A simple sensor calibration technique for estimating the 3D pose of endoscopic instruments

Area of Science:

• Medical instrumentation
• Surgical robotics
• Calibration techniques

Background:

• Accurate tracking of endoscopic instruments is crucial for minimally invasive surgery.
• Existing calibration methods can be complex and require specialized equipment.

Purpose of the Study:

• To present a simple, user-friendly calibration method for estimating the pose of rigid endoscopic instruments.
• To determine the tip position and orientation relative to an electromagnetic tracking device.

Main Methods:

• A two-step calibration protocol was developed.
• Instrument shaft orientation determined via 360° rotation around its shaft using a surgical trocar.
• Instrument tip 3D position determined by contact with a planar surface.

Main Results:

• Achieved submillimeter accuracy for tooltip position estimation.
• Achieved subdegree accuracy for shaft orientation estimation relative to a reference frame.
• Demonstrated utility in augmented reality simulation applications.

Conclusions:

• The proposed method is simple, inexpensive, and requires no special calibration frames.
• Potential applications include surgical training systems and intraoperative guidance.
• Offers a practical solution for enhancing endoscopic instrument tracking.