An event monitor is a device used to diagnose unexplained fainting that may be caused by irregular heartbeats. Often the spells are infrequent, making it difficult to diagnose. Willis-Knighton offers the world’s smallest event monitor. The device is about the size of a paperclip and can be injected under the skin. The procedure can be performed as an outpatient and left in for an extended period of time until this irregular heart beat occurs, helping the physician identify where it originated so the irregularity can be treated.