Abstract: An adjustable seal includes a first ring extending about an axis and including a plurality of first teeth. The adjustable seal also includes a second ring extending about the axis and including a plurality of second teeth. The first ring and the second ring cooperatively defining a passage extending along the axis. The adjustable seal has a locked configuration in which the second teeth engage the first teeth and prevent movement of the first ring relative to the second ring, and an unlocked configuration in which the first ring is able to rotate relative to the second ring. The adjustable seal also includes a flexible member attached to the first ring and the second ring. Rotation of the first ring relative to the second ring in the unlocked configuration of the adjustable seal causes the flexible member to extend across at least a portion of the passage defined by the first ring and the second ring.

Abstract: Among the various aspects of the present disclosure is the provision of devices, systems, and methods for tracking the positions and orientations of at least one bone screw implanted within a surgical site. The disclosed device includes an extension that includes an extension base configured to couple to the bone screw, a marker arm coupled at one end to the extension base in a hinged arrangement, and an optical marker attached to a free end of the marker arm opposite the hinged attachment. The optical marker includes a pair of lenticular arrays in a coplanar arrangement in which the major axes of the lenticular arrays are mutually perpendicular. Each lenticular array is configured to display different hues at different viewing angles. The disclosed method includes transforming a single image of a surgical site containing at least one bone screw and extension into the global positions of each bone screw based on the pixel positions and hues corresponding to the lenticular arrays of each optical marker.

Abstract: The disclosure provides for a variable stiffness catheter. The catheter may include an inner layer forming an inner lumen, a middle layer surrounding the inner layer, and an outer layer surrounding the middle layer. The middle layer may include an annular lumen and a plurality of strings within the annular lumen, and the plurality of strings may be connected to the inner layer. Applying a vacuum and evacuating the annular lumen of the middle layer alters a frictional force between the inner layer and the outer layer and thereby changes the catheter's flexural rigidity.