Thoracic Artificial Lung Design.

[摘要] Currently there is no sufficient bridge to lung transplant for patients with end-stage lung disease. Thoracic artificial lungs (TAL) are being developed for this purpose. TALs are attached to the pulmonary circulation, and thus their blood flow is provided by the right ventricle (RV). Current TALs possess blood flow impedances greater than the natural lungs, resulting in low cardiac output (CO) when implanted in series with the natural lung or in parallel under exercise conditions. In series attachment is desired so that the natural lung will still filter blood and perform its non-respiratory functions.However, in parallel attachment may allow for high flow applications. The goal of this research was to design a device with minimal impedance which does not cause a significant decrease in CO when attached in series, or in parallel with cases of high device flows, such as exercise.This was done both through the examination of geometry changes to the TAL housing and through the use of a compliant housing material. A new compliant TAL (cTAL) was designed, prototyped and tested both in vitro and in vivo. First, computational fluid dynamics (CFD) and fluid-structure interaction (FSI) modeling were used to investigate inlet and outlet expansion and contraction angles, θ, of 15°, 45°, and 90° in both hard-shell TALs and cTALs. The 45° model was chosen for the cTAL prototype and tested in vitro and in vivo in the acute setting, attached both in parallel and in series with the native lungs. The combination of a gradual entrance and exit to the device, as well as a compliant housing resulted in a device impedance of 0.5 mmHg/(L/min), much lower than the native lungs and all other existing TAL designs. The fiber bundle of the cTAL provided excellent gas transfer, with a rated flow well above 7 L/min. The cTAL developed with this research is capable of lower flow PA-PA attachment, with up to 50% of CO to the cTAL. PA-LA attachment of the cTAL will allow for excellent exercise tolerance and unloading of the RV in patients with pulmonary hypertension.

[发布机构] University of Michigan

[效力级别] Impedance

[关键词] Thoracic Artificial Lung;Impedance;Compliance;End Stage Lung Disease;Biomedical Engineering;Engineering;Biomedical Engineering