Telescoping Biopsy Needle Rigid Extension for Tracking Accuracy
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Solution Overview
Problem
Minimally invasive surgical procedures using flexible, steerable needles face challenges in accurate guidance and tracking due to the variability in needle shape and susceptibility to tissue characteristics, leading to deviations from the target trajectory.
Innovation Solution
A medical device comprising an elongate sheath with a rigid distal portion and a flexible proximal portion, along with a holding mechanism, allows for the extension of a rigid distal section of an instrument, enabling precise insertion and tracking of the needle within the sheath, which includes a sensor system for real-time position evaluation and adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a flexible, steerable needle is used to navigate tortuous pathways, then the ability to reach target locations is improved, but the accuracy and stability of needle positioning deteriorates due to shape variability and tissue interaction
Solution Approach 1:
The needle system is divided into multiple segments including a flexible needle portion and a rigid extension portion that can be independently controlled. This segmentation allows the flexible portion to navigate tortuous pathways while the rigid portion maintains stable, accurate positioning at the target site, resolving the contradiction between adaptability and measurement precision
Solution Approach 2:
A rigid extension portion acts as an intermediary between the flexible needle and the target tissue. This intermediary element provides a stable, trackable interface that maintains geometric relationship with the target while allowing the flexible needle to adapt to pathway variations, thereby preserving positioning accuracy despite needle flexibility
2Measurement precision
If a rigid instrument is used for biopsy, then the stability and tracking accuracy are improved, but the ability to navigate tortuous pathways and avoid intervening anatomy deteriorates
Solution Approach 1:
The instrument is segmented into a flexible needle portion for pathway navigation and a rigid extension portion for stable tracking and biopsy. This allows each segment to perform its optimal function - the flexible portion adapts to tortuous pathways while the rigid portion maintains tracking accuracy
Solution Approach 2:
The system transitions from a static rigid structure to a dynamic configuration where the rigid extension can be deployed and retracted relative to the flexible needle. This dynamic adjustment allows the system to optimize between flexibility for navigation and rigidity for tracking accuracy based on procedural needs
3Length of moving object
If the needle length is increased to reach deep target locations, then the ability to access internal organs is improved, but the control and steerability of the needle deteriorates
Solution Approach 1:
The long needle is divided into a flexible distal portion and a rigid proximal extension. The rigid extension provides leverage and control points closer to the operator, improving steerability and control of the overall long needle assembly while maintaining the necessary length to reach deep targets
Solution Approach 2:
The rigid extension portion serves as a control intermediary that transmits operator input more effectively to the flexible needle portion. This intermediary structure improves the mechanical advantage and control authority over the long needle, making it easier to steer and position accurately
Data Source
AI summary
A medical device comprises an elongate sheath comprising a rigid distal portion and a flexible proximal portion and defining a first lumen. The medical device further comprises an elongate instrument that fits within the lumen. The elongate instrument comprises a flexible proximal section and a rigid distal section. The rigid distal portion of the sheath is at least as long as the rigid distal section of the instrument. In a non-extended condition of the instrument, the distal section of the instrument is entirely within the distal portion of the sheath. In an extended condition of the instrument when the instrument is distally extended within the lumen of the sheath, at least a portion of the distal section of the instrument is outside of the distal portion of the sheath and a portion of the proximal section of the instrument is within the distal portion of the sheath.