S-Shaped Bone Saw Blade for Safer Subcutaneous Sternotomy

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing bone saw blades are difficult to guide beneath a patient's skin, particularly when sawing a sternum, leading to a high risk of inadvertent injury to soft tissue due to their design, which causes uncontrolled swivel movements and engagement of saw teeth with skin.

Innovation Solution

A saw blade with a coupling region and a row of saw teeth configured in an S shape, allowing the central axis to be aligned at an angle relative to the coupling direction, enabling tangential movement and reducing the risk of soft tissue injury by preventing the last teeth from catching in bone material.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the distal free front edge of the saw blade is formed to be curved corresponding to the orbit, then the last teeth are prevented from getting caught in bone material, but the saw blade becomes difficult to guide beneath the patient's skin

Engineering Contradiction:

Improveprevention of uncontrolled vibrating motionVSAvoidguidance of saw blade beneath skin

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent introduces an angular dimension by aligning the central axis of the saw blade at approximately 45 degrees to the inserting direction, rather than keeping them parallel. This dimensional change allows the curved distal edge to follow the orbital path while the insertion path remains straight, resolving the contradiction between preventing tooth engagement and enabling guidance beneath skin.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If the saw blade is aligned at an angle with the machine housing, then the central axis can be perpendicular to the orbit, but the machine requires complex adjustments that increase cost

Engineering Contradiction:

Improvealignment of central axis perpendicular to orbitVSAvoidadjustment mechanisms

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The angular relationship between the central axis and inserting direction is pre-configured during manufacturing at approximately 45 degrees. This preliminary action eliminates the need for complex adjustable mechanisms during surgery, achieving precise alignment while keeping the device simple and cost-effective.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If the central axis of the saw blade is aligned perpendicular to the row of saw teeth, then the sawing effect is optimized, but the last teeth engage with soft tissue causing injury

Engineering Contradiction:

Improvesawing efficiencyVSAvoidsoft tissue injury

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The distal free front edge is formed with a curved configuration that follows the orbital path of the oscillating motion. This curvature ensures that the last teeth move tangentially along the orbit rather than perpendicular to it, preventing engagement with soft tissue while maintaining effective bone cutting through the oscillating sawing action.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Data Source

PatentUS11324517B2Saw blade

Publication Date: 2022.05.10 AESCULAP AG

AI summary

A saw blade of a bone saw machine includes a distally arranged or configured row of saw teeth and a proximally arranged or configured coupling region for coupling the saw blade with an oscillating rotating tool receptacle of the bone saw machine. The saw blade is designed with two counter-rotating curvatures or bends approximately in the manner of an S shape.