Ecg adquisision

buen dia tengo un problema y quiciera ver si alguien me puede ayudar, el asunto es que estoy tratando de adquirir una señal electrocardiografica con arduino y labview el problema es que al obtenerla con un osciloscopio tradicional la señal se muestra sin problemas y al tratar de visualizarla en labview con el mismo electrocardiografo ya no se muestra de forma clara como en un osciloscopio, ni siquiera se parece a la grafica de una señal cardiaca, espero me puedan ayudar gracias.

Hola jhguzman,
Investigando un poco sobre la frecuencia de muestreo necesaria para graficar una señal electrocardiografica, encontré éste link dónde hablan de una frecuencia de muestreo de 250 muestras por segundo.
http://www.ncbi.nlm.nih.gov/pubmed/4033100
Es posible que tu señal se grafique de manera inadecuada por esa razón. Me quedan algunas dudas sobre tu implementación:
- ¿Qué tarjeta de Arduino estás utilizando? (por ejemplo: Uno, Duemilanove, Mega, etc.). Esto para poder determinar las limitantes de velocidad del FTDI correspondiente a la tarjeta.
- ¿Qué microcontrolador tiene tu tarjeta? (por ejemplo: ATMEGA328, ATMEGA128, etc.). Para poder determinar la frecuencia máxima de muestreo y la resolución del ADC.
- ¿Estás trabajando con el Toolkit de Arduino o directamente con Arduino?
Otro factor importante es la amplitud de la señal que estás midiendo, es posible que la amplitud de la señal no sea lo suficientemente grande para ser medida con la resolución del ADC del Arduino, en este caso tendrías que realizar una amplificación para adaptarlo a los rangos del ADC del Arduino.
- ¿Qué sensor estás utilizando?.
- ¿Qué rangos de voltaje tiene tu sensor?.
- ¿Estás leyendo directamente el sensor o tienes alguna etapa de amplificación?.
En caso de que no estés trabajando con el Toolkit de Arduino para LabVIEW, sería múy útil que compartieras el código del .pde (el código de Arduino) para poder corroborar si no hay otras instrucciones que retrasen la lectura del sensor, o bien si el Baudrate de transmisión es el adecuado para evitar que el buffer del ADC se llene y se pierdan lecturas y una pantalla del VI para corroborar el método de adquisición que estás utilizando.
Quedo a la espera de tu respuesta jhguzman.
David Porras
National Instruments
Ingeniería de Aplicaciones
www.ni.com/soporte
David P.
National Instruments
Applications Engineer
www.ni.com/soporte

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Ecg baseline wandering[need quick expert help]

Hello everyone!
I'm new user here, and I have an urgent problem considering my faculty project.
I have looked at previous topics on this matter, and also I've checked the tutorial here
http://zone.ni.com/devzone/cda/tut/p/id/6349
but I didnt find the exact thing I need.
So here is the thingd:
I have baseline wandering, but how can I fix it without using additional
Digital Filter Design Toolkit (DFDT). I have access only to labview 8.5 at laboratory at my faculty
and I dont have DFDT there.
I have attached what I have done so far, and it would mean a lot if someone could help me
by explaining me how to create/or create for me the filter for wandering.
I would upload the ecg txt file that I use but it's 35mb.
Thanks in advance people!
Attachments:
Semestralni.vi ‏63 KB

I agree with Steve. Also remember that if your goal only is to extract heart rate you will only be interested in the QRS complex. The rest of the ECG complex that have lower frequency content may be shaved away with filtering. In your signal you have a large bump just before sample 8000. This is caused by electrode movement. Securing the electrodes is important. But your biggest problem is that you do not use the "Peak Detector.vi" correct.
Here is some useful tips for the Labview beginner (we have all been there some time)
1)Then starting a new Labview session enable context help (Ctrl+h) Do not be afraid to use the detailed help option
2)Then stuck, go to help in the toolbar then select find examples
Ps. I also noticed that your Labview programming style is somewhat mixed-up. It is hard to follow the data flow.
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How can I get rid of baseline drift in an ecg without having the dfdt or advanced signal processing toolkits?

