Others > Biofeedback - EEG, ECG, EKG

Accuracy of MOD-PULSE (Pulseoxmeter)


Hi there,

I just obtain a MOD-PULSE (Pulseoxmeter) but the accuracy of the board is very low.
think, it is due to its infant running software or because of its sensor?
any idea to improve it?


ps: https://www.olimex.com/Products/Modules/Biofeedback/MOD-PULSE/


We haven't had other complain about the accuracy so it might be your sensor. It might be related to the mathematical model in the design: http://www.ti.com/lit/an/slaa458/slaa458.pdf.

I can't find any suggestion of the accuracy or accuracy proof in any of the documents by Texas so it would be hard to determine whether it meets any ratings.

Which part of the measures are not accurate - the pulse meter or the oximeter?

Best regards,


I am having a similar issue. The oxygen saturation and pulse rate value seem to be incorrect. The readings on the LCD screen and LabView GUI fluctuate a lot (http://imgur.com/y55NQTV). I have tried with multiple sensors without success. I used the Nelcor sensors that are recommended with this product. Do you have any suggestions as to what maybe causing the issue?



I just brought the MOD-PULSE board toon and, I've got the exactly same problem. I tested with another working out-out-the-bow oxymeter. The oxymeter has no problem to show values <80%SpO2 when i'm holding my breath for a (long) minute, while the MOD-PULSE board shows almost no change at all (~95%), and this with two different probes. The values from the serial port are also erroneous, but the scope values seem to be OK.

Some infos by Olimex by email:
About MOD-PULSE - it is hard to say what is the expected precision, however one thing to notice is that it is based on the original hardware proposal described in document “slaa274b.pdf”; since then TI proposed major hardware changes in the design in another document “slaa458.pdf” which had NOT been applied to MOD-PULSE. I recommend checking on both the original proposed documents:



It is open-source project you have access to all the documents and resources that we have access to. We encourage customers improving on the software (or the hardware if they are capable enough). Any future feedback or suggestions are also more than welcome.

Is someone managed to make it work and how?


[0] Message Index

Go to full version