ADS1293: ECG Data Composition

Shawn Wang1

Part Number: ADS1293

Hi,

When I using the ADS1293 to get stable ECG data from different channel, I found same rule of 3-channel. In contents of upper byte, first 6 bits are the same value.
Why 3-channel has same phenomenon? It means the first 6 bits are DC component or other information?

over 5 years ago

0 Alexander Smith over 5 years ago

TI__Guru 58642 points

Hi Shawn,

The first bits are the most significant, meaning that they represent a larger portion of the voltage being sampled. If the voltage level is not changing significantly, then these bits will remain the same.

This BIOFAQ post may help: https://e2e.ti.com/support/data-converters/f/73/p/772488/2856893#2856893

0 Shawn Wang1 over 5 years ago in reply to Alexander Smith

Prodigy 30 points

Hi Alex,

Many thanks for your reply.

Because I am planing some method for optimize ECG raw data processed. So according to your description, maybe I can ignore the first 6 bits of ECG data if the voltage level is not changing significantly?
Besides, could you please suggest suitable methods of ignore most significant bits base on if the voltage level is not changing significantly?

0 Alexander Smith over 5 years ago in reply to Shawn Wang1

TI__Guru 58642 points

Hi Shawn,

That would work for this specific case, but I am concerned that something could cause the input signal to drift within the common-mode range, such as the patient moving while the electrodes are connected. Instead of truncated the most significant bits, I would suggest truncating the least significant bits as some of them may be purely dominated by noise.

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ADS1293: ECG Data Composition