Dissolution Catheter Shear Fragmentation and Wash-Off Barrier
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Solution Overview
Problem
Current methods for removing thrombi and embolisms from blood vessels often result in incomplete removal, with remnants causing further blockages due to fragments being washed away and re-depositing in narrower vessels, leading to complications and potential organ loss.
Innovation Solution
A device comprising a removal catheter with a sleeve-shaped stator and rotor, featuring axially arranged circular holes with shear edges, which ensures thorough fragmentation and prevents blockages by using the sheath catheter's funnel-shaped end piece as a wash-off barrier, allowing for safe and complete removal without re-depositing material in distant locations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a removal catheter with rotor and stator is used to fragment thrombi, then the removal rate is improved, but fragments may be washed away and cause new blockages in distal vessels
Solution Approach 1:
A protection sheath with a funnel-shaped distal end is introduced as an intermediary component between the removal catheter and the blood vessel. The funnel shape directs blood flow and captured fragments toward the suction inlet, while the sheath acts as a barrier preventing fragments from escaping into distal vessels. This mediator structure resolves the contradiction by enabling effective fragmentation while simultaneously preventing fragment wash-off.
2Reliability
If the end piece is made liquid-permeable to allow blood flow, then vascular integrity is maintained, but fragments may pass through and cause distal blockages
Solution Approach 1:
The end piece is designed with non-uniform properties: the distal end is shaped as a funnel with specific flow characteristics, while the lateral surface features a suction inlet for fragment capture. The liquid-permeable material allows blood flow through the end piece while the funnel geometry and suction system locally concentrate and capture fragments before they can pass through, resolving the contradiction between maintaining vascular integrity and preventing fragment passage.
3Productivity
If the funnel-shaped end piece is expanded to close the vessel, then fragment capture is improved, but complete vessel occlusion may occur
Solution Approach 1:
The end piece is constructed from liquid-permeable material that allows controlled fluid passage. When expanded, the funnel-shaped end piece creates a barrier that captures fragments through the combination of flow direction and suction, while the inherent permeability prevents complete occlusion by allowing blood to pass through the material itself, thus resolving the contradiction between fragment capture and complete occlusion.
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 achieves a high removal rate with minimal risk of blockages, ensuring safe and effective thrombus removal, preventing re-deposition and maintaining vascular integrity.
Implementation Method 1
Due to the negative pressure generated by the conveyor screw, the deposits to be removed are sucked through the inlet openings into the stator
Implementation Method 2
where they are fragmented by the shearing effect between the stator and the conveyor screw
Implementation Method 3
the sheath catheter's funnel-shaped end piece as a wash-off barrier, allowing for safe and complete removal without re-depositing material in distant locations
Data Source
Figure 1~3
Figure 4~10
Figure 5
AI summary
The invention relates to a device and a method for aspirating, fragmenting and extracting removable material from hollow bodies, in particular thrombi and emboli from blood vessels. To this end, a guide wire (11) is introduced into the hollow body (1) via an opening. The material is removed by means of a dissolution catheter (3) comprising a working head (6) with a stator (8) and a rotor (9), wherein the rotor (9) is connected to a flexible delivery screw (10) surrounding the guide wire (11). The circumference of the stator (8) comprises a lateral inlet opening (8a). The inlet opening (8a) of the stator (8) is designed as two circular holes disposed axially behind one another in relation to the longitudinal axis of the dissolution catheter (3). Material forced into the inlet openings (8a) and/or the aspirated and/or detached thrombi (2) and emboli shear and/or fragment between the peripheral edges of the inlet openings (8a) of the stator (8) and the rotor (9). A flexible casing (7) surrounding the delivery screw (10) and connected to the stator (8) is used to discharge the ablated material and/or the detached thrombi and emboli fragments. Before introducing the dissolution catheter (3), a sheath catheter (4) is introduced into the hollow body (1) until it lies in front of the material to be removed. The cross-section of the hollow body (1) is then closed at least partially by means of the sheath catheter (4), thus preventing detached thrombi or emboli fragments from being accidentally washed away.