Steerable Medical Device Tendon Segmentation for Small Vessel Navigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current steerable guidewires and catheters have outer diameters greater than 5 mm due to complex construction, making them unsuitable for interventional cardiology and neuroradiology procedures that require navigation through smaller vessels, such as those with diameters as small as 0.5 mm.
Innovation Solution
Development of extremely low-profile, elongate steerable devices with a bendable distal region and a proximal handle region, featuring multiple tendons coupled to axial translation regions, allowing for precise bending and navigation through small vessels without compromising diameter, and a controller system for manual or robotic control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If mechanical tension wires are housed within a lumen of the guidewire/catheter to enable steering, then the device becomes steerable, but the outer diameter increases to greater than 5 mm
Solution Approach 1:
The device is divided into multiple independent tendons (first tendon, second tendon, third tendon, fourth tendon) that can be selectively tensioned. Each tendon is coupled to a respective axial translation region, allowing independent control of each tendon's tension to achieve precise steering of the distal tip without requiring a large outer diameter housing for all wires.
Solution Approach 2:
The invention transitions from a single-lumen wire configuration to a multi-dimensional tendon arrangement where tendons are positioned at different radial locations and coupled to different axial translation regions. This spatial distribution of tendons allows steering control without increasing the overall outer diameter, as the tendons utilize the internal volume and radial space efficiently.
2Length of moving object
If the outer diameter is reduced to less than 1 mm for navigation through small vessels, then the device becomes suitable for interventional cardiology and neuroradiology, but the steering capability and structural integrity are compromised
Solution Approach 1:
The device employs dynamic tensioning of individual tendons through axial translation regions that can be selectively moved. This allows the distal tip to be dynamically steered to different positions and orientations during navigation through small vessels, maintaining steering capability despite the reduced outer diameter of less than 1 mm.
Solution Approach 2:
The device utilizes composite construction with a flexible elongate body made of coil or multiple coils, combined with multiple tendons and axial translation regions. This composite structure provides both the flexibility needed for navigation through small vessels and the mechanical integrity required for effective steering, resolving the contradiction between small diameter and steering capability.
3Measurement precision
If multiple tendons are coupled to axial translation regions to enable precise bending control, then the device achieves improved steering precision, but the device complexity increases
Solution Approach 1:
Each axial translation region serves multiple functions: it couples to a tendon for bending control, provides a interface for robotic or manual actuation, and can be independently controlled to achieve precise distal tip positioning. This multi-functionality reduces the need for separate control mechanisms, thereby managing complexity while maintaining high bending precision.
Solution Approach 2:
The tendons are housed within the elongate body structure, with the axial translation regions integrated into the proximal end. The first and second tendons are coupled to first and second axial translation regions respectively, creating a nested arrangement where the control mechanism is contained within the device structure itself, reducing overall complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables navigation through small vessels with diameters as low as 0.5 mm while maintaining device functionality, providing a solution for interventional cardiology and neuroradiology procedures with reduced outer diameter and increased flexibility.
Implementation Method 1
each axial translation region is configured to move in a distal to proximal line to axially translate the tendon coupled to the axial translation region and thereby deflect the distal tip
Implementation Method 2
The elongate body may generally be formed as a coil (e.g., helical coil), and may generally include the bendable distal tip region, an intermediate region and the proximal handle region
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 2C
AI summary
The invention is directed to an elongate steerable device (200) for insertion into a subject's body. The device has an elongate body having a distal bending region (201), an intermediate region (203) and a proximal handle region (209), and it comprises one or more tendons attached to the distal bending region (201) and one or more axial movable actuating regions (205) arranged along an outer surface of the proximal handle region (209). Each of the axial movable actuating regions is coupled to a tendon, and configured to move in a proximal to distal line to axially translate the tendon, thereby deflecting the distal tip (201). The proximal handle region (209) is configured to permit a passage of another device over this elongate steerable device.