Impedance ratio method for urine conductivity-invariant estimation of bladder volume

Thomas Schlebusch, Jakob Orschulik, Jaakko Malmivuo, Steffen Leonhardt, Dorothea Leonhäuser, Joachim Grosse, Michael Kowollik, Ruth Kirschner-Hermanns, Marian Walter


Non-invasive estimation of bladder volume could help patients with impaired bladder volume sensation to determine the right moment for catheterisation. Continuous, non-invasive impedance measurement is a promising technology in this scenario, although influences of body posture and unknown urine conductivity limit wide clinical use today. We studied impedance changes related to bladder volume by simulation, in-vitro and in-vivo measurements with pigs. In this work, we present a method to reduce the influence of urine conductivity to cystovolumetry and bring bioimpedance cystovolumetry closer to a clinical application.


electrical impedance tomography; cystovolumetry; bladder volume

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