2-DOF auto-calibration for a 3D endoscope system based on active stereo

Area of Science:

• Medical Imaging
• Surgical Technology
• Biomedical Engineering

Background:

• Accurate measurement of lesion size and shape is crucial for endoscopic medical treatments.
• Previous 3D endoscope systems increased diameter by mounting projectors externally, raising patient burden and risks.
• A minimally invasive approach is needed to improve patient outcomes and procedural efficiency.

Purpose of the Study:

• To develop a 3D endoscope system with an internally housed pattern projector for measuring living tissue shape and size.
• To introduce an auto-calibration technique for intra-operative extrinsic parameter calibration.
• To validate the system's accuracy and demonstrate 3D reconstruction capabilities.

Main Methods:

• Integrated a pattern projector within the endoscope's instrument channel, deployable as needed.
• Developed an auto-calibration method using a point marker on the projector observed on the target surface for intra-operative extrinsic parameter determination.
• Performed experiments to calibrate external parameters and validate 3D reconstruction accuracy.

Main Results:

• The internal projector design successfully avoided increasing the endoscope's diameter.
• The auto-calibration technique effectively determined extrinsic parameters intra-operatively.
• Accurate 3D reconstructions of human tissue were achieved, with validated epipolar constraints.

Conclusions:

• The developed 3D endoscope system with an internal projector offers a less invasive solution for accurate lesion measurement.
• The auto-calibration technique ensures precise 3D measurements without increasing endoscope size.
• This technology has the potential to improve diagnostic accuracy and treatment planning in endoscopic procedures.