Miniature fiber-optic force sensor for vitreoretinal microsurgery based on low-coherence Fabry-Pérot interferometry

Area of Science:

• Biomedical Engineering
• Ophthalmology
• Surgical Instrumentation

Background:

• Vitreoretinal surgery demands precise tool control, but human touch cannot detect sub-millinewton forces.
• Current surgical tools lack the sensitivity to prevent delicate retinal tissue damage.
• A sensitive force sensor (FS) integrated with surgical tools is needed to improve outcomes.

Purpose of the Study:

• To design and develop a miniature force sensor (FS) for vitreoretinal surgery.
• To enable detection of sub-millinewton forces during surgical procedures.
• To enhance surgical precision and minimize tissue trauma.

Main Methods:

• A fiber-optic common-path phase-sensitive optical coherence tomography (OCT) system was employed.
• A miniature Fabry-Pérot (FP) cavity was created between an optical fiber tip and a surgical tool.
• Interferometric signals from a broadband light source were analyzed to measure cavity length changes and infer force.

Main Results:

• The developed force sensor (FS) demonstrated linear response to axial forces.
• The system achieved a force sensitivity better than 0.25 millinewton.
• The phase of the interferometric signal correlated directly with applied force.

Conclusions:

• The miniature fiber-optic force sensor is suitable for vitreoretinal surgery applications.
• This technology can provide surgeons with crucial haptic feedback, preventing tissue damage.
• The developed FS offers a promising solution for enhancing safety and efficacy in delicate surgeries.