csv Raw Data Processing PLOT

rd0804

Hi,

What type of DSP the raw data in the cvs files undergoes to make the plot in Matlab look like the one you get in “Processing”?

1. High Pass Filter = 0.5Hz to remove the DC Offset
2. Notch Filter @ 60Hz to remove the AC line noise
3. Band Pass Filtering = 7Hz - 13Hz, etc. ...

I applied these 3 steps to the raw data in Matlab and the waveform looks very close except for the amplitude. Do you know if the raw data undergoes some form of normalization besides the filters?. Also, why is the Y-axis label in the plot “uVrms” and not just “uV”?. are you plotting the Voltage RMS?, if so, is the RMS value calculated wrt 1 sec window or the 5 sec window in the plot?. What equation do you use?

And last, if the vertical scale in the "Processing" plot is set to 200uV, is this from -100uV to +100uV? or from -200uV to +200uV? 

Thank you

rd0804

Also, is the raw data in the cvs file saved with a default GAIN setting from ADS1299 applied?, if so, which GAIN is this?

Billh

The Y axis is microvolts, and should not be the least-square average. The notation on the graph in the lower right hand corner is microvolts root mean square, and is I believe the RMS of the part of the data shown currently on the graph. The window size in time may vary, but is 5 sec by default.

Billh

I believe the Y axis scale in the gui plot is -100 to +100 uV.

The ADS1299 gain setting is factored into the data conversion processing from raw digital numbers to physical uV units, so the gain shown on graph should be 1 for microvolts or 10^6 for volts.

rd0804

Thanks much, this helps a lot!

shengyun

@rd0804 said:
Thanks much, this helps a lot!