TRUMPF iLED

When heading for the hospital for surgery, probably the last thing you’d ever think about is the lighting in the surgical suite. That’s something we take for granted. But what could be much more important than how well your surgeon can see to do his or her job?

Surgical lighting today is light years ahead of what it was 20 or even 10 years ago. No longer is a light just a light; now they’re ‘systems,’ really and truly. All manner of whistles and bells have been added since then. "The lighting system is no longer merely a great light; it must provide the infrastructure that allows imaging and control for today and the future, control systems that can adjust multiple devices in the room, and video routing systems built in that are ready for digital imaging," observed James Norris, marketing manager, critical care, STERIS Corporation, Mentor, OH.

With so many options available now, it’s important to know factors necessary for good surgical lighting. Healthcare Purchasing News talked to some experts in the field about what to look for in good surgical lighting, how good surgical lighting meets the needs of surgeons and nurses, some exciting options, and new developments on the horizon.

Randy Tomaszewski, vice president of marketing, Skytron, Grand Rapids, MI, agreed: "Quality surgical lighting delivers high-intensity lighting to the surgical site without glare or shadowing, to assist surgeons to best see and interpret tissue, vessels, etc., with the highest degree of accuracy. Visualiza- tion is of critical importance to the surgeon and surgical team.
Next to the surgeon’s eyes, no other surgical tool is more important than lighting. Many surgeons will do two and three cases a day under high-intensity illumination. Highly intense but soft illumination without glare allows surgeons to get optimal light to the surgical site for long periods without associated eye fatigue."

Reduced shadow is one advantage of iLED surgical lighting, developed by TRUMPF Medical Systems Inc., Charleston, SC. Maik Walther, managing director, explained "iLED lets the surgical team redistribute the light according to need. For example, turning off the LEDs on the edge–there are 184 separate LEDs–and concentrating the total luminosity on the middle, where the light best reaches the deep-set body openings, is an option. Even if all the LEDs are not in use, the light field remains constant and almost shadow-free. This arrangement enables each LED to illuminate exactly the same area as all LEDs together, where their cones of light overlap, reinforcing one another. If LED beams come up against obstacles in the way, people or objects, enough other beams do their job and the surgeon’s view remains unimpaired."

The MAQUET ALM X’Ten Major Surgical Light from Getinge USA (Rochester, NY) features a unique cross-shaped lamp head and patented micro-lens technology. The cross-shaped design helps to divert light around the surgeon’s head thus reducing shadows while the micro-lens creates thousand of diverging light beams resulting in a homogenous distribution of light.

Skytron SkyVision Communications Control System

"Reflective and diverging light technology is one of the largest advantages of MAQUET Surgical lights," said Pam Rockow, senior product manager, MAQUET Surgical Workplace, Getinge USA. "We achieve shadow reduction through the utilization of prisms and microlens light guides. The light passes through prisms or micro-lenses resulting in overlapping light beams. Shadows caused by obstructions such as a surgeon’s head are reduced," she explained. "Other technologies require constant focusing by surgeons and staff becuase the light converges to a focal point and must be adjusted with the light handle when the patient is moved or to pin-point the light."

Rockow adds, "The best surgical light provides two things - the correct amount of illumination for the procedure and the right patch size. Brighter does not mean better. Too much [intensity] can fatigue the surgeon’s eyes and cause glare." She explains that overlapping light beams allow for ample illumination without the need for extra brightness. "We concentrate on the quality of light, and not quantity of light."

Color temperature
"The unit of measurement for color temperature is degrees kelvin (K)," explained Campbell. "Different light sources have different color temperatures. Noon sunlight measures about 5,000 K; light bulbs in stores and houses are between 2,000 K and 3,600 K; most surgical lights are 4,000 K to 4,500 K."

BERCHTOLD Chromophare D660

The color of the light serves a purpose, Campbell added: "Color differentiation helps the surgeon to determine where and what to cut. Lower color temperature lights, which appear yellow, have more of their energy in the red end of the color spectrum, overwhelming the blue and purple tones, producing a washed-out appearance. High color temperatures, which appear white or blue, are more balanced, mimicking the true white light of noon-day sun, giving surgeons the subtle contrasts they need to distinguish one structure from another."

"Surgical-light color temperatures can be up to 4,500 K and higher. The higher the color temperature, the cooler the light," explained Tomaszewski. "Intensity, on the other hand, is measured in lux. There is a fine balance between surgical-light color temperature and lighting intensity, or brightness. Too high an intensity and/or color temperature can approximate sunlight quality, which is the ideal light quality but can produce the side effect of ‘seeing spots,’ as is common after looking directly into sunlight. This would be too harsh for human eyes to work under over any period of time. Surgical lights need to be bright, but not blinding, to the human eye, particularly for those cases lasting over an extended period of time. The ideal temperature of 4,000 K and a Coloring Rendering Index (CRI) of 93 permit optimal and comfortable interpretation of body tissue, closely matching those of surgical tissues, permitting the surgeon to work even for long periods of time under high-intensity lights without seeing spots."

