Ultrasonic Sonotrode for Bone Cutting with Contoured Edge

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Solution Overview

Problem

Existing bone punches lack efficiency in cutting through dense cortical bone and deep into cancellous bone, while also generating excessive heat and risk of heat injury and infection due to reuse.

Innovation Solution

The development of a sonotrode for ultrasonic surgical instruments with a distal cutting edge that corresponds to the contour of the tissue area to be punched out, featuring a hollow blade or long, curved cutting edge, and incorporating reinforcing ribs to prevent bending and torsion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a sonotrode with a distal cutting edge corresponding to the contour of the tissue area is used, then cutting performance for cortical bone is improved, but the sonotrode becomes more complex and prone to bending movements

Engineering Contradiction:

Improvecutting performanceVSAvoidsonotrode structure

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The sonotrode is divided into functionally distinct segments: a proximal handle portion and a distal cutting edge portion with different geometries. The distal end piece is designed as a separate functional element with a cutting edge that corresponds to the contour of the tissue area to be punched out, allowing optimized cutting performance without compromising the overall structural integrity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the sonotrode are designed with locally optimized properties: the distal cutting edge has a specific geometry matching the tissue contour for efficient cutting, while the proximal portion maintains structural simplicity for vibration transmission. The blade thickness is locally optimized to be sufficient for cutting performance but thin enough to minimize bending movements

Inventive Principle:

Principle #3Local quality

2Stability of the object's composition

If a thicker blade is used to prevent bending movements, then structural stability is improved, but cutting performance for dense cortical bone deteriorates

Engineering Contradiction:

Improvestructural stabilityVSAvoidcutting performance

Core Design Contradiction:

Stability of the object's compositionVSProductivity

Solution Approach 1:

The blade thickness is locally optimized along its length: thicker portions provide structural stability and resist bending movements, while thinner portions maintain cutting sharpness and performance for dense cortical bone. This gradient thickness design allows simultaneous achievement of both stability and cutting efficiency

Inventive Principle:

Principle #3Local quality

3Productivity

If conventional bone punches are used to cut through dense cortical bone, then cutting capability is achieved, but excessive heat is generated causing heat injury and infection risk

Engineering Contradiction:

Improvecutting capabilityVSAvoidheat injury

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The conventional mechanical cutting system is replaced with an ultrasonic vibration-based cutting system. The sonotrode utilizes high-frequency ultrasonic vibrations to cut through dense cortical bone, substituting mechanical force with vibrational energy, thereby reducing heat generation and associated harmful effects while maintaining cutting capability

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Ease of manufacture

If reusable blades are used to reduce cost, then economic efficiency is improved, but heat injury and infection risk increase

Engineering Contradiction:

Improveeconomic efficiencyVSAvoidinfection risk

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The sonotrode is designed as a disposable, single-use component. This approach eliminates the need for cleaning and sterilization of reusable blades, thereby reducing infection risk while maintaining economic efficiency through simplified disposal protocols. The low cost of the disposable sonotrode makes this approach economically viable

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

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 sonotrode achieves improved cutting performance for cortical bone, reduces heat generation, and allows for precise cutting and removal of bone tissue with reduced risk of heat injury and infection.

Implementation Method 1

a sonotrode suitable to be used with an ultrasonic surgical instrument... having a distal end piece being equipped as a stamp or a blade for penetration of bones using mechanical vibration

Methodology Applied

Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Implementation Method 2

Common blades for arthroscopic surgery consist of an outer hollow sheath and an inner hollow rotating cannula with corresponding windows for suction and cutting

Methodology Applied

Scientific EffectSuction: Suction

Data Source

PatentUS12324593B2Device and method for punching bone

Publication Date: 2025.06.10 BOSONIC AG

AI summary

A sonotrode suitable for use with an ultrasonic surgical instrument for cutting or punching bones, as well as a method for manufacturing the sonotrode.