Composite Saw Blade Plastic Sliding Element Friction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current medical saw blades for femur and tibia resection experience significant friction-related issues with saw templates, leading to material abrasion, corrosion, and heat generation, compromising patient safety and requiring high battery power due to increased oscillating mass.

Innovation Solution

A composite saw blade with a biocompatible plastic sliding element and a rigid metal core, forming a lattice or herringbone framework, which reduces friction and abrasion by using plastic and steel as friction partners, allowing for a lighter design and easier manufacturing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a conventional steel saw blade is used with a metal saw template, then the saw blade can effectively cut bone, but significant friction causes material abrasion, corrosion, and heat generation compromising patient safety

Engineering Contradiction:
Improvefriction-induced abrasion and heatVSAvoidguidance accuracy and template service life
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent introduces a plastic coating layer as an intermediary between the steel saw blade and the metal saw template. This plastic layer acts as a mediator that reduces direct metal-to-metal contact, thereby minimizing friction-induced abrasion and heat generation while protecting the template from corrosion and maintaining guidance accuracy throughout the template's service life.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite structure by coating the steel saw blade with plastic material. This composite construction combines the cutting effectiveness of steel with the low-friction, protective properties of plastic, resolving the contradiction between effective bone cutting and reduction of harmful friction effects on the template.

Inventive Principle:
Principle #40Composite materials

2Power

If the saw blade is made with high oscillating mass for effective bone cutting, then cutting performance is improved, but battery power requirements and instrument weight increase significantly

Engineering Contradiction:
Improvecutting capabilityVSAvoidsaw blade mass
Core Design Contradiction:
PowerVSWeight of moving object

Solution Approach 1:

The patent changes the physical parameters of the saw blade by applying a plastic coating that reduces the overall mass while maintaining structural integrity. The plastic material has lower density than metal, allowing the blade to achieve effective cutting performance with reduced oscillating mass, thereby lowering battery power requirements and instrument weight.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If ceramic contact elements are used to minimize abrasion, then friction-related wear is reduced, but manufacturing complexity and cost increase due to additional processing steps

Engineering Contradiction:
Improveabrasion on saw bladeVSAvoidmanufacturing process simplicity
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent employs a plastic coating on the saw blade that can be applied through relatively simple coating processes. While the coating may wear over time, it protects the expensive ceramic alternatives and can be reapplied or the blade replaced, offering a cost-effective solution that balances abrasion protection with manufacturing simplicity.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the material parameter from ceramic to plastic for the contact surface. Plastic materials can be applied through simpler coating processes compared to ceramic sintering and post-processing, thereby reducing manufacturing complexity while still providing effective abrasion protection for the saw blade.

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

The composite saw blade minimizes friction and heat generation, extends the service life of saw templates, reduces noise, and decreases battery power requirements, enhancing patient safety and surgical precision.

Implementation Method 1

The tribological conditions were redesigned and optimized within the scope of the invention by using plastic and steel as friction partners instead of the interaction between steel and steel

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

The sliding element comprises or consists of a biocompatible and/or bioresorbable plastic... the saw templates are subject to high levels of wear, which impairs the guidance properties of the saw template and can lead to inaccurate saw cuts or necessitate repositioning of the saw template. Furthermore, increased heat generation occurs at the friction partners.

Methodology Applied
Scientific EffectCorrosion resistance:

Data Source

PatentEP3769701B1Composite saw blade for a medical bone saw
Publication Date: 2024.11.13 AESCULAP AG
  • EP3769701B1 patent drawingFigure 1
  • EP3769701B1 patent drawingFigure 2~4
  • EP3769701B1 patent drawingFigure 5~7

AI summary

The present invention relates to a saw blade (1) for a medical bone saw, in particular for femur and/or tibial resection, comprising a proximal holding area (4) which serves for coupling to a saw device, a guide area (5) with at least one sliding element (6) which is arranged on a rigid saw blade core (8) and provides a contact surface for guiding the saw blade (1) in a guide slot (2) of a saw template (3), and a distal saw area (7) having saw teeth, wherein the sliding element (6) and the saw blade core (8) have different materials or consist of different materials, wherein the sliding element (6) has or consists of a biocompatible and/or bioresorbable plastic.