Abstract: Variations of integral navigation controls may be used in conjunction with a medical instrument to provide navigation functions for an image guided surgery (IGS) system that is in communication with the integral navigation controls. In some variations, a medical instrument with integrated navigation wheels allows movement of a cursor of the IGS system along the x and y axis by scrolling the wheel, or allows selection, zooming, or other controls by combined clicking and/or scrolling of wheels, and may be sterilized or discarded along with the device. In some other variations, a control overlay may be temporarily attached to the medical instrument to provide additional controls, such as buttons or a pointing stick, and then removed and sterilized or discarded after a procedure. In each variation, inputs may be communicated via wire or wirelessly to an IGS system to provide navigation of images during a surgical procedure.

Abstract: A process for preparing polyether thiocarbonate polyols comprising the step of reacting carbon disulfide and at least one alkylene oxide in the presence of a double metal cyanide catalyst and at least one H-functional starter compound, wherein before first contact with carbon disulfide the double metal cyanide catalyst has previously been contacted with at least one alkylene oxide the the invention likewise relates to a polyol obtainable by the process according to the invention.