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For some years patient safety has been an important topic for the design of the healthcare systems in many countries. In Germany we are still in the starting phase of this development. Here, patient safety is not a main focus for research and there is only little funding for these topics. Thus most findings on patient safety have been derived in foreign studies. Slowly, some find their way into the clinical routine in Germany. This paper summarises the state of development of patient safety from a trans-sectoral point of view and outlines essential fields of action for the German healthcare system.

Mono- and multi-segmental testing methods are required to identify segmental motion patterns and evaluate the biomechanical behaviour of the spine. This study aimed to evaluate a new testing system for multisegmental specimens using a robot combined with an optical motion analysis system. After validation of the robotic system for accuracy, two groups of calf specimens (six monosegmental vs. six multisegmental) were mounted and the functional unit L3-4 was observed. Using rigid body markers, range of motion (ROM), elastic zone (EZ) and neutral zone (NZ), as well as stiffness properties of each functional spine unit (FSU) was acquired by an optical motion capture system. Finite helical axes (FHA) were calculated to analyse segmental movements. Both groups were tested in flexion and extension. A pure torque of 7.5 Nm was applied. Statistical analyses were performed using the Mann-Whitney U-test. Repeatability of robot positioning was -0.001±0.018 mm and -0.025±0.023° for translations and rotations, respectively. The accuracy of the optical system for the proposed set-up was 0.001±0.034 mm for translations and 0.075±0.12° for rotations. No significant differences in mean values and standard deviations of ROM for L3-4 compared to literature data were found. A robot-based facility for testing multisegmental spine units combined with a motion analysis system was proposed and the reliability and reproducibility of all system components were evaluated and validated. The proposed set-up delivered ROM results for mono- and multi-segmental testing that agreed with those reported in the literature. Representing the FHA via piercing points determined from ROM was the first attempt showing a relationship between ROM and FHA, which could facilitate the interpretation of spine motion patterns in the future.

The rolling and shear textures of aluminium (f.c.c.) and Fe-16% Cr (b.c.c.) have been compared. First a 90° rotation relationship about the transverse direction was found experimentally between the stable orientations of the rolling textures and the shear textures. This was explained with the symmetry of the glide systems and the orientation relationship between both coordinate systems. Second for both kinds of deformation namely rolling and shear a 90° rotation relationship about the transverse direction was also found between the stable b.c.c. and f.c.c. orientations. This was explained with the Taylor theory and the Sachs model making use of the orientation relationship between f.c.c. and b.c.c. glide systems.