Development of personalized non-invasive ventilation masks for critically ill children: a bench study

Abstract

Background: Obtaining a properly fitting non-invasive ventilation (NIV) mask to treat acute respiratory failure is a major challenge, especially in young children and patients with craniofacial abnormalities. Personalization of NIV masks holds promise to improve pediatric NIV efficiency. As current customization methods are relatively time consuming, this study aimed to test the air leak and surface pressure performance of personalized oronasal face masks using 3D printed soft materials. Personalized masks of three different biocompatible materials (silicone and photopolymer resin) were developed and tested on three head models of young children with abnormal facial features during preclinical bench simulation of pediatric NIV. Air leak percentages and facial surface pressures were measured and compared for each mask.

Results: Personalized NIV masks could be successfully produced in under 12 h in a semi-automated 3D production process. During NIV simulation, overall air leak performance and applied surface pressures were acceptable, with leak percentages under 30% and average surface pressure values mostly remaining under normal capillary pressure. There was a small advantage of the masks produced with soft photopolymer resin material.

Conclusion: This first, proof-of-concept bench study simulating NIV in children with abnormal facial features, showed that it is possible to obtain biocompatible, personalized oronasal masks with acceptable air leak and facial surface pressure performance using a relatively short, and semi-automated production process. Further research into the clinical value and possibilities for application of personalized NIV masks in critically ill children is needed.

Keywords: 3D printing; Acute respiratory failure; Customization; Face mask; Non-invasive respiratory support; Pediatric intensive care unit.

Fig. 1

A schematic overview of the bench test setup for pediatric non-invasive ventilation simulation with details on the test head model (A) and the personalized mask (B). The personalized mask consist of a frame, frame ring, holder and a personalized cushion. The mask is placed on the accompanying test head model, which contains facial pressure components that follow the outline of the ventilation mask. The pressure sensors underneath the components are connected to the laptop through a microcontroller (Arduino). The test head model has a 3-mm silicon layer to create an airtight connection to the mechanical lung simulator. The mask is connected to the ventilator, which directly provides information on the inspiration (insp) and expiration (exp) volumes, flows and pressures (P) to the laptop for data collection

Fig. 2

An overview of the personalized cushion materials. From left to right: silicone urethane (SU) printed on a DLS printer, silicone (Si) printed on an FDM printer, and soft photopolymer resin (SPR) printed on a DLP printer

Fig. 3

Air leak percentages (L_air) for the commercial mask (CM) and each personalized non-invasive ventilation (NIV) mask (silicone urethane (SU) small and large; silicone (Si) small and large; and soft photopolymer resin (SPR) small and large) during pediatric NIV bench test simulation at three different ventilation pressure steps (peak-inspiratory pressure/positive end-expiratory pressure: 15/5 cmH₂O, 20/5 cmH₂O and 25/5 cmH₂O). The boxplots and error-bars depict median/IQR and range, respectively. *CM versus SU_small, SU_large, Si_small, Si_large, SPR_small and SPR_large (p < 0.05); **SPR_small versus Si_small and Si_large (p < 0.05); ***SPR_small versus Si_small (p < 0.05); ****SPR_large versus Si_small and Si_large (p < 0.05) as analyzed by Friedman non-parametric test with post hoc testing

Fig. 4

Facial surface pressures (N/cm²) (average for all six sensors, nose bridge and chin region) for the commercial mask (CM) and each personalized non-invasive ventilation (NIV) mask (silicone urethane (SU) small and large; silicone (Si) small and large; and soft photopolymer resin (SPR) small and large) during pediatric NIV bench test simulation at a peak-inspiratory pressure of 15 cmH₂O and a positive end-expiratory pressure of 5 cmH₂O. The boxplots and error-bars depict median/IQR and range, respectively. *CM versus SU_small, SU_large, Si_small, Si_large and SPR_small (p < 0.05); **SPR_large versus SU_small and Si_small (p < 0.05)