Simultaneous ranging and force sensing on a single-mode fiber for minimally invasive interventions

Area of Science:

• Biomedical Engineering
• Optical Sensing
• Minimally Invasive Surgery

Background:

• Minimally invasive interventions require precise real-time feedback on distance and force.
• Existing probes often lack integrated sensing capabilities, limiting their application in delicate procedures.
• Miniaturization and intrinsic alignment are crucial for effective endoscopic tools.

Purpose of the Study:

• To develop a compact, coaxial fiber probe integrating optical coherence tomography (OCT) ranging and fiber Bragg grating (FBG) force sensing.
• To enable synchronized distance-force feedback for enhanced control during minimally invasive interventions.
• To demonstrate the probe's utility in endoscopic palpation and subretinal injection procedures.

Main Methods:

• A coaxial fiber probe design incorporating a single-mode fiber with a short no-core and graded-index fiber segment.
• Utilizing OCT for precise distance measurement and FBG for force sensing.
• Developing a weakly focused beam to extend the depth of focus while maintaining a miniature probe design.

Main Results:

• The probe successfully distinguished stiff inclusions from surrounding tissue during endoscopic palpation.
• Simultaneous detection of contact and puncture was achieved during a subretinal injection model, evidenced by changes in distance and force.
• The integrated system demonstrated synchronized distance-force feedback capabilities.

Conclusions:

• The developed coaxial fiber probe offers a scalable platform for integrated optical sensing.
• This technology has significant potential for robotic microsurgery and other precision manipulation tasks.
• The probe's miniature design and synchronized feedback enhance safety and efficacy in minimally invasive interventions.