STERIS Harmony

According to Rockow, MAQUET is one of the few in the industry that uses a 3,500 K surgical light. Although it is really a surgeon’s preference, she explains that a lower color temperature allows for more yellow and red tones, which are a more true color representation of tissue. "It helps to differentiate good tissue from poor tissue."

Changing color temperature according to surgeons’ needs is something that has only recently become possible with iLED, said Walther. "By adjusting color temperature, the surgical team can optimize contrast, based on factors including the type and depth of the surgery, blood flow, surgeon’s preference, and even his or her degree of fatigue. The key to adjusting color temperature is in the ability to change the ratio of white to color LEDs, thus ‘mixing’ the desired color tone. Bathed in warm, nonglare light (about 3,500 K), skin and light-tissue parts reflect less, and the contrast remains intact. Colder light colors (up to 5,000 K), however, were preferred by the ‘test’ surgeons for deeper-lying body areas and for longer surgeries. One reason for this is that, when the eyes get tired and concentration lapses, we perceive cold, or blue, color tones as a relief to the eye. Either way, the surgical team, whether working on shorter outpatient procedures or longer surgeries, has their choice."

Ease of movement, flexibility
"A few years ago, a tire commercial was built around the theme ‘Power is nothing without control,’" said Campbell. "That’s true with surgical lights, too. People in the operating room (O.R.) need to be able to position the light where they need it, with a minimum of effort and time, so it’s important for the light to be easy to move. High mass is the enemy of mobility. If the lighthead is too heavy, it either is difficult to move or it tends to drift away. The suspension must give the ability to move the light with little force, yet not be so loose that it runs into other arms, equipment, or staff."

Tomaszewski continued: "Having to move the lighthead up or down can be distracting and break the surgeon’s concentration during a surgical case. Minimal interruption to the surgical procedure is maintained if the lights can be moved easily. If the suspension system requires frequent attention, critical attention to the patient is diverted, and the case is prolonged. Good lighting systems are easy to overlook, because they allow surgeons to perform surgery safely and easily; bad lighting systems, on the other hand, are rarely forgotten, because too much attention is required to position them properly."

The MAQUET ALM X’Ten includes a ring of LED lights that are integrated into the light head that provides ideal lighting conditions for minimally invasive surgery. "One advantage to the X’Ten is that the LED control is located on the lamp head," said Rockow. "Having the control easily accessible allows for surgical staff to quickly and conveniently switch back to return to full surgical power lighting. This is a safety advantage as you eliminate the possiblity of tripping over equipment or cords in order to locate the power supply."

Campbell believes that flexibility also is an important quality of a surgical-lighting system, too. "Some companies go for the cookie-cutter approach, but Berchtold has more flexibility in customizing lighting systems because we actually build the lights in the United States. This allows us to build up quickly any configuration to meet customers’ needs." In addition to the experience that comes from having designed over 2,000 O.R.s, Berchtold also has a program that can model customers’ O.R. in 3-D. "The customer can see what they need and how it will fit into their O.R. before the lights are even ordered. If it doesn’t work onscreen, it probably won’t work in the O.R."

Thermal control
Another important factor is how comfortable the lights are to work under, because lights produce heat. Tomaszewski explained: "Thermal management of the light must, by design, minimize beam temperature and radiant energy toward the surgical field. A combination of low energy consumption together with proper heat dissipation guards against tissue desiccation and, just as importantly, provides optimal comfort for the surgeon and surgical team working under the surgical lights."

Whistles and bells
Have you ever heard that old Ray Stevens song that asks can you "whistle Dixie while eating crackers and covering one eye?"1 Today’s surgical lighting systems can do all that and more; in fact, options are pretty mind-boggling.

"In the past, purchasers of lighting systems were focused on two main features: optical quality and suspension systems," said Norris. "These are still important, because when all is said and done, surgeons will always need to see the surgical site crisply and clearly, without distortion. However, with the current and expected growth in minimally invasive surgery, surgical video, image-guided procedures and telemedicine, the purchasing decision tree now requires an O.R. manager to ask additional questions":

• How will the lights integrate into an advanced O.R.?
• How will they work with a specific control system?
• Will they integrate with the various camera systems my surgeons use?
• Can I add the correct type and number of flat-panel monitors we need?
• Will the system be flexible enough to accommodate imaging and technology upgrades surgeons will require over the next 5 to 7 years?

