Passive Vacuum System
How it works
Passive vacuum systems usually consist of a soft liner, a one-way valve and a knee sleeve. Excess air is expelled through the valve with the help of body weight, and is unable to stream back in.
A knee sleeve is used with transtibial prostheses to create an airtight seal at the top edge of the system. In transfemoral prostheses, the Sealing Liner ring is used to create an airtight seal at the top of the system.
Passive vacuum, also referred to as a ‘one-way valve’, provides a high level of socket comfort when a vacuum is created between the suspension sleeve and the liner/skin. When the amputee begins to walk the air is driven out of the socket to form a solid connection.