479 - 3D printed neonatal fluidic automated pressure cycled resuscitator. A mix method laboratory experiment.

Publication Number: 1459.479

Brian K.. Walsh, University of Texas Medical Branch, Galveston, TX, United States; Zack Cooper, University of Texas Medical Branch School of Medicine, GALVESTON, TX, United States

Background: While 10% of newborns globally require resuscitation at birth, delivering safe and effective resuscitation remains a worldwide challenge. The current standard tool for rescue breathing is bag valve mask (BVM), which can be labor-intensive and complex due to factors like the required short inspiratory times, fast respiratory rates, small tidal volumes, mask leaks and airway obstructions to name a few. Inadequate mechanical ventilation during neonatal resuscitation can lead to injury and even death. This study presents the development and assessment a fluidic-powered automatic neonatal resuscitator (FRD) device operating without electronic components.

Objective: Overcome the shortcomings of manual ventilation and ensures precise and consistent ventilation, offering potential use in emergency or resource-limited settings by leveraging fluidic design with no moving parts. Operates without complex controls, well-suited for low-resource settings where access to skilled personnel and advanced medical equipment is limited.

Design/Methods: Leveraging fluidic geometry knowledge and design we were able to design a FRD for neonatal application. Rapid prototyping via 3D printing (FormLabs) of a 3-channel device designed to target 3 size neonates (1, 2, 3 Kg) to achieve a PIP of 18 and PEEP of 4 cmH2O while producing appropriate breath characteristics and escalating minute ventilation. Using the ASL 5000 lung simulator set to 1-3kg lung characteristics, we tested 15 channels built within 5 devices. The best performing channel design was tested in an in vivo model of RDS (rabbits) weighing 1-4 kg follow lung injury with surfactant washout technique. Ten minutes of FRD was compared to 10 minutes of conventional mechanical ventilation (CMV) provided by the Hamilton ventilator using ABG analysis.

Results: We successfully designed, and tested in vitro and in vivo for the targeted population that runs on 1.5-3.0 L/min gas flow. See Figure 1 and Table 1 for targets and results. We successfully ventilated the 6 animals with varying lung disease severity with no significant differences in pH, PaCO2, and PaO2. See Table 3

Conclusion(s): We were able to achieve the PIP and PEEP produced devices with a print failure rate of 33% with a very low flow rate making this reasonable alternative in resource limited areas. However, the current minute ventilation in vitro is too high and will need to be adjusted down as to not hyperventilate a premature neonate. This will push the limits of 3D printing such small channels. We did not experience hyperventilation in the in vitro model.

Figure 1: Demonstrate Pressure and Volume Tracings of Performance.
Desired targets lines are identified in each graph.

Table 1: Demonstrates the results from the in vitro study.
Target ranges are below the parameters.

Table 2: Provides the ABG results from the in vivo experiment.
Table 2.jpeg