Conversion Electron Stent for Localized Restenosis Treatment

Solution Overview

Problem

Current medical devices, such as vascular stents, face challenges in effectively and safely delivering radiation to treat restenosis and hyperplasia, as existing radiation-emitting stents often affect surrounding tissue and have unknown long-term consequences on heart and non-cardiac tissue.

Innovation Solution

The development of a luminal prosthesis with a conversion electron emitting source (CEES) that emits radiation within a controlled distance of 0.2-0.3 mm, allowing for selective treatment of hyperplasia and neoplasia by providing conversion electrons directly to the affected area, with a stent design that includes a non-uniform distribution of CEES for targeted radiation delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If radiation-emitting stents are used to treat hyperplasia, then restenosis is reduced, but surrounding tissue is affected and long-term consequences are unknown

Engineering Contradiction:

Improverestenosis reductionVSAvoidsurrounding tissue damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by using conversion electron emitting sources with very short emission distances (0.2-0.3 mm) to deliver radiation locally to the vessel wall where hyperplasia occurs, while preventing radiation from affecting surrounding tissues. The non-uniform distribution of CEES along the stent provides localized treatment at specific locations where hyperplasia is most likely to occur.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the radiation emission parameters by using conversion electrons instead of beta particles, fundamentally altering the radiation type and its penetration depth. This parameter change enables the radiation to be confined to a very short distance (0.2-0.3 mm) from the stent surface, providing precise local treatment without affecting surrounding tissues.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If beta particle emitting radioisotopes are attached to stents, then hyperplasia is inhibited, but the radiation dose decreases excessively deep into tissue

Engineering Contradiction:

Improvehyperplasia inhibitionVSAvoidradiation penetration depth

Core Design Contradiction:

ReliabilityVSLength of stationary object

Solution Approach 1:

The patent changes the radiation emission parameters by using conversion electrons instead of beta particles, fundamentally altering the radiation type and its penetration depth. This parameter change enables the radiation to be confined to a very short distance (0.2-0.3 mm) from the stent surface, providing precise local treatment without affecting surrounding tissues.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

Instead of using beta particles that penetrate deeply into tissue, the patent inverts the approach by using conversion electrons with extremely short range (0.2-0.3 mm). This inversion of the radiation type achieves the opposite effect - limiting radiation to only the immediate vicinity of the stent surface where hyperplasia occurs, rather than allowing deep penetration.

Inventive Principle:

Principle #13The other way round (Inversion)

3Productivity

If uniform CEES distribution is used on stent, then treatment is comprehensive, but precision and control over treatment location is reduced

Engineering Contradiction:

Improvetreatment coverageVSAvoidtreatment location control

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies local quality by using conversion electron emitting sources with very short emission distances (0.2-0.3 mm) to deliver radiation locally to the vessel wall where hyperplasia occurs, while preventing radiation from affecting surrounding tissues. The non-uniform distribution of CEES along the stent provides localized treatment at specific locations where hyperplasia is most likely to occur.

Inventive Principle:

Principle #3Local quality

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

This approach significantly reduces hyperplasia by at least 30% and prevents 50% to 75% of uncontrolled hyperplasia, minimizing radiation damage to surrounding tissue and enabling precise treatment of vascular and other luminal conditions.

Implementation Method 1

a conversion electron emitting source (CEES) associated with selected locations of the body member, with the CEES providing conversion electrons that are emitted to provide radiation dosimetry immediately adjacent the selected locations

Methodology Applied

Scientific EffectConversion electron emission:

Data Source

PatentUS8834338B2Dosimetry implant for treating restenosis and hyperplasia

Publication Date: 2014.09.16 BROOKHAVEN SCIENCE ASSOCIATES LLC

AI summary

The present invention discloses a method of selectively providing radiation dosimetry to a subject in need of such treatment. The radiation is applied by an implant comprising a body member and 117mSn electroplated at selected locations of the body member, emitting conversion electrons absorbed immediately adjacent selected locations while not affecting surrounding tissue outside of the immediately adjacent area.