Testing phase

https://www.spservices.ie/item/O-TwoMedical_SMARTBAGVentilationTrainerBoxwithSMARTStandardBVM_51_63_3688_1.html

has a bag-valve-mask test kit, which can show  if the lungs are over-inflated or the delivered flow rate is too high, the high airway pressure generated will cause air to enter the stomach. In real life this can only be seen when the patient's abdomen distends and/or they begin to vomit.

 Also:
1 cmH2O (conventional)= 98.0665 pascals
 or approximately 
1 cmH2O (conventional)≈ 100 pascals
 or
1 cmH2O (conventional)≈ 1 hectopascal


https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/maximal-inspiratory-pressure appears to have an incorrect obscure or deceptive diagram for inspiratory lung pressures on the x-axis it seems to contradict the text.


https://www.ncbi.nlm.nih.gov/pubmed/16677384  details maximum inspiratory pressure for healthy people .

In  women, maximum expiratory pressure increased with volume from 39 to 61 cmH2O and maximum inspiratory pressure decreased with volume from 66 to 28 cmH2O. In men, maximum expiratory pressure increased with volume from 63 to 97 cmH2O and maximum inspiratory pressure decreased with volume from 97 to 39 cmH2O. Equations describing pressures for both sexes are: 
Pe/Pmax = 0.1426 Ln( %VC) + 0.3402 
R2 = 0.95 
Pi/Pmax = 0.234 Ln(100 - %VC) - 0.0828 
R2 = 0.96

VC=Vital Capacity is the maximum amount of air a person can expel from the lungs after a maximum inhalation



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