Pressure Loaded Drive Control for Bone Resection Drills

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Solution Overview

Problem

Existing cutting devices, such as bone drills, lack a reliable safety mechanism to prevent unintended cutting of sensitive anatomy or non-anatomical objects beyond the target, posing a risk of damage.

Innovation Solution

A drill assembly with a pressure loaded drive control assembly that includes a driven member and a drive member, where the driven member is biased to decouple from the drive member once the cutting tool penetrates the object, preventing further rotation and energy transfer, thereby ensuring safety by disengaging the cutting tool from power source.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a continuous drive system is used for the cutting tool, then the cutting operation can be maintained throughout the procedure, but the risk of unintended cutting beyond the target object increases

Engineering Contradiction:
Improvecontinuous cutting operationVSAvoidunintended cutting damage
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The drive system transitions from a static continuous connection to a dynamic pressure-loaded engagement. The driven member is biased against the drive member by a spring, creating a pressure-loaded connection that automatically disengages when cutting resistance is lost, thus dynamically adapting the power transmission state based on cutting conditions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses mechanical feedback through the pressure-loaded connection between the driven and drive members. When the cutting tool encounters resistance from the target object, force is transmitted back through the driven member to the spring, maintaining engagement. When resistance is lost (cutting through the object), the feedback mechanism causes automatic disengagement, providing real-time control based on cutting conditions

Inventive Principle:
Principle #23Feedback

2Duration of action of moving object

If the cutting tool remains engaged with the power source throughout the procedure, then operational continuity is maintained, but safety control and precision are reduced

Engineering Contradiction:
Improveoperational continuityVSAvoidsafety control
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The pressure-loaded drive control assembly creates a dynamic engagement system where the driven member is biased by a spring against the drive member. This dynamic connection maintains engagement during cutting (when force is applied) and automatically disengages when cutting resistance is lost, providing both continuity and safety control

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The spring bias creates a preliminary counter-force that prevents unintended engagement. The system is pre-configured with the driven member biased against the drive member, so that engagement only occurs when sufficient cutting resistance overcomes this preliminary counter-action, preventing accidental or unintended cutting

Inventive Principle:
Principle #9Preliminary anti-action

3Reliability

If a pressure loaded drive control assembly with biased driven member is used, then safety control and precision are improved, but device complexity increases

Engineering Contradiction:
Improvesafety controlVSAvoiddrive control structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The drive control assembly is self-regulating through the spring-biased driven member that automatically engages and disengages based on cutting conditions. The system serves itself by using the cutting resistance force to control the engagement state, eliminating the need for external control mechanisms or additional complexity

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The drive control assembly merges the drive transmission function with the safety control function into a single integrated mechanism. The pressure-loaded connection between driven and drive members combines power transmission with automatic disengagement control, reducing overall system complexity while maintaining both operational and safety functions

Inventive Principle:
Principle #5Merging (Combining)

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 effectively reduces the risk of cutting beyond the intended object, providing an additional layer of safety and control during anatomical and non-anatomical cutting procedures by ensuring the cutting tool is idle once it has completed the cut, thus protecting sensitive tissues and objects.

Implementation Method 1

a biasing member, such as a spring, in direct or indirect cooperation with the driven member and configured to bias the driven member in the inactive configuration

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3988038B1Pressure loaded drive control for bone resection
Publication Date: 2024.09.18 MEDTRONIC XOMED INC
  • EP3988038B1 patent drawingFigure 1
  • EP3988038B1 patent drawingFigure 2~3A
  • EP3988038B1 patent drawingFigure 3B

AI summary

A drill assembly including a cutting tool slidably movable along a longitudinal axis of the drill assembly and drivable to cut an object. In an active configuration, a pressure loaded drive control assembly transfers energy from a motor to the cutting tool to drive the cutting tool. In an inactive configuration, the pressure loaded drive control assembly prevents energy transfer from the motor to the cutting tool. A biasing member of the pressure loaded drive control assembly is configured to bias the pressure loaded drive control assembly in the inactive configuration. Depressing the cutting tool against the object moves the cutting tool along the longitudinal axis and moves the pressure loaded drive control assembly to the active configuration. The biasing member returns the pressure loaded drive control assembly to the inactive configuration when the cutting tool is no longer depressed against the object.