2 Lead dry electrode ECG circuit

Udaya,

We have a design that requires contact with both thumbs and oppossing fingers. Basically, this is a 3-wire connection with two being for differential input and one for common-mode drive. It is a dry contact system. Would this be of interest to you?

Thomas

PA - Linear Applications Engineering

Thomas,

            Thanks for the reply. Yes i am looking for that circuit. Can you share with me the recommended part number, ideas, application notes & the circuit diagram if possible.

            I am eagerly waiting for your reply...

Thanks again

Udhay

Hi Udhay,

Can you provide me your email address? I have a TI Tech Day ECG PowerPoint presentation that I would like to send directly to you. It contains the circuit information. It is a very large file and I may need to do some work on it to get it down to a size that doesn't get blocked by our system.

If you do not wish to list your email address on the forum, send a message to me at mine:

kuehl_tom@ti.com

Regards, Thomas

PA - Linear Applications Engineering

Dear Thomas,

              Please send me the information to my email address (udhay@trock.in). If any EVB kit available please share the detail also...

Thanks & regards

Udhay

Thomas,

               Sorry my email id ( udhay@trock.in ) Can you resend the email please....

Thank you

Udhay

Hi Uday,

The ECG presentation will be sent to the email address you have provided. The ECG board was developed for demonstration purposes and was never produced as a EVM. I do think there is enough information in the session that you should be able to construct your own prototype.

Note that in the presentation the INA326 instrumentation amplifier is used in the ECG circuit. It is fine for the application, but a newer higher performance instrumentation amplifier is now available, the INA826. It uses much less power and has lower noise than the INA326. You may wish to consider the newer device for your application. The pin-outs are different and some other minor circuit changes may be required to use the INA826.

Regards, Thomas

PA - Linear Applications Engineering

Dear Thomas,

                        Thank you very much for the PPT. The circuits & explanations are teach me a lot about DAS/ECG. But the presentation doesn't show me a real output of the ECG waveform from your circuit.  I hope the output will be very good and noise free. There is no EVM to purchase. So please do not close the conversation, i will come back with my result.

Thank you

Regards

Udhay

Hello Udhay,

The PowerPoint is intended to provide basic ECG concepts and some circuit ideas behind constructing a ECG demo circuit. The demo circuit is capable of producing an ECG output that can be displayed on a common DSO. When the session was presented in the past an audience volunteer would be used to observe their ECG waveform. We always had them clean their hands first with a pre-moistened wipe, allow their fingers to dry and then contact the PC board thumb/finger contacts as shown in the slides. The volunteer was seated and needed to be still while grasping the board during the measurement. Usually, it is not difficult to obtain a good, clean ECG waveform from voulnteer. I don't recall the exact DSO vertical volts per division setting, but I do think it was on the order of 50, or 100 mV/div.

Some engineering will be required to get your ECG prototype going, but the circuits are straightforward and shouldn't be difficult to get working.

Regards, Thomas

PA - Linear Applications Engineering

Dear Thomas,

yes, the circuit in the powerpoint is to measure the heart beat not exactly for ECG waveