Deflection of a flexible needle during insertion into soft tissue

Area of Science:

• Robotics and Medical Devices
• Biomechanical Engineering
• Surgical Navigation

Background:

• Percutaneous diagnosis and therapies rely on accurate needle insertion into soft, inhomogeneous tissues.
• Flexible needles with bevel tips commonly used in these procedures are prone to deflection during insertion.
• Needle deflection can lead to inaccurate tip placement and deviation from the planned trajectory.

Purpose of the Study:

• To investigate the relationship between needle base forces/torques and needle deflection during insertion.
• To develop a model for estimating needle deflection in soft tissues.
• To enhance the accuracy of needle tip placement in percutaneous interventions.

Main Methods:

• Analysis of forces and torques applied at the needle base during insertion.
• Development of a biomechanical model correlating applied forces/torques with observed needle deflection.
• Experimental validation of the proposed model in soft tissue phantoms or ex vivo models.

Main Results:

• Quantified the correlation between specific needle base forces/torques and the degree of needle shaft curvature.
• Demonstrated the model's ability to predict needle deflection based on applied forces and tissue properties.
• Identified key parameters influencing needle path deviation during insertion.

Conclusions:

• The developed model provides a method to estimate needle deflection during insertion into soft tissues.
• Integration of this model into trajectory generation algorithms can improve the accuracy of needle placement.
• This research contributes to enhanced precision in image-guided interventions and robotic surgery.