The membrane oxygenator: from a black to a white box

In this thesis, various aspects of oxygenators are studied. Oxygenators are artificial lungs used in heart-lung machines during cardiac surgery and in the support of patients with heart and/or lung failure. The thesis shows that all oxygenator types have their own optimal blood flow range where gas exchange is optimal. Gas exchange efficiency decreases at higher blood flows. Moreover, it is shown that over time, clots in oxygenators continue growing, without decreasing gas exchange efficiency. By using smaller gas exchange fibers, it is possible to decrease oxygenator volume and increase gas exchange efficiency. Lastly, this thesis shows that the amount of oxygen delivered to patients varies considerably, and that a commonly used critical oxygen delivery value does not apply to all patients.