TITLE:
A resonance-mode piezoelectric device for measurement of respiratory mechanics
AUTHORS:
Hamed Hanafi Alamdari, Lucas Posada, Swati A. Bhatawadekar, Jeremy A. Brown, Geoffrey N. Maksym
KEYWORDS:
Forced Oscillation Technique FOT; Respiratory Mechanics; Tidal Volume
JOURNAL NAME:
Journal of Biomedical Science and Engineering,
Vol.6 No.11,
November
25,
2013
ABSTRACT: This
paper presents the design of a novel oscillometry device for the measurement of
respiratory mechanics based on piezoelectric bimorph actuator technology. To
predict performance for measurement of human respiratory mechanics, a dynamic
model was developed based on a bimorph piezoelectric actuator driving a linear
resistance mesh screen including subject’s respiratory impedance loads, and
realistic breathing noise. Model performance was also validated in a prototype device. We found that while breathing noise substantially lowered SNR, the model could produce sufficient pressure
and flow for acceptable SNRs exceeding 35 dB, and accuracies exceeding 99%. Satisfactory
accuracy could be achieved with load impedance errors less than 3%. Maintaining
the air-gap around the oscillating mesh with a resistance against the leak greater than 0.38 cmH2O/L/s maintained
good performance, with an acceptable 4 dB decrease to SNR. Moreover,
this work provides multiple solutions to host higher amounts of noise and
nonlinearities. These results indicate that the development of an accurate lightweight portable single frequency FOT device is feasible.