Hello,
I am recieving a lot of baseline drift in my ECG signal and was wondering how I can get rid of it? I saw examples at NI .com but they used the digital filter design toolkit and the advanced sgnal processing tollkit. I have neither one of these and since I am a student and this is my senior project I have no means to get these toolkits. I tried using a high pass filter but this did not work.\
Ray

Ray,
When you say that something did not work, you are not giving much information for us to use to try to help you. Did the filter not work or did it not remove the drift?
How big is the drift, compared to the desired signal? How fast does it drift? How long are your sample sets? What are you doing with the ECG data? Looking at heart rate or analyzing a single-beat waveform for morphological changes? I think you can see that different end goals might require different approaches to baseline compensation.
If the drift is always fairly slow, you might be able to take small segments and subtract the mean of each segment. This may result in some offset or shift at the segment boundaries, but it is very simple and can easily be implemented without requiring a special toolkit.
Another approach is to low pass filter the ECG signal to extract an estimate of the baseline which can then be subtracted. Remember that all filters have a transient response and many will have a phase shift between the input and output.
Lynn

Finding peaks in an ECG-signal

How can I find the T-wave and P-wave in an ECG-signal? Can I do a bach/forward search from the QRS-peak?
Thank you!

One method would to find the peaks of T wave, QRS and P wave.
Then probably, you can index out the relevent section of the waveform that will comprise your T and P wave
Look at an example vi I have attached
Attachments:
DETECT_PEAKS.vi ‏27 KB

E-commerce Gateway - Extract POs automatically on to the ECG data file

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Currently, we transmit POs to suppliers via EDI by MANUALLY running the "OUT: Purchase Order (850/ORDERS)" ECG Program.
Is it possible to AUTOMATICALLY extract the PO information in to the data file with out running the above program? Is there any setup to do this? Please advise. Thanks.

Guess no setup available. Try launching conc program from approval workflow or via trigger is you dont want to launch manually.
Regards,
Praveen

Converting Dynamic ECG to Arrays

Hi, im new to this forum and LABView program.
I am doing an HRV analysis using LABView for a project in school, with the help of the NI developer's Zone HRV guide.
All are good while using a static .txt array for the input, but now i need to get a dynamic signal using a DAQ and an ECG simulator, and i am unable to write the DDT to arrays.
I have search the site for other people's query on this matter, but none of the method work on my program.
Anyone with around care for a help? I have i picture of my program uploaded:

The first thing to do is put your data acquisition and this code inside a while loop so that it run more than once. Then you can place a shift register on the while loop. Right click on the edge of the while loop and select Add Shift Register. Shown below is the basics.
Attachments:
Basic Shift Register.PNG ‏5 KB

Need to solve this ecg amplifier using multism

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theoretical the gain should be around 2000
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I will be very happy with any of your answers and help
my e-mail is [email protected]
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Attachments:
amplifier.ms11 ‏123 KB

Hi,
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How i enter the ECG signal to the lab view through the sound card

first i open the help and find example the display the signal of the mic
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but when displaied the ECG appearied only one period on the chart so on if the chart with full screen you can see only one period
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Attachments:
ECG with sound card.vi ‏20 KB
Untitled.jpg ‏37 KB

I do not have LabVIEW version 9, only 8.6
Without looking at your program can take a guess. Have you set the property "chart history length" of the graph? If you consider that an individual has a heart rate of up to 50Hz, or period of 20ms. Soon the number of points required is (3 * 20ms) / (sample time).
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Program to read ecg and determine r to r minute segment

Hello,
I'm doing a final project that is a bit late to change now, and is unfortanutely quite over my head. My group tested about 15 people, while an ecg signal. The ecg segment we saved is about a minute long. 30 seconds leading up to the "test" and then thirty seconds after the test. I have this information and it looks like this: (see attached image)... what i need to figure out how to do is, create (or use an already created..) labview program that can analyze this data and spit out the r-r interval average. otherwise i will have to go through each test subject and figure it out by hand (which takes about an hour), and its right before finals! help?
Attachments:
old pictures-extras-46.jpg ‏564 KB

