Eccentric Oscillation Drive for Minimally Invasive Bone Resection

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Solution Overview

Problem

Current surgical instruments for resecting soft tissue or bone in constrained environments, such as minimally-invasive procedures, suffer from poor ergonomics leading to musculoskeletal disorders, reduced accuracy, and risk of nerve damage due to inadequate control and visualization, with existing tools often obstructing the surgeon's view and damaging tissues.

Innovation Solution

A powered cutting system with an oscillating or continuously rotating blade, housed within a mechanism that prevents unintentional resection, utilizing a mechanical transmission to achieve high-frequency oscillations and a crescentic blade design to minimize nerve damage and improve cutting efficiency, along with ergonomic interfaces and visualization features.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a rotating blade is used for tissue resection, then cutting efficiency is improved, but nerve damage risk increases due to tissue tangling and excessive strain

Engineering Contradiction:

Improvecutting efficiencyVSAvoidnerve damage risk

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies high-frequency oscillating motion (mechanical vibration) to the cutting blade instead of continuous rotation. This oscillating motion prevents soft tissue and nerves from tangling around the blade while maintaining efficient cutting performance through rapid back-and-forth movements at controlled amplitudes.

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The patent changes the motion parameters from continuous rotation to high-frequency oscillation with limited angular displacement. This parameter change allows the blade to cut through tissue effectively while minimizing the strain and tangling that would occur with rotational motion, thereby reducing nerve damage risk.

Inventive Principle:

Principle #35Parameter changes

2Loss of time

If minimally invasive surgical techniques are used, then patient recovery time is reduced, but surgical difficulty increases due to constrained access and limited visualization

Engineering Contradiction:

Improvepatient recovery timeVSAvoidsurgical difficulty

Core Design Contradiction:

Loss of timeVSEase of operation

Solution Approach 1:

The patent employs a nested design where the oscillating blade mechanism is housed within a protective housing that can be inserted through minimally invasive access ports. The blade oscillates within confined spaces defined by the housing, allowing surgical operations deep within the body through small incisions while maintaining control and visualization.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The surgical instrument is segmented into modular components including a housing, oscillating blade mechanism, and drive system. This segmentation allows the instrument to be inserted through narrow access ports while maintaining the complex oscillating cutting function needed for effective tissue resection in constrained environments.

Inventive Principle:

Principle #1Segmentation

3Device complexity

If manual operation is used for tissue resection, then device complexity is reduced, but surgical accuracy decreases due to muscle activation and fatigue

Engineering Contradiction:

Improvedevice complexityVSAvoidsurgical accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements a self-oscillating mechanism where the blade automatically oscillates at high frequency through an integrated drive system. This eliminates the need for manual back-and-forth manipulation by the surgeon, providing consistent, fatigue-free operation with precise control over cutting amplitude and frequency while maintaining relatively simple device architecture.

Inventive Principle:

Principle #25Self-service

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 solution enhances precision and reduces surgeon fatigue by minimizing muscle activation, prevents nerve damage through controlled tissue interaction, and allows for accurate bone resection with reduced tissue destruction, improving the safety and efficiency of minimally-invasive procedures.

Implementation Method 1

a powered cutting system using a crescentic blade that cuts tissue or bone by oscillating without spinning through a complete rotation

Methodology Applied

Scientific EffectMechanical vibration: Vibration

Implementation Method 2

utilizing a mechanical transmission to achieve high-frequency oscillations

Methodology Applied

Scientific EffectMechanical transmission: Gear

Data Source

PatentUS11350948B2Bone and tissue resection devices and methods

Publication Date: 2022.06.07 MEDOS INT SARL

AI summary

Embodiments of devices for converting continuous rotational motion into oscillating motion are disclosed herein. In one embodiment, an oscillation device can include an input shaft that rotates about a first axis, a portion of the input shaft defining an eccentric section that defines a second central axis offset from the first axis, a connector rotatably coupled around the eccentric section, an oscillating shaft offset from the input shaft that rotates about a third axis, and a pin coupled to the oscillating shaft and extending towards the connector. The connector includes a sleeve slidably receiving an end of the pin, and continuous rotation of the input shaft about the first axis causes an eccentric movement of the connector, and the eccentric movement of the connector oscillates the sleeve along the pin and oscillates the pin with respect to the oscillating shaft, thereby oscillating the oscillating shaft about the third axis.