ECHOGENIC COATINGS WITH OVERCOAT

摘要

An ultrasonically visible solid device for inserting into a non-gas target medium comprises an echogenic surface having structures entrapping gas when the device is in the target medium, the entrapped gas causing the device to be ultrasonically visible, wherein the gas-entrapping structures are covered wi th a flexible overcoat that does not significantly reduce the compressibility o f the gas trapped in the structures.