Abstract: A method for calibrating a robot arm with the aid of a measuring device that has a first calibration element and a calibration element which is fixed to the robot arm and which can be moved relative to the first calibration element by adjusting joints of the robot arm. The first calibration element and the calibration element fixed to the robot arm are designed such that, in the event of a displacement of the calibration element fixed to the robot arm relative to the first calibration element in an advance direction, the calibration element fixed to the robot arm is guided by the first calibration element from various starting positions to the same defined end position. The method includes positioning the calibration element fixed to the robot arm relative to the first calibration element in one of the starting positions, and moving in a force-controlled manner the calibration element fixed to the robot arm relative to the first calibration element in the advance direction with the aid of the robot arm.

Abstract: A dihydroxyphenyl cross-linked macromolecular network is provided that is useful in artificial tissue and tissue engineering applications, particularly to provide a synthetic, implantable tissue matrix material for a wide variety of tissue types. In particular, artificial or synthetic cartilage, vocal cord material, vitreous material, soft tissue material and mitral valve material are described. In an embodiment, the network is composed of tyramine-substituted and cross-linked hyaluronan molecules, wherein cross-linking is achieved via peroxidase-mediated dityramine-linkages that can be performed in vivo. The dityramine bonds provide a stable, coherent hyaluronan-based hydrogel with desired physical properties.