Many thanks Jess and Dana for clarifying things. It seems to me that I ve done something wrong. May be because I solved the inverse problem for all beats together, but now when I solved for one beat only, it gave me a reasonable solution ( lower than the ground
truth).
Regards
Ali
From: Dana Brooks <brooks@ece.neu.edu>
Sent: Tuesday, January 15, 2019 3:29:50 AM
To: Jess; Ali Rababah
Cc: scirun-users@sci.utah.edu
Subject: Re: [SCIRUN-USERS] ECG Inverse Solution
Ali, hi,
Just to add to Jess' excellent reply -- usually Tikhonov solutions are *lower* than ground truth due to the effect of regularization, so it definitely sounds like something is wrong. On the other hand, if there is any noise in your data or model and you
are not regularizing (or not regularizing enough) you could be amplifying noise due to the ill-posedness of the inverse solution ?
just a couple of guesses ...
best,
Dana
On 1/14/19 2:21 PM, Jess wrote:
Hi Ali,
Thanks for your question. I assume you are using the Tikhonov method? Is the gold standard recorded data? Are you using measured body surface potentials as the input? Are these processed the same? Without know more about your setup, I would
guess that there may be a difference in how the data are referenced. Can you provide some images or data to illustrate what the problem is?
cheers,
Jess
Dear Sir,
I hope you are doing very well.
When I use SCIRun for solving the inverse problem using body surface ECG, the value of the solution is much higher than the gold standard although there is some correlation between them. What is your advice in that please?
Kind Regards
Ali Rababah
PhD Researcher
ECME Project
Ulster University
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