Surgical Shaft Extrusion with Complementary Lumens

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Solution Overview

Problem

Surgical forceps face challenges in precisely sealing and dividing tissue due to the need for accurate control of clamping pressure and electrosurgical energy, as well as the complexity of mechanical and electrical connections within the instrument.

Innovation Solution

The design incorporates a shaft with lumens configured for complementary-shaped components, including a drive bar and electrical wire lumens, allowing for precise movement of jaw members and energy transmission, along with a metal outer sleeve and plastic inner shaft for structural support and insulation, facilitating the transition between sealing and cutting conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple mechanical and electrical connections are extended through the shaft to permit operation of the end effector assembly, then the functionality and operation capability are improved, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improveoperation capabilityVSAvoidmechanical and electrical connections

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements nesting by placing drive bars, wires, and other components inside lumens (hollow channels) of the shaft. The shaft contains multiple internal lumens that house various mechanical and electrical connections, allowing these elements to be nested within the shaft structure rather than extending externally, thereby reducing overall device complexity while maintaining full operational capability.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The shaft is segmented into multiple functional lumens, each dedicated to specific components (e.g., drive bar lumen, wire lumen). This segmentation organizes the complex mechanical and electrical connections into separate, manageable pathways within the shaft, reducing interference between components and simplifying assembly and manufacturing processes.

Inventive Principle:

Principle #1Segmentation

2Manufacturing precision

If the shaft is formed to accommodate multiple components with complementary cross-sectional configurations, then the manufacturing precision and component fit are improved, but the manufacturing process complexity increases

Engineering Contradiction:

Improvecomponent fitVSAvoidshaft formation process

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The shaft is pre-formed with lumens having specific cross-sectional configurations that complement the components to be inserted. By preparing the lumens in advance with the correct geometry during shaft manufacturing, the patent ensures precise fit for drive bars, wires, and other components without requiring complex post-processing or adjustment, thereby maintaining manufacturing precision while managing process complexity.

Inventive Principle:

Principle #10Preliminary action

3Object-affected harmful factors

If an electrically-insulative material is used for the shaft, then the electrical insulation and safety are improved, but the mechanical strength and structural integrity may be reduced

Engineering Contradiction:

Improveelectrical insulationVSAvoidstructural integrity

Core Design Contradiction:

Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent employs composite construction by combining an electrically-insulative shaft material (such as biocompatible polymer) with metal components (drive bars, outer sleeve) that provide structural strength. The insulative shaft maintains electrical safety while the embedded metal components and reinforcement structures ensure adequate mechanical strength and structural integrity for surgical operations.

Inventive Principle:

Principle #40Composite materials

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 configuration enables precise tissue sealing and division by ensuring accurate mechanical and electrical operation, enhancing the instrument's ability to grasp, seal, and cut tissue effectively while maintaining structural integrity and electrical insulation.

Implementation Method 1

a shaft formed via extrusion. The shaft has one or more lumens extending therethrough

Methodology Applied

Scientific EffectExtrusion: Extrusion

Implementation Method 2

The inner shaft is formed via molding and includes one or more lumens extending therethrough... formed from an electrically-insulative material, e.g., a plastic

Methodology Applied

Scientific EffectElectrical insulation: Dielectric

Data Source

PatentUS9060780B2Methods of manufacturing shafts for surgical instruments

Publication Date: 2015.06.23 COVIDIEN LP

AI summary

A surgical instrument includes a shaft formed via extrusion. The shaft has one or more lumens extending therethrough. The lumen(s) each define a cross-sectional configuration. An end effector assembly is coupled to a distal end of the shaft. One or more components are coupled to the end effector assembly. The component(s) extend proximally from the end effector into the lumen(s) of the shaft. One or more of the components is formed via stamping. The component(s) define a cross-sectional configuration substantially complementary to the cross-section configuration of the lumen into which they extend.