Expandable Rotating Cutting Device for Calcified Stenosis

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Solution Overview

Problem

Existing medical devices for treating stenosed sites in coronary arteries, such as those caused by plaque or thrombus, often damage normal blood vessels and struggle with hardened stenosis substances, particularly when the stenosed site is calcified or located in a bifurcated portion.

Innovation Solution

A medical device with a rotatable tubular drive shaft, an expandable cutting part, and a support portion, featuring struts with alternating openings for cutting, which can be adjusted to fit the vessel diameter and minimize contact with biological tissues, reducing the risk of damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If expandable and contractible bars are used to fit the blood vessel diameter, then the device can adapt to different vessel sizes, but the edge of the bars comes into contact with the blood vessel causing damage to normal blood vessels

Engineering Contradiction:

Improvevessel size adaptationVSAvoidblood vessel damage

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The cutting device is divided into multiple struts that can be independently positioned and controlled. Each strut can be selectively engaged or disengaged from the blood vessel wall, allowing the operator to apply cutting force only where needed while leaving healthy tissue untouched. This segmentation enables precise control over which areas contact the cutting elements.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The device employs dynamically adjustable struts that can change their radial position during the procedure. The struts can be extended to contact and cut stenotic material, then retracted to avoid contact with normal blood vessel walls. This dynamic positioning allows the device to adapt its contact pattern based on the specific anatomical conditions encountered.

Inventive Principle:

Principle #15Dynamics

2Productivity

If the rotating body is rotated inside the coronary arteries to cut the stenosis substance, then the cutting function is achieved, but hardened stenosis substance is caught in gaps between bars causing device damage

Engineering Contradiction:

Improvecutting efficiencyVSAvoiddevice durability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The struts are constructed from composite materials that combine the hardness needed to cut calcified plaque with the toughness required to resist fracture. The cutting edges may use diamond-coated or cobalt-chromium alloys that provide both cutting effectiveness and resistance to damage from contact with hardened stenotic material.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The device design anticipates the possibility of encountering extremely hard calcified plaque by incorporating struts with sufficient structural reinforcement and support. The strut design includes internal strengthening features and appropriate material selection that provide a buffer against the high stresses encountered when cutting through calcified lesions, preventing device failure before it occurs.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Strength

If the cutting part is expanded to cut hardened stenosis substance, then the cutting capability is improved, but the device complexity increases

Engineering Contradiction:

Improvecutting capabilityVSAvoiddevice structure

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The device combines multiple functions into integrated components. The struts serve both as structural support elements and as the cutting tools themselves. The expansion mechanism that deploys the struts also positions them for cutting, eliminating the need for separate deployment and cutting initiation systems. This merging reduces overall device complexity while maintaining cutting capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The struts are designed as multi-functional elements that provide structural support, enable vessel expansion, and perform cutting functions. This universal design reduces the number of separate components needed in the device, simplifying the overall structure while achieving multiple objectives including cutting hardened plaque and maintaining device stability within the vessel.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 enables precise cutting of stenosis substances while minimizing damage to normal blood vessels and allowing for adjustable expansion to fit various vessel sizes, enhancing treatment efficacy.

Implementation Method 1

a cutting part configured to rotate around the axial direction in correspondence with the rotation of the tubular drive shaft

Methodology Applied

Scientific EffectAbrasion: Abrasion

Data Source

PatentUS12426914B2Medical device and treatment method

Publication Date: 2025.09.30 TERUMO KK

AI summary

A treatment method and medical device are disclosed for cutting a substance inside a body lumen. The medical device for cutting substances inside a body lumen including a rotatable tubular drive shaft; an expanding part connected to a distal side of the tubular drive shaft; a cutting part covering the expanding part; and an elongated tube extending through the tubular drive shaft and connected to the expanding part, wherein a distal end of the expanding part is placed distal to a distal end of the cutting part.