With digital camera signals you can make copy after copy and each will look as good as the original. Digital cameras can be connected directly to personal computers for image transfer, and most offer software that allows the images from the camera to be manipulated or altered with ease."

Smith & Nephew  360-370

Chain reaction
Hospitals and outpatient care facilities use digital technology to feed their marketing machine in competitive environments to recruit and retain staff and surgeons, as well as attract patients and increase procedural volume. "No one wants to look like they’re behind tech-wise," Deppmeier said. "They want to appear on the cutting edge."

Digital imaging technology has progressed to the point that a surgeon could send high-resolution color stills and video to a laptop computer for analysis without altering the original signal. And those digital signals can be compressed so that they require less space for archiving and storage. On paper it sounds so promising; in practice it’s a bit more complicated.

Why? Healthcare facilities neglect to look at the big picture.

"Whether a camera is digital or analog it’s still only one element in the entire optical chain, and that imaging chain is only as strong as its weakest link," said Matt Fahy, director of marketing for surgical products, Olympus America. "Why overpay for a product without thinking about other elements in the chain that may not support the level of resolution, color and brightness it can deliver?"

As a case in point, Fahy refers to laparoscopes used in minimally invasive surgery that incorporate rod-lens optics designed more than 40 years ago. Fahy likens it to looking through paned glass. "Glass-to-glass interfaces progressively offer a level of diffraction and impurity," he said. "The more panes you have the higher the diffraction and the lower the clarity. Why spend money on a high-end digital camera only to hook it up to an inferior laparoscope? That may be your weakest link. If you have a high-end camera distributing an image that’s inferior to start with then you can’t make that image better. So why not upgrade your scopes first?"

STERIS camera

Stephen Bradley, video imaging specialist at Karl Storz Endoscopy-America (Culver City, CA), agreed. "Hospitals sometimes fail to see all the components that make up an image on the screen," he said. "The camera is a big part of the picture, but more importantly, the endoscope is the key component of a good image. Endoscopes that are older, damaged or repaired by a third-party repair group are the largest cause of poor picture quality."

Said Sam Gordon, director of engineering and operations at ConMed Integrated Systems (Portland, OR): "If I have the world’s highest resolution camera and try to focus it through frosted glass all that resolution isn’t going to do me any good."

Besides the age of the scope another challenge to digital camera performance is the size of the scope, which represents a functional collision between optics and electronics. "In surgery the trend is for surgeons to use smaller scopes; in imaging and electronics, the trend is to go with higher resolution," Deppmeier said. "The problem is that smaller scopes work with less light."

With less light transmitted inside the body cavity to reflect off the desired organ or tissue the lower the resolution of the captured image of that organ or tissue is projected on the monitor. "If your lighting is inadequate then it doesn’t matter how good the camera is," Fahy said.

Older generation scopes aren’t the only devices that can affect digital camera and video system performance. Healthcare facilities have to look at room lighting, surgical lighting, video monitors, video processors and also the signals being transmitted between devices and equipment.

"Poor quality fiber-optic light cables are also a cause of less-than-optimal pictures," Bradley said. "When materials managers are getting ready to purchase new video equipment they should also strongly consider buying new endoscopes and light cables. Many times those items are overlooked and not budgeted for."

Although Fahy acknowledged that budget constraints may force facilities to choose between upgrading a camera one year and scopes the next that strategy can be short-sighted. "When you don’t upgrade the remaining components in the rest of the chain you don’t realize the full benefits of the upgrades you do make," Fahy added.

"Any weak link in that chain ultimately is the end product you get," Shapiro noted. "It’s the least common denominator in the jigsaw puzzle that matters. Oftentimes that’s not clearly understood until you have the equipment in place and start using it."

Crossed signals
Trying to determine whether a camera marketed as digital truly is digital can be an art form. But knowing what to look for and understanding some of the basic principles behind the technology you should be able to make an informed decision.

"It can be tricky at times to determine whether a camera is digital or not because some manufacturers label their cameras with titles such as DSP (digital signal processing)," Irwin said. "Though the camera is an analog camera it can be perceived to be digital, and though the processing internally is done by digital means the signal output remains an analog waveform."

Healthcare purchasers also may mistakenly believe a camera is digital because it includes a CCD chip, which actually is an analog device. "If the camera signal were digitized in a device apart from the camera then it should be viewed as an analog camera," Irwin continued. "Digital cameras incorporate the digitizer inside the camera right off the CCD in order to minimize read-out and electrical noise. A digital camera will typically not incorporate the connector types that are used by analog cameras."

Bradley acknowledged that the term "digital" can be misleading. "Older cameras are analog, but the signal that was being displayed was digitally enhanced within the camera box and then converted back to analog and displayed on the monitor as an analog signal," he noted. "The analog signal is converted to digital and is displayed that way. A true digital camera will have digital outputs to the monitor. The analog signal is converted to digital at the CCD and then is sent through the camera box out to the monitor as a purely digital signal. Digital signals include SDI (serial digital interface), DVI (digital visual interface), and/or DV (digital video), also known as Firewire. If the camera box does not have any of these outputs, the signal is not digital. It is analog. Customers need to ask if the camera has a digital output and can it be connected to a digital input on an LCD monitor."

