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"For the last 70 years there’s only been one surgical lighting technology," said Alan Campbell, product manager, Berchtold Corporation (Charleston, SC). "There have been different ways of focusing the light, different ways of directing the light, creating a spot, but the light engine itself has been halogen bulbs, probably since at least the 1930s or 1940s."

"Halogen is a great technology to create light," he added. "You can get an extremely bright, high quality spot with a halogen bulb. The issue with a halogen bulb is everybody knows it doesn’t last very long. And it’s not terribly efficient so it creates a lot of heat. The advanced lighting technology category, in my mind, are all of those products which are more efficient at producing light and last longer."

Skytron Aurora LED surgical lighting system

The most common advanced lighting technology being introduced in new models by surgical lighting manufacturers is LED, including Skytron’s Aurora LED; TRUMPF Medical System’s 5-pod iLED 5 and 3-pod iLED 3; the MAQUET PowerLED; and STERIS Corporation’s recent introduction, the Harmony LED Surgical Lighting and Visualization System. Berchtold’s newest offering is the CHROMOPHARE X 66, which uses HID technology.

When it comes to features in lighting sought after by surgical staff, little has changed. Light intensity, color temperature, heat control, shadow control, maneuverability, flexibility, and surgeons’ comfort, continue to be top priorities.

The advantages of these new technologies over traditional halogen can be found in more efficient, longer-lasting, and cooler lights. For example, while halogen bulbs are rated to last between 1,000 and 2,000 hours, LEDs can last as long as 20,000 to 30,000 hours depending on the design of the system.

"That’s ten years of clinical use," said Randy Tomaszewski, vice president of marketing for Skytron (Grand Rapids, MI). "You don’t have to worry about the lights burning out. Perhaps over ten years of steady clinical use there may be a slight reduction over time of the intensity of the light, but even at ten years, our lights will maintain over 90 percent of their original intensity."

Campbell noted that the HID bulb used in Berchtold’s Chromophare X66 – which provides 160,000 Lux of intensity from a 70 watt commercially available bulb – has a life expectancy of approximately 5,000 hours or five years. The bulb features a gas capsule versus a filament that’s used in a halogen bulb. "As a result, there’s no filament to suddenly break," he said. "When this bulb hits the end of its life, it very slowly degrades. Some of the color will start to drop out, the intensity will start to drop off, but it happens very slowly. There’s not that catastrophic failure mode that you get in halogen, where suddenly the filament breaks and the light goes out. And with a five-year life, changing bulbs turns into a preventative maintenance function. Clinicians don’t ever have to worry about changing bulbs again."

HID and LED also require less wattage than halogen in order to produce high-intensity light. "The energy consumption of this lighting system is a green technology," said Tomaszewski. LEDs are able to provide the same or higher lighting intensity with about half the energy consumption of halogen lights, he explained. Long life and lower energy costs may help offset the 15 to 20 percent upfront premium you’ll typically pay for this innovative technology.

With virtually no infrared or ultraviolet wavelengths being emitted, LEDs provide a much cooler working environment for surgeons.

Chris Walters, product manager for surgical lighting at STERIS Corporation (Mentor, OH), explained, "Halogen lights throw off energy at all different wavelengths, but LEDs can be designed so they only emit light or energy at the wavelengths you want – so you’re only creating visible light without the excess energy that you’re not going to be able to use. You also don’t have to worry about filtering excess light and energy with LED sources, since you’re not creating it in the first place. That’s one of the reasons that LED produces less heat. The other factor is the way in which it produces light. A halogen bulb produces light essentially by heating up a filament until it gets so hot it begins to glow. With an LED source, the way it fundamentally produces light is cooler."

MAQUET PowerLED

While surgeons need a bright, high-intensity light in order to properly visualize the surgical site — models are available ranging from 110,000 Lux to a maximum of 160,000 Lux — it’s also important that the light be non-glaring and shadow-free.

"You need to have the ability to interpret tissue, and depth perception. Harsh shadows that are in the field are not acceptable at all," said Tomaszewski. Skytron’s Aurora LED eliminates shadows through the use of individual LED pods with cold mirror reflectors.

Berchtold’s Chromophare X66 features a polygon reflector with mirrored segments, each of which shines a pattern down on the surgical field. "It’s very difficult to block enough of that light to disturb the pattern," Campbell said. "Our single bulb/reflector approach also allows us to concentrate light in the center of the head, for a spotlight effect that gives you superior deep cavity penetration."

MAQUET achieves shadow control through a large-sized lamp head that houses 168 individual LEDs – each covered with a diverging and refracting Fresnel lens – each of which produces an 8.3-inch patch of light. "It doesn’t matter if I’m blocking ten of the LEDs, I have 158 of them that are still producing an 8.3-inch patch," said Pam Rockow, senior product manager, MAQUET Surgical Workplaces (Rochester, NY).

