Bladder Monitoring Systems: State of the Art and Future Perspectives

Abstract

The lower urinary tract (LUT) is sensitive to nervous system pathologies, injuries and dysfunctions that may lead to the loss or reduction of bladder fullness sensation. Urination assistive devices aimed at supporting bladder emptying and continence control have been proposed so far. However, patients may not perceive the urge to urinate and activate the device accordingly. In this framework, bladder pressure and volume monitoring is crucial and would lead to optimize the use of assistive devices and reduce side effects for the patient. Despite its centrality in restoring LUT functions, urinary bladder monitoring remains not fully explored, yet. In this review paper, we summarize the efforts performed at the clinical and research level towards efficient bladder monitoring. The analysis of the current state of the art enabled to identify the challenges of the field and to draw potential future directions in LUT dysfunction management by engineering solutions. After the introduction of technologies to support urination, a major focus is placed on three groups of monitoring devices, that is, instruments for a clinical setting, wearable devices for continuous and domestic monitoring, and implantable sensors for chronic monitoring. Finally, the main challenges are identified and discussed, highlighting the most crucial points and the main treatment opportunities.INDEX TERMS Bladder pressure monitoring, bladder volume monitoring, implantable biorobotic organs, implantable sensors, urinary dysfunctions. FIGURE 3. Examples of clinical imaging instruments to monitor the urinary bladder. Ultrasound-based volume reconstruction systems (Bladder Scan BVI 9400 [253]) through (a) 2D and (b) 3D methods [102], Copyright 1998, Published by Elsevier Inc., [105]. Bioimpedance tomography device employed for EIT [132], Copyright 2016, Taiwanese Society of Biomedical Engineering, with 16 electrodes arranged along different configurations for bladder volume reconstruction and imaging [128], ((c) EIT electrodes [254], Copyright 2020, IEEE). NIRS method exploiting water or oxyhemoglobin as chromophores and detecting light absorption variations during the filling-voiding cycles (d) [142], Copyright 2018, IEEE, and NIRS device [255]. MRI (picture of Michal Jarmoluk from Pixabay): Cavalieri method to compute the volume (e) [153], and representation of a commercial scanner.

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

“…Over the last few decades, advancements in technology have led to the improvement and optimization of ultrasound devices for BUV monitoring [3,37,[45][46][47][48]. Van Leuteren et al [45] presented another wearable ultrasound device called SENS-U, which is positioned on the lower abdomen using a skin-friendly adhesive.…”

“…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.…”

“…Bladder monitoring is the process of measuring and assessing the function and health of the bladder. It is an essential aspect of urological care, as it allows healthcare professionals to evaluate the bladder's ability to store and empty urine and to detect abnormalities or problems that may be present [3].…”

“…There are various bladder monitoring methods, including invasive and non-invasive techniques for the diagnosis and management of a wide range of urological conditions, such as urinary incontinence, urinary tract infections, bladder cancer and voiding dysfunction. They can also be used in evaluating treatment efficacy and identifying potential alterations or adverse events during treatment [3][4][5][6][7].…”

“…Accurate and reliable diagnosis and UI management is essential for improving patient outcomes [8,9]. BUV monitoring, on the other hand, assesses bladder function and health by measuring the bladder's capacity for storing and voiding urine, thereby enabling the identification of deviations or issues that may exist [3,10]. Both UI management and BUV monitoring could be performed using invasive and non-invasive techniques.…”