Tissue Retraction System with Multi-Axis Gear Actuation

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Solution Overview

Problem

Current minimally invasive surgical techniques require multiple inputs to achieve customized exposure of the surgical site, which can be time-consuming and complex, lacking a system for reproducible and efficient tissue retraction.

Innovation Solution

A tissue retraction system featuring a drive gear and linking members that rotate along multiple axes, allowing for simultaneous or independent movement of retractor blades via a single input source, with a linking member selector to control blade actuation modes, enabling customized exposure with reduced complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple inputs are used to actuate components in multiple directions, then customized exposure to the surgical target site is achieved, but device complexity and procedural time increase

Engineering Contradiction:
Improvecustomized exposureVSAvoidmultiple inputs
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system employs a single input mechanism (crank handle) that can control multiple retractor arms through a shared gear system. The drive gear can be selectively engaged with different idler gears (first, second, and third idler gears) to actuate different arms, allowing one input to perform multiple functions of customized exposure without requiring separate controls for each arm.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

Multiple retractor arms that would traditionally require independent control mechanisms are merged into a single coordinated system. The gear train integrates the control of multiple arms into one unified input motion, combining what would be separate operations into a single procedural action while maintaining the ability to create customized exposure configurations.

Inventive Principle:
Principle #5Merging (Combining)

2Adaptability or versatility

If multiple inputs are used to actuate components in multiple directions, then customized exposure to the surgical target site is achieved, but procedural time increases

Engineering Contradiction:
Improvecustomized exposureVSAvoidprocedural time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The gear system enables continuous and coordinated action of multiple retractor arms through a single continuous input motion. As the crank handle rotates, the drive gear continuously engages with selected idler gears to continuously actuate the corresponding arms, eliminating the need to stop and restart between different arm actuations and maintaining productive action throughout the exposure creation process.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The system allows preliminary selection of which arm(s) will be actuated by engaging the drive gear with the appropriate idler gear before beginning the actuation sequence. This preconfiguration enables the surgeon to prepare the surgical site exposure in a planned, efficient sequence rather than making adjustments reactively during the procedure.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If a single input controls multiple retractor blades, then productivity increases, but device complexity increases

Engineering Contradiction:
Improvesurgical corridor creation speedVSAvoidgear system
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system introduces intermediary idler gears (first, second, and third idler gears) that mediate between the single drive gear and the multiple retractor arms. These idler gears transmit and redirect the rotational motion from the drive gear to the appropriate arms, enabling a single input to control multiple outputs while distributing the mechanical complexity into manageable intermediary components rather than requiring a complex direct control system.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3986286B1Tissue retraction system
Publication Date: 2024.10.16 NUVASIVE INC
  • EP3986286B1 patent drawingFigure 1
  • EP3986286B1 patent drawingFigure 2
  • EP3986286B1 patent drawingFigure 3

AI summary

A tissue retraction system comprising a drive gear coupled to a shaft. The tissue retraction system includes a first plurality of linking members located along a second axis and configured to rotate along the second axis based on contact with the drive gear as the drive gear is rotated. The tissue retraction system includes a linking member selector configured to rotate along the first axis, wherein the linking member selector comprises a cylindrical body integrally formed with a handle. The tissue retraction system includes a right arm assembly, a left arm assembly, and a center arm that are each configured to move along trajectories. The tissue retraction system includes a first retractor blade, a second rector blade, and a third retractor blade. The tissue retraction system includes an array with tracking markers.