EEG monitoring

Amir Safavi

Other Parts Discussed in Thread: ADS1299, ADS1298, ADS1299EEGFE-PDK, CC2541

I want to monitor the EEG signal. I see that ADS1298-9 do the work. But it sounds that they are a little old. Does TI have any other chip for that purpose?

over 8 years ago

0 Praveen Aroul over 8 years ago

TI__Mastermind 49176 points

Hello Amir,

Welcome to the TI E2E forum.
I am moving your post to the Precision Data Converters forum who are better suited to respond to your query.
Additionally you may consider searching the forum for similar posts.

0 Brian Pisani over 8 years ago

TI__Mastermind 38745 points

Hey Amir,

The ADS1299 is the device which I would recommend if you were in the market for an integrated analog front end and precision ADC. Are there any specs you are concerned about?

Regards,
Brian Pisani

0 Amir Safavi over 8 years ago in reply to Brian Pisani

Prodigy 140 points

Hi Brian,

Thank you for the answer. Yes, there are some specs that I'm looking for. I'm looking for the

1. Best signal to noise ratio needed (I think 24-bit is one of the highest range)

2. Smallest and most flat possible board and battery

3. Best quality dry electrode

I checked the documentation for ADS1299, but couldn't find any reference design. Is there any?

I'm specifically looking to send the EEG signal over Bluetooth. Do you have any suggestion on that?

Thanks,

Amir

0 Brian Pisani over 8 years ago in reply to Amir Safavi

TI__Mastermind 38745 points

Hey Amir,

1. The noise levels on the ADS1299 are phenomenal, so you've picked a great solution there.
2. This is a system level spec, so I'm not the expert here.
3. TI does not give recommendations on electrodes since we are not the experts there.

Unfortunately the closest thing to a reference design that we have is the ADS1299EEG-FE PDK which is really an evaluation module rather than being an example application. You can find it here: www.ti.com/.../ads1299eegfe-pdk

As far as Bluetooth is concerned, TI offers a great variety of options and I'm confident you'll be able to find what you are looking for: www.ti.com/.../overview.page
I'm not the Bluetooth expert though, so if you have questions or need recommendations, I'd refer you to the Bluetooth e2e forums.

Regards,
Brian

0 Amir Safavi over 8 years ago in reply to Brian Pisani

Prodigy 140 points

Hi,

For the power supply, I use a single cell 3.6V LI-Ion battery. However, ADS1299 needs 4.75 V to 5.25 V to drive the analog part which is not possible in this case. However, there is no such a need for ADS1298. What are the main differences between ASD1299 and ADS1298?

Do you have any recommendation on the EEG AFE selection and also on the power-supply solution? The total consuming current is less than 50mA.

Thanks,

Amir

0 Brian Pisani over 8 years ago in reply to Amir Safavi

TI__Mastermind 38745 points

Hey Amir,

The ADS1298 and ADS1299 are different structurally since the ADS1299 needs to produce a higher PGA gain and lower noise than the ADS1298 and thus the ADS1299 requires a higher voltage power supply. One potential solution would be to produce a higher voltage with a DC-to-DC converter and regulate it at 5V with an LDO. You can find information about TI's power management ICs here: www.ti.com/.../power_portal.page

I'm not the power expert, but I know some TI engineers who could give you much better guidance: e2e.ti.com/.../

Regards,
Brian Pisani

0 Amir Safavi over 8 years ago in reply to Brian Pisani

Prodigy 140 points

Thank you for the response.

DC-to-DC converter sounds a good option to me. Can you please refer me to someone that can help me?

0 Brian Pisani over 8 years ago in reply to Amir Safavi

TI__Mastermind 38745 points

Hey Amir,

The last link I provided is to the home page for power management e2e forums. Someone over there should be able to help you.

Brian Pisani

0 Amir Safavi over 8 years ago in reply to Brian Pisani

Prodigy 140 points

Hi Brian,

I want to order the evaluation kit for ASD1299, ADS1299EEG-FE Performance Demonstration Kit. Do I need to order the motherboard separately or ADS1299EEGFE-PDK also includes the motherboard?

