Hybrid Bladder Phantom to Validate Next-Generation Optical Wearables for Neurogenic Bladder Volume Monitoring.

Area of Science:

• Biomedical Engineering
• Optical Instrumentation
• Medical Imaging

Background:

• Optics-based wearables for bladder volume monitoring are an emerging technology.
• A lack of standardized phantoms hinders the validation of these novel devices against established methods like ultrasound.
• This study addresses the need for a reliable validation tool for optical bladder monitoring systems.

Purpose of the Study:

• To introduce and demonstrate the performance of a novel hybrid bladder phantom.
• To validate near-infrared spectroscopy (NIRS)-based bladder monitoring devices.
• To compare the performance of optical devices with ultrasound as a gold standard.

Main Methods:

• A hybrid bladder phantom was developed and tested for repeatability with water volumes from 100 mL to 350 mL.
• Diffuse optical spectroscopy (DOS) using a near-infrared optical device was performed.
• Machine learning models were utilized to predict bladder volume from optical signals.

Main Results:

• The phantom demonstrated consistent size and position during repeatability tests.
• Seven machine learning models were evaluated using DOS data.
• The top two models achieved an average absolute volume error between 12.7 mL and 19.0 mL.

Conclusions:

• A hybrid bladder phantom was successfully developed for validating NIRS-based bladder monitoring devices.
• The phantom provides a reproducible and robust tool for device validation.
• This work supports the advancement of optical wearables for bladder volume monitoring.