American Shared Hospital Services outsources gamma knife stereotactic radiosurgery equipment and services to medical centers. Gamma knife services are provided through American Shared's majority-owned subsidiary, GK Financing, the world leader in gamma knife stereotactic radiosurgery services. GK Financing provides gamma knife services at more than 20 hospitals, clinics and research centers, including The Johns Hopkins Hospital in Baltimore, Mercy Health Center in Oklahoma City and the Boston Gamma Knife Center. ASHS also offers The Operating Room for the 21st Century, which provides state-of-the-art surgical suites at major medical centers on a fee-for-use or other shared basis. OR21 operating rooms incorporate diagnostic imaging equipment and robotic technology to guide surgical procedures. Another cornerstone of the OR21 is the computer-controlled, motorized operating room tables and ICU beds with on-board sensors and dispensers for oxygen, anesthetic gases and intravenous fluids. American Share Hospital Services is headquartered in San Francisco.