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 patient marker couples to an anchoring device via a base having a base axis, base connections and a first indicator. The marker includes: an adapter having a first surface with connections configured to mate with the base connections, and a second surface with connections congruent with the base connections, and at least one second indicator. The marker includes an alignment target, having a target region with an alignment pattern, and a socket connected to the target region with socket connections congruent with the first surface connections. In a first configuration the socket couples to the base by mating the first surface connections with the base connections and mating the socket connections with the second surface connections. In a second configuration, the socket fits onto the base by mating the socket connections with the base connections. One of the indicators indicates a target orientation angle 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 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 medical marking device, consisting of a radiotransparent plate having a first plurality of radiopaque elements embedded therein in a first predefined pattern and a second plurality of optical reflectors positioned on a surface in proximity to the plate in a second predefined pattern. The device also includes a sigmoid mounting arm having a first end connected to the radiotransparent plate and a second end containing one or more fastening receptacles.

Abstract: A tool adapter, consisting of an adapter arm having a proximal end terminating with a connection and a distal end having a circular coupling, the circular coupling having a center and defining an axis orthogonal to the circular coupling and passing through the center. The adapter also has a tool grip rotatingly connected to the circular coupling so as to permit rotation of the tool grip about the axis, the tool grip being configured to fixedly retain a tool along the axis.

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 registration marker (40), consisting of a radiotransparent substrate (44) and a pattern (58) formed in at least two dimensions, which is disposed on the substrate and is optically visible. The registration marker also has a multiplicity of radiopaque elements (60), which are disposed in the substrate and are spatially arranged in at least two dimensions to provide a unique pattern.

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: A medical marking device, consisting of a radiotransparent plate having a plurality of radiopaque elements embedded therein in a predefined pattern. The device also has a sigmoid mounting arm having a first end connected to the radiotransparent plate and a second end containing one or more fastening receptacles.

Abstract: Apparatus, consisting of a hinge defining a hinge axis, and a pair of opposing jaws, including a movable jaw and a fixed jaw having a predetermined part radiopaque, so that the fixed jaw location is identifiable from a fluoroscopic image of the fixed jaw. The opposing jaws terminate at proximal and distal regions, and the proximal regions are connected to the hinge so that the movable jaw rotates about the hinge between a jaws closed state and a jaws open state. The jaws are curved in planes parallel to the hinge axis, and terminate in narrowed ends at the distal regions, so that in the closed state the jaws grip one or more sections of vertebrae. The apparatus also has a support structure that retains the hinge and the pair of opposing jaws, and a multiplicity of sharp teeth disposed on respective inner surfaces of the opposing jaws.

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: 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 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: 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.