Analysis of measurement electrode location in bladder urine monitoring using electrical impedance

Abstract

PurposeThe aim of this study was to document more appropriate electrode location of a four-electrode-based electrical impedance technology in the monitoring of bladder filling, and to characterize the relationship between bladder filling duration and the measured electrical impedances.MethodsA simulation study, based on a 2-dimension computational model, was conducted to determine the preferable locations of excitation and measurement electrodes in a conventional four-electrode setup. A human observation study was subsequently performed on eight healthy volunteers during natural bladder urine accumulation to validate the result of the simulation study. The correlation between the bladder filling time and the measured electrical impedance values was evaluated.ResultsThe preferable location of measurement electrodes was successively validated by the model simulation study and human observation study. Result obtained via the selected electrodes location revealed a significant negative correlation (R = 0.916 ± 0.059, P < 0.001) between the measured electrical impedance and the urine accumulation time, which was consistent with the result of simulation study.ConclusionsThe findings in this study not only documented the desirable electrodes location to monitor the process of bladder urine accumulation using four-electrode measurement, but also validated the feasibility of utilizing electrical impedance technique to monitor and estimate the bladder urine volume for those with urological disorders.

A modified voltage changes ratio (MVCR) for in-vitro volume estimation

“…Figure 7 shows that IRM has the lowest accuracy when compared to |GI| -1 , VCR, and MVCR. The studies [11,14,15] show that both GI and VCR have good accuracy in the volume estimation of in-vivo experiments, which is consistent with the simulation results presented in Figures 7a, 7c, and 7d. The GI obtained the lowest error (-4.6E-4), followed by MVCR (1.8E-3) and VCR (2.2E-3).…”

“…Modified VCR VCR associates the voltage change with the volume of the object under study [11]. This is calculated considering one reference measurement (𝑉𝑉 0 ) and one perturbed measurement (𝑉𝑉) (Equation 5).…”

“…EBI is a promising method for monitoring tissue state and the functioning of organs in-vivo [8][9][10]; This technology is increasingly employed in the estimating and monitoring of bladder volume [11]. Schlebusch and collaborators [6,7,12] proposed the GI approach, which is linear and negatively correlated with bladder volume.…”

“…IRM, unlike VCR, does not require these two types of measurements. The accuracy of IRM and VCR indexes is highly dependent on the location of the electrodes [11,12]. The proposed MVCR approach employs redundant bioimpedance measurements based on the injection and measurement patterns proposed in [11], which are obtained by the system described in [15].…”

Electrical Impedance Tomography: Hardware Fundamentals And Medical Applications

“…Current applications of medical images with EIT include: the analysis of intrapulmonary gas [41], [42], monitoring blood pressure [43], detection of intracranial hemorrhages [44], [45], resuscitation of volume of bladder urine [46], [47], establishing bone density [48], cardiac minimization after cardiac arrest [49]. Then, the pathologies…”