ADS1298R: (Augmented) limb leads in analog domain - lead III noise

Hi,

For, "However, when the patient (or the patient simulator) is not connected, channel 4 (F-L measurement, thus lead III) measures enormous noise signal while other leads (CH2, CH3, CH5, CH6, and CH7) are flat lines - what can be the result of such inconsistent behaviour?"

Would you please provide some screen shots? e.g. the ADC Register-> Channel Registers page and the Analysis->Scope page to show a comparison between CH4 and any 1 of the good channel?

What are the noises peak to peak of Channel 4 compare to any 1 of other channel you think is good?

1. Could you not connect any signals to inputs and restart the EVM and GUI, i.e. everything is default(the Channel Input should be all Input Short), and then click ACQUIRE, how does Channel 4 compare to any 1 of other channel?

2. Then, repeat 1, but change the Channel Input to Normal Electrode.

For, "In such configuration (lead I - CH2, lead II - CH3, lead III - CH4) how should I configure RLD registers for the best results, as RLDN2, RLDP2, and RLDP3 only or rather RLDN2, RLDP2, RLDN3, RLDP3, RLDN4, and RLDP4?"

May I ask what you mean by "best results"?

RLD registers settings heavily depend on cases by cases that depend on, but not limited to the following sources and factors -

environment/surroundings noises, EMI, electrodes/patches materials, cables/wires materials/lengths, external circuits, board designs, RC/integrator circuit tuning, experiment setup.

And then, during the product/system prototyping and developing stages, results will depend on products'/systems power supplies, PCBAs, mechanical, chassis, shielding, grounding, enclosures designs, data transmission cables to computer, computer and/or any other power adapters, and the operating/usage environments.

Then, when contacting with human, results depend on electrodes/patches materials/conditions, cables/wires materials/lengths, gels, skin conditions, body, breathing, air in lung, walking/talking, etc.

Any of above could affect the signal integrity and/or SNR, so RLD registers settings are the combinations that customers need to play around/adjust to find the appropriate combinations/configurations with respect to customers' products designs and applications and operating environments.

Therefore, designers and/or engineers need to do tests&trials to test, collect data, study, data analysis, verify and validate, and then tune, reiterate/revise before making final decisions.

Thanks.

Hi,
I'm sorry to tell you that this issue was assigned a lower priority and I was not able to provide you with the screenshots you've asked. 
Looking at the planning I'll be able to provide you with some additional information by the end of the next week the earliest. 

If it's not according to your policy to have a thread open for a longer time, please, close this one. I'll open a new one once I'm working on the issue again.

Have a nice day!

Hi,

It's okay to keep this thread open if it's still pending.

And, it's better and easier to come back to review and understand what have been discussed, tried and the progress.

Thanks for letting me know.