during the trials when the reported breathing rate was
above 12 bpm. This suggests that Walabot with the
FFT techniques overcomes the user movement chal-
lenge. Results from the horizontal, vertical and user
movement variation procedures revealed the high ac-
curacy and reliability of the FFT technique when the
reported breathing rate is above 12 bpm.
FFT technique yielded results with higher accu-
racy than the Peak Detection technique. The primary
reason for this is that the FFT method is not signifi-
cantly affected by the noise in the shape signal, while
the Peak Detection method is highly affected. For this
reason, the FFT method should be the primary focus
in future testing. However, the FFT technique is not
sufficiently robust at this point. An adjustable window
size can increase the accuracy of the FFT technique.
6 CONCLUSIONS
The development of a robust and fully functional
UWB radar based system has the potential to pro-
vide accurate monitoring of breathing rate. However,
current UWB radar based systems have issues which
hinder their accuracy or reliability. Six criteria were
identified: cost, user location, user orientation, user
movement, system placement and signal processing.
We designed and performed a comparative evaluation
in which data was collected by following four proce-
dures: breathing rate variation, horizontal placement
variation, vertical placement variation and user move-
ment variation. Results from this study were promis-
ing and suggested a high potential for Walabot cou-
pled with the FFT technique. Specifically, it was de-
termined that this system meets the cost, user loca-
tion, and system placement criteria. However, further
testing is required to determine if the system can fully
meet the user orientation, user movement and signal
processing criteria. The results support feasibility of
Walabot as a commodity breathing rate monitor for
health monitoring in homes.
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