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I wonder why they chose to use compressed helium to fill the bag. I don't know much about these things, but helium is not cheap, and surely you don't need its lighter-than-air properties in this application. Couldn't you use compressed carbon dioxide, or even just compressed air? For comparison, apparently automotive airbags are inflated with nitrogen gas.

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Automotive airbags are inflated with an explosive which has Nitrogen gas as the majority byproduct, it's rare for actual compressed Nitrogen to be used.

As to why they chose Helium for this application, it's hard to say. It might mean that they are compressing the gas to very high pressures which would result in liquifaction of other gases, but that's just speculation.

Maybe the container which holds the gas has to be small so helium would require a smaller storage container which is able to fill the volume of the device.

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