I need help regarding measurement of "time domain parameters of Heart rate variability" using labview.

[Joaana]

I need help regarding measurement of "time domain parameters of Heart rate variability" using labview.
I am using Labview 8 ... I  need to develop a software to accquire the ECG data (simulated enironment ) and compute the time domain parameters of Heart rate variability like "SDNN, SDANN...etc". Can some 1 plllzzzz help me out.Plzz help me if u can.Thanx in advance.

[xntricity]

Hi Joaana,

We'll need some more information from you on your problem before we can offer you any more help on this one.

Firstly, what is the form of the ECG data? Are you trying to acquire this data from an IO card or perhaps a text file?

Secondly what are the calculations SDNN, SDANN etc.?

The only advice I could offer at the moment is to suggest using Labview to collect and process your ECG data, but perhaps software such as Excel would be more suited to performing statistical analysis on that data.

Regards,

Andy

[Joaana]

Hi Andy,

  Thanx for responding.  The input is from a text file. SDNN, SDANN,etc are  the timedomain parameters of heart rate variability.

 SDNN: the

standard deviation of the NN or RR interval  i.e. the square root of variance.

SDANN:the standard deviation of the averageNN interval calculated over short periods, usually 5 min,which is an estimate of the changes in heart rate due tocycles longer than 5 min

SDNN index, the meanof the 5-min standard deviation of the NN intervalcalculated over 24 h,

 RMSSD: the square root ofthe mean squared differences of successive NN intervals

NN50: the number of interval differences of successiveNN intervals greater than 50 ms, and

pNN50 the proportionderived by dividing NN50 by the total numberof NN intervals.

The problem is dat I am a fresher to the world of Labview. I have jus recently started working on it. Can u please suggest me some some idea as soon as possible.

  As i said  I have the ECG data in the form of text files..I need to create sort of GUI to calculate the time domain parmeters....I need help urgently. Plzzz help me if u can. If u have and .vi example to calculate the RR interval plzz send it to me ASAP.
Thanku

[johnsold]

Joaana,

One way to approach such a challenge is to break down the overall problem into smaller tasks.

Also, designing the program before you start wiring up VIs is also very important.

You indicate that you are new to LabVIEW. A good place to start is with the tutorials which are available on line and the examples and help files which come with LV.

As a starter, I would suggest that some of the tasks are:
1. Read data from text file and convert to a numeric representation.
2. Find peaks (QRS) and extract RR intervals.
3. Perform statistics calculations.
4. Create GUI for user input and display of results.

I do not think you will find any single VIs which will perform completely any of the tasks I listed, but some of the tasks are not too complex. Try some of these things and post back with specific questions.

Lynn

[Joaana]

Do u have any vi for RR interval xtraction and storage???? I nees to meet some dead line so it is sort of urgent...tried using cursors..etc..but its getting real slow.Plz tell me if u hav an RR interval xtractor.

[johnsold]

Joanna,

I did some RR interval studies about 10 years ago. I doubt that I have any of the VIs any longer. What is the format of your ECG text files? Can you post a sample file? I will take a look to see what I have and whether it would be applicable to your data.

Lynn

[Joaana]

I actually simulated the ECG using matlab first...am attaching the data file.

[johnsold]

Joanna,

Here is a little VI which will calculate RR intervals provided your ECG data is VERY clean. It works fine on the simulated data. If the T waves are too large or many ectopic beats are present, the simple threshold detector will not be adequate. You simulation has only one RR interval so it is not possible to calculate any variation. It says 82 because I used LV 8.2 to create it, but it should be saved in version 8.0.

I obtained the data in the "all rows" control by running Read from Spreadsheet File.vi with the output connected to an indicator. I made Current Values Default, saved, and converted the indicator to a control.

Lynn

[Joaana]

Thank u sooo much for the timely help

Regards,

Joaana

[Joaana]

Hi

   Do u hav any idea abt the "heart rate variability"??? actually I have a .pdf file on the labview implementation of HRV ..but i have some doubts in it.....Canu plz clear them if possible.

 If u can give me ur email ID i'll forward it ASAP.

Regards,

Joaana