Fig. 2 How the BVS 5000 works: Note the passive filling, the two 1-way valves, and how the pneumatic drive is triggered by 80 cc of air displaced through the exhaust during pump diastole.

Reprinted from Ann Thorac Surg 1995;59(2 Suppl):S31–8, with permission from the Society of Thoracic Surgeons.