Dr. Matthew R. Myers, research physicist, talks with Don Marlowe about computer analysis of side-port spinal needles. A proposed design modification for these needles has been analyzed via computational fluid dynamics simulation by researchers at FDA/CDRH. The computer simulations showed that the reduced orifice of the modified needle leads to a substantially redirected anesthetic jet (relative to the original design), and the potential exists for this jet to mix poorly with the ventral wall of the spinal canal and eventually pool in high concentrations. The researchers alerted the clinical community to this potentially adverse effect in a journal publication. Computer simulations reduce the need for device testing and enable the FDA to respond more quickly in medical-device evaluations.