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Re: [SCIRUN-USERS] ECG Inverse Solution


Chronological Thread 
  • From: Ali Rababah <Rababah-A@ulster.ac.uk>
  • To: Jess <jess@sci.utah.edu>, Dana Brooks <brooks@ece.neu.edu>
  • Cc: "scirun-users@sci.utah.edu" <scirun-users@sci.utah.edu>
  • Subject: Re: [SCIRUN-USERS] ECG Inverse Solution
  • Date: Tue, 15 Jan 2019 09:56:30 +0000
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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






On Jan 14, 2019, at 5:41 AM, Ali Rababah <Rababah-A@ulster.ac.uk> wrote:

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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This email and any attachments are confidential and intended solely for the use of the addressee and may contain information which is covered by legal, professional or other privilege. If you have received this email in error please notify the system manager at postmaster@ulster.ac.uk and delete this email immediately. Any views or opinions expressed are solely those of the author and do not necessarily represent those of Ulster University.
The University's computer systems may be monitored and communications carried out on them may be recorded to secure the effective operation of the system and for other lawful purposes. Ulster University does not guarantee that this email or any attachments are free from viruses or 100% secure. Unless expressly stated in the body of a separate attachment, the text of email is not intended to form a binding contract. Correspondence to and from the University may be subject to requests for disclosure by 3rd parties under relevant legislation.
The Ulster University was founded by Royal Charter in 1984 and is registered with company number RC000726 and VAT registered number GB672390524.The primary contact address for Ulster University in Northern Ireland is Cromore Road, Coleraine, Co. Londonderry BT52 1SA



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