Abstract: A device is provided for precision positioning of a medical instrument within a biotic structure through a hole in an exterior wall of the biotic structure. A structural member of the instrument extends through the hole of the biotic structure at a puncture point with the instrument disposed on the structural member at a first end within the biotic structure. A medical instrument holder disposed at a second end of the structural member outside the biotic structure is provided for retaining a medical instrument at a predetermined angle. The device also includes instrument manipulating apparatus for supporting and positioning the instrument holder to position the medical instrument at the desired location while maintaining the structural member substantially stationary in the plane of the exterior wall at the puncture point. A selectively moveable support has legs that are independently pivotally rotatable about a joint, such as a ball and socket joint.