Electrosurgical Shears Knife Auto-Return for Jaw-First Cutting
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Solution Overview
Problem
Existing electrosurgical instruments lack a compact and efficient mechanism for tissue cutting and sealing that ensures proper jaw closure before cutting, preventing accidental tissue damage and ensuring consistent energy application.
Innovation Solution
A compact electrosurgical instrument with a resilient arm that flexes for enhanced jaw closure, a central trigger for easy actuation, and a lockout mechanism to ensure proper jaw closure before cutting, combined with an automatic knife return feature to prevent accidental exposure of the cutting edge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional electrosurgical instrument is used without a lockout mechanism, then the device complexity is reduced, but the reliability of ensuring proper jaw closure before cutting deteriorates
Solution Approach 1:
The lockout mechanism performs a preliminary check to ensure jaw closure is achieved before allowing the cutting function to be activated. This preliminary action prevents accidental tissue damage by verifying the proper configuration state before the cutting element is exposed and made active.
Solution Approach 2:
The lockout mechanism acts as an intermediary between the jaw closure action and the cutting activation. It mediates the transition by requiring a specific sequence of actions (jaw closure first, then cut activation) and preventing the cutting function from being activated unless the jaw closure condition is met.
2Ease of operation
If the cutting element is always exposed, then the ease of operation is improved, but the object-generated harmful factors increase due to accidental tissue damage risk
Solution Approach 1:
The lockout mechanism applies a preliminary anti-action by preventing the cutting element from being activated or exposed until the jaw closure condition is satisfied. This counteracts the potential harmful effect of accidental tissue damage by creating a protective barrier that must be overcome through proper operational sequence.
Solution Approach 2:
The exposure state of the cutting element is made dynamic rather than static. The cutting element transitions from a retracted/protected state to an exposed/active state only after the jaw closure condition is met, allowing the system to adapt its configuration based on the operational context and reduce harmful factors when not in use.
3Reliability
If a resilient arm is added to enhance jaw closure, then the reliability of tissue sealing is improved, but the device complexity increases
Solution Approach 1:
The resilient arm changes the mechanical parameter of jaw closure by providing an elastic restoring force that actively pushes the jaws together. This parameter change (adding elastic force) improves the reliability of tissue sealing without requiring a completely different mechanical system, thus limiting the increase in device complexity.
Solution Approach 2:
The resilient arm provides self-service by automatically generating the closing force needed for jaw closure through its elastic properties. This eliminates the need for additional active actuators or complex mechanical linkages, improving sealing reliability while keeping the complexity increase minimal.
4Reliability
If an automatic knife return feature is implemented, then the safety against accidental exposure is improved, but the device complexity increases
Solution Approach 1:
The automatic knife return feature performs a preliminary safety check by ensuring the cutting element returns to its safe, retracted position after use. This preliminary action (automatic return) prevents accidental exposure of the cutting edge and reduces the risk of tissue damage without requiring continuous manual monitoring.
Solution Approach 2:
The automatic knife return mechanism incorporates feedback by detecting when the cutting element has completed its cutting function and automatically reversing its position. This feedback loop ensures the cutting element is safely retracted after use, improving safety against accidental exposure while using a relatively simple mechanical feedback system.
Data Source
AI summary
A surgical instrument includes an end effector, a handle assembly, a trigger assembly, an input driving body, and a coupling body. The end effector includes a pair of jaws, a knife, and an RF electrode assembly. The input driving body drives the knife between the pre-fired position and the fired position when traveling between the first position and the second position. The engagement body of the trigger assembly drives the input driving body from the first position to the second position when the coupling body is in the engaged position. The input driving body returns to the first position when the coupling body is in the disengaged position. The coupling body moves from the engaged position to the disengaged position is response to the input driving body traveling from the second position to the third position such that the input driving body returns to the first position.