Cutting Device for Minimally Invasive Retrieval of Entrapped Tissue

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Solution Overview

Problem

Existing medical retrieval devices face difficulties in cutting and removing large tissue or stone fragments from body lumens, as they often exceed the lumen diameter, leading to obstruction and trauma during minimally invasive procedures.

Innovation Solution

A medical device comprising a sheath with a cutting device at the distal end, an elongate member, and a retrieval assembly that can entrap and cut objects using a hypotube with a sharp edge or cutting wire, allowing for size reduction of entrapped material for safe removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a retrieval device is used to capture large tissue or stone fragments, then the material can be entrapped within the device, but the diameter of the retrieval assembly exceeds the inner diameter of the narrowed lumen, preventing removal

Engineering Contradiction:

Improvesize of entrapped materialVSAvoidremoval through narrowed lumen

Core Design Contradiction:

Volume of moving objectVSEase of operation

Solution Approach 1:

The cutting device divides the entrapped material into multiple smaller segments or reduces its overall size by making cuts, allowing the fragmented material to pass through the narrowed lumen more easily while remaining contained within the retrieval assembly

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The cutting device performs size reduction of the material before the retrieval assembly is withdrawn from the body, preparing the material in advance to fit through the constricted lumen during the removal phase

Inventive Principle:

Principle #10Preliminary action

2Reliability

If the retrieval assembly is expanded to capture the object, then the object can be entrapped effectively, but the assembly cannot be compressed sufficiently to pass through the narrowed lumen

Engineering Contradiction:

Improveentrainment of objectVSAvoiddiameter of retrieval assembly

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The retrieval assembly transitions between expanded and compressed states dynamically - expanding to capture the object reliably, then compressing to a smaller diameter to pass through the narrowed lumen, and finally expanding again to secure the cut material for removal

Inventive Principle:

Principle #15Dynamics

3Reliability

If known retrieval assemblies are used, then material can be captured, but cutting the entrapped material once captured is difficult or impossible

Engineering Contradiction:

Improvecapture of materialVSAvoidcutting capability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The cutting device integrates a cutting mechanism directly into the retrieval assembly, combining the functions of capture and size reduction in a single device, allowing the operator to cut the entrapped material after capture without requiring a separate instrument

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS8979832B2Cutting device and related methods of use

Publication Date: 2015.03.17 BOSTON SCIENTIFIC SCIMED INC

AI summary

A device and related methods of use are provided for the capture and removal of various unwanted objects present within the body's anatomical lumens. In an embodiment of the present disclosure, the device includes a sheath, a cutting device, an elongate member, and a retrieval assembly connected to the elongate member and retractable within and extendable from a lumen extending through the sheath and cutting device.