Structural flexibility of laparoscopic instruments: implication for the design of virtual reality simulators

Area of Science:

• Surgical Simulation
• Biomechanical Engineering
• Medical Device Design

Background:

• Practice Specificity Theory emphasizes realistic training models for effective learning.
• Virtual reality (VR) simulation is explored as a tool for surgical education and evaluation.
• Current VR simulators aim to replicate operating room (OR) conditions but may lack instrument fidelity.

Purpose of the Study:

• To quantify the structural flexibility of laparoscopic instruments under varying stress conditions.
• To investigate the influence of material and diameter on instrument deviation.
• To inform the development of more realistic VR surgical simulators.

Main Methods:

• Measured instrument shaft deviation using infrared markers under applied stress.
• Tested laparoscopic instruments of various materials and diameters.
• Compared instrument deviations in simulation to those observed during porcine liver cholecystectomy.

Main Results:

• All tested laparoscopic instruments exhibited significant deviation from their pre-stress positions.
• Small disposable instruments showed the largest deviations, while large reusable instruments showed the least.
• A linear relationship was found between applied stress and instrument deviation, influenced by instrument diameter.

Conclusions:

• Laparoscopic instruments are not rigid and undergo substantial deviation during procedures.
• The structural flexibility of instruments varies with size and material.
• Accurate modeling of laparoscopic instrument flexibility is crucial for enhancing the fidelity of VR surgical simulators.