Thrombolysis Patient Selection Using Imaging Penumbra Assessment

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Solution Overview

Problem

Current thrombolytic stroke therapies are limited by a narrow time window and high risk of intracranial hemorrhage, failing to effectively treat all eligible patients and exposing some to unnecessary risks.

Innovation Solution

Selecting patients based on individual imaging assessments of tissue at risk and artery occlusion, using a non-neurotoxic plasminogen activator like desmoteplase, and administering it outside the traditional 3-hour time frame to target those with salvageable brain tissue and occlusions, thereby reducing hemorrhagic transformation risks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If thrombolytic therapy is extended to the 3-4.5 hour time window, then more patients can be treated, but the incidence of intracranial hemorrhage significantly increases

Engineering Contradiction:

Improvetime window for treatmentVSAvoidincidence of intracranial hemorrhage

Core Design Contradiction:

Loss of timeVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by using imaging techniques to identify specific regions of salvageable brain tissue (penumbra) in individual patients. Treatment is targeted to those with demonstrated tissue at risk, rather than applying a blanket time-based criterion to all patients. This localized approach allows extension beyond 3 hours for patients with viable tissue while avoiding treatment in those without salvageable tissue, thereby reducing overall hemorrhage risk.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the selection parameter from a fixed time criterion to a tissue-based criterion using imaging parameters. Instead of treating all patients within a time window, the invention uses imaging to assess tissue viability (penumbra identification) as the primary selection parameter, allowing flexible time window extension for patients meeting tissue criteria while maintaining safety.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If restrictive criteria are applied to reduce hemorrhage risk, then safety improves, but fewer patients who could benefit from treatment are included

Engineering Contradiction:

Improverisk of intracranial hemorrhageVSAvoidnumber of treatable patients

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent uses imaging to locally identify salvageable tissue (penumbra) in individual patients, allowing precise selection of those who will benefit from treatment. This approach moves beyond restrictive time-based criteria to identify patients with viable tissue regardless of time since onset, thereby increasing the number of treatable patients while maintaining safety through tissue-based selection.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent replaces the mechanical time-based selection system with an imaging-based tissue assessment system. Instead of using fixed time windows as the selection mechanism, the invention substitutes imaging technology to directly assess tissue viability, allowing more accurate identification of patients who need treatment while reducing unnecessary exclusions.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If thrombolytic therapy is administered to all patients within the time window, then treatment accessibility improves, but patients with minor or transient events are exposed to unnecessary hemorrhage risk

Engineering Contradiction:

Improvetreatment accessibilityVSAvoidunnecessary hemorrhage risk

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by using imaging to identify specific patients with salvageable tissue rather than treating all patients uniformly. This allows the system to distinguish between patients with significant ischemic events needing treatment and those with minor or transient events, providing targeted treatment to those who truly need it while avoiding unnecessary exposure to hemorrhage risk.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent inverts the traditional approach by not treating all patients within the time window, but rather selectively treating those who demonstrate salvageable tissue on imaging. This inversion of the selection criterion (from time-based inclusion to tissue-based inclusion) allows the system to maintain accessibility for those who need treatment while excluding those who would benefit little and face unnecessary risk.

Inventive Principle:

Principle #13The other way round (Inversion)

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 increases the efficacy and safety of thrombolytic stroke therapy by identifying patients who truly need treatment, reducing unnecessary exposure to hemorrhagic risks, and allowing treatment beyond the traditional 3-hour window, potentially improving clinical outcomes for stroke patients.

Implementation Method 1

The administration of thrombolytics - such as plasminogen activators - to the patient in acute ischemic stroke therapy aims to rescue the 'tissue at risk'

Methodology Applied

Scientific EffectFibrinolysis:

Data Source

PatentEP2211898B1Novel patient subgroups for thrombolysis

Publication Date: 2016.12.07 H LUNDBECK AS

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AI summary

A method for treating a stroke patient with thrombolysis, whereas prior treatment the patient is diagnosed in particular for exhibiting cerebral tissue at risk, a cerebral artery occlusion and/or an absolute 'mismatch volume'.