A device for converting a characteristic of a flowing fluid into an electronic signal and a respiratory monitor for monitoring fluid flow

摘要

A device (1) for converting the flow rate of a flowing fluid intoan electronic signal indicative of the flow rate comprises a tubular member (2) having a bore (3) extending between an upstream end (5) and a downstream end (6) through which the flowing fluid is passed. A deformable resilient membrane (8) is located in thebore (3) an is deformable in response to the rate at which the fluid is flowing. The membrane (8) is of a piezo electric materialwhich outputs an analogue voltage signal proportional to the amount of bending of the membrane (8). The voltage signal is outputted on a cable (16) an may be used in its analogue form or converted to a digital signal for relaying to a computer for in turn displaying a graphical representation of the flow rate of the fluid on a monitor. The device (1) may also be used for training a subject to breath correctly by displaying a graphical representation of the flow rate of air being inhaled and exhaled by the subject during breathing against a graphical representation of the flow rate of an ideal breathing cycle.