Fig 1.
Schematic diagram showing how a single patient could be connected to the VentMi system in ‘stand by’ mode, awaiting a second patient (A) and schematic of both patients connected to VentMi with one patient having inspiratory pressure downregulated by the regulator, and the second controlled by the ventilator.
Fig 2.
Picture and schematic diagram of the connection of the dual animal study to the VentMi circuit.
The pig’s PIP was controlled by the ventilator and PEEP upregulated by PEEP boosters during the 6 hour co-ventilation experiment, while the sheep was regulated by the inspiratory regulator with the ventilator controlling the PEEP.
Table 1.
Pressure results of benchtop testing on PB840 ICU ventilator with VentMi system.
Fig 3.
Pressure tracings from single-patient swine model demonstrating the balloon [top green tracing] compared to the pig [bottom green tracing] ventilation profiles.
(A) demonstrates the downregulated PIP for the pig. (B) demonstrates the minimal effect on the pig from simulated coughing [squeezing] in the balloon. (C) demonstrates the global loss of pressure seen with an open circuit [disconnected balloon].
Table 2.
Testing conditions performed with single-animal swine model.
Fig 4.
Ventilation pressures across different testing conditions.
Graph shows measured average circuit pressures for the swine (orange) and sheep (yellow) during various clinical scenarios. The top of the bar represents the average PIP, while the bottom represents the average PEEP. As noted, when a PEEP booster was added to intentionally create differential pressure ventilation, the two animals were statistically different. However on individual ventilation and initial pairing, they were the same. Occlusion of the sheep’s endotracheal tube did not result in any significant differences for the pig’s ventilation profile.
Table 3.
Comparison of swine and sheep ventilatory parameters at various testing conditions.
Table 4.
Effects of different swine testing conditions on sheep ventilatory parameters.
Fig 5.
Photographic demonstration of the coventilation during the swine’s flap surgery.
This operation was intended to cause stress to the swine and observe for any changes in coventilation parameters for either animal. Both animals remained very stable, with unchanged ventilation parameters when compared to the prior ventilation settings.