The development, fabrication and characterization of two novel dry bioelectrodes--conductive and capacitive ones--for biopotential monitoring are presented. The new electrodes have the potential to improve the applicability of dry electrodes in ambulant recording of ECG by reducing motion artifacts as well as the contact impedance to the skin. Furthermore, a passive filter network is integrated into the new electrodes to suppress slow offset fluctuation of the ECG signal caused e.g. by motions like breathing or changes in the electrode-skin interface properties. Compared to standard gel electrodes these new electrodes exhibit equivalent and superior contact impedances and biosignals. The integrated filter network effectively suppresses fluctuating offset potentials.

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The Mpv17 gene encodes a mitochondrial inner-membrane protein that has been implicated in the metabolism of reactive oxygen species. The loss of function in Mpv17-/- mice leads to early sensorineural deafness associated with severe inner ear degeneration and late onset of kidney failure. The present study demonstrates that the onset of the degeneration of the cochlear neuroepithelia is related to the onset of auditory function and appears to be first restricted to the outer hair cells (OHC), which subsequently undergo rapid degeneration. At the age of 18 days, the OHC lateral membrane degenerates and extensive vacuolization of the cytoplasm is followed by lysis of the OHCs. Such degenerative processes have been seen for the first time in relation to auditory dysfunction. The structural degeneration pattern of the OHC appears to be similar to the described paraptotic processes (an alternative form of programmed cell death) discussed in the literature as a cause of cytoplasmic neurodegeneration. In contrast, the melanocyte-like intermediate cells that are of neural crest origin and that are located in the stria vascularis, undergo apoptosis, as documented ultrastructurally. A lack of Mpv17 protein function in mitochondria thus seems to initiate tissue-specific cell-death pathways resulting in the pathology seen during the degeneration process.

Objective. Minimally invasive procedures minimize iatrogenic tissue damage and lead to a lower complication rate and high patient satisfaction. To date only experimental minimally invasive single-port approaches to the lateral skull base have been attempted. The aim of this study was to verify the feasibility of a minimally invasive multiport approach for advanced manipulation capability and visual control and develop a software tool for preoperative planning. Methods. Anatomical 3D models were extracted from twenty regular temporal bone CT scans. Collision-free trajectories, targeting the internal auditory canal, round window, and petrous apex, were simulated with a specially designed planning software tool. A set of three collision-free trajectories was selected by skull base surgeons concerning the maximization of the distance to critical structures and the angles between the trajectories. Results. A set of three collision-free trajectories could be successfully simulated to the three targets in each temporal bone model without violating critical anatomical structures. Conclusion. A minimally invasive multiport approach to the lateral skull base is feasible. The developed software is the first step for preoperative planning. Further studies will focus on cadaveric and clinical translation.