US Patent 7798016 Flow sensor with double obstruction

The present invention refers to a flow sensor with double obstruction disclosing a simple and innovative structure, able to promote a series of advantages and new technical effects from the combination of fixed and variable obstruction elements. More particularly, the present invention comprises a front main body (12) and a main body (40) fitted to each other so to press two obstruction elements, the first one being fixed (30) and the second being variable (50), so to increase sensitivity and reduce the annoying noise, being especially useful to monitor patients for long periods.