The blue plot, representing the commercial (Zacurate-brand) device uses more of the A/D converter's 0-3.3 VDC range, and doesn't have the slow rise time of the fabricated sensor (orange plot). In both lines, the fast pair of pulses show the photodiode response to the IR and red LED signal. See the Background section for more information on how these sensors work, the Apparatus section for more information and code related to the first prototype, and [my NMM page](file:///home/zach/Documents/NMM/site/people/zach/final.html) for a look at data processing.
The blue plot, representing the commercial (Zacurate-brand) device uses more of the A/D converter's 0-3.3 VDC range, and doesn't have the slow rise time of the fabricated sensor (orange plot). In both lines, the fast pair of pulses show the photodiode response to the IR and red LED signal. Here is an early pass at an algorithm to calculate SpO<sub>2</sub> from the commercial device's signal (blue) compared to its displayed output (orange); the fabricated sensor is still a work-in-progress:
See the Background section for more information on how these sensors work, the Apparatus section for more information and code related to the first prototype, and [my NMM page](file:///home/zach/Documents/NMM/site/people/zach/final.html) for a look at data processing.
