Design Strategies Toward Implementing Leading-edge Cath Lab Technologies

While catheterization has become the staple of minimally invasive cardiac interventional procedures, new methodologies go beyond capabilities that were unheard of a few years ago. The continued trend toward less invasive interventional procedures depends largely on physicians' desire to improve access to the deepest organ and vascular systems. Furthering the Trend One instrument in particular, the Niobe Magnetic Navigation System (Stereotaxis, Inc., St. Louis, MO), exceeds standard manual procedures for coronary artery disease and arrhythmias. Not only can it perform a host of challenging catheterization procedures, but its latest clinical applications extend to intracerebral and neurovascular applications as well. When the Niobe system was installed in April 2005 at Saint Mary’s Hospital, Mayo Clinic, in Rochester, Minnesota, fewer than a dozen existed in the nation. The Niobe system’s computer-controlled magnets, which are positioned externally to the body, steer magnetically-enabled catheters and guide wires throughout the cardiovascular and neurovascular systems. The Stereotaxis equipment differs from magnetic resonance imaging (MRI) devices in that it works as a navigation tool in lieu of manual manipulation with no magnetic imaging capabilities. The Niobe system is designed to work with the Siemens Axiom Artis dFC digital fluoroscopy system, which shows the devices as surgeons manipulate them. Mayo brought together cath lab cardiologists and radiologists with a facilities team. Together, this new team collaborated on a financial effect analysis (FEA) which made the case to the lab, to the department and to the institution for internally installing the equipment. The team considered instruments that could perform procedures too difficult for normal human intervention, i.e., if the anatomical pathway was too tortuous or occluded. The FEA outlined the benefits of minimally invasive treatments for patients, including more positive outcomes. It also noted research benefits, as well as the return on investment from the increased number of procedures performed. Overall, the business plan made a case that installing the Niobe and Siemens equipment would be a win-win situation for all. Design Challenges & Strategies The Niobe system is employed in only a handful of healthcare facilities worldwide and no standard building code or practice model exists. Thus, strategies to design a space that would accommodate the new technology required groundbreaking planning. Technical challenges included the Niobe equipment's two 2,000-pound superconducting magnetic assemblies and a 360-degree, omni-directional rotation. To create a technically sound lab, major stakeholders including the architectural and engineering team, the lab facility's owners and users, and the building contractor met on a weekly basis. The team also included the vendors because involving them early on would be critical for a successful outcome. Footprinting for Success The first limitation was space. If a new lab were to be created, its optimal size would be 20 percent larger than a retrofit or conventional renovation/replacement. One of the difficulties, however, was that the new magnetic cath lab would have to literally fit into an existing standard-size cath lab, about 480 square feet. Furthermore, the lab would still need to perform normal catheterization procedures along with the enhanced modalities. At the outset, the design team laid the existing floor plan over schematics provided by the Siemens and Stereotaxis representatives. To blend imaging with cath procedures, the planning team examined the number and type of staff that the equipment would require and the footprint would allow. The new procedure might mean a cardiologist, radiologist or RT, anesthesiologist or CRNA and one or two RN's all be present. Planners then studied each staff member's function and created zones for each role. Next, designers looked at the equipment in both engaged and parked positions. The navigation system has two super magnets, which are placed on each side of the table, floor mounted traveling on a circular track from a parallel position to a perpendicular position at the center of the patient. The table slides back and forth on a long axis as with all conventional, fluoroscopy equipment. Therefore, plans had to take into account the new technology, of substantial size, requiring floor area directly at the center of the patient as well as healthcare staff, all requiring a presence directly at the patient and all potentially in motion. In addition, designers were required to coordinate all items in motion in the ceiling space, such as monitors and shielding devices. Structural Needs The vendors provided all structural, mechanical, electrical, environmental and transportation delivery requirements. Planners consulted with structural engineers to make certain the structure would sufficiently support heavy magnets. Halls and doors also needed to be wide enough to have the required structural stability to accommodate equipment transport through including vertically. Floor-to-floor height is often a problem in retrofits accommodating new technology. Equipment manufacturers usually prefer a ceiling height between 9' 8" and 10'. At Saint Mary’s Hospital, however, the floor-to-floor height was 12'-2", which could only yield a 9' 6" ceiling height. Planners and equipment vendors collaborated to resolve these issues. Safety and Environmental Needs Of course, any interventional-use space triggers design around contemporary rules and regulations, including scrub sink locations as well as air-change and low air return regulations, which required modifications to the existing space. The entire room needed shielding so the magnetic field wouldn't drift, and so radio frequencies (RF) from outside could not enter and interfere with the magnet technologies. Engineers thus were required to wrap the room in a continuous metal box made of overlapping 1/8-inch steel plates, which included grinding down the floor. The structure above the room was also shielded, which required all mechanical, electrical and plumbing (MEP) systems to be removed. An electrical and mechanical study showed that the new technology and efficiency of the replacement cath lab equipment from Siemens would compensate for the added heat the Niobe system generates. Since the core drilling through the floor for new electrical feeds required a temporary, albeit costly, shut-down of patient rooms below, the retrofit was coordinated during a slower-use period (nights and weekends). This minimized revenue loss. Gutting the space provided an opportunity to manage and organize the ceiling. Lighting and large box monitors, for instance, were changed out to make way for more efficient fixtures and flat-screen monitors. All finishes including the floor were removed and replaced, allowing designers to introduce a more soothing color palette. Electrical Needs Designers also had to consider where the remote operator would be situated and where the system's data would be stored. Emergency power was another important consideration. Delays during such critical surgery are unacceptable, so the new room needed an emergency power and an uninterruptible power supply. Planners were concerned about system upgrades that would be needed for increased electrical loads. These loads, however, were actually offset by changing out old equipment with more efficient electrical and computer devices. The electrical upgrade turned out to be insignificant to cost and scope. In addition, the floor area required in the computer or cold room was actually less. Lessons Learned The space did not need to adhere to the same regulations as prior MRI modalities. For example, the planner, a medical/imaging architect, has a paradigm for an MRI facility that requires certain RF and magnetic field shielding, as well as special cooling and venting system requirements. In the Mayo case, however, the magnetic field is not as high. Therefore, the planner didn't need to be quite as concerned with shielding as in conventional MRI spaces; however, mapping the field to assure that no pace maker traffic would occur was still required. Bringing in many professionals ensured a true "outside-the-box" design. While an existing process doesn't exist for magnetic imaging surgery space design, creating an original design for such revolutionary technology is an exciting endeavor. The lab has since passed its one-year anniversary without requiring any significant changes. In the end, team collaboration and cohesiveness were the keys to design success. Bernie Gehrki can be reached at 402-399-1000

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