Sleep Lab Equipment

All across the country, hospitals are waking up to the importance of sleep medicine. If forecasts prove correct, 5 years from now the hospital that does not offer a service diagnosing and treating sleep disorders will be the exception rather than the norm.

That means clinical engineers (CEs) and biomedical equipment technicians (BMETs) practically everywhere will be called upon to inspect, maintain, and repair equipment belonging to a sleep lab.

“Sleep labs are big moneymakers for hospitals, which is one of the reasons they’re being started by more and more institutions,” says Russell E. Rozensky, RRT, RPSGT, CPFT, a clinical instructor of respiratory care at the School of Health Technology and Management at Stony Brook University in Stony Brook, NY, and formerly a supervisor of the sleep lab at John T. Mather Memorial Hospital in Port Jefferson, NY. “Sleep medicine is coming to be seen as an essential service, one that is every bit as necessary as respiratory care, physical therapy, or dietary.”

Fueling the growth is consumer demand. “The public is becoming very aware of the importance of a good night’s sleep,” Rozensky says. “People are discovering that sleep debt is responsible for making problems such as hypertension, stroke, diabetes, and congestive heart failure worse than they otherwise would be.”

Do Not Disturb
Sleep labs exist to answer the question of why an individual suffers sleep debt. Labs accomplish this by evaluating the ease or difficulty with which a patient drifts off once his or her head hits the pillow, and then for how long and how well he or she remains in a state of somnolence. Once those questions are answered, labs offer therapy or make treatment recommendations to the patient’s referring physician.

All of this takes place in a room designed to resemble the cozy sleeping quarters in a home, on the theory that sleep studies are more accurate and reliable if the testing occurs in a truly comfortable, quiet environment. That is why sleep labs are often self-contained units located well away from the lights and hurly burly of the typical hospital floor. In fact, a trend is to situate sleep labs entirely off campus, most commonly and cost-efficiently in nice hotels.

Labs assign one patient per room. Depending on the size of the lab, the number of rooms could be as few as one or two, or as many as 10 or more. Each room contains

electronic sleep-testing and sleep-treatment equipment. However, the most basic piece of equipment is the bed. Many labs prefer the exact same type as found at home. Others opt for a mix of household beds and bariatric beds, the latter to accommodate moderate to severely obese patients. Since excessive girth contributes to the majority of sleep disorders seen in the lab, a significant percentage of any sleep lab’s business includes patients who weigh more than 350 pounds.

Seeing In the Dark
Positive-airway pressure (PAP) devices count as another commonly encountered item in sleep labs. These are frequently complemented by a heater-humidifier system that plugs into the airway circuit to enhance patient comfort and prevent nosebleed-inducing dryness of the nasal passages. In many labs, the PAP machines are wired to be monitored and adjusted remotely by sleep technologists occupying a nearby control room, Rozensky notes.

The primary use of the PAP machines is therapeutic, whereas most other items found in a sleep lab serve a diagnostic purpose. The main diagnostic tools are the sensors patients wear, such as special belts to measure chest and belly expansion and contraction during each breathing cycle; or sensors that attach to the fingers, arms, chest, head, and legs. The sensors connect to pulse oximeters, electroencephalogram readers, and electrocardiogram units, among others.

Usually present in the room is a see-in-the-dark infrared digital video camera, which works in conjunction with an infrared emitter lamp and monitors patient activity during the course of the study. There is also an intercom that produces a digital sound recording of the slumbering—and in all likelihood, loudly snoring—patient. Data from the camera, the intercom, and the different monitors flow through a headbox/amplifier, and all are subsequently correlated to provide a complete picture of the patient’s sleep habits.

The correlating takes place in the control room, which contains a computer with software designed expressly for the study of sleep.

The control room system in the 10-bed sleep lab at Reading Hospital in Reading, Pa, is basically a stock PC. Its software permits interfacing with a digital pre-amp so that up to 64 channels of information per patient can be displayed, even though normally, just 20 channels are needed to develop a sufficient understanding of the test subject’s problems. There is one computer, display monitor, and pre-amp for each bed, reports Larry E. Rochowicz, CBET, a senior member of the hospital’s 11-man biomedical equipment team.

