Millions of outpatient procedures are performed each year; they outnumber inpatient visits and are growing. Out patient or ambulatory care simply refers to operations, lab tests or treatments that don't require an overnight stay in a hospital (although hospitals also perform outpatient services). Examples include dialysis, diagnostic scans and imaging, drug infusions, biopsies, blood transfusions, and rehab therapy. Surgeries such as dental, cataract, reconstructive (plastic) and elective cosmetic operations are also usually performed same-day in a surgery center or clinic. These routine medical procedures are meant for healthier patients; higher-risk cases would be admitted to hospitals for overnight treatment, medication and observation. Outpatient care can be safely performed within a relatively short time by having trained healthcare personnel and the right equipment. Some physicians even outfit their offices for minor procedures. Ambulatory care is less time-consuming and less expensive than treatment in overnight institutions; doctors, nurses and patients all benefit. Ambulatory care centers are able to process samples using basic lab equipment such as balances, tube rockers and cold storage. They also have the capability of maintaining aseptic conditions by sterilizing rooms and instruments with sanitizers such as disinfecting ultra-violet light systems and autoclaves. Supplies are organized using clean storage and dispensers, and biological samples are transferred to other rooms using convenient pass-through chambers. See these and other necessary equipment and supplies below for creating a sanitary outpatient care center.