Patent ID: 7717919
Filing Date: 2010-05-18
Classification: A61B

Abstract:
1. An apparatus for aligning an external target path relative to an internal target path, the apparatus comprising: a first guide pin with a first distal tip to designate a first point on the internal target path; a second guide pin with a second distal tip to designate a second point on the internal target path; a first hinged mechanism connected to the first guide pin and to a reference bar with a first hinge between the first guide pin and the reference bar; a second hinged mechanism connected to the second guide pin and to the reference bar with a second hinge between the second guide pin and the reference bar, the second hinged mechanism capable of movement along the reference bar to alter a distance between the connection of the first hinged mechanism to the reference bar and the connection of the second hinged mechanism to the reference bar; spacing landmarks on the first and second hinged mechanisms sufficient to allow a creation of a first parallelogram involving the first and second hinged mechanisms such that the reference bar is placed parallel to the internal target path; and an external target path guide connected to a hinged parallelogram, the hinged parallelogram connected to the reference bar so that the external target path guide is always parallel to the reference bar but may move relative to the reference bar, whereby placing the hinged parallelogram parallel to either guide pin after creation of the first parallelogram sets the external target path guide to establish an external target path with a slope that is equal to a slope of the internal target path and a predictable offset from co-linear with the internal target path.