ASHRAE Journal, Apr. 2014.
http://tinyurl.com/p5b8gah

"Health-care design evolves constantly, reflecting improvements and advancements in surgical techniques, equipment (such as MRIs and robotic surgical equipment), clinical practices, hospital design trends, energy efficiency, sustainable design, and other factors. Ventilation for health-care facilities must change to be aligned with the changing needs of health-care facilities design, patients, surgeons, clinical staff, and visitors."