What do the letters “PAS” stand for in respects to the boots used in hospitals to prevent DVT’s?

These boots are used in the hospitals, they are electrical and apply some intermittant pressure. But, I dont know what the letters “PAS”stands for.

PAS privat attachment show

Pas Medical Abbreviation

There is no medical mnemonic for PAS in relation to deep vein thrombosis,given that some treatments for DVT include pressure stockings to force a clot out to a installed filter in the vena cava,I can only derive that PAS is a brand abbreviation…”pressure or pnuematic”_____ ____.

Pneumatic antiembolic stockings.