Sterile Pad Assembly with Ridges for Limb Positioning

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Solution Overview

Problem

Conventional surgical positioning and distraction systems fail to effectively secure and hold larger, heavier limbs in place during medical procedures, leading to tissue trauma, slippage, and increased pressure on the circulatory system and bones, which can result in harm to patients.

Innovation Solution

A pad assembly and system that includes a sterilizable foam pad with a cage assembly and ridged enclosure designed to securely attach to a support bar, distributing pressure and preventing slippage, using a combination of adhesive and friction fit mechanisms to maintain position and reduce the need for high pressure on the patient's tissues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional foam pads and wraps are used to protect patient tissues, then pressure distribution is improved, but the pads slip or shift when distraction is applied during surgery

Engineering Contradiction:
Improvetissue protection from pressure sores and abrasionsVSAvoidpad position stability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The pad assembly is divided into multiple functional components: a foam pad for pressure distribution, a cage assembly for structural support, and a ridged enclosure for securing to the support bar. This segmentation allows each component to specialize in its function, with the ridged enclosure specifically addressing the slippage problem while the foam pad maintains tissue protection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The solution moves from a two-dimensional flat pad to a three-dimensional cage assembly with ridged enclosure. The added dimensionality provides multiple contact points and mechanical interlocking features with the support bar, preventing slippage in multiple directions while maintaining the pressure-distributing surface area against the patient's tissue.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If increased pressure is applied to the pad to prevent slippage during distraction, then position stability is improved, but harm to the circulatory system, tissues, and bones increases

Engineering Contradiction:
Improvepad position stabilityVSAvoidharm to circulatory system, tissues, and bones
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The ridged enclosure is pre-configured with friction-fit features and adhesive surfaces that create immediate mechanical engagement with the support bar upon assembly. This preliminary mechanical securing eliminates the need for increased distraction pressure to maintain pad position, as the pad is already locked in place before the surgical procedure begins.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The ridged enclosure acts as an intermediary mechanical interface between the pad assembly and the support bar. It provides a friction-fit connection that mediates the force transmission, allowing the pad to remain securely positioned without requiring excessive distraction forces that would harm the patient's tissues, bones, or circulatory system.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If conventional wraps and foam pads are used for sterilization, then infection prevention is improved, but the pads must be single-use increasing waste and cost

Engineering Contradiction:
Improveinfection preventionVSAvoidsingle-use material waste
Core Design Contradiction:
Object-affected harmful factorsVSLoss of substance

Solution Approach 1:

The pad assembly is designed to be reusable after proper sterilization. The sterilizable construction allows the pad to be discarded after use, sterilized through autoclaving or other medical sterilization processes, and then recovered for subsequent use. This eliminates the single-use requirement while maintaining infection prevention, significantly reducing material waste and operational costs.

Inventive Principle:
Principle #34Discarding and recovering

4Ease of manufacture

If the pad design is simplified for ease of manufacture, then production cost is reduced, but the ability to resist slippage during distraction of heavier limbs is compromised

Engineering Contradiction:
Improvepad manufacturing simplicityVSAvoidslip resistance for heavier limbs
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The cage assembly and ridged enclosure are constructed from flexible yet structurally sound materials that can be molded into the required shapes using standard manufacturing processes. The flexibility allows for easier manufacturing and assembly while the rigid ridged structure provides the necessary mechanical interlocking to prevent slippage even when supporting heavier limbs during distraction.

Inventive Principle:
Principle #30Flexible shells and thin films

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

The system effectively reduces tissue trauma and slippage, maintaining the pad's position and distributing pressure to minimize harm to the circulatory system, bones, and nerves, while allowing for reduced pressure on the patient's tissues during surgical procedures.

Implementation Method 1

The one or more ridges are useful to distribute pressure over a large area of the distal femur so as to reduce the direct application of pressure an tissues, vessels and the popliteal nerve

Methodology Applied
Scientific EffectPressure distribution: Pascal's Law

Implementation Method 2

using a combination of adhesive and friction fit mechanisms to maintain position

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 3

using a combination of adhesive and friction fit mechanisms to maintain position

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3207913B1Assembly and system for distractor and/or positioner
Publication Date: 2020.01.08 INNOVATIVE MEDICAL PRODS
  • EP3207913B1 patent drawingFigure 1~5
  • EP3207913B1 patent drawingFigure 6A~7B
  • EP3207913B1 patent drawingFigure 8~13

AI summary

A sterile pressure pad assernbly, system, kit and method uses a cage assembly comprising an enclosure and a pad assembly configured as a generally rectangular pad disposed adjacent the patient's limb near the joint to be extended and/or distended. The pad may be affixed by adhesive to the outer surface of an arcuate side and formed from suitable foam and cell structure materials that can be sterilized such as, for example, polyurethane-based foam. The enclosure of the cage assembly is configured with one or more ridges to sufficiently optimize a material strength to the arcuate side of the enclosure so as to not crush under pressure from the surgical distractor unit and/or the weight of the patient's limb of the patient when the sterile cage assembly and pad support a limb of a patient on a support bar as a surgical distractor unit positions the pad in abutment with a popliteal arm of a patient's knee joint during a medical procedure.