Noninvasive Bladder Volume Monitoring Using Bioimpedance

Abstract

Due to the electrical conductivity of the urine, several bioimpedance techniques have been considered for bladder volume monitoring. This chapter shows several approaches for bladder volume estimation; among these, Global Impedance (GI), presents a high accuracy in volume estimation. Other proposed approaches are Voltage Change Ratios (VCR), Impedance Ratio Method (IRM), and Focused Impedance Method (FIM), which presents highly sensitive to changes in the conductivity, just like GI. Therefore, these approaches are not suitable for long-term monitoring of the bladder, because the conductivity of urine varies with health status and diet. The proposal FIM-IE presents a low sensibility to the conductivity uncertainty; being a promising technique for long-term monitoring of the bladder and would support the assisted bladder emptying process.