CRT monitors will only accept analog signals, Deppmeier emphasized. As a result, some camera manufacturers enable users to convert analog signals to digital and back to analog again, if needed, which contributes to signal degradation, he noted. "In its purest form the digital signal – DVI or SDI – should be sent to an LCD monitor," he added.

While digital equipment facilitates integration with picture archiving and communication systems (PACS) and any other storage applications due to standard data formats, analog equipment requires converters or translation software to make this happen, which can degrade the image, according to Gordon.

"When you process an image in the computer to change it from analog to digital or from one digital resolution to another the image loses clarity and breaks down visually," Gordon said. "Digitizing an analog image once and storing it only to digitize it again causes a loss in image quality. However, if you digitize it once and store it as a digital file you can transfer it without losing image quality."

Still, converters will affect image quality.

"Though converters allow you to send an analog signal into a digital device and vice versa it is not always practical to do so," Irwin noted. "If you start with a digital signal and connect to an analog device you now have a signal that is susceptible to noise, which can decrease the quality of the image. In the same respect, if you have an analog signal to start with the signal may be affected by noise, limiting the overall quality of the image, but when you connect it to a digital device it will not increase the quality of the image. In essence you’re simply digitizing a lower quality image."

One quick way to determine whether a digital camera lives up to its billing is to check its resolution statistics and output type, according to Jim Norris, product manager for surgical lighting and visualization systems, STERIS Corp. (Mentor, OH). "This will tell you if the digital camera converts to only analog outputs or if there is no conversion and a digital output is available," Norris said. "Most cameras still only offer analog output. Some new ones, however, will offer both." Monitors play a key role, too. "Many digital cameras have to convert images to analog for inputs into most monitors," he said. "Monitors are just now coming to market with digital inputs. Camera digital output was useless until monitors had digital input capability. Now they do."

Concurred Gordon: "All you have to do is look at the back of a camera to see that it’s capable of handling analog and digital output to VCRs and other devices."

Of course, the camera may not be digitizing the image either. "Every system is different," said Joe Williams, director of visualization at Smith & Nephew Endoscopy (Andover, MA). "Digitization occurs at different stages of different systems depending on the product."

Digitization of an analog signal may take place in the router, or in the monitor itself or in the computer controller. Converting an analog signal to digital can take some time, too, and that affects viewing, recording, editing and archiving and storage capabilities. Performance-wise, the difference may be marginal, Deppmeier said, but adding the digitizer to the camera head itself can increase the camera’s cost.

Digital limitations
While compatibility with existing equipment poses an enormous hurdle to realizing the full benefits of digital technology it is by no means the only hurdle.

"Most hospitals cannot afford to buy all new digital input monitors so analog conversion capability is still necessary to allow hospitals to use their current monitors," Norris said. "Also, resolution and frames per second are still limited. Fast speeds are necessary for medicine so that no ‘digital smear or trails’ are observed."

Bradley indicated that while CCD technology remains "the best imaging platform" and chip sizes are reduced clinicians are hesitant to change based on picture quality fears. Also, camera heads still need to be connected to the camera box via a cable, and signal strength over distances play a role. For example, "SDI is preferred because it can send a video signal 300 feet without any degradation of quality," he said. "DVI and DV can only be used for shorter runs (30 feet) without using expensive repeaters."

Irwin pointed to cable length as a limitation, too, with digital using "dramatically shorter" cable than analog. "Unlike analog signals that gradually degrade over long cable runs digital signals have a critical point where you have 100% of the signal or you don’t," Irwin noted. Other challenges include a greater variety of resolutions and standards for digital compared to analog, and the need for more bandwidth for digital. "For the transmission of video signal an allotted amount of bandwidth is required and is directly proportional to the image quality," Irwin said. "The more bandwidth the better the image quality. But there are other variables that affect this as well, such as the sampling rate of the camera itself and how much the original signal has been compressed."

Migrating forward
"Digital equipment and systems must be digital from end-to-end in order for them to be truly digital," Shapiro noted. "Having only one piece of the puzzle does not make it true for the entire process." Even so, Olympus focuses on analog-to-digital conversions because that’s what the market supports right now.

"While it’s difficult to know if a system is truly digital we know that every system has an analog component," said Marc Filerman, director of digital OR at Smith & Nephew Endoscopy.

Bradley concurred. "There is still a huge installed base of analog monitors, printers and VCRs that we must be able to work with," he said. "Some of the benefits of digital are lost, particularly resolution, but the customer can save money by not buying new image capture devices and monitors and still get an excellent image on the screen."

But maybe not for too long as analog components go the way of LPs and 8-track audio tapes.

"We live in an analog world that’s moving to digital because analog has maxed itself out," Williams said. "Digital can take us where we haven’t gone before."