Rotational Atherectomy Piloting Tip Bushing Eccentric Abrasion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rotational atherectomy devices face limitations in effectively opening arteries to desired diameters due to restricted size capabilities, lack of control over diameter opening, and potential for embedding or screwing into lesions, which can lead to ineffective tissue removal and stent restenosis.
Innovation Solution
A high-speed rotational atherectomy device with a piloting tip or bushing mounted distally to the abrasive element, featuring a concentric profile and eccentric abrading head, allows for the creation of a piloting hole before the abrading head contacts the stenosis, enabling the device to open the artery to a larger diameter than the abrading head's nominal size by using a guide wire with a smaller diameter and a flexible drive shaft with an eccentric abrading head.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a burr is used to remove stenotic tissue, then tissue removal is achieved, but the artery can only be opened to a diameter equal to or slightly larger than the maximum outer diameter of the burr, requiring multiple burr sizes
Solution Approach 1:
The device is divided into two functional segments: a pilot hole-forming burr and an enlarged eccentric abrading section. The pilot burr creates an initial hole, while the eccentric section provides the additional opening capability, eliminating the need for multiple burr sizes.
Solution Approach 2:
The enlarged eccentric section is positioned offset from the rotational axis, creating orbital motion that opens the artery in a radial dimension beyond the burr's outer diameter. This eccentric positioning allows the artery to be opened to a diameter substantially larger than the maximum outer diameter of the burr.
2Adaptability or versatility
If the enlarged eccentric section is made flexible to allow larger diameter opening, then artery opening capability is improved, but control over the diameter of the artery actually abraded is reduced
Solution Approach 1:
The pilot burr forms a pilot hole through the stenotic tissue before the enlarged eccentric section engages. This preliminary action creates a defined pathway that guides and constrains the subsequent abrading action, ensuring precise control over the diameter of the artery that is actually abraded.
Solution Approach 2:
The pilot hole acts as an intermediary structure between the burr and the enlarged eccentric section. It mediates the interaction by providing a controlled pathway that limits the radial excursions of the eccentric section, thereby maintaining precision in the abraded diameter.
3Productivity
If the enlarged eccentric section is placed within the stenotic tissue to achieve abrasion, then tissue removal is effective, but the device cannot be placed through stenotic tissue that completely blocks the passageway
Solution Approach 1:
The pilot burr performs the preliminary action of creating a pilot hole through completely blocked stenotic tissue. This initial penetration establishes a pathway that allows the enlarged eccentric section to subsequently engage and perform effective abrasion, solving both placement and effectiveness issues.
Solution Approach 2:
The device is segmented into a pilot hole-forming component and an abrading component. The pilot burr handles the difficult task of penetrating complete blockages, while the enlarged eccentric section handles the tissue removal, dividing the challenging functions into manageable stages.
4Ease of operation
If a concentric abrasive tip is used to create a pilot hole, then device placement is improved, but the path and diameter of treatment is limited to the minimum size lesion
Solution Approach 1:
The enlarged eccentric section is positioned offset from the rotational axis, creating orbital motion that treats tissue beyond the concentric path. This dimensional change from concentric to eccentric motion expands the treatment diameter beyond the minimum lesion size while maintaining ease of placement.
Solution Approach 2:
The eccentric positioning of the enlarged abrading section creates asymmetric orbital motion during rotation. This asymmetry allows the abrading surface to contact tissue at varying radial distances from the center, treating a broader diameter of tissue than the concentric pilot hole alone.
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 device effectively opens stenotic lesions to diameters larger than the abrading head's size, preventing embedding and ensuring effective tissue removal while maintaining control, thus addressing the limitations of prior devices.
Implementation Method 1
an abrasive section... When rotated at high speeds, the abrasive segment is capable of removing stenotic tissue from an artery
Data Source
Figure 1
Figure 2~5
Figure 6~9
AI summary
A high-speed rotational atherectomy device for opening a stenosis in an artery having a given diameter, comprising: a guide wire; a flexible elongated, rotatable drive shaft advanceable over the guide wire, the drive shaft having a proximal end and a distal end; an abrading head; and a piloting member fixedly attached to the drive shaft and disposed distally of the abrading head. When the piloting member is advanced to a stenosis, the piloting member creates a piloting hole when the drive shaft at a sufficient rotational speed. The eccentric abrading head is then advanced through the piloting hole and distally across the stenotic lesion, thereby opening the stenotic lesion to a diameter larger than the nominal diameter of the eccentric enlarged diameter section.