Tricorder v6 off to assembly
April 22nd, 2008
A long time in the works, but this version adds full pulse oximetry support, includes a mini-B usb connector for interfacing and battery charging, and a lot of RF filtering to help make the ECG signal more stable in noisy environments. 
EDIT: Forgot to mention, we’re also switching to the LIS302DL accelerometer, same one as in the iPhone, and we’ve switched our reference voltage amp to the AD8644 to help with the SP02 stuff. The new design frees up some A2Ds which we’re using to monitor battery voltage and bringing out the other unused channels to the big connector on the bottom.
It’s clear that you accumulated a lot of experiences about pulse oximeter.
Some article use equation: SpO2 = a – b*R;
some use: SpO2 = A*R^2 + B*R + C
Here, R = [AC_vs / DC_vs] / [AC_ir / DC_ir]
In your opinion, which one is better in the real product world?
Do you use Index 2XL to determine coefficients (a and b or A, B and C) when your pulse oximeter is being calibrated?
My Email: rockywjj@gmail.com I’m waiting for your help…
Rocky