A micro-optical system for endoscopy based on mechanical compensation paradigm using miniature piezo-actuation.

Area of Science:

• Optical Engineering
• Medical Device Technology
• Miniaturization

Background:

• Endoscopic procedures require advanced optical systems for visualization.
• Miniaturization of optical components is essential for minimally invasive diagnostic and surgical tools.
• Existing endoscopic optics face limitations in zoom capability and form factor.

Purpose of the Study:

• To investigate the feasibility of a novel miniaturized optical system for endoscopic applications.
• To design and model an optical system with integrated zoom and focus capabilities.
• To develop and test a closed-loop actuation system for precise lens movement.

Main Methods:

• A 14-lens optical system was designed with a mechanical compensation paradigm.
• Optical performance metrics including focal length, field of view, and aberrations were modeled.
• A closed-loop actuation unit utilizing piezo-motors and Hall effect encoders was implemented.
• System performance was evaluated using a prototypical test board.

Main Results:

• The optical system achieved a zoom factor of approximately 2.8x and a field of view up to 56°.
• Predicted lens travel was under 3.5mm, with image plane height consistency across magnification.
• Aberrations and distortion were within acceptable limits (e.g., astigmatism ≤ 25μm, distortion ≤ 12%).
• The actuation system demonstrated positioning accuracy below 5μm over a 4.0mm travel path.

Conclusions:

• The study confirmed the feasibility of the miniaturized optical design for endoscopy.
• The proposed actuation approach is viable for precise lens control in miniaturized systems.
• Manufacturing and opto-mechanical tolerances are critical factors influencing optical performance and require careful management.