Search found 5 matches

by NVanderStoep
Mon Oct 01, 2018 11:01 am
Forum: EEG data analysis
Topic: ABR Peaks Positive or Negative
Replies: 0
Views: 14026

ABR Peaks Positive or Negative

Dear Coen, we are measuring ABRs in our lab with BioSemi ABR electrodes. We finally have pretty clean ABR measurements. However, now that we are analysing data from a study, I am doubting whether we are labeling the peak in the right way. The wave V latency is quite early with 90dB clicks if we inte...
by NVanderStoep
Thu Jun 07, 2018 5:20 pm
Forum: BioSemi all other topics
Topic: Unwanted triggers during ABR measurement
Replies: 7
Views: 18109

Re: Unwanted triggers during ABR measurement

The problem may be that your trigger generator does not switch the separate lines (bits) within one sample period (62 microsecond). Try using trigger values that switch only one line, e.i. 1,2,4,8,16,32,64 and 128. High (unconnected) lines 9-16 do not cause false triggers. Best regards, Coen (BioSe...
by NVanderStoep
Tue Apr 24, 2018 5:04 pm
Forum: BioSemi all other topics
Topic: Unwanted triggers during ABR measurement
Replies: 7
Views: 18109

Re: Unwanted triggers during ABR measurement

Hi Coen,

your suggestion resulted in zero unwanted triggers with 24000 samples. That is great. However, we need more than 8 trigger codes. Do you have any idea how we could make this happen?

Best,
Nathan
by NVanderStoep
Fri Apr 13, 2018 9:35 pm
Forum: BioSemi all other topics
Topic: Unwanted triggers during ABR measurement
Replies: 7
Views: 18109

Re: Unwanted triggers during ABR measurement

Thanks for the quick reply and suggestion. I will check whether this resolves the issue coming week and report back.

Kind regards,
Nathan
by NVanderStoep
Fri Apr 13, 2018 11:19 am
Forum: BioSemi all other topics
Topic: Unwanted triggers during ABR measurement
Replies: 7
Views: 18109

Unwanted triggers during ABR measurement

Dear sir, madam, recently we have acquired the ABR cord and input and have been able to record decent ABRs using a stimulus with fixed intensity and a single triggercode (sent synchronously with the click onset). We are now also able to present clicks with different amplitudes and different triggerc...