Biopsy Needle Locking Mechanism for Low-Translation Sampling

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Solution Overview

Problem

Existing biopsy needle devices experience significant axial translation during tissue sample collection, which can lead to inaccuracies and complications in obtaining precise tissue samples.

Innovation Solution

A biopsy needle device with a cannula and trocar mechanism that utilizes a gear and wobble member to control the axial movement of the needle, minimizing axial translation through a continuous rotational motion of a torque converter, allowing precise tissue sampling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a biopsy needle device is used to collect tissue samples, then tissue sampling capability is achieved, but significant axial translation occurs during sample collection leading to inaccuracies

Engineering Contradiction:
Improvetissue sample accuracyVSAvoidaxial translation
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The biopsy needle device employs a dynamic locking mechanism that transitions between unlocked and locked states during the biopsy procedure. The locking member is initially unlocked to allow needle advancement, then locks at the desired depth to prevent axial translation during tissue sampling, and finally unlocks to allow needle withdrawal. This dynamic state change resolves the contradiction by enabling controlled movement when needed while preventing harmful translation during sampling.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The locking member acts as an intermediary component between the needle assembly and the hub. It mediates the axial movement by engaging with the needle to prevent translation while allowing rotational movement for sample collection. This intermediary mechanism selectively restricts axial translation only during the tissue sampling phase, thereby improving measurement precision without compromising the overall biopsy capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If axial translation is prevented during tissue sampling, then sampling accuracy is improved, but device complexity increases due to additional locking mechanisms

Engineering Contradiction:
Improvetissue sample accuracyVSAvoidlocking mechanism complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The locking mechanism is merged with the existing needle assembly and hub structure rather than being a separate independent system. The locking member integrates with the needle shaft and engages with features on the hub, combining multiple functions (locking, unlocking, depth control) into a unified mechanism. This merging approach prevents axial translation while minimizing the increase in device complexity by utilizing existing structural elements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The locking mechanism is designed to be self-actuating through user manipulation of the hub. The practitioner can engage and disengage the locking member by simple rotational or linear movements of the hub, without requiring additional actuators, motors, or complex control systems. The mechanism serves itself by using the operator's input to transition between locked and unlocked states, thereby improving sampling accuracy while keeping the device relatively simple.

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 device achieves precise and controlled tissue sampling by reducing axial translation, enhancing the accuracy and efficiency of tissue collection.

Implementation Method 1

a gear and wobble member to control the axial movement of the needle

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Implementation Method 2

a gear and wobble member to control the axial movement of the needle

Methodology Applied
Scientific EffectGear mechanism: Gear

Data Source

PatentEP3624698B1Semi-automatic biopsy needle device
Publication Date: 2025.12.31 MERIT MEDICAL SYSTEMS INC
  • EP3624698B1 patent drawingFigure 1
  • EP3624698B1 patent drawingFigure 2~2A
  • EP3624698B1 patent drawingFigure 3~3A

AI summary

A biopsy needle device is disclosed. The biopsy needle device may be configured to be advanced to a predetermined tissue sample, collect and sever the tissue sample utilizing an actuator comprising a linear displacement mechanism, and extract the tissue sample from a body tissue of a patient.