ADS1298 weird ECG signal

Ekrem Bayraktar

Other Parts Discussed in Thread: ADS1298

Hi all,

Does anyone have idea about the below ECG signal, I think that it is about the SPI clock division and changed it but do not succeed. My SPI clock division is 25, data rate is 8k and heart rate is 240 bpm for the shown image.

I appreciate your help.

7077.weirdECG.tif

over 13 years ago

0 Tony Calabria over 13 years ago

TI__Mastermind 43915 points

Hi Ekrem,

Every fifth pulse looks as if you are missing data as the amplitude does not reach that of the other pulses. I hope that you are using a simulator for your testing as 240bpm seems very high for a person. Try slowing the heart rate on the simulator to see what your results look like. There is somewhat of a pattern in the data which shows a very low S segment on half of your pulses which may be due to incorrect data. Try changing the data rate to see what behavior you see.

Regards,

Tony Calabria

0 Ekrem Bayraktar over 13 years ago in reply to Tony Calabria

Expert 1190 points

Hi Tom,

Thank you for your answer, yes I am using an ECG simulator for the data. I have tried the same simulation with HR of 120 bpm, the result is the same. In fact, I do not think it is related with HR since my sampling rate is 8k, am I right or missing a point? It seems as if a very slow signal is modulating my signal which is not reasonable.

I added the recent waveform below.

Regards.

1425.weirdECG_2.tif

0 Tony Calabria over 13 years ago in reply to Ekrem Bayraktar

TI__Mastermind 43915 points

Ekrem,

If you are using an ECG simulator, you should see basically the same pulse across time. Make sure that the RLD is connected to the simulator. I would recommend using an EVM with our software to get you up and running and then you can fly wire into our eval board. This would, at the very least, assure you that your hardware is correct so you can debug your software.

Regards,

Tony

0 Ekrem Bayraktar over 13 years ago in reply to Tony Calabria

Expert 1190 points

Hi Tony,

Thank you for your help, I figured out my problem, it was about timing of SPI and ADS1298.

Regards.

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ADS1298 weird ECG signal