Abstract: An apparatus includes: a structure for coupling to a patient; a plurality of reflective markers coupled to the structure, wherein the reflective markers are configured to reflect non-visible light; and a securing mechanism configured to secure the structure relative to the patient. An apparatus includes: a first light source configured to project a first structured light onto an object, wherein the first structured light is non-visible; a first camera configured to obtain a first image of the first structured light as projected onto the object; a second camera configured to obtain a second image of the first structured light as projected onto the object; and a processing unit configured to process the first and second images from the first camera and the second camera; wherein the first camera and the second camera are configured for non-visible light detection.

Abstract: An elongated web or strip (200) comprising a wall portion bounded by edge portions and adapted to form a conduit by spirally winding said web and joining adjacent edge portions. The edge portions (210, 220) are adapted to permit relative movement between adjacent portions of the spiral conduit and thereby provide radial alteration of the conduit. The web includes a compensation portion (300) to alter the dimension of the web (200) upon radial alteration of the conduit and thereby compensate for creep in the spiral conduit. In a particularly preferred embodiment the edge portion comprises a primary lock (214, 224) and a secondary or sacrificial lock (212, 222). The sacrificial lock is disengaged by release of the mechanism 215 to permit relative movement there between and thereby effect radial alteration of the conduit.

Abstract: An elongated web or strip (200) comprising a wall portion bounded by edge portions and adapted to form a conduit by spirally winding said web and joining adjacent edge portions. The edge portions (210, 220) are adapted to permit relative movement between adjacent portions of the spiral conduit and thereby provide radial alteration of the conduit. The web includes a compensation portion (300) to alter the dimension of the web (200) upon radial alteration of the conduit and thereby compensate for creep in the spiral conduit. In a particularly preferred embodiment the edge portion comprises a primary lock (214, 224) and a secondary or sacrificial lock (212, 222). The sacrificial lock is disengaged by release of the mechanism 215 to permit relative movement there between and thereby effect radial alteration of the conduit.