Retractable High-Frequency Knife Electrode
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Solution Overview
Problem
Existing high-frequency knives for endoscopic tissue excision face challenges in efficiently incising tissues and effectively managing bleeding during procedures, particularly in maintaining the bulging height of excised mucous membrane portions without requiring frequent tool repositioning and additional fluid injections.
Innovation Solution
A high-frequency knife design featuring a flexible sheath with a conduit line, an insulated supporting member, and a rod-shaped electrode that can advance and retract, along with a larger-diameter portion and auxiliary electrodes, allows for precise incision and fluid injection without exposing the electrode in the pull-back state, enabling continuous procedure execution without tool repositioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the rod-shaped electrode is exposed during incision, then tissue incision can be performed, but the electrode may accidentally contact non-excised tissues
Solution Approach 1:
The rod-shaped electrode is nested within the sheath during the pull-back state, with the larger-diameter portion serving as a protective barrier. The electrode is only exposed when pushed forward for incision, creating a nested configuration that prevents accidental contact while maintaining incision capability.
Solution Approach 2:
The electrode transitions between exposed and retracted states dynamically. During incision, the electrode is pushed forward to be exposed for cutting. During pull-back, it retracts into the sheath to prevent accidental contact. This dynamic positioning resolves the contradiction between operational exposure and safety.
2Object-affected harmful factors
If the electrode is pulled back to prevent accidental contact, then safety is improved, but the incision function cannot be performed
Solution Approach 1:
The electrode is designed to be movable between pushed-forward and pulled-back positions. When pushed forward, it performs incision. When pulled back, it prevents accidental contact. This dynamic capability allows the device to switch between incision mode and safety mode as needed.
Solution Approach 2:
The electrode assembly is segmented into the rod-shaped electrode and the larger-diameter portion. The rod-shaped electrode can move independently relative to the larger-diameter portion, allowing selective exposure of the cutting element while maintaining the protective barrier in place.
3Reliability
If fluid injection is performed frequently to manage bleeding, then hemostasis is improved, but procedure time increases
Solution Approach 1:
The fluid injection function is merged with the electrode assembly by forming the injection hole directly in the larger-diameter portion. This integration allows fluid to be injected at the exact location of the incision without requiring separate injection tools or repositioning, reducing procedure time while maintaining effective hemostasis.
Solution Approach 2:
The fluid injection hole is pre-formed in the larger-diameter portion during manufacturing, so that fluid can be immediately injected when needed during the procedure. This preliminary preparation eliminates the need for intraoperative hole creation or repositioning, reducing procedure time.
4Ease of operation
If the electrode is pushed forward for incision, then cutting capability is improved, but the electrode is exposed to accidental contact
Solution Approach 1:
The rod-shaped electrode is nested within the sheath when not in use, with the larger-diameter portion providing an additional protective layer. The electrode is only exposed when pushed forward for cutting, creating a nested configuration that minimizes exposure time and reduces the risk of accidental contact.
Solution Approach 2:
The electrode is pushed forward quickly and precisely to the required depth for incision, then immediately pulled back. This rapid movement minimizes the time the electrode is exposed, reducing the opportunity for accidental contact with non-excised tissues.
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
This design enhances the efficiency of tissue incision and hemostasis by allowing continuous operation without needing to adjust the bulging height of excised mucous membrane portions, facilitating rapid and effective fluid injection for hemostasis, and preventing accidental contact with non-excised tissues.
Implementation Method 1
The tissue coming into contact with the knife for an electrode can be incised by applying a high-frequency voltage through the operating wire
Implementation Method 2
applying a high-frequency voltage through the operating wire in a state where the operating wire is moved (pushed in) to a distal end side
Implementation Method 3
The conduit line and an opening of the opening hole on a distal end side communicate with each other so that the fluid is capable of flowing through a gap between an outer peripheral surface of the rod-shaped electrode and an inner peripheral surface of the opening hole
Implementation Method 4
The guide hole is smaller than the opening of the opening hole and is located further toward a radial inner side than an outer edge of the opening and further toward a radial outer side than the rod-shaped electrode
Data Source
AI summary
A high-frequency knife conduit line and opening hole opening communicate allowing fluid to flow between a rod-shaped electrode outer peripheral surface and the opening hole inner peripheral surface. The guide hole is smaller than the opening and is further toward a radial inner side than the opening outer edge and further toward a radial outer side than the rod-shaped electrode. The fluid is released from the opening to the outside of the sheath over the whole circumference of the rod-shaped electrode on the radial outer side while an electrode portion protrudes toward the sheath distal end portion separating a larger-diameter portion from a supporting member. The fluid is injected to the larger-diameter portion front through the guide hole as the opening hole and the guide hole communicate while the electrode portion is pulled back toward the sheath proximal end portion so that the larger-diameter portion abuts against the supporting member.