Minimally Invasive Rake Retractor with Nested Needle Deployment

Solution Overview

Problem

Current minimally invasive surgical instruments, particularly retractors, require initial incisions and result in significant scarring due to larger port sizes and limited maneuverability within the body cavity, especially in confined areas like children's abdomens.

Innovation Solution

A minimally invasive surgical assembly featuring a hollow needle with a sharp distal end and a rake retractor with mechanically biased elongated members that expand externally and collapse internally, allowing for insertion and retraction without initial incisions and minimizing scarring, utilizing a locking mechanism for secure positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If larger trocar ports are used to accommodate retractors, then retractor functionality is improved, but wound size and scarring increase

Engineering Contradiction:

Improveretractor functionalityVSAvoidwound size and scarring

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The retractor is nested within a hollow needle, allowing the retractor to be inserted through a small gauge needle tract. The hollow needle serves as a delivery mechanism that constrains the retractor during insertion, then allows deployment of the retractor tines into the body cavity through the needle's opening.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The retractor transitions from a constrained state within the hollow needle to an expanded state with deployed tines in the body cavity. The tines are mechanically biased to expand outward when released from the needle, providing retraction functionality through a dynamic shape change.

Inventive Principle:

Principle #15Dynamics

2Ease of operation

If multiple ports are placed in limited area, then instrument access is improved, but scarring and wound complexity increase

Engineering Contradiction:

Improveinstrument accessVSAvoidscarring and wound complexity

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The retractor is nested within a hollow needle, allowing the retractor to be inserted through a small gauge needle tract. The hollow needle serves as a delivery mechanism that constrains the retractor during insertion, then allows deployment of the retractor tines into the body cavity through the needle's opening.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The retractor is segmented into multiple independent tines that can be individually deployed and positioned. This segmentation allows the retractor to access and manipulate tissue in confined spaces while being delivered through a single small puncture site rather than requiring multiple ports.

Inventive Principle:

Principle #1Segmentation

3Object-affected harmful factors

If retractor is constrained within hollow needle, then wound size is reduced, but retractor maneuverability is limited

Engineering Contradiction:

Improvewound sizeVSAvoidretractor maneuverability

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The retractor transitions from a constrained state within the hollow needle to an expanded state with deployed tines in the body cavity. The tines are mechanically biased to expand outward when released from the needle, providing retraction functionality through a dynamic shape change.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The retractor's physical parameters change from a compact, constrained configuration during insertion to an expanded configuration with splayed tines for tissue manipulation. The mechanical bias of the tines enables this parameter change, allowing the retractor to achieve optimal maneuverability after deployment.

Inventive Principle:

Principle #35Parameter changes

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

Enables surgical procedures with reduced scarring and increased instrument maneuverability by allowing the rake retractor to expand and collapse within a small needle diameter, facilitating precise tissue manipulation without the need for stitches and minimizing wound size.

Implementation Method 1

each elongated member being mechanically biased such that when said elongated members extend externally to said needle into an open position said elongated members automatically expand relative to each other, and when said hollow needle extends over said elongated members in a closed position, said elongated members are forced to collapse relative to each other against the mechanical bias

Methodology Applied

Scientific EffectMechanical bias: Spring

Data Source

PatentUS8313507B2Minimally invasive rake retractor and method for using same

Publication Date: 2012.11.20 TELEFLEX MEDICAL LLC

AI summary

A rake retractor for use in minimally invasive medical procedures such as laparoscopic surgery includes a handle shaft, rake prongs, and end configurations that can be used to move elements within a body cavity. The prongs of the rake retractor are biased to an open position such that when the rake prongs extend out of the needle they open, and they are closed by relative movement of the needle over them. The end configurations are offset so that they may be compactly brought together within the narrow space of a needle having a diameter typically not greater than 2.5 mm.