Development of an Implantable Wireless and Batteryless Bladder Pressure Monitor System for Lower Urinary Tract Dysfunction

Abstract

Background: Closed-loop neuromodulation based on bladder pressure is an effective therapy for lower urinary tract dysfunction. The catheter-based cystometry normally used for bladder pressure measurement is not conducive to patient health because it will bring great mental stress to the patient and increase the risk of infection. Method: This paper designs and implements an implantable wireless and batteryless bladder pressure monitor system that monitors bladder storage in real time by implanting a miniature packaged sensor which transmits the feedback signal to the external receiver through BLE (Bluetooth Low Energy). The implanted part is powered by a dedicated magnetic resonance based wireless power transmission system, which means no battery is needed. Results: The maximum distance to which power can be transmitted is 7cm. The in vitro experiment proves that the system performance can meet the requirement of bladder pressure monitoring. The animal experiment uses rabbits as a model to verify the effectiveness of the system. After implantation, this system can work for a long time without replacing the battery. Conclusion: This system can monitor the pressure of the bladder and provide a basis for Closed-loop neuromodulation in patients with lower urinary tract dysfunction. INDEX TERMS Long-term implantation, real-time bladder pressure measurement, sensor, wireless power transmission.

Micro-/Nano-Structured Biodegradable Pressure Sensors for Biomedical Applications

“…Despite of the recent development in biodegradable pressure sensors, there are still some issues, such as sensitivity, operating range, and controllability of biodegradability, essentially to be improved for accurate pressure monitoring of various tissues and organs. In other words, regarding there are huge recent demands for healthcare and diagnosis of diseases in early stage through the pressure sensing of diverse tissues and organs, such as intracranial pressure [ 152 , 153 , 154 , 155 , 156 , 157 ], intraocular pressure [ 158 , 159 , 160 , 161 , 162 , 163 ], heartbeat [ 164 , 165 , 166 ], and bladder pressure [ 167 , 168 , 169 , 170 ], we expect that the high-performance biodegradable pressure sensors will be much more important for diverse biomedical applications in the future.…”

Applications of Microwaves in Medicine

“…A similar method was used to power an implant without a battery at the resonant frequency of 140 kHz via a rectangular coil wrapped around the device. The pressure data was transmitted by Bluetooth BLE after analog-to-digital conversion of pressure signals obtained by a commercial liquid pressure sensor [110]. Another example of a batteryless implantable bladder sensor had a flexible diaphragm that transduced pressure variations to capacitance changes [111].…”

Materials and Biomedical Applications of Implantable Electronic Devices

“…Reproduced with permission. [240] Copyright 2020, IEEE. f) Images of the expandable and implantable bioelectronic complex for the urinary bladder.…”

“…[14] The implantable bladder sensors with microsize have attracted great interest for chronic pressure monitoring. There are the implantable wireless monitoring system for bladder pressure (Figure 8e), [240] and the implantable pressure and acceleration sensor to measure the small-scale autonomous movements relevant to bladder physiology. [241] Jang et al reported an expandable and implantable bioelectronic complex for the urinary bladder (Figure 8f).…”