Variable issue in pulse app in DL11

[gigblasters]

Will try to keep it brief.  We have a fairly complex worksheet done in Dasylabs 11.  Basically it measures pulse, from animals not electronics.  Because of that there are obviously a lot of inbuilt checks, amplitude of wave peaks, frequency etc.  Basically the worksheet displays the current BPM and changes every second and is always averaged over the last few readings to give smoother curve.

All is working fine except one thing.  When the electrodes lose contact with the animal (happens on occasion, they dont always stay still!) sometimes when there is good contact again and the trace on the screen is perfect, it can take 20 - 30 secs for the numbers on the display, in other words the current BPM, to change.  There is a variable 'gain' and when we get no reading the contents of that is E-MAX and every time just before that the previous reading in the gain var is always 1.28.  Nobody seems to know what E_MAX means and which module is causing it to be in the variable.

I am not an electronic programmer and unfortunately the guy who did it has now left his company and his replacement isnt anywhere near as good!

Any help would be very welcome

[CJ_Butler__DASYLab_Pro]

EMAX is going to be infinity or negative infinity... aka divide by zero.

If you can figure a way to detect that the electrodes have lost connection, then use a trigger and an Action module to reset the average module so that you can drop the bad readings more quickly.

Alternately, you can use a trigger/relay to drop out the bad data completely. 

[CJ_Butler__DASYLab_Pro]

My daughter worked in a rat lab... one guy would wait for her to turn around before pulling out his wiring.... so, we are sympathetic to live animal testing.

[gigblasters]

Well...live animal testing.  They are exactly the same as ecg electrodes that would be used on you at a doctors!  Except these have no wires attached.  They are also used on horses that cost tens of thousands of pounds / dollars.  So we are hardly doing something horrible to animals, like making them listen to a coldplay cd 🙂

[gigblasters]

Thanks, sounds sensible.  It does happen after the horse moves a lot so lots of rubbing over the surface of electrode, so too many signals in laymans terms!  Electrodes are basically on a handle that you hold against horse so obviously excessive movement will do that

[CJ_Butler__DASYLab_Pro]

Can you make a data file with the example of an electrode disconnecting? Post it here as a *DDF (DASYLab Binary file format) file, so that I can see if there is a trigger that makes sense.

If you can also post or private message your worksheet file... that would let me look at the logic and understand the error.