AFE4400SPO2EVM: help in SPO2 / PR

Yogesh Joshi

Part Number: AFE4400SPO2EVM

By using Debugger we are able to program EVM AFE4400, as per code given for EVM AFE4400 we got 6 values in decimal. As per document provided for SPO2 calculation we need values for

R = (ACrms of Red / DC of Red) / (ACrms of IR / DC of IR) but from these 6 values we are not able to understand what is a value foe ACrm of red , DC of RED, AC rms of IR, DC of IR so please help regarding this and in EVM as we capture data then values are calculated and create a exec file. in code how these values are calculated?

Please find the images of result of code , EVM

over 7 years ago

0 Prabin Yadav over 7 years ago

TI__Genius 12575 points

Hi Yogesh,

Please refer to following post for the formula.
e2e.ti.com/.../526335

For the second part, please help me understand the question as images are not visible.

Regards,
Prabin

0 Yogesh Joshi over 7 years ago in reply to Prabin Yadav

Intellectual 655 points

Ok.. in the code of EVM we got the values of 1. Read Red data 2. Read ambient data 3. Read IR data 4. Read ambient data 5. Read RED - ambient data 6. Read ir ambient data. For these six parameters in result we received the values in decimal. So by using the formula we are calculating the spo2. But we in formula these decimal values are useful ? Or we have to convert it ?

1. Read red data - 29391, 2. Read ambient dta - 16770074, 3. Read Ir data- 90573 4. Read ambient data - 16767839 5. Red ambient data- 36533 , 6. IR ambient data - 99950 we got these values.

0 Prabin Yadav over 7 years ago in reply to Yogesh Joshi

TI__Genius 12575 points

Hi Yogesh,

The EVM gives the data in terms of the ADC code ( 22 bit wide).
Since formula of R is ratio of different parameters, you can use either voltage ( after converting the ADC code ) or you can use ADC code as it is.

Regards,
Prabin

0 Yogesh Joshi over 7 years ago in reply to Prabin Yadav

Intellectual 655 points

Thank you sir. As we got the formula for spo2, but formula for pulse rate? By using afe4400

0 Prabin Yadav over 7 years ago in reply to Yogesh Joshi

TI__Genius 12575 points

Yogesh,

I am closing this thread as I have answered the question in other thread from you.

Regards,
Prabin

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AFE4400SPO2EVM: help in SPO2 / PR