Bipolar Scissor Tip With Canted Coil Spring Electrical Contact

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Solution Overview

Problem

Conventional bipolar surgical instruments face structural weaknesses due to thermal expansion and contraction stresses from laminating materials with different properties, compromising their durability and effectiveness in surgical procedures.

Innovation Solution

The design incorporates a bipolar surgical instrument with an inner, intermediate, and outer shaft assembly, featuring a canted coil spring electrical contact that allows uninterrupted rotation and axial movement, eliminating the need for conducting wires and enhancing structural integrity by providing continuous power transfer and misalignment tolerance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If laminated materials with different properties are used in bipolar surgical instruments, then electrical isolation and shearing functionality are improved, but thermal expansion and contraction stresses weaken the structural integrity

Engineering Contradiction:
Improveelectrical isolationVSAvoidstructural integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

A metal insert is introduced as an intermediary component between the ceramic blade and the metal handle. This insert acts as a stress-absorbing intermediary that accommodates thermal expansion differences while maintaining structural integrity. The insert is mechanically coupled to both the ceramic blade and the metal handle, distributing thermal stresses and preventing structural failure during temperature cycling.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention employs a composite construction combining ceramic, metal insert, and metal handle materials. Each material is selected for its specific properties: ceramic for electrical isolation and heat resistance, metal insert for stress absorption and thermal compatibility, and metal handle for structural support. The composite structure leverages the strengths of each material while mitigating their individual weaknesses through proper interface design.

Inventive Principle:
Principle #40Composite materials

2Use of energy by moving object

If conventional wired electrical contacts are used in shaft assemblies, then power transfer is achieved, but structural complexity and points of failure increase

Engineering Contradiction:
Improvepower transferVSAvoidshaft assembly complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the conducting wire from the shaft assembly, replacing it with direct electrical contact through the mechanical interface of the removable section. This removes the wire from the system, eliminating associated complexity, potential failure points, and maintenance requirements while maintaining continuous power transfer capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The mechanical connection interface between the removable section and the main body serves dual functions: both mechanical support and electrical conduction. The inherent metal-to-metal contact at the interface provides electrical power transfer without requiring separate conducting elements, allowing the structure to serve its own electrical needs.

Inventive Principle:
Principle #25Self-service

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 durability and effectiveness of bipolar surgical instruments by ensuring constant electrical contact and reducing invasiveness, while maintaining structural integrity and improving tissue cutting and coagulation capabilities.

Implementation Method 1

a canted coil spring electrical contact configured to electrically contact a peripheral surface of at least one of the inner, intermediate and outer shafts. In this regard, the at least one electrical contact may be configured to allow uninterrupted and continuous rotation of the main body housing relative to the at least one of the inner, intermediate and outer shafts which the electrical contact contacts

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

bipolar surgical instruments have an inherent advantage over monopolar surgical instrument of containing energy generated at the surgical instrument. In a bipolar surgical instrument, both the active and the return electrodes are placed on the surgical instrument

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3545892B1Scissor tip for bipolar high frequency endoscope
Publication Date: 2020.12.23 MICROLINE SURGICAL INC
  • EP3545892B1 patent drawingFigure 1
  • EP3545892B1 patent drawingFigure 2
  • EP3545892B1 patent drawingFigure 3

AI summary

A bipolar scissor for cutting and coagulating tissue includes a first blade having a first cutting edge and a first shearing blade surface and a second blade having a second cutting edge and a second shearing blade surface. Additionally, one of the first and second blades includes a non-conductive material having an embedded electrode.