Endurance tests on the ambu bags showed failure after 160’000 cycles. Bags were fully depressed at 1Hz. This translates to failure after 3 days of RR=35 BPM at full volume (1000 mL).
Failure mode is a tear near the hard, plastic endcap of the ambu bag.
![](https://breathney.cc/wp-content/uploads/2020/04/IMG_20200407_145743-1-683x1024.jpg)
![](https://breathney.cc/wp-content/uploads/2020/04/IMG_20200406_084455-768x1024.jpg)
We have updated the plunger design, to a narrower & more rounded version. This still achieves the requires Vt of 800mL , while putting less stress on the edges of the ambu bags.
![](https://breathney.cc/wp-content/uploads/2020/04/IMG_20200408_160407671-768x1024.jpg)
The test version also did not have the silicone covers.
This updated version has been sent to the test facility.