Step-Design Cannula for Reflux-Resistant Convection-Enhanced Delivery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current convection-enhanced delivery (CED) techniques for therapeutic substances into the central nervous system are limited by low infusion rates and reflux, leading to prolonged treatment times, increased risk of infections, and reduced efficacy due to the lack of a standardized cannula design and high risk of drug leakage.
Innovation Solution
A novel step-design cannula with a non-uniform outer diameter that decreases from the proximal end to the distal end, minimizing tissue damage and reflux, allowing for higher flow rates and more efficient distribution of therapeutic agents without introducing air or inducing reflux, thereby enhancing the therapeutic index of CED.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional cannula design is used for CED, then device simplicity is maintained, but reflux occurs and infusion rate is limited
Solution Approach 1:
The cannula is divided into multiple segments with different outer diameters along its length. The proximal segment has a larger outer diameter while distal segments have progressively smaller outer diameters, creating a stepped configuration that prevents reflux while maintaining high infusion rates
Solution Approach 2:
Different portions of the cannula have different outer diameters tailored to their specific functions. The proximal portion with larger diameter facilitates high flow rates, while distal portions with smaller diameters prevent reflux, optimizing both infusion rate and reflux prevention locally
2Loss of time
If higher flow rates are used for faster CED, then treatment time is reduced, but reflux and tissue damage increase
Solution Approach 1:
The cannula structure segments the flow path with varying diameters that allow high flow rates at the proximal end while preventing backflow and tissue damage at distal ends through progressively smaller diameters
Solution Approach 2:
The outer diameter parameter of the cannula changes along its length, transitioning from larger proximal diameters that accommodate high flow rates to smaller distal diameters that prevent reflux and minimize tissue damage, enabling fast infusion without harmful effects
3Reliability
If standardized cannula design is implemented, then device complexity increases, but reliability and reflux prevention improve
Solution Approach 1:
The cannula employs a standardized multi-segment design with consistent stepped configurations that can be manufactured reliably while preventing reflux through the systematic variation in outer diameters across segments
Solution Approach 2:
The stepped cannula design serves multiple functions simultaneously: it enables high flow rates, prevents reflux, minimizes tissue damage, and provides standardized manufacturing characteristics, making it a universal solution for CED applications
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 step-design cannula enables reflux-resistant and fast CED with higher flow rates, reducing infusion time, minimizing tissue damage, and ensuring effective distribution of therapeutic agents, potentially improving the clinical efficacy and safety of CED by preventing reflux and air introduction.
Implementation Method 1
Convection-enhanced delivery (CED) is a direct intracranial drug delivery technique that utilizes a bulk-flow mechanism to deliver and distribute macromolecules to clinically significant volumes of solid tissues
Data Source
AI summary
A step-design cannula and delivery system for chronic delivery of therapeutic substances into the brain using convention-enhanced delivery of therapeutic substances and which effectively prevents reflux in vivo and maximizes distribution in the brain.