Hey,
There can be some workarounds using some array functions, trying to find the maximums of the array and the time between them. However, this solution is not very reliable when we are talking about human health applications. I just can suggest the Biomedical Signal Analysis.
http://www.ni.com/white-paper/9037/en
Regards,

Looking to calculate the peaks and bpm of an ecg signal

Hello,
i was hoping some one could tell me what i am doing wrong. i have an ecg in the form of a text file. i am trying to display that ecg signal, show the peaks and then calculate the bpm. as you can see the program aint working. the messages on the forum all use continuouslly acquired signals. cant seem to find anything with a signal from a file.
thanks
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Attachments:
ECG Signal.vi ‏42 KB

Let us asume that your peak detection is correct. Then the first beats pr second will be ->1/(( peak postion(1)-peak postion(0) )*dt),
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Message Edited by t06afre on 03-02-2009 11:13 AM
Besides which, my opinion is that Express VIs Carthage must be destroyed deleted
(Sorry no Labview "brag list" so far)

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How Can I make the led come on from the time the graph is at the middle of the 2nd highest peak till it turns off at the middle of the lowest peak, and stays off untill it reaches the middle of the 2nd highest peak again, and so on....?
I thought of 2 ways, firstly to find the highest peak and use equations based on the BPM (note: the vi given is for 60BPM) to offset the triggers on the 2nd and lowest peaks. And a much simpler,; to find the requied peaks by finding peaks within a certain threshold range. But how can i look for a peak within a range of amplitudes? The find peaks and valleys function only has one threshold input.
Thanks in advance
Attachments:
Untitled 1.vi ‏60 KB

Thanx for the reply. the data is attachted.
I got it from exporting data from a graph using the vi from http://zone.ni.com/devzone/cda/epd/p/id/6188
What im stuck on is triggering/ turning an LED on (for example), by triggering from the highest peak. Also the other problem, which I need to tackle first is how do I make the ECG wave continuous. I couldnt find a continuous waveform ECG, so I used that one, and converted it like i have, but after that wave finishes then the amplitude is zero, but i want the wave to continue, or restart, in order to be able to trigger on the peak, and then keep the led on until the 2nd highest peak, when it is turned off.
Let me know if I have not explained something properly.
And I have now taken off the overall while while loop, but theres no point me attaching that, thers no change to the output.
Attachments:
Datacsv.csv ‏654 KB
Data.xlsx ‏575 KB

Need sample ecg signals

Hi I need some sample ecg signals through which I want to check my ecg analysis module(that do filtering of signal and takes FFT of them).
Anyone can send me that plz.........

I had some sample signals many years ago. I will look for them. I can't remember the format, but I think it was just a 1D array of numbers.
Have you tried researching some Med School websites (Universities?)
ECG: electrocardiogram

Is labview able to record the peak to peak value from an ECG wave automatically?

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Here is an attachement.
Labview user
Attachments:
gg.JPG ‏102 KB

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Actually, NI offers Labview basic courses in many areas of the world. See this thread.
The course is well worth the investment.
Or alternatively, try breaking down the problem into smaller pieces and ask advice on this forum along the way.
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50 Hz noise ECG filtering using FFT and its inverse in LabVIEW

I have to write a LabVIEW Program to put the 50 HZ noise in the ECG spectrum using the FFT and then with the Inverse of the FFT I must take it out,but without using any filter.so if anybody can help me with that, I will be thankful.

I have a normal EGG signal,and its Spectrum. Then I add the 50 Hz noise.In the Spectrum I will get this long peak at the x-axis at 50Hz.So,what I'm trying to do with LabVIEW, is to get out this noise without using a filter,but with the FFT and of course with its inverse to reconstruct the signal.
(the EGG signal is created at first with a simulator and not with human body, the signal is going through the "line-in" of the soundcard in the computer)
I hope you understand a little bit what I mean, I will attach what I did in the program till now,maybe you can understand it better.
Thank youMessage Edited by b_rani on 05-18-2005 01:46 PM
Attachments:
Soundin1_030505.vi ‏80 KB

Ecg adquisision

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