Nested Hysteroscopic Tissue Cutting Sleeve for Small-Diameter Resection

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Solution Overview

Problem

Existing hysteroscopic resection methods for uterine fibroids face challenges due to the large diameter of instruments requiring anesthesia and risk of intravasation from fluid uptake, necessitating a system that can effectively cut and remove fibroid tissue through a small diameter hysteroscope.

Innovation Solution

A tissue cutting device with an elongated structure comprising an outer and inner sleeve, where the inner sleeve moves relative to the outer sleeve to cut and extract tissue, featuring a distal cutting edge and a dielectric material around the cutting window to manage electrical current, and a motor for relative movement to facilitate cutting and extraction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional hysteroscopic resection instruments are used, then fibroid tissue can be cut and removed, but the large diameter of the instruments requires anesthesia and operating room environment

Engineering Contradiction:

Improveminimally invasive capabilityVSAvoidinstrument diameter

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The device employs a nested structure where an inner cutting sleeve is positioned within an outer sleeve. The inner sleeve contains the cutting edge and extraction lumen, while the outer sleeve provides structural support and houses additional components. This nesting allows the cutting functionality to be achieved within a compact overall diameter, enabling minimally invasive hysteroscopic resection without requiring large-bore instruments that would necessitate anesthesia.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Area of stationary object

If high pressure fluid is used to distend the uterine cavity, then a working space is created for viewing and manipulation, but there is a significant risk of intravasation into cut blood vessels

Engineering Contradiction:

Improveuterine cavity working spaceVSAvoidintravasation risk

Core Design Contradiction:

Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The device introduces a dielectric material positioned around the cutting window and along the inner sleeve. This dielectric material serves as an intermediary that blocks RF current conduction through the distending fluid, preventing intravasation of electrical current into blood vessels. The dielectric barrier allows the use of adequate distending fluid pressure to create necessary working space while eliminating the harmful electrical intravasation risk associated with RF electrosurgical procedures.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of operation

If a small diameter hysteroscope is used to reduce invasiveness, then minimally invasive procedures are enabled, but the extraction lumen may become clogged with tissue

Engineering Contradiction:

Improveminimally invasive capabilityVSAvoidextraction lumen patency

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The device employs a dynamic extraction mechanism where the inner sleeve can move relative to the outer sleeve. The inner sleeve features an extraction lumen that can be dynamically opened or closed by advancing or retracting the inner sleeve. This dynamic capability allows the system to clear the lumen of clogged tissue by retracting the sleeve, restoring patency while maintaining the small overall diameter necessary for minimally invasive hysteroscopic procedures.

Inventive Principle:

Principle #15Dynamics

4Productivity

If RF electrosurgical resection is used to cut tissue, then effective cutting is achieved, but unwanted fluid uptake occurs leading to serious complications

Engineering Contradiction:

Improvetissue cutting efficiencyVSAvoidfluid uptake complications

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The device replaces RF electrosurgical cutting with a mechanical cutting mechanism. The inner sleeve features a sharp cutting edge that mechanically severs tissue as the sleeve advances. This mechanical cutting substitution eliminates the need for RF current entirely, thereby eliminating the risk of RF-induced intravasation of distending fluid into blood vessels while maintaining effective tissue cutting capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

Enables effective cutting and removal of uterine fibroids through a small diameter hysteroscope, reducing the risk of intravasation and tissue clogging, while allowing for minimally invasive procedures.

Implementation Method 1

the inner sleeve will typically have a distal cutting edge, such as a sharpened edge, an electrosurgical edge, or the like, which allows the inner sleeve to be advanced past the cutting window in the outer sleeve in order to cut, sever, or otherwise remove tissue which intrudes inwardly through the window

Methodology Applied

Scientific EffectDielectric: Dielectric

Data Source

PatentUS20250275806A1Tissue extraction devices and methods

Publication Date: 2025.09.04 AXORA MEDICAL INC

AI summary

A tissue cutting device has an outer sleeve with a distal window and an inner cutting sleeve which moves past the window to cut tissue. The inner cutting sleeve has a lumen which may have a larger proximal diameter than distal diameter. A perimeter of the window may comprise a dielectric material. A distal edge of the inner sleeve may be displaced inwardly.