Norris outlined some options offered by STERIS: "Harmony LA Surgical Lighting and Visualization System provides excellent optics in a highly flexible modular system that offers the lowest cost of ownership of any lighting system on the market. This system’s control center, a "laptop on the wall," processes more than 1,000 instructions per second, including self-diagnostics. The suspension of the Harmony LA system is modular and pre-cabled, which saves downtime and expense when it is time to upgrade the system. Harmony LC Surgical Lighting System provides the same optics as the Harmony LA system, but with a more basic control package and traditional "open" suspension that is cabled on-site. This system can be configured with an optional in-light camera and monitors at the time of purchase and can be integrated for minimally invasive surgery. To complete both systems, a broad array of technologies is available from STERIS, including patented Automation Control Technology interface for future technological advances; a full range of monitors, providing standard or high-definition screen resolution; a full range of camera types, including a lighthandle camera, headlight camera, a 3CCD camera on its own suspension arm, and a broadcast quality high-definition camera."

Tomaszewski also provided a rundown of some types of options that currently are being offered by Skytron: "Skytron lighting can be equipped with a portable, surgical-light miniature-handle camera, transferable from room to room," said Tomaszewski. "The increasing demands of multiple image management for in-room cameras, surgical light cameras, minimally invasive cameras, C-arms, PACS images, fluoroscopy, and so forth have required that surgical lighting be integratable with other video and communications control systems within the O.R. Stellar Lights are also frequently equipped, from the same mount, with a flat-screen monitor(s) and equipment-carrier boom systems providing endoscopic and/or laparoscopic equipment to the surgeon, as well as medical gas, including carbon dioxide for insufflators, nitrogen systems, and power and video outlets. With Skytron lighting and booms, hospital-design teams, architects, equipment planners, and clinicians don’t have to choose a side for mounting support equipment. The O.R. and the entire system are ultimately flexible all of the time. In addition, Skytron Stellar Lights are optionally voice and touch-screen activated."

Getinge is introducing a new mounting system called the Satellite that offers three ports to place arm systems. The system could hold a set of dual lights in the center, a flat panel, and still have an open port for future expansion. Rockow explained that as opposed to traditional mounting systems on the market today that have just one mount, the Satellite allows you to put the arms to the side and out of the way, versus having one axle from which multiple arms hang and tend to crowd the surgical field. One big advantage in future upgrades will be the ability to add a third or fourth arm without taking down the lights already installed, she said.

Should cost be a factor?
Unfortunately, cost always rears its ugly little head when purchasing decisions are being made, but should it be the primary consideration when purchasing surgical lighting? Norris suggested, "Rather than price, the most important factor is the total cost of ownership, which includes how the lighting will perform over the next 5 to 7 years as the surgeons update technologies to meet new standards of surgical practice; how much time and expense will be involved to update the lighting technology (modular systems make change-out easy and quick, requiring little downtime or technical assistance); the quality of the optics over the life of the lighthead; and what is involved to maintain the system. STERIS systems offer competitive pricing but, more importantly, they also provide owners with the lowest total cost of ownership available today."

Tomaszewski suggested some questions to ask when weighing cost against performance of the product. "Price is always a necessary reality when selecting the most optimal surgical-lighting system for surgeons and the surgical team. What needs to be looked at closely is the value delivered. Is the light easy to use? Does it provide optimal intensity? Do you see spots when looking away from the surgical field; are the eyes strained due too strong intensity? Is the light cool to work under? Does the light offer excellent positioning and maneuverability? Do all surgeons like using the lights for their respective specialty areas? Do the lights meet clinical objectives, performing well under demanding circumstances? Price is not always the key consideration. I haven’t met a surgeon yet who has endorsed the purchase of a lighting system with adequate light versus excellent light."

Walther concurred: "Price is always a factor, but quality of patient care is the real key. Facilities need to look for solutions that deliver the best combination of benefits that are not only financially feasible but can also help their staff provide the best possible patient care."

MAQUET ALM X’Ten from Getinge

According to Rockow, different parties will have different features that are important to them in choosing a surgical light. "From the surgeon’s standpoint it’s going to be good illumination and shadow control, from the nurse’s standpoint it may be easy maneuverability, and Biomed will look for ability as well as ease of integration. Illumination, shadow control, heat management, color and the ability to integrate products are all important factors. Each staff member of the O.R. ranks each of these factors a little differently."

On the horizon
Surgical lighting is constantly evolving, and more changes are on the horizon. Campbell believes that "bulb technology will continue to evolve. There probably will be new versions of existing technology and new technology as well. Light quality will remain the most important factor. There will also be greater adoption of device-driven O.R. suites, with more features, more functions, enabling nurses to control things from one place. There will still continue to be a drive for less obstructive, more compact equipment. We want equipment to serve nurses and doctors, not the other way around, which won’t happen if the equipment is big, heavy, and in the way."

REFERENCES
1. Kalb CW Jr. Can he love you half as much as I? Nash ville, TN: Ray Stevens Music; 1986, 1987, 1995.