Bistable Puncturing Tool for Retinal Vein Cannulation

An innovative surgical tool prototype dedicated to safe puncturing has been developed for the treatment of retinal vein occlusions (RVOs). The tool is manufactured monolithically by femtolaser printing in fused silica. It consists of a programmable bistable mechanism equipped with a puncturing needle and a fluidic channel to transport and inject drugs into retinal veins. The outer diameter of the segment of the tool entering the eye is below 1mm. The innovative approach used for the manufacturing of the long flexible fluidic channel is based on a series of chimneys reducing the etching time, which are then sealed by CO2 laser melting. First tests made by a medical surgeon with tool prototypes show that the puncturing function is successful: the rapid and repeatable puncturing motion of the tool tip provided by the bistable mechanism allows safe vein puncturing, while the programming allows the tuning of the puncturing stroke.