Catheter Backend Mechanism for Compact Steerable Control
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Solution Overview
Problem
Current backend mechanism control systems for minimally invasive medical procedures, particularly those involving steerable elongate devices like catheters, face challenges in providing stability, compactness, and predictable action, which are essential for successful surgical outcomes.
Innovation Solution
A control system that includes a chassis with a pulley and capstan mechanism, utilizing pull wires to steer the elongate member, combined with a shape-sensing optical fiber for precise control and communication, and a sealed housing to prevent fluid ingress, ensuring stability and repeatable action.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a backend mechanism control system uses a compact design with pulley and capstan components, then the device size is reduced, but the stability and predictability of control may be compromised
Solution Approach 1:
The backend mechanism is divided into distinct functional segments: a pulley component for initial wire routing and a capstan component for precise tension control. This segmentation allows each component to be optimized for its specific function while maintaining overall compactness. The pulley handles bulk wire movement while the capstan provides fine-adjustment stability, resolving the contradiction between small size and reliable control.
Solution Approach 2:
The pull wire acts as an intermediary element connecting the compact pulley-capstan mechanism to the elongate medical device. This intermediary transmits control forces reliably from the small backend mechanism to the larger device, enabling stable and predictable control despite the reduced size of the control system itself.
2Ease of repair
If the control system components are made removable for sterilization, then ease of maintenance is improved, but device complexity increases
Solution Approach 1:
The backend mechanism is designed as a separable assembly where the pulley and capstan components can be independently removed from the housing. This segmentation enables selective sterilization of components that require it while leaving other parts in place, simplifying the sterilization process despite the presence of multiple components.
Solution Approach 2:
The housing serves multiple functions: it protects internal components, provides mounting structures for the pulley and capstan, and facilitates sterilization through its removable design. This multi-functionality reduces the need for separate protective structures, thereby limiting the increase in overall device complexity.
3Manufacturing precision
If the capstan is designed with a helical groove for pull wire routing, then the control precision is improved, but manufacturing complexity increases
Solution Approach 1:
Instead of using complex mechanical routing structures or multiple components to achieve precise pull wire control, the invention uses a helical groove pattern on the capstan surface. This geometric feature naturally guides the pull wire through the required path, providing precise control through a simple, single-piece component that is relatively easy to manufacture using standard machining or molding processes.
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
The system enhances the stability and predictability of steerable elongate devices during minimally invasive procedures, allowing for consistent and effective control, thereby improving surgical outcomes.
Implementation Method 1
The pulley may be rotatable about a first axis
Implementation Method 2
The capstan may have a pull wire-supporting surface that permits the pull wire to wrap around the capstan
Implementation Method 3
a shape-sensing optical fiber for precise control and communication
Data Source
AI summary
A backend mechanism of a control system for a steerable elongated medical instrument includes a plurality of drive components and steering components arranged to provide a compact, reliable, steering control to the elongated medical instrument.