Rotational Atherectomy Catheter With Outer Tube Rotation Limit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing medical devices for removing objects in blood vessels, such as plaques or thrombi, face challenges in treating hardened or bifurcated stenosed sites, and often result in guide wire entanglement or device damage due to excessive rotation.
Innovation Solution
A medical device with a rotatable drive shaft and outer tube limited by a moving member within a predetermined range, using grooves and housings to restrict excessive rotation, preventing guide wire entanglement and device damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the outer tube rotates to adjust the cutting portion position, then the position control precision is improved, but the guide wire becomes entangled and the device may be damaged due to excessive rotation
Solution Approach 1:
The device transitions from a static rotation limit to a dynamic solution where the drive shaft rotates independently within the outer tube. This dynamic configuration allows the cutting portion to be precisely positioned through drive shaft rotation while the outer tube remains stable, eliminating guide wire entanglement and device damage caused by excessive outer tube rotation.
Solution Approach 2:
The device is segmented into functionally independent components: the outer tube provides structural stability and guides the guide wire, while the drive shaft performs rotation to position the cutting portion. This segmentation allows each component to specialize in its function, with the drive shaft handling rotation without causing outer tube entanglement.
2Ease of operation
If the outer tube is made rotatable to enable cutting portion adjustment, then the ease of operation is improved, but the device complexity increases due to additional rotation limiting mechanisms
Solution Approach 1:
The device uses dynamic independence between the drive shaft and outer tube, where the drive shaft can rotate freely within the non-rotating outer tube. This eliminates the need for complex rotation limiting mechanisms, grooves, or interlocking structures, simplifying the device while maintaining ease of operation for cutting portion adjustment.
Solution Approach 2:
The rotational function is extracted from the outer tube and assigned to the drive shaft. This separation removes the need for the outer tube to have rotation-limiting features, simplifying its structure to just a protective and guiding component, while the drive shaft handles all rotation-related operations.
3Device complexity
If the guide wire lumen is disposed only at the distal portion, then the device structure is simplified, but the guide wire becomes entangled with the proximal portion when the distal portion rotates
Solution Approach 1:
The device implements dynamic independence where the drive shaft (containing the guide wire lumen) can rotate within the stationary outer tube. This allows the guide wire to rotate with the drive shaft without becoming entangled with the proximal outer tube, maintaining structural simplicity while ensuring guide wire reliability.
Solution Approach 2:
The device segments the guide wire containment function to the drive shaft, which is rotationally independent from the outer tube. This segmentation allows the guide wire to move with the rotating drive shaft without conflicting with the stationary proximal outer tube structure.
Data Source
AI summary
A medical device that removes an object in a body lumen, includes a rotatable drive shaft, an outer tube that accommodates the drive shaft and is rotatable independent of the drive shaft, a cutter attached to a distal portion of the drive shaft for cutting the object, a first housing that accommodates a proximal portion of the drive shaft and has an outer surface including a first groove that extends around a rotation axis of the drive shaft, a second housing interlocked with a proximal portion of the outer tube and rotatable around the first housing, the second housing having an inner surface that faces the outer surface and includes a second groove that extends along the rotation axis, and a moving member that fits into the first and second grooves and is movable along the first and second grooves according to rotation of the second housing.