ADS1294R respiration resistance calculation

Felipe L

Other Parts Discussed in Thread: ADS1294R, ADS1298R

Greetings,

We are currently working in a project involving the ADS1294R for cardiac and respiration monitoring. The cardiac functionality is implemented and working, however the we are having trouble to get a good quality in the respiration signal (Only considerable respiratory afforts are perceived).

I'm thinking it is due to very low current flowing trough the body because the increase in body impedance, the electrodes are shared between channel 1 for respiration and channel two for EKG (the same configuration as in sbau181).

So i guess the question is Do you know what value of injection current will be adecuate to obtain a good quality signal.

The setup is AVSS = -1.5, AVDD = 1.5, DVDD = 3v. I guess the injection current is around 30uA if body resistance is assumed to be 500 Ohm.

Thanks in Advance.

over 13 years ago

Tom Hendrick over 13 years ago

TI__Guru**** 181021 points

Hi Felipe,

We did a few experiments with the ADS1298R to try and determine some optimal values of R and C values at different gains and respiration frequencies. We'll get something put together for you and either post it in the Design Notes section here or send it along in a separate e-mail.

Felipe L over 13 years ago in reply to Tom Hendrick

Prodigy 250 points

Thank You Mr. Hendrick, your help is really appreciated.

Regards,

Felipe Lennis.

Dirk Bergholz over 10 years ago in reply to Tom Hendrick

Prodigy 10 points

Hi Tom,

we have the save problem with the ADS129xR. Please, can you send me the documents from your experiemts with the ADS1298R?

Thank you.

Dirk

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ADS1294R respiration resistance calculation