Trajectory guide, access port, and fiducial marker alignment

Inventors

Solar, Matthew S. • Pagan, Craig J. • Perry, Glenn D. • Wittfeldt, Anthony Adam-Henry

Assignees

C2C DEVELOPMENT LLC

Abstract

A trajectory guide for introducing an instrument into a human or animal subject is described. A guide stem can be removed in sections without disturbing the aligned instrument. An access port portion of the trajectory guide can be left in place, without disturbing trajectory alignment, and can allow overlying skin to be sutured closed. The access port can provide infusate delivery, such as using an injection port, catheter or the like. A fiducial marker arrangement can provide easy and accurate trajectory alignment, for use with the present trajectory guide, another trajectory guide, or without any trajectory guide.

Core Innovation

The invention relates to a cranial trajectory guide apparatus for a human or animal subject, including a base configured to be affixed substantially in a burr hole in a skull and a socket located in the burr hole when the base is affixed. A spherical or other ball is located in and pivotable with respect to the socket, with a central pivot point of the ball located below a surface of the skull when the base is affixed. The ball includes therethrough a pivotably adjustable instrument guide ball passage that provides an adjustable instrument trajectory defined longitudinally by the ball passage.

An engageable ball retainer is configured to be located in and engageable into the socket, contained substantially within the burr hole when the base is affixed, and engaged into the socket to secure the ball and inhibit pivoting of the ball to hold the instrument trajectory substantially constant. The retainer includes a plurality of upward-facing user-engageable receptacle features configured to engage the retainer from above the burr hole to permit threading the retainer into the socket. An elongate guide stem having a bore is configured such that a distal end of the guide stem engageably concentrically aligns the bore with the ball passage, with the guide stem extending longitudinally outward from and supported by the ball.

The apparatus further includes fiducial marker arrangements with a first set of one or more fiducial markers defining a unique first plane extending orthogonal to the trajectory and a centroid defined in the first plane at a specified or determinable relationship to where the first plane is intersected by the trajectory. A second set of one or more fiducial markers defines a unique second plane extending orthogonal to the trajectory and spaced apart from the first plane, thereby enabling trajectory alignment verification using the defined planes and centroid relationships. The document also describes fiducial marker configurations including discrete fluid-filled markers and concentric ring-shaped fiducial markers in first and second planes orthogonal to the trajectory.

Claims Coverage

The independent claims are directed to a trajectory guide apparatus using a ball-and-socket mechanism with a concentrically aligned guide stem, and to the same trajectory concept combined with two orthogonal fiducial-marker-defined planes including centroid relationships. The main inventive features include the burr-hole base with socket, the pivotable ball defining an adjustable instrument trajectory via a ball passage, the ball retainer that secures the ball to inhibit pivoting, the elongate guide stem with a bore concentrically aligned with the ball passage, and the fiducial-marker planes spaced apart from each other.

Across the independent claims, the core coverage requires a burr-hole affixable base with a socket, a pivotable ball defining an adjustable instrument trajectory via a ball passage, and a ball retainer that secures the ball to inhibit pivoting. The elongate guide stem bore concentrically aligns with the ball passage to support the trajectory, and a further independent claim specifies fiducial-marker structures that define a first plane and a second plane orthogonal to the trajectory and spaced apart, with a centroid relationship to the trajectory intersection.

Stated Advantages

Documented Applications