Here is a link to an interesting paper entitled "Biophilia: Designing with Nature in Mind."  This paper discusses the healthcare interior design movement biophilia, or "dealing with human’s basic interaction and love of nature... into healthcare design as a way to improve patient and employee wellness."  Check it out - interesting stuff:

http://www.healthcaredesignmagazine.com/sites/healthcaredesignmagazine.com/files/whitepapers/Lamin-Art_Whitepaper042913.pdf