US Patent 11439413 Epidural/subdural minimally invasive access tool

A cranial drill guide includes a housing and a drill guide sleeve assembly pivotally attached to the housing. The drill guide sleeve assembly has at least two degrees of freedom to allow the drill guide sleeve assembly to be moved to a first pivoted position for forming an angled burr hole through a cranial surface. The two degrees of freedom can comprise a pivoting motion of the drill guide sleeve assembly and an axial motion of a portion of the drill guide sleeve assembly.