Puncture instrument

摘要

A surgical trochar has a housing (3) around a drive device, a lancet (4) and a plate (11) with an aperture (12) that is applied to the patient's skin. The plate is retained by a screw thread (14) which sets the distance to which the lancet penetrates the patient's body tissue by rotating to the required position and is anchored at the correct distance by an intermediate piece (13) that may be rotated with respect to the housing. A guide (17a, 17b) prevents rotation of the plate (11) with respect to the housing.