Ordinarily, the information technology (IT) department would claim ownership of these computers, but not this time. “We have control over them,” Rochowicz says. “We’re responsible for their servicing and upgrading.”

That is surprising. So is the fact that the biomedical department at Reading Hospital has jurisdiction over the local area network (LAN) into which the sleep lab computer and monitoring equipment are tied—also IT territory.

“It took some persuasive dialoguing, but we were able to convince IT that we were in a better position to take care of the sleep lab’s LAN,” Rochowicz says. “Since it doesn’t connect to IT’s hospital-wide network, and because the lab’s LAN is too small for IT to worry about, they agreed to let us have it. Same with the computers in the lab.”

Keep ‘Em Flying
Keeping equipment in good working order at all times is particularly important in a sleep lab. “When systems go down, it’s possible the patient’s sleep study will have to be cancelled and rescheduled,” Rochowicz says. “The problem with that is these labs often are backlogged by 2 or 3 months—that’s how much in demand they are. So, the patient whose test is cancelled might not get back in for quite a long while to receive the diagnosis that he or she needs. And, if the test is delayed, so will the start of treatment be delayed.”

The risk of that happening can be minimized with regular preventive maintenance (PM), Rozensky says. At Reading Hospital, PM scheduling of sleep lab equipment is handled by automation. “We have biomedical management software that generates a work order every 6 months for each individual piece of equipment in the lab,” Rochowicz explains. “Technicians will print out a PM procedure sheet that tells us what we need to inspect, clean, and replace on that

individual unit. The procedures are model-specific and were developed by us in-house by reviewing service manuals and other manufacturer-supplied technical information available at the time we purchased that piece of equipment.”

No less than other departments, sleep labs are sticklers for having PM work thoroughly documented. “They need good documentation as part of their accreditation process,” Rozensky says. Accreditation is hugely important to sleep labs: Earning the stamp of approval from the Joint Commission on the Accreditation of Healthcare Organizations or the American Academy of Sleep Medicine gives them a competitive leg up. Prospective patients want to know they will be spending the night in a lab that is not just comfortable, but safe. Moreover, insurance companies that reimburse for sleep services and those that underwrite the labs themselves against liability want assurances of safety, too, and accreditation speaks volumes in that regard.

Eyes Wide Open
Because biomed departments tend to be open at hours when sleep labs are closed (and vice versa), labs by custom are outfitted with redundant systems so that studies can proceed despite a disabling malfunction suddenly striking a mission-critical piece of equipment. It is therefore rare for a biomed department to receive a call in the middle of the night from a panicked sleep technologist needing to arrange for an emergency repair. Even so, when equipment breaks down and no backup unit is available, the lab technologists seldom hesitate to call biomedical’s private 9-1-1 line and request immediate servicing. Most repairs, emergency and otherwise, are performed right in the lab; only rarely is it necessary to cart equipment back to the biomedical shop for major teardown and reassembly.

At Rochowicz’s shop, they strive for same- or 1-day turnaround on repairs of sleep-lab equipment, which is doable provided that the replacement parts are in stock, which they normally are.

However, parts held in inventory today may be doing little more than gathering dust 5 years from now, because of new equipment expected to come onto the market that will render obsolete some of the mainstay items currently used. “I expect that PAP units will be more compact and portable, with more diversity of power-source options,” Rozensky says.

“Additionally, I’m looking for PAP machines to be endowed with vastly greater data-collection and transmission capabilities. I also see a big move to wireless communications technology. Today, when we do a sleep study, the electrodes we attach to the patient’s body have wires running back to the monitors and the headbox. If the patient needs to get up during the night to go to the bathroom, he or she can’t leave the bed until we come into the room and disconnect the wires. That won’t be a problem when we convert to electrodes that have no wires, electrodes that instead send a signal to a receiver somewhere in the room.” 24x7

Rich Smith is a contributing writer for 24x7.