A Strain Gauge-Based Implantable Bladder Volume Monitoring Sensor

Sensory awareness of bladder fullness can be compromised after spinal cord injuries or due to certain medical conditions, significantly impacting the quality of life for affected individuals. Implantable medical devices that can monitor bladder activity and fullness are being developed to address this issue. In this study, we present a novel strain gauge-based sensor encapsulated in silicone designed to monitor urine volume in the bladder. The sensor is anchored on the bladder wall using hooks, limiting the need for glue or sutures, and enabling minimally invasive implantation. The sensor was validated on both a synthetic bladder phantom and on a pig's bladder during an in-vivo study. The results demonstrate the capability of the sensor to provide a linear indication of the infill volume using the bladder wall's strain. This measurement technique was found to be a superior indicator of urine accumulation compared to intravesical pressure, making it a promising choice for restoring sensory awareness through chronic bladder monitoring. Further optimization of the anchoring technique could enhance the accuracy and usability of this approach. This research contributes to the advancement of implantable bladder sensors, with potential applications in improving the management of bladder-related conditions and enhancing the quality of life of people suffering from bladder dysfunction.