Short Sheath Biliary Stent Delivery System Single-Handed Operation
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Solution Overview
Problem
Existing biliary metal stent delivery systems require coordinated two-person operation to precisely deploy stents in biliary ducts, making single-person operation difficult and increasing the risk of stent misplacement or failure due to friction and relative motion issues during sheath withdrawal.
Innovation Solution
A short sheath delivery system for biliary metal stents via an endoscope, comprising a delivery device with a short sheath, a handle connected by a connection thread, and a fixing device that allows single-handed operation by integrating a guidewire and injection tube for precise stent deployment, with X-ray opaque markers for positioning and a fixing mechanism to secure the delivery device within the endoscope biopsy port.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a long outer sheath is used to deliver the stent, then the stent can be contained and delivered through the endoscope, but the sheath suffers friction from the operating channel causing difficulty in operation and requiring two-person coordination
Solution Approach 1:
The delivery system is divided into distinct segments: a short outer sheath, an inner rod, and a stent. The short sheath is specifically designed to be shorter than the inner rod, allowing the inner rod to extend beyond the sheath tip. This segmentation enables independent control of each component, eliminating the need for coordinated two-person operation while reducing friction from the operating channel.
2Manufacturing precision
If the operator pulls out the sheath from the operating channel while the assistant pulls back the sheath, then the sheath can be delivered, but synchronized movement is required to prevent stent deviation
Solution Approach 1:
Instead of pulling the sheath out while simultaneously pulling back, the system inverts the sequence: the inner rod is advanced first to position the stent, then the short sheath is pulled back independently. The inner rod extends beyond the sheath tip, allowing the stent to be positioned before sheath removal, eliminating the need for synchronized movement.
3Reliability
If relative motion occurs between the inner rod and sheath during sheath withdrawal, then the sheath can be removed, but the stent deviates from the predetermined site
Solution Approach 1:
The inner rod is designed to extend beyond the tip of the short sheath, allowing the stent to be positioned at the target site before the sheath is completely removed. This preliminary positioning action ensures that even if relative motion occurs during sheath withdrawal, the stent remains at the predetermined site because it has already been deployed or is in the process of deploying.
Data Source
Figure 1A~2A
Figure 2A1~2A6
Figure 2A7~2B
AI summary
The invention discloses a short sheath delivery system for a biliary metal stent via an endoscope. The short sheath delivery system comprises a delivery device for a stent and a fixing device, wherein the delivery device is used for delivering a stent part on a stricture lesion via an endoscope along a guidewire; the fixing device is used for fixing the delivery device on an endoscope biopsy port. The delivery device comprises a tip, an inner rod, a secondary rod, a main rod, a sliding rod, a trailing end, a guidewire cavity, an injection tube, a stent, a short sheath, a connection thread and a handle; the stent is preloaded in an empty cavity formed by the inner rod and the short sheath; the length of the short sheath is longer than that of the stent, and is less than that of the secondary rod; the external diameter of the secondary rod is less than the inner diameter of the short sheath, and the external diameter of the main rod is equal to or greater than that of the short sheath; the handle is sleeved around the sliding rod; and the handle is connected with the short sheath by the connection thread. When the short sheath delivery system is operated, the fixing device fixes the main rod part of the delivery device on the endoscope biopsy port, and an operator pulls the handle by a single hand therefore the handle slides along the sliding rod; the connection thread drives the short sheath to move and to sleeve on the secondary rod, therefore the stent is accurately deployed by a single-person without any migration.