He points out that our veins have one-way valves in them.

It was like a man breathing through a respiratory system, with some sort of one-way valve.

Healthy veins carry blood to the heart through a series of one-way valves.

Most veins have one-way valves that keep blood from going backwards.

The device that makes this possible is called a one-way valve.

The one-way valve you propose could maintain a pressure difference between the volumes.

Your veins have one-way valves that keep blood flowing toward the heart.

This is a one-way valve located between the small and large intestines.

They may contain a one-way valve to keep the air or gas flowing the right way.

This is a 15Fr chest tube with a one-way valve.