Tangential Flow Filtration for CSF Clogging and Lysis Control
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Solution Overview
Problem
Existing filters for biologic fluids, such as dead-end and depth filters, are ineffective for large volumes and prone to clogging, and can cause lysis of materials like blood, necessitating improved systems for efficient filtration.
Innovation Solution
A tangential flow filtration system is used to separate cerebrospinal fluid (CSF) into permeate and retentate, with adjustable parameters like flow rate and pressure to manage filtration, and optional re-filtration of retentate through additional filters, combined with sensors for real-time monitoring and control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If dead-end or depth filters are used for filtering biologic fluids, then the filters are easy to use and come in many pore sizes, but their small surface area prevents them from being used for larger volumes and they quickly clog
Solution Approach 1:
The patent transitions from dead-end filtration (one-dimensional flow perpendicular to filter surface) to tangential flow filtration (two-dimensional flow parallel to filter surface). This dimensional change increases the effective filtration area and prevents clogging by continuously sweeping the filter surface, enabling processing of larger volumes while maintaining ease of operation through standardized filter modules
2Device complexity
If dead-end filters are used for filtering biologic materials, then the filtration process is simple, but the material is lysed when filtered through dead-end filters
Solution Approach 1:
The patent changes the flow direction parameter from perpendicular (dead-end) to parallel (tangential) relative to the filter surface. This parameter change eliminates the high shear forces and pressure gradients that cause lysis, while maintaining filtration simplicity through standardized operating procedures and automated flow control
3Productivity
If tangential flow filtration is used to filter large volumes of biologic fluid, then clogging and lysis are prevented, but the system complexity increases with multiple parameters to control
Solution Approach 1:
The patent implements self-regulating tangential flow filtration systems where the cross-flow rate automatically adjusts based on transmembrane pressure feedback. This self-service mechanism maintains optimal filtration conditions without requiring manual intervention for multiple parameters, enabling large volume processing while reducing operational complexity
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 system effectively filters contaminants from CSF while maintaining fluid balance, preventing clogging and lysis, and allows for continuous operation with minimal disruption to the subject.
Implementation Method 1
filtering the volume of fluid into permeate and retentate using a tangential flow filter of the filtration system
Data Source
AI summary
Systems and methods for filtering materials from biologic fluids are discussed. Embodiments may be used to filter cerebrospinal fluid (CSF) from a human or animal subject. The method may include the steps of withdrawing fluid comprising CSF, filtering the volume into permeate and retentate by passing the fluid through a tangential flow filter, and returning the permeate to the subject. During operation of the system, various parameters may be modified, such as flow rate.