Pico Technical Support and Discussion Forum

portner · Newbie Joined: 05 Jul 2004 Posts: 1

Hello,

I use Picoscope for recording body muscle and nerve data generated by EMG equipment.

I am unaccustumed with the spectrum measurement part of the software.

My question is: could I obtain an ECG tracing (the heart rhythm) and then aplly time and/or frequency domain analysis to find where the "power" is concentrated (the physiological power ranges goes form 0.04 to 0.2 Hz usually with a peak around 0.1)?

If this is possible, could I export it as a text file with all the data in a single column?

Thanks in advance,

Martin Portner
Brazil

markspencer · Site Admin Joined: 07 May 2003 Posts: 610

Hi,

Thank you for your post.

The spectrum anayliser is an indication of power distribution of a waveform, voltage (db) over frequency, with the most power at the fundamental (frequency of signal).

When using the spectrum, there are a few criteria that needs to be considered, the maximum bandwidth you wish to view, the number of FFT points.

In Picoscope the maximum bandwidth can be set, and usually has either a dropdown box with selectable bandwidths or the facility to increment or decrement the bandwidth. There will also be a minimum 'maximum bandwidth that can be selected.

The number of FFT points can be between 128 and 4096 points depending on the unit you are using. The number of points will help reduce the bin size and thus give greater accuracy.

It is also possible to save the spectrum as a text file, by selecting File | Save as. This will give you the readings in voltage (db) and frequency.

Best regards,

Pico Technology

Pico Technical Support and Discussion Forum