Urinary bladder phantom mimicking mechanical properties and pressure during filling

Area of Science:

• Biomedical Engineering
• Medical Device Development
• Urology

Background:

• Phantoms mimicking organ properties are crucial for surgical planning, training, and medical device development.
• Accurate bladder phantoms are needed for urodynamic studies assessing lower urinary tract symptoms, as current models lack realistic stretching and compliant behavior.

Purpose of the Study:

• To develop and validate a versatile method for fabricating accurate bladder phantoms using water-soluble 3D-printed molds.
• To create a bladder phantom that precisely mimics the mechanical properties and pressure-volume curves observed during physiological bladder filling.

Main Methods:

• Fabrication of phantoms using water-soluble 3D-printed molds and silicone rubber.
• Incorporation of a wire net to control silicone expansion and model cystometric capacity.
• Development of a mathematical model to describe pressure increase due to passive hyperelastic properties.

Main Results:

• The fabricated phantom accurately reproduced the bladder's mechanical properties during filling.
• The phantom exhibited a pressure-volume curve typical of cystometric studies, with a compliance of 25.2 ± 1 ml/cmH2O.
• A low root-mean-square error (2.7 cmH2O) was achieved between the theoretical model and experimental data.
• Phantom properties (compliance, wall thickness, capacity) are tunable to simulate various pathologies and human variability.

Conclusions:

• The water-soluble 3D printing method is effective for creating realistic soft, hollow organ phantoms.
• The mathematical model enables the design of phantoms to model healthy or diseased bladders.
• These phantoms can enhance the development and validation of medical devices for bladder-related applications, complementing animal studies.