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Updated: Jun 19, 2025

Ex Vivo Porcine Experimental Model for Studying and Teaching Lung Mechanics
Published on: April 19, 2024
Characterising applied forces during positive pressure ventilation: a randomised cross-over simulation study
Jacqueline Hannan1, Gary Weiner2, Leia Stirling3,4
1Industrial and Operations Engineering, University of Michigan, Ann Arbor, Michigan, USA jhannan@umich.edu.
Objective:
To characterise applied force on the face and head during simulated mask ventilation with varying mask, device and expertise level.
Design:
Randomised cross-over simulation study.
Setting:
A quiet, empty room in the children's hospital.
Participants:
Neonatal healthcare providers, categorised as novices and experts in positive pressure ventilation (PPV).
Interventions:
PPV for 2 min each in a 2×2 within-subjects design with two masks (round and anatomic) and two ventilation devices (T-piece and self-inflating bag (SIB)).
Main Outcome Measures:
Applied force (Newton (N)) measured under the head and at four locations on the manikin's face (nasal bridge, mentum, left and right zygomatic arches) and symmetry of force applied around the mask rim.
Results:
For the 51 participants, force applied to the head was greater with the SIB than the T-piece (mean (SD): 16.03 (6.96) N vs 14.31 (5.16) N) and greater with the anatomic mask than the round mask (mean (SD): 16.07 (6.80) N vs 14.26 (5.35) N). Underhead force decreased over the duration of PPV for all conditions. Force measured on the face was greatest at the left zygomatic arch (median (IQR): 0.97 (0.70-1.43) N) and least at the mentum (median (IQR): 0.44 (0.28-0.61) N). Overall, experts applied more equal force around the mask rim compared with novices (median (IQR): 0.46 (0.26-0.79) N vs 0.65 (0.24-1.18) N, p<0.001).
Conclusion:
We characterised an initial dataset of applied forces on the face and head during simulated PPV and described differences in force when considering mask type, device type and expertise.
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