Is there any other extra part that I need to order to get ADS1299EEGFE-PDK work?

Thanks,

Amir

0 Brian Pisani over 8 years ago in reply to Amir Safavi

TI__Mastermind 38745 points

Amir,

That item will include everything necessary.

Regards,
Brian Pisani

0 Amir Safavi over 8 years ago in reply to Brian Pisani

Prodigy 140 points

Hi Brian,

I am trying to run the ADS1299EEGFE EVM on Win 8. Now, I get missing file error.

I checked these topics as well, but didn't find any solution.

e2e.ti.com/.../828237

https://e2e.ti.com/support/data_converters/precision_data_converters/f/73/t/228515#pi318173=1

Do you have any suggestion?

Amir

0 Brian Pisani over 8 years ago in reply to Amir Safavi

TI__Mastermind 38745 points

Hey Amir,

Unfortunately we do not support our this EVM's software for Windows 8. However, there are people on the forum that have gotten it to work: e2e.ti.com/.../291784

Apologies,
Brian Pisani

0 Amir Safavi over 8 years ago in reply to Brian Pisani

Prodigy 140 points

Hi,

I'm looking for the schematic and PCB library for ADS1299 and CC2541 parts. Do you have those libraries?

Thanks,

Amir

0 Amir Safavi over 8 years ago in reply to Brian Pisani

Prodigy 140 points

Thank you. I could install the required drivers in Win 8 following the instruction in that page.

0 Brian Pisani over 8 years ago in reply to Amir Safavi

TI__Mastermind 38745 points

Hey Amir,

I know we do not for the ADS1299, but I do not support the CC2541 so I do not know if one exists for that product. You can get the answer from this forum: e2e.ti.com/.../538

Regards,
Brian Pisani

0 Amir Safavi over 8 years ago in reply to Brian Pisani

Prodigy 140 points

Hi,

I'm working with ADS1299 EVM and tryingto get a reasonable EEG signal from it. I have tried both differential and single-ended inputs. I use a reference electrode and two other electrodes. I follow the instruction in the user guid, but, I can not get any good signal. Nothing close to what is shown in Fig 30 in ADS1299EEG-FE user guide. What do you advise?

Regards,
Amir

0 Brian Pisani over 8 years ago in reply to Amir Safavi

TI__Mastermind 38745 points

Hey Amir,

How are you setting the bias for the inputs. Are you using the BIAS amplifier on the ADS1299?

Regards,
Brian Pisani

0 Amir Safavi over 8 years ago in reply to Brian Pisani

Prodigy 140 points

No, I don't use the BIAS amplifier and all of BIASPs and BIASNs are disabled. Should I use the BIAS amp?

0 Brian Pisani over 8 years ago in reply to Amir Safavi

TI__Mastermind 38745 points

Amir,

Yes, otherwise there is now way to know if the signals you are measuring are within the rails of the converter.

Regards,
Brian Pisani

0 Amir Safavi over 8 years ago in reply to Brian Pisani

Prodigy 140 points

Given that I have 3 electrodes, one reference and one differential pair at channel 8, how should I set the BIAS option and jumpers? Also, how should I connect the reference electrode?

Also, for using dedicated reference and patient BIAS electrodes with 3 electrodes, how should I connect electrodes? How should I set the BIAS option?

0 Brian Pisani over 8 years ago in reply to Amir Safavi

TI__Mastermind 38745 points

Hey Amir,

You can connect the bias output to the reference electrode when the bias amplifier is configured as a simple buffer.

Regards,
Brian Pisani

0 Amir Safavi over 8 years ago in reply to Brian Pisani

Prodigy 140 points

Thank you for the help.

Also, is there anyway that I can change the code so that I get real-time EEG readings?

0 Brian Pisani over 8 years ago in reply to Amir Safavi

TI__Mastermind 38745 points

Hey Amir,

There may be a way to do it, but there is no way with the release fw/sw and we do not support code changes on the forum.

Regards,
Brian Pisani

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EEG monitoring