Patent ID: 7052502
Filing Date: 2006-05-30
Classification: A61B

Abstract:
1. Medical instrument for creating a cavity for an endoscopic intervention in a human or animal body, comprised of a hollow cylindrical encasing trocar tube which can be inserted into an artificial body opening and an expander which can be extracted from and retracted into said trocar tube, characterized in that the expander comprised of a retaining element arranged outside the trocar tube in addition to at least two spring blades which are made of a flexible material and form an arc in the respective middle sections, whereby said at least two spring blades are shifted toward one another on the retaining element in such a way that the plane surface created by the arcs are intersecting and the two ends of each blade are fixed to the retaining element, extending through the tube of the trocar, wherein the trocar tube comprises two coaxial sleeves arranged one inside of the other and at a distance to one another, an outer one of the two coaxial sleeves having a generally cylindrical inner surface and an inner one of the coaxial sleeves having a generally cylindrical outer surface, the inner surface of the outer sleeve and the outer surface of the inner sleeve defining a generally annular gap, the generally annular gap extending substantially along a length of the trocar, and wherein the spring blades fixed in said retaining element extend through the annular gap formed between said coaxial sleeves.