A novel wearable pump-lung device: in vitro and acute in vivo study

Abstract

Background: To provide long-term ambulatory cardiopulmonary and respiratory support for adult patients, a novel wearable artificial pump-lung device has been developed. The design features and in vitro and acute in vivo performance of this device are reported.

Methods: This device features a uniquely designed hollow-fiber membrane bundle integrated with a magnetically levitated impeller that together form one ultracompact pump-lung device, which can be placed like current paracorporeal ventricular assist devices to allow ambulatory support. The device is 117 mm in length and 89 mm in diameter and has a priming volume of 115 ml. In vitro hydrodynamic, gas transfer and biocompatibility experiments were carried out in mock flow-loops using ovine blood. Acute in vivo characterization was conducted in an ovine model by surgically implanting the device between right atrium and pulmonary artery.

Results: The in vitro results show that the device with a membrane surface area of 0.8 m(2) was capable of pumping blood from 1 to 4 liters/min against a wide range of pressures and transferring oxygen at a rate of up to 180 ml/min at a blood flow of 3.5 liters/min. Standard hemolysis tests demonstrated low hemolysis at the targeted operating condition. The acute in vivo results also confirmed that the device can provide sufficient oxygen transfer with excellent biocompatibility.

Conclusions: Based on in vitro and acute in vivo study findings, this highly integrated wearable pump-lung device can provide efficient respiratory support with good biocompatibility and it is ready for long-term evaluation.

Figure 1

(a) Drawing of the cross-section and the impeller/diffuser assembly of the APL device; (b) Photo of the device; and (c) Photo of the motor/controller system.

Figure 2

(a) In-vitro pumping performance of the APL device; and (b) In-vitro gas transfer performance of the APL device (Error bar represents standard deviation.).

Figure 3

Photos of the in-vivo animal study: (a) The APL device fixed on the back of the sheep; and (b) Enlarged view of the APL device.

Figure 4

(a) Oxygen transfer results of the in-vivo studies; and (b) Inlet and outlet oxygen saturation variation during the in-vivo studies.