Wearable bladder volume monitoring device based on bioimpedance

WANG Sirui; YANG Jiantao; TANG Yi; SHI Ping

doi:10.19529/j.cnki.1672-6278.2025.01.07

Abstract：Aiming at the problem of untimely urination due to the inability to perceive bladder filling with patients recovering from bladder nerve dysfunction,we designed a wearable real-time urine filling monitoring device based on bioimpedance.The device was composed of bioimpedance acquisition hardware and a mobile terminal.Four electrodes and sensors were fixed to the abdominal surface of the bladder through textile tape.A pair of stimulation electrodes could generate a sinusoidal excitation current of 840 μA at 50 kHz,while the other pair of sensing electrodes,collected bioimpedance data every 500 ms.Firstly,the impedance data obtained from the ac-quisition electrode were sent to the mobile terminal via Bluetooth for pre-processing,and the baseline drift caused by the change of body position was alleviated by collecting human posture information.Then,the processed data were fed into a fitting algorithm to com-pute bladder fullness levels.Finally,based on user information and the current impedance data,a linear support vector machine(SVM)model was used to determine bladder fullness,an alert and vibration alarm were triggered when the fullness condition was reached.The experimental results showed that the root mean square error(RMSE)and linear correlation coefficient R2 of the regression model was 56.43 mL and 0.82,respectively,and the accuracy of the linear SVM algorithm was 95.2%.The device can monitor the bladder fullness level in real-time,which is of great significance for the health management of patients recovering from neurogenic bladder dysfunction.