• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 46 subscribers
  • Views 428 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

ADS1293: unstable ECG values

Jerome Mirnu
Prodigy 10 points
Part Number: ADS1293

Hi IT experts,

I'm using the ADS1293 as an ECG front end module. The collected ECG Data is sent to the PC via the ATSAM3X8E MCU (from Atmel). I may like asking for your kind help.

The Testing is done by connecting 5 electrode pads on a human as shown in the below image. I also used the Right-Leg Drive Amplifier to improve the ECG signal quality, by connecting the output of the RLD amplifier internally to pin IN4.

ADS1293 5-Lead ECG Application 

But as I plot the ECG signal, I see a lot of noise and some inconsistent reading as you can see in the image below.

The ADS1293 Schematics:

ADS1293 Schematic

The Registers values:

(0x01, 0x11);
(0x02, 0x19);
(0x03, 0x2e);
(0x0a, 0x07);
(0x0c, 0x04);
(0x0d, 0x01);
(0x0e, 0x02);
(0x0f, 0x03);
(0x10, 0x01);
(0x12, 0x04);
(0x14, 0x00);
(0x21, 0x02);
(0x22, 0x02);
(0x23, 0x02);
(0x24, 0x02);
(0x27, 0x08);
(0x2f, 0x70);
(00, 0x01);

Jerome

  • 0
    TI__Genius 11550 points

    Hi Jerome,

    Welcome to the E2E forum !!!

    I do not see any issue with the schematic or the register setting for the 5-lead ECG application you shown. However, I recommend testing the setup first with an ECG simulator to isolate any design issue prior to testing with a patient. There are several reasons why you may not get proper ECG signals from the patient. These include significant powerline 50/60Hz noise, electrode impedance, electrode placement, etc. Using the RLD drive and additional digital filter may help to improve the ECG signal quality.

    The inconsistent reading in the waveform may be due to the data capture issue. For debugging, you may want to use the Test Mode feature internal to the ADS1293 to verify your data capture robustness. Please refer to Section 8.3.3 in the datasheet for more information on the Test Mode.

    Thanks

    -TC

  • 0 in reply to TCT
    Prodigy 10 points

    Hi TC,

    Thanks for your recommendation.

    I was able to identify that the root cause for the inconsistent reading, was instability of the power circuit delivering 3.3V for the ADS1293 to work. Replacing it solve this issue.

    Regards,

    Jerome