Handheld histology-equivalent sectioning laser-scanning confocal optical microscope for interventional imaging.

Area of Science:

• Biomedical Optics
• Microscopy Engineering
• Medical Imaging

Background:

• Conventional histology relies on microtome sectioning for tissue analysis.
• Interventional imaging requires high-resolution, portable diagnostic tools.
• Existing imaging techniques may lack the necessary resolution for certain diagnostic and surgical applications.

Purpose of the Study:

• To report a novel handheld, forward-imaging, laser-scanning confocal microscope (LSCM).
• To demonstrate optical sectioning capabilities comparable to conventional histology.
• To target the device for interventional imaging applications.

Main Methods:

• Fabrication of a 2-axis microelectromechanical system (MEMS) scanning mirror using complementary metal-oxide-semiconductor (CMOS) compatible methods.
• Integration of the MEMS mirror and micro-optics into a cost-effective, rapid-prototyped probe (18 mm outer diameter, 54 mm rigid length).
• Utilizing ZEMAX simulations for optical design and experimental validation of resolution and field of view.

Main Results:

• Achieved optical sectioning comparable to microtome slice thicknesses.
• Experimental lateral and axial resolutions measured at 0.5 microm and 4.2 microm, respectively, with a 200 x 125 microm field of view.
• Demonstrated reflectance imaging of ex vivo swine liver and fluorescence imaging of tumor biomarkers in human breast tissue.

Conclusions:

• Inexpensive, portable handheld optical microscopy based on silicon micromirror technology is feasible.
• This technology can significantly enhance interventional imaging.
• Potential applications include improved disease diagnosis, image-guided microsurgery, and monitored photodynamic therapy.