Squeeze bulb pumps are often found on blood
In a blood pressure cuff air is pumped in first, before any
measurements are taken. Then a needle valve is slightly opened and air is allowed
to escape while the pressure is read from a sphygmomanometer (or sphygmometer).
Here, the air intake is on the right side of the drawing and the tube connects
to the blood pressure cuff which is strapped to the patient's arm (not shown.)
In this squeeze bulb the valves are just rubber flapper valves like those
used in many fish tank diaphragm air pumps. Other valve configurations are possible.