Handheld ultrahigh speed swept source optical coherence tomography instrument using a MEMS scanning mirror

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Optical Engineering

Background:

• Optical Coherence Tomography (OCT) is crucial for retinal imaging.
• Existing OCT systems can be bulky and limited in speed and field of view.
• Handheld OCT devices offer potential for broader clinical applications.

Purpose of the Study:

• To develop an ultrahigh-speed, handheld swept source optical coherence tomography (SS-OCT) ophthalmic instrument.
• To evaluate the ergonomic designs of handheld SS-OCT devices.
• To assess the feasibility of SS-OCT for early retinal disease screening.

Main Methods:

• Utilized a 2D MEMS mirror and a vertical cavity surface-emitting laser (VCSEL) for SS-OCT.
• Achieved an axial scan rate of 350 kHz with 10 µm axial resolution.
• Implemented motion correction algorithms for volumetric data acquisition.
• Acquired standard (6x6 mm²) and wide-field (10x10 mm²) volumetric scans in 1.4 seconds.
• Obtained high-definition B-scans (10 mm and 6 mm) in 0.57 seconds.

Main Results:

• The handheld SS-OCT instrument demonstrated an ultrahigh speed of 350 kHz.
• Achieved 10 µm axial resolution and a 3.08 mm imaging range in tissue.
• Successfully generated motion-corrected volumetric OCT data (6x6 mm² and 10x10 mm²).
• Produced high-definition B-scans with excellent detail.
• Enabled the generation of en face OCT images registered to fundus features.

Conclusions:

• The developed handheld SS-OCT instrument is a promising tool for ophthalmic imaging.
• Its high speed and resolution facilitate early detection of retinal diseases.
• The technology has potential for diverse applications beyond traditional clinics, including pediatrics and remote healthcare.