Biopsy Probe with Recessed Electrodes for Impedance Measurement

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Solution Overview

Problem

Existing biopsy devices lack the capability to effectively measure tissue impedance, which is crucial for determining tissue type and penetration depth during tissue sampling.

Innovation Solution

A biopsy apparatus equipped with an impedance measuring probe featuring a metal elongate member with recessed longitudinal channels housing conductive wire electrodes, which are electrically insulated and exposed at the distal end to measure tissue impedance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a sharp probe is used to penetrate tissue for biopsy sampling, then tissue penetration capability is improved, but the ability to measure tissue impedance and determine tissue type/penetration depth deteriorates

Engineering Contradiction:
Improvetissue penetration capabilityVSAvoidtissue impedance measurement capability
Core Design Contradiction:
ForceVSMeasurement precision

Solution Approach 1:

The patent combines the mechanical biopsy function (sharp probe for tissue penetration and sampling) with the electrical measurement function (electrodes for impedance measurement) into a single integrated probe structure. The electrodes are embedded within the stylet of the biopsy probe, allowing simultaneous tissue penetration and impedance measurement without requiring separate devices.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The biopsy probe is designed to perform multiple functions: mechanical tissue penetration, tissue sampling, and electrical impedance measurement. The stylet serves both as a mechanical cutting/sampling tool and as a carrier for electrodes that enable electrical measurements, making the device universal for both mechanical and electrical diagnostic purposes.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If electrodes are placed on the surface of the probe for impedance measurement, then measurement capability is improved, but electrical insulation and signal accuracy deteriorate due to interference from the metal probe body

Engineering Contradiction:
Improveimpedance measurement capabilityVSAvoidelectrical interference from metal probe body
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The electrodes are nested within recessed channels formed in the stylet body. This nesting arrangement places the electrodes inside protective grooves that are surrounded by insulating material, shielding them from electrical interference caused by the conductive metal probe body while maintaining their measurement functionality.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

An insulating material is introduced as an intermediary substance between the conductive metal stylet and the conductive electrodes. This insulating layer prevents electrical interference and signal distortion caused by the metal probe body, ensuring accurate impedance measurements by electrically isolating the electrodes from the conductive stylet structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If the probe structure is simplified for ease of manufacture, then manufacturing cost is reduced, but the capability to house insulated electrodes for accurate impedance measurement deteriorates

Engineering Contradiction:
Improveprobe manufacturing simplicityVSAvoidelectrode insulation and positioning accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The recessed channels are formed directly within the stylet body as integral features, creating nested protective structures that house the electrodes. This nesting approach provides built-in mechanical protection and electrical insulation pathways without requiring separate external insulating components, maintaining manufacturing simplicity while ensuring electrode protection.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The probe structure combines conductive metal material for the stylet body with insulating material for the recessed channels and electrode coating. This composite material approach allows the same component (the stylet) to provide both mechanical functionality and electrical insulation, simplifying the overall structure while maintaining measurement precision.

Inventive Principle:
Principle #40Composite materials

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 enables accurate tissue type determination and penetration depth measurement, enhancing the precision and effectiveness of tissue sampling procedures.

Implementation Method 1

measure an impedance of tissue adjacent to the electrodes

Methodology Applied
Scientific EffectElectrical Impedance: Electrical Resistance

Data Source

PatentEP3723619B1Impedance measuring probe and biopsy apparatus
Publication Date: 2025.04.16 CR BARD INC
  • EP3723619B1 patent drawingFigure 1~2
  • EP3723619B1 patent drawingFigure 3~4B
  • EP3723619B1 patent drawingFigure 5A~5B

AI summary

An impedance measuring probe for use in a biopsy apparatus includes a metal elongate member having an elongate surface, a proximal end portion, and a distal end portion. The elongate surface has a recessed longitudinal channel having a depth that longitudinally extends from the proximal end portion into the distal end portion. A conductive wire electrode, having a connection end and a sensing end, is located in and extends along the recessed longitudinal channel. The connection end extends from the proximal end portion of the elongate member and the sensing end is located at the distal end portion of the elongate member. An insulation material is disposed in the recessed longitudinal channel of the elongate member and around the conductive wire electrode so as to electrically insulate the conductive wire electrode, and with the sensing end of the conductive wire electrode being exposed.