Compliant Glass Mechanism Instrumented with a Bragg Grating to Measure Indentation Force.

Area of Science:

• Biomedical Engineering
• Optical Sensing
• Materials Science

Background:

• Accurate mechanical characterization of biological tissues is vital for disease diagnosis.
• Current methods for tissue analysis may lack the precision needed for early detection.
• Minimally invasive tools are required for in-situ tissue assessment.

Purpose of the Study:

• To develop and characterize a novel optical force sensor for mechanical tissue discrimination.
• To enable in-situ measurement of mechanical properties within the bronchial tree.
• To investigate the feasibility of using mechanical signatures for differentiating healthy from cancerous lung tissue.

Main Methods:

• Design and fabrication of a compliant glass mechanism integrated with a waveguide and Bragg grating.
• Optimization of sensor production parameters through experimental studies.
• Experimental characterization of sensor stiffness and optical response to applied force.

Main Results:

• The developed force sensor exhibits a linear and repeatable response to applied forces.
• The sensor demonstrated a precision of ±26 mN over a force range of 0 to 250 mN.
• Successful characterization and validation of the sensor's performance across multiple trials and samples.

Conclusions:

• The optical fiber force sensor is suitable for measuring mechanical properties of biological tissues.
• The sensor's design allows for potential insertion into the bronchial tree for in-situ analysis.
• The repeatable and linear response supports its application in differentiating lung tissue types based on mechanical signatures.