Rather than using reflective techniques to help eliminate shadows, MAQUET’s diverging and refractive technology delivers thousands of overlapping light beams. "Point and shoot" lighting provides consistent and homogenous volumes of light with no adjustments necessary.

An optional Automatic Illumination Management (AIM) system available with the MAQUET PowerLED features sensors that will detect when a surgeon’s head is in the way, then blacken out the LEDs directly above the surgeon’s head and boost the illumination around the peripheral helping to ensure a consistent level of illumination. "It’s compensating for any blockage that you may have during surgery," said Rockow.

According to STERIS’ Walters, while halogen lights typically feature a reflector surrounding one bulb, LED lighting systems contain many smaller LED sources, resulting in improved shadow control. "Each individual LED creates the entire pattern of light. So even if you blocked all of the LEDs except one, you would still get a round circle at the bottom."

"The TRUMPF iLED combines two solutions that compensate for shadowing created by surgeon positioning or the depth of the wound," said Dave Rector, marketing manager, TRUMPF Medical Systems (Charleston, SC). "One solution overlaps the pools of light cast by each LED. There are 184 individual LEDs in the iLED 5. The overlapping pools mean unobstructed LEDs compensate for those that are blocked. The other solution is to provide specific light distribution patterns that are selectable based on the surgical situation. The patterns virtually eliminate shadows and redistribute the emitted light to maintain intensity and optimize illumination of the surgical site. That means you still have up to 160,000 Lux of illumination, not blocked by the surgeon’s head, illuminating even deep cavity procedures."

Berchtold Chromophare X 66

Tomaszewski described the unique focus capability of the Aurora LED. "We’ve maintained our focus control capability, which all of our lighting systems have always had, where the surgeon can control the focus capability of the light itself. If the surgeon is operating in a deep cavity and wants to increase intensity focused on a particular point of the surgery, he can do so without having to move the surgical lighthead. Focus control and enhanced optics move the column of light intensity when and where it is needed most, even at extended distances making the surgical site very clear. Fixed focus lighting systems require the surgeon to reach up and grab the light and pull it down as needed when working on deep cavity incisions or for surgical cases such as cardiovascular, urology and orthopedic procedures requiring greater distances from the surgical field. With Skytron’s LED system, or any other light that we’ve had, you don’t have to reposition the light. With a quarter turn of the surgical sterile handle, you can refocus that light up to 60 inches away and you’ve recaptured 100 percent of the light intensity. That’s the benefit of the focus control that Skytron has always had for our surgical lights. We’ve maintained one of our product strengths which surgeons really appreciate."

Options for minimally invasive surgeries are also being built into lighting systems. For example, the MAQUET PowerLED includes a ring of LEDs inside the lighthead that are dedicated to ambient lighting technology. Called "LEDinside", the feature allows the light intensity to be turned down to a very low Lux of around 5 percent of full intensity and be positioned directly over the tray of instruments.

"Our ambient light solution is a little bit different," said Walters of the STERIS Harmony LED. "We actually put a green ring around the top of our canopy up at the ceiling. The green ring automatically turns on whenever you turn the lights off and it will light up the whole room in this low-level, soft green lighting. We use green because it’s been shown to be the best kind of ambient light for low-level lighting situations," he explained.

"This ambient lighting lets the people in the room see to move around safely without interfering with the surgeon who’s trying to work off the monitors," he continued. "It won’t throw glare on the monitors to distract him, and it won’t cause his pupils to constrict so he can’t see the monitors as well. At the same time, it will allow everyone else to see what’s going on in the room. It’s a little bit more expensive than some of the options out there but I think it’s just a fundamentally better approach to ambient lighting."

Color temperature will also affect how the surgeon is able to interpret tissue and visualize the surgical site. Measured by a unit called the Kelvin (K), a lower color temperature of around 2,700 to 2,800 K will appear "warmer" and yellowish-white in color (consider the common household bulb), while higher color temperatures will appear "cooler" or more bluish-white. The color temperature of daylight sun is around 5,000 K.

Manufacturers approach color temperature in a number of different ways. STERIS, for example, has always offered a color temperature of around 4,400 to 4,500 K, Berchtold’s Chromophare X66 emits light at 4,500 K, and the MAQUET PowerLED provides a steady color temperature of 3,750 K.

Alternatively, both Skytron and TRUMPF offer users a choice of color temperatures with their LED lighting systems. The Skytron Aurora offers two choices of color temperatures, a soft white (4,000 K) or a bright white (4,500 K). The TRUMPF iLED, offers four separate settings of 3,500 K, 4,000 K, 4,500 K and 5,000 K.

"The ability to adjust color temperature allows the surgical team to improve contrast and tissue differentiation, based on factors including the type and depth of the surgery, blood flow and surgeon’s preference," said Rector. "Surgeons use this feature with the TRUMPF iLED to bring out specific colors and differentiate the finer details in tissue."

Said Tomaszewski, "If you have 30 or 40 surgeons, or more, practicing in a facility, each one of those surgeons is likely to have a personal preference of color temperature that they want to use with the lighting system."

Manufacturers with fixed color temperature systems contend that a choice of color temperature may add confusion to OR setup, and that always providing the same color temperature may give the surgeon a better frame of reference while performing surgeries.

Achieving the desired color temperature is also easier with these new advanced lighting technologies than it is with halogen lights. "A typical halogen bulb is very yellow, with a color temperature of around 3,200 K," explained Walters. "So to get it from there to 4,400 K we have to put in filters and reflective coatings to filter out some of that yellowness, and to make it appear whiter. But LED technology can be designed intrinsically to be the color temperature you want."

Because advanced lighting technology will last for many, many years it’s important that your new system will accommodate future upgrades and be able to incorporate emerging technologies. Camera-ready lightheads as well as suspension systems that enable additional lightheads or monitors to be added at a later time will help ensure the future sustainability of your investment.

STERIS Harmony LED Surgical Lighting and Visualization System

The suspension system of STERIS’ Harmony LED system is designed so you can add an additional lighthead or monitor at any time. Walters noted that STERIS’ "value offering", the Harmony LC Surgical Lighting System, "doesn’t have the upgradeability that our LED solution has. When people start to gravitate towards the value, I always challenge them by saying, do you know these lights are going to be hanging for a decade? Do you know where you’re going to be in ten years, and what procedures you’re going to try to do in ten years? I always challenge them to think backwards ten years to the kinds of procedures they were doing ten years ago, and could they have imagined where they are now? When they think about it, they start to see the value in that flexibility and upgradeability." He emphasized, "You’re making an equipment purchase that you’re going to have to live with for ten or 12, or sometimes 15 years. So don’t let a few thousand dollars up front cause you to regret this decision for a very long time."

In addition to STERIS’ current medium-sized, 585 mm. lighthead, which provides 150,000 Lux of intensity, the company will soon be introducing a larger-sized 785 mm. lighthead with an even higher intensity. "Some customers like the idea of having a main light and a satellite source. So for customers who like that combination we’ll be able to provide that also."

With both three and five-pod options available in the TRUMPF iLED line, "hospitals are using configurations including two 5’s, and a 5 and a 3," said Rector. "The iLED 3 is also being used alone in cath labs and ICUs as a procedure light. So flexibility is inherent in the possible configurations and the different models. The TruVidia Super CDD camera and TruVidia HD camera provide additional options."

Skytron has also built flexibility into its LED lighting system, said Tomaszewski. "Our Aurora lighting systems have the ability to accommodate camera systems that are transportable, moveable from room to room. They can also be equipped with flat panel displays or booms and flat panel arms requiring only one mount in the room versus several."

MAQUET’s Satelite suspension system offers three ports of suspension from one single mount to accommodate lights and flat panels. "It allows for flexibility and upgradeability as technologies continue to change and emerge, without putting new structure in your ceiling," said Rockow.

Integrating cameras with a choice of integrated zoom or fixed focus are also available with the MAQUET PowerLED, allowing for cameras to be shared between several rooms, an optional cost-saving solution.

Berchtold’s X66 utilizes a 7-pole data path in its 360° rotating suspension that is designed to accept future generations of Berchtold lights. Starting this year all other Berchtold lights will also be upgradeable to accommodate future lighting technologies. "The cost for an upgrade is substantially reduced, and also the time that it takes to do it. If somebody has to go in and start ripping parts out of the ceiling, that’s going to mean down-time, and that’s where the real money starts to add up," said Campbell.

As Tomaszewski puts it, "If you’re going to spend the money you might as well make sure that it’s going to not just meet minimum standards, but really hit the expectations for a decade to come." He asked buyers to consider, "If there are limitations to the product today that you can identify, just let a year or two go by and see how much more magnified those immediate limitations are now becoming."

Walters suggested that end-users try before they buy. "I would never make an investment of this magnitude without taking it for a test drive," he said. "If you’re worried about the time and expense of shutting down the room and having people hang lights, at least have the manufacturer bring them in on a mobile stand, which everybody can do, because then you can put them there side by side in an OR, and let all of the surgeons come in and see the different features. You’re not getting the full feel of it with the suspension, but you’ll at least get to see the optics, whose light is brighter, whose light is whiter, and whose light the surgeons prefer."

"The critical assessment of the quality of the light field is best left to the surgeon’s discerning eye during a light trial," added Rector.