Development of a Self-Power Peak Expiratory Flow Meter

Abstract

For a regular Digital Peak Respiratory Flow Metter, a strain gauge or similar probe is used to detect the strength of the blowing. The signal is then be analyzed by computer. In this innovative Self-Power Peek Respiratory Flow Meter, however, a generator is used. The generator is “one stone for two birds”: it serves as the digital signal generator to present the air flow data; it also provides the energy source to re-power the batteries. This allows people to use the equipment whenever and anywhere without worry of recharge or change batteries. Another advantage of the machine is its reliability. The blowing chamber is separated from the generator by magnetic (shaft-less) coupling, therefore, the moisture from blowing has no way to corrode the electric circuit or contaminate the instrument. Because of this innovative instrument is “Green”, “Digital” and easy of use, the application would be expanded. The Coreless Permanent Magnet Disk Generator technology (AFPM) is utilized to eliminate the cogging torque. Moreover, energy saving circuit design also implemented to make the self-power instrument a reality.