Research on dynamic urine volume detection system based on smart flexible textile sensors

Abstract

Urine leakage volume is an important indicator reflecting the severity of incontinence in patients. Currently, there are limited smart diapers capable of continuous dynamic monitoring of urine volume. This study developed two types of urine volume sensors, resistive and capacitive, which were integrated with traditional diapers to assess urine leakage levels: mild leakage (0-5 mL), moderate leakage (6-12 mL), and severe leakage (above 12 mL). Three patterns of resistive urine volume sensors were designed, and the results showed that the A pattern could accurately determine urine volume and frequency levels. Additionally, three electrode spacing designs were tested for the capacitive urine volume sensors. The results indicated that the sensor with a 1 cm electrode spacing could determine the urine volume range, with each 1 mL increase in urine causing a capacitance rise of approximately 1.5-1.8 pF, with an error of about ± 0.5 mL per increment. Both resistive and capacitive methods showed high accuracy in monitoring urine volume and frequency. This study validated the feasibility of smart flexible fabric sensors in detecting urine volume and frequency, providing a potential solution for better assessing and managing the condition of incontinence patients.

Keywords: Capacitance method; Resistance method; Urinary incontinence; Urinary volume monitoring; Urination frequency; Wearable fabric.

Fig. 1

(a) Resistive urine volume sensor structure and liquid absorption diagram; (b) capacitive smart diaper structure and liquid absorption diagram.

Fig. 2

(a) Urine volume sensor design; (b) resistive urine volume sensor physical image.

Fig. 3

(a) Urine volume sensing design diagram; (b) capacitive urine volume sensing prototype.

Fig. 4

(a) Schematic diagram of resistive urine volume measurement; (b) physical setup for resistive urine volume measurement.

Fig. 5

(a) Schematic of capacitance-based urine volume testing; (b) physical setup for capacitance-based urine volume testing.

Fig. 6

Schematic diagram of module A structure and sampling amplitude change graphs for different urine volumes (a)1 mL, (b) 2 mL, (c) 3 mL.

Fig. 7

Depicts the schematic diagram of module B, illustrating the amplitude variation in sampling for different urine volumes (a) 1 mL, (b) 2 mL, (c) 3 mL.

Fig. 8

Structure schematic of Module C—Sampling amplitude change graph for different urine volumes (a) 1 mL, (b) 2 mL, (c) 3 mL.

Fig. 9

Capacitance variation with different urine volumes (a) 1 mL, (b) 2 mL, (c) 3 mL; (d) physical setup for urine volume testing.

Fig. 10

Capacitance variation with different urine volumes. (a) 1 mL, (b) 2 mL, (c) 3 mL; (d) physical setup for urine volume testing.

Fig. 11

Capacitance variation with different urine volumes (a) 1 mL, (b) 2 mL, (c) 3 mL; (d) physical setup for urine volume testing.

Fig. 12

Capacitance variation graph for random urinary volume titration.

Fig. 13

(a) Upper body test image; (b) upper body test data graph.

Fig. 14

Variation of sampling amplitude with different urine volumes.