Steerable Stylet and Flexible Needle System
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Minimally invasive medical procedures face challenges in accurately guiding and tracking flexible, steerable needles due to their variability and susceptibility to tissue characteristics, which can lead to deviation from the target trajectory, and existing systems often have larger diameters that hinder smooth passage through anatomical structures.
Innovation Solution
A minimally invasive system comprising a flexible proximal portion fixedly coupled to a rigid distal portion, with a stylet that includes a steerable portion and a sensor element, and actuation cables to control bending, allowing precise steering and position tracking of the needle within the patient's anatomy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If flexible, steerable needles are used to navigate complex anatomical paths, then the ability to reach target tissue locations is improved, but the needle is more susceptible to deviation from the intended trajectory due to tissue characteristics
Solution Approach 1:
The needle system transitions from a static, rigid structure to a dynamic, multi-segmented flexible structure with articulation points that allow controlled bending and steering. The segments can dynamically adjust their configuration to navigate anatomical obstacles while maintaining trajectory control through active steering mechanisms at each articulation point.
Solution Approach 2:
The system incorporates sensors at the needle tip and along the shaft that provide real-time feedback on position, orientation, and tissue interaction forces. This feedback is used by the control system to continuously adjust the steering of each segment, compensating for deviations caused by tissue characteristics and ensuring accurate trajectory following.
2Stability of the object's composition
If the outer diameter of the needle is increased to improve structural stability, then the needle can maintain its shape better, but the needle cannot pass smoothly through narrow anatomical structures
Solution Approach 1:
The needle is divided into multiple thin segments connected by articulation points, allowing each segment to be slender enough to pass through narrow anatomical structures while the collective arrangement of segments provides the necessary structural stability and shape maintenance through controlled configuration.
Solution Approach 2:
The needle employs flexible, thin-walled segments that can bend and conform to narrow passageways while maintaining sufficient structural integrity. The flexibility allows the needle to navigate tight spaces, while the engineered wall thickness and material properties ensure the segments maintain their intended shape during insertion and positioning.
3Ease of operation
If conventional rigid instruments are used for minimally invasive procedures, then the instruments are easier to control and track, but they cause more tissue damage and require larger incisions
Solution Approach 1:
The rigid instrument structure is replaced with flexible, thin-walled segments that can bend and conform to anatomical structures, enabling minimally invasive access through smaller incisions and natural orifices while reducing tissue trauma. The flexibility allows the instrument to navigate complex paths without requiring large incisions or causing excessive tissue disruption.
Solution Approach 2:
The static, rigid control mechanism is replaced with dynamic, active steering of flexible segments. Each segment can be independently controlled to change orientation and direction, providing ease of operation comparable to rigid instruments while achieving minimally invasive access. The active control system compensates for the flexibility, maintaining precision and controllability.
Data Source
Figure 1
Figure 2
Figure 3A~3C
AI summary
What is described is a minimally invasive system comprising an elongate instrument and a stylet slidably disposed within the lumen of the elongate instrument. The instrument includes a flexible proximal portion fixedly coupled to a rigid distal portion, and a lumen extending from a proximal end to a distal end through the flexible proximal portion and the rigid distal portion and defining a longitudinal axis of the instrument. The stylet includes a flexible body fixedly coupled to a steerable portion and a sensor element extending through the flexible body. The stylet is movable within the instrument between a retracted condition in which the steerable portion is retracted within the instrument and an extended configuration in which the steerable portion at least partially extends from the rigid distal portion of the instrument.