Abstract: Apparatus for mounting in a bone of a patient, consisting of a rigid elongated member having an axis of symmetry and a distal section, a proximal section, and an intermediate section connecting the distal and proximal sections. The apparatus has n helical blades, formed in the distal section, distributed symmetrically about the axis, each of the blades having a helix angle greater than zero and less than 45°. A cross-section of the distal section, taken orthogonally to the axis of symmetry, includes n mirror planes containing the axis of symmetry, wherein n is a whole number greater than one, and wherein the blades are configured to penetrate into the bone and engage stably therein. Adapters coupling the apparatus to different types of markers are also described.

Abstract: An imaging system, including a head-mounted display worn by a system operator. A marker defines a plane when attached to a human subject. Optically reflective elements are disposed on the marker and on opposing sides of the plane in a non-symmetrical arrangement with respect to the plane. A memory stores a graphical representation of a tool used in a procedure performed on the human subject, and an image of anatomy of the human subject. A camera attached to the display acquires an image of the marker and the tool. A processor analyzes the image to identify the plane and to identify a side of the plane wherein the camera is located, and to render to the display the image of the anatomy of the human subject with the graphical representation of the tool superimposed thereon from a point of view in the identified side of the plane.

Abstract: Apparatus and methods are described including tracking a tool portion and a patient marker from a first line of sight, using a first tracking device disposed upon a first head-mounted device that includes a display. The tool portion and the patient marker are tracked from a second line of sight, using a second tracking device. When a portion of the patient marker and the tool portion are both within the first line of sight, an augmented reality image is generated upon the first display based upon data received from the first tracking device and without using data from the second tracking device. When at least the patient marker portion and the tool portion are not both within the first line of sight, a virtual image of the tool and anatomy of the patient is generated using data received from the second tracking device. Other applications are also described.

Abstract: Apparatus, including a retaining structure (54), positioned near a subject's eye that has a pupil with a diameter, an optical combiner (52A) mounted on the structure before the eye, and a pixelated screen (60A) having an array of variably transparent pixels coating the combiner. There is an image capturing device (68A) mounted on the structure to capture an image of a scene viewed by the eye, and a projector (64A) is mounted on the structure to project at least one of a portion of the captured image and a stored image onto a section of the screen at a selected location thereof. A processor (26) renders the screen section at least partially opaque, selects the section location in response to a region of interest in the scene identified by analysis of the captured image, and determines a dimension of the section in response to the pupil diameter.

Abstract: A marker for image guided surgery, consisting of a base, having a base axis, connecting to a clamp; and an alignment target. The alignment target includes a target region having an alignment pattern formed thereon, and a socket connected to the target region and configured to fit rotatably to the base, whereby the alignment target is rotatable about the base axis. The alignment target also includes an optical indicator for the socket indicating an angle of orientation of the alignment target about the base axis.

Abstract: An imaging system, including a head-mounted display worn by a system operator. A marker defines a plane when attached to a human subject. Optically reflective elements are disposed on the marker and on opposing sides of the plane in a non-symmetrical arrangement with respect to the plane. A memory stores a graphical representation of a tool used in a procedure performed on the human subject, and an image of anatomy of the human subject. A camera attached to the display acquires an image of the marker and the tool. A processor analyzes the image to identify the plane and to identify a side of the plane wherein the camera is located, and to render to the display the image of the anatomy of the human subject with the graphical representation of the tool superimposed thereon from a point of view in the identified side of the plane.

Abstract: A positioning marker, consisting of a base having a retroreflective surface. The marker also has a cover, which is fitted over and fastened to the base and has a plurality of openings through which the retroreflective surface is visible.

Abstract: Apparatus, consisting of a hinge, defining a hinge axis, and a pair of opposing jaws terminating at respective proximal regions and distal regions. The proximal regions are connected to the hinge so that at least one of the jaws is configured to rotate about the hinge between a closed state and an open state of the jaws. In addition, the jaws are curved in respective planes parallel to the hinge axis, and terminate in respective narrowed ends at the respective distal regions, wherein in the closed state the jaws are configured to grip one or more sections of vertebrae. The apparatus also has a support structure that is configured to retain the hinge and the pair of opposing jaws. A multiplicity of sharp teeth are disposed on respective inner surfaces of the opposing jaws.

Abstract: Apparatus, including a retaining structure (54), positioned near a subject's eye that has a pupil with a diameter, an optical combiner (52A) mounted on the structure before the eye, and a pixelated screen (60A) having an array of variably transparent pixels coating the combiner. There is an image capturing device (68A) mounted on the structure to capture an image of a scene viewed by the eye, and a projector (64A) is mounted on the structure to project at least one of a portion of the captured image and a stored image onto a section of the screen at a selected location thereof. A processor (26) renders the screen section at least partially opaque, selects the section location in response to a region of interest in the scene identified by analysis of the captured image, and determines a dimension of the section in response to the pupil diameter.

Abstract: Apparatus, including a retaining structure (54), positioned near a subject's eye that has a pupil with a diameter, an optical combiner (52A) mounted on the structure before the eye, and a pixelated screen (60A) having an array of variably transparent pixels coating the combiner. There is an image capturing device (68A) mounted on the structure to capture an image of a scene viewed by the eye, and a projector (64A) is mounted on the structure to project at least one of a portion of the captured image and a stored image onto a section of the screen at a selected location thereof. A processor (26) renders the screen section at least partially opaque, selects the section location in response to a region of interest in the scene identified by analysis of the captured image, and determines a dimension of the section in response to the pupil diameter.

Abstract: Apparatus, including a retaining structure (54), positioned near a subject's eye that has a pupil with a diameter, an optical combiner (52A) mounted on the structure before the eye, and a pixelated screen (60A) having an array of variably transparent pixels coating the combiner. There is an image capturing device (68A) mounted on the structure to capture an image of a scene viewed by the eye, and a projector (64A) is mounted on the structure to project at least one of a portion of the captured image and a stored image onto a section of the screen at a selected location thereof. A processor (26) renders the screen section at least partially opaque, selects the section location in response to a region of interest in the scene identified by analysis of the captured image, and determines a dimension of the section in response to the pupil diameter.