A Small 8-Electrode Electrical Impedance Measurement Device for Urine Volume Estimation in the Bladder

Abstract

Urinary incontinence is prevalent among elderly people. Recent studies have demonstrated the effectiveness of continence care based on urine volume measurement for elderly people who maintain their urinary storage function, but have difficulty feeling bladder fullness owing to dementia or neurological disorders. Electrical impedance measurement is a feasible technique that can be adopted in the diaper or underwear for continuous and unobtrusive urine volume measurements. We developed a small sensor device that can measure electrical impedance with a resolution of 0.017 Ω, which is sufficiently small to capture abdominal impedance alterations triggered by urine accumulation. The results obtained from a preliminary feasibility test in a young healthy volunteer suggested that the 8-electrode electrical impedance measurement with linear regression can estimate urine volume in the bladder in humans for the first time.

Technological Solutions for Urinary Continence Care Delivery for Older Adults

“…2,5,6,12,13,17,21 Most studies involved the use of sensors or telemonitoring system for continence care. 6,[14][15][16]19,20,[22][23][24] Studies using sensors described how the sensors had the potential to measure urine volume and thus containment product saturation, facilitating the delivery of appropriate and timely continence care for those with contained incontinence. 14,16,[20][21][22] A quasiexperimental, controlled quantitative-qualitative study used a smart sensor for the construction of a continence care plan with which to manage the continence and toileting needs of older adult nursing home residents.…”

“…A review article focused on the need for novel and more advanced methods of UI management, and how technology-based devices may be used for urine volume estimation 2,25. The clinical trials included evaluated the efficacy of “smart” undergarments for UI management and the performance of a measurement device in estimating human bladder urine volume 21,23. The abstract was a clinical trial examining the performance of a smart sensor-based continence management system, and how such a device could potentially contribute to a reduction in the manual checks of incontinence products (Table).…”

“…Most studies involved the use of sensors or telemonitoring system for continence care 6,14–16,19,20,22–24. Studies using sensors described how the sensors had the potential to measure urine volume and thus containment product saturation, facilitating the delivery of appropriate and timely continence care for those with contained incontinence 14,16,20–22.…”

State of the Art of Non-Invasive Technologies for Bladder Monitoring: A Scoping Review

“…The technology is used to measure the electrical properties of biological tissue, and it is based on applying a small high-frequency electric current on the specific body segment, and measuring the resulting voltage generated from that segment, using conventional or dry electrodes [22,37,55]. Several studies have used electrical bioimpedance technology to obtain different information, such as the bladder state (full or not full) at any time, and for the monitoring of BUV [3,36,[56][57][58][59][60][61][62][63][64][65][66]. A schematic of the electrical bioimpedance technology's method of operation can be seen in Figure 4.…”

“…In another study, Noyori et al [65] were inspired by the EIT technique to estimate BUV by using eight-electrode electrical impedance measurements. They developed a device based on the HUZZAH32 board, and the system on chip AFE4300, which is an integrated analogue front-end that uses a tetrapolar I-V method for each electrical impedance measurement channel.…”