MD Buyline's Intelligence Briefings has an interesting story on the ever problematic topic of cell phone interference. Last month, MD Buyline reported on the Mayo Clinic's latest study on cell phone interference (also noted on this site). Their article generated this feedback from MD Buyline reader Terrance Clemans:

After some initial EMC
testing that identified several significant potential problems (e.g.,
ventilator failure), St. Margaret Mercy adopted a no cell phone use policy in
lieu of continued EMC testing. Clemans reported the facility had a recent
incident that resulted in the loss of all collected data by a relatively new
(two-year-old) diagnostic EKG on a patient when a family member's cell phone
rang in the patient's room. They had to reload data and completely redo the
test. "That's a non-life threatening error, of course," Clemans
stated, "but it goes back to the fact that we still can't predict what the
medical equipment will do in all situations."

Unintentional interference - from cell phones, noisy electric moters, florescent lights, or a slew other sources - will never be completely eliminated. The latest Mayo study found no problems at a distance greater than 32 inches. Findings like this are why the trend in hospitals is to allow cell phone use anywhere except the ICU. One of the variables in cell phone interference is the distance of cell sites from the hospital and the amount of energy required for mobile phones to communicate with those distant sites. A low cost solution for this is the Spotwave active repeater.