Actually, cell phones are only prohibited on certain floors of the hospital. On others, such as the orthopedics floor, it's fine to use a cell phone. It's only on floors that use the telemetry (like ICU or the coronary units..., etc.) that ban cell phone use.
Actually, my brother was in hospital recently and we were told no mobiles anywhere in the hospital because it interferes with things like heart pacemakers not just hospital equipment.
Mind you it didn't stop one doctor who took a call just saying "Is anyone on a pacemaker? no? good" and he just used it anyway.
As a long time hospital employee I know that no hospital allows cellular use within the building due to the old myth of radio waves interfering with equipment. However, from actual tech. stand point this is just that myth. There have never been any cases of equipment malfunction from cellular phone usage. Reality has never stopped hospitals from continuing the ban or with the "I'm not part of the ban because I'm a doctor." violators of said rules. So, if Sloan chooses to use a cell. inside he would be the rule and not the exception.