Soft Prosthesis Insert Manufacturing Without a Positive Model

Solution Overview

Problem

Existing methods for manufacturing soft inserts for prostheses require a positive model of the stump, which is not feasible when the prosthesis socket is generated directly via three-dimensional scanning and printing, leading to a manufacturing gap.

Innovation Solution

A method involving three-dimensional scanning to acquire stump shape information, generating prosthesis socket shape information, and using a three-dimensional printer to output the socket, followed by a suction process to shape thermoplastic soft material into a soft insert without a positive model, utilizing fabric and a bag to prevent bag breakage and ensure even thickness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a three-dimensional printer is used to directly generate a prosthesis socket from scanned stump data, then the manufacturing process is simplified and productivity is improved, but the conventional soft insert manufacturing method that requires a positive model cannot be applied

Engineering Contradiction:

Improvemanufacturing efficiencyVSAvoidsoft insert manufacturability

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The soft material is pre-shaped into a tubular form with predetermined dimensions before being placed in the prosthesis socket. This preliminary shaping allows the material to be properly positioned and conform to the socket geometry during the suction process, enabling soft insert manufacturing without requiring a positive model of the stump.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A suction process is applied to the closed space containing the soft material and prosthesis socket. The vacuum suction forces the soft material to conform precisely to the inner surface of the prosthesis socket, creating an even-thickness soft insert that fits the socket geometry directly, eliminating the need for conventional positive model-based manufacturing.

Inventive Principle:

Principle #29Pneumatics and hydraulics

2Ease of manufacture

If soft material is placed directly into the prothesis socket without pre-shaping, then the process is simpler, but the soft insert will not have even thickness or proper fit

Engineering Contradiction:

Improveprocess simplicityVSAvoidsoft insert thickness uniformity

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The soft material is pre-shaped into a tubular form with predetermined dimensions before being placed in the prosthesis socket. This preliminary shaping allows the material to be properly positioned and conform to the socket geometry during the suction process, enabling soft insert manufacturing without requiring a positive model.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A suction process is applied to the closed space containing the soft material and prosthesis socket. The vacuum suction forces the soft material to conform precisely to the inner surface of the prosthesis socket, creating an even-thickness soft insert that fits the socket geometry directly.

Inventive Principle:

Principle #29Pneumatics and hydraulics

3Device complexity

If a bag is used for suction without fabric protection, then the setup is simpler, but the bag may break during the suction process

Engineering Contradiction:

Improvesetup complexityVSAvoidbag durability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

Fabric is introduced as an intermediary layer between the bag and the soft material/prosthesis socket assembly. This fabric layer protects the bag from direct contact with sharp edges or rough surfaces that could cause tearing or breakage during the suction process, while still allowing the vacuum force to effectively shape the soft material.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 the manufacturing of a soft insert that fits the prosthesis socket efficiently, even without a positive model, ensuring even thickness and improved work efficiency through pre-shaping and suction techniques.

Implementation Method 1

a suction step of performing suction of a closed space containing the output prosthesis socket and a soft material placed along an inner surface of the prosthesis socket to shape the soft material into a soft insert

Methodology Applied

Scientific EffectSuction: Suction

Implementation Method 2

If the soft material is thermoplastic, it may be placed onto the inner surface of the prosthesis socket after being heated enough to be deformable

Methodology Applied

Scientific EffectThermal heating: Heating

Data Source

PatentEP4582066A1Soft insert manufacturing method, device, and system

Publication Date: 2025.07.09 INSTALIMB INC

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AI summary

A method of manufacturing a soft insert is provided, including: a socket outputting step of outputting a prosthesis socket with a three-dimensional printer based on three-dimensional prosthesis socket shape information; and a suction step of performing suction of a closed space containing the output prosthesis socket and a soft material placed along an inner surface of the prosthesis socket to shape the soft material into a soft insert.