Experimental evaluation of a coaxial needle insertion assistant with enhanced force feedback

Area of Science:

• Robotics
• Biomedical Engineering
• Surgical Technology

Background:

• Accurate detection of tissue property changes during needle insertion is crucial for diagnosis and preventing damage to vital structures.
• Small force variations from deep membranes can be masked by needle shaft friction, limiting operator perception, especially in delicate procedures like brain surgery.
• Existing methods lack sufficient force feedback to reliably distinguish subtle tissue variations.

Purpose of the Study:

• To develop and evaluate a novel robotic coaxial needle insertion assistant designed to enhance operator force perception.
• To improve the detection of subsurface tissue structures, such as membranes, during needle insertion procedures.
• To differentiate between needle tip forces and shaft friction forces for clearer haptic feedback.

Main Methods:

• Development of a force-controlled (admittance control) robotic coaxial needle insertion assistant.
• Separation of cutting force at the needle tip from shear friction on the needle shaft within the coaxial design.
• Experimental testing with users performing blind needle insertions into artificial tissues with membranes under two feedback conditions: combined shaft/tip force versus tip force only.

Main Results:

• Users demonstrated a significantly higher success rate in detecting membranes when provided with feedback solely from the needle tip force.
• The robotic assistant effectively separated tip forces from shaft friction, providing clearer sensory information.
• The system's performance was found to be compliant with clinical application requirements.

Conclusions:

• The robotic coaxial needle insertion assistant significantly improves the ability to detect subsurface tissue changes by providing enhanced, filtered force feedback.
• Focusing haptic feedback on needle tip interaction, rather than combined forces, is critical for improving surgical precision and safety.
• This technology holds promise for enhancing diagnostic capabilities and procedural safety in various medical interventions requiring needle insertion.