FeatherTone Technology
Our prototype uses an completely new approach to measuring air velocity. Our new FeatherTone™ thin film technology enables us to simultaneously measure air velocity as well as auditory vibration emanating from the lung.
Notice in the Spirogram above that the vibrations in the velocity vs. volume curve that oscillations are also observed at the same point in time that the 2-D FFT figure shows below.
FeatherTone Technology Measuring the Auscultation of an Adult Male. Fast Fourier Transforms from the recorded wav file are plotted vs. time. Our thin-film sensor has clearly pliable and electrically responsive to low frequencies which are of interest in the diagnoses of lung diseases. Below is a Figure showing the tones emitted during the spirometry of an adult male. The exhale cycle shows a number of frequencies between 25-250 region and higher pitched sounds after PERF. The inhale cycle is richer in tones and again shows peaks ~ 250 Hz.
Response
to single frequency sound source shows an excellent response transfer
characteristic.
Below is the Fast Fourier Transform response to single frequency stimulation at
80 Hz:
This response was during wind tunnel tests using a speaker upstream of the air flow. The frequency was generated by computer code. The large peak at 79.5 Hz (cycles/sec) nearly matches the predicted 80 Hz computer generated frequency indicating excellent transfer characteristics.
The response curve to sinusoidal stimulus is shown in the following 2-D figure. The signal to noise is absolutely superb. Notice that Mode 1 and Mode 2 are clearly evident. See the movie below to find out what Mode 1 is and how it differs from Mode 2. Feather Sensors has the technology to change the frequency response to suit an number of applications.
Feather Sensors offers excellent spirometry and at the same time listens to tones in the exhaled and inhaled cycle.
To see the modes of our vibrating sensor click the feather:
What does it mean?
From a single sensor we are quantitatively measuring both spirometry and auscultation.