Developing a 3D Printed Fluidic Positive Airway Pressure Device: A Bench Comparison

Abstract

Background: Positive airway pressure (PAP) falls in the category of hyperinflation therapy. Hyperinflation therapy is used to prevent or reverse atelectasis, reduce air trapping in obstructive diseases, aids in mobilization of retained secretions and/or optimizes inhaled drug delivery. PAP devices are separated from positive expiratory pressure (PEP) devices, due to the addition of flow that adds inspiratory as well as expiratory positive pressure. There are two types of PAP devices on the market today: threshold and flow resistors. The threshold resistors are more accurate regardless of flow due to a spring-loaded valve but are more expensive to manufacturer. Flow resistors are less precise due to varying inspiratory and expiratory flows of the patient but cheaper to manufacturer. The UTMB CRAVE lab in partnership with FluidIQ, Inc with their combined knowledge of fluidics set out to create a more accurate flow resistor PAP device, we labeled FPAP.

Methods: Two commercially available PAP devices (AccuPAP and VersaPAP) were compared to three of the best versions of FPAP (V13, V14, V15) 3D printed in the CRAVE lab. All devices were tested using the ASL 5000 (IngMar) in two patient conditions: low (PIF 21.4, PEF 12.7 L/min) and high flow (PIF 53.9, PEF 48.4) breathing characteristics. All devices were set to achieve 5, 10, 15, and 20 cm H₂O and flow recorded on a calibrated flow meter (Fluke) prior to experiment. Each device was tested for 50 breaths (25 low and 25 high flow). ± 2 cm H₂O of desired target PAP was considered significant.

Results: Table 1 provides a summary of the results. Using commercially available devices as the standard, V13 (62.5%) fell below, while V15 (75%) matched and V14 (78.6%) exceeded the % acceptable PAP delivery.

Conclusions: 3D printing allows for the rapid prototyping and testing of new PAP designs aimed at improving efficiency (gas consumption) and precision of delivered PAP. Through this novel design we were able to produce 2 devices that match or exceed currently available products PAP delivery in a simulated model.

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Table 1.