TPMS-based membrane lung with locally-modified permeabilities for optimal flow distribution

Abstract

Membrane lungs consist of thousands of hollow fiber membranes packed together as a bundle. The devices often suffer from complications because of non-uniform flow through the membrane bundle, including regions of both excessively high flow and stagnant flow. Here, we present a proof-of-concept design for a membrane lung containing a membrane module based on triply periodic minimal surfaces (TPMS). By warping the original TPMS geometries, the local permeability within any region of the module could be raised or lowered, allowing for the tailoring of the blood flow distribution through the device. By creating an iterative optimization scheme for determining the distribution of streamwise permeability inside a computational porous domain, the desired form of a lattice of TPMS elements was determined via simulation. This desired form was translated into a computer-aided design (CAD) model for a prototype device. The device was then produced via additive manufacturing in order to test the novel design against an industry-standard predicate device. Flow distribution was verifiably homogenized and residence time reduced, promising a more efficient performance and increased resistance to thrombosis. This work shows the promising extent to which TPMS can serve as a new building block for exchange processes in medical devices.

Computer based visualization of clot structures in extracorporeal membrane oxygenation and histological clot investigations for understanding thrombosis in membrane lungs

“…The stacked fiber mats of the ML could trap clots that have previously formed in the extracorporeal circuit, suggesting that the ML is the effector point but not the trigger for thrombogenesis ( 26 , 50 ). Second, changes in blood flow and shear rates upon entry into the ML could activate clotting, leading to clot formation in the ML itself ( 51 , 52 ). Both theories supported the results that clots mainly formed in the vicinity of the blood entrance of the ML.…”

Design of artificial vascular devices: Hemodynamic evaluation of shear-induced thrombogenicity

“…Furthermore, novel biomimetic scaffolds based on triply periodic Frontiers in Mechanical Engineering frontiersin.org minimal surface (TPMS) theory were developed for fluid-circulation devices. Using a permeability-based design approach, membranes display modules with improved flow distribution overcoming nonuniform and stagnant patterns found in hollow fibres membranes of oxygenators (Hesselmann et al, 2022). TPMS-scaffolds morphology has a markedly high surface area to volume ratio and highly controlled porosity similar to native cellular conditions (Vijayavenkataraman et al, 2018).…”

Additive Manufacturing of Intertwined Electrode Pairs ‐ Guided Mass Transport with Gyroids

“…[10] Triply periodic minimal surface (TPMS) structures offer high surface-to-volume ratios and excellent mass transport properties, as has been presented for heat exchangers and membrane modules [22] as well as for artificial lungs in biomedical applications. [23][24][25][26] In this article, we present the design of 3D-structured electrode pairings in the shape of TPMS structures from selective laser melting (SLM). With the intertwined structure of the working electrode (WE) and counter electrode (CE), high specific surface areas are achieved at a small build volume and with homogeneously small electrolyte gaps.…”

“…Triply periodic minimal surface (TPMS) structures offer high surface‐to‐volume ratios and excellent mass transport properties, as has been presented for heat exchangers and membrane modules [ 22 ] as well as for artificial lungs in biomedical applications. [ 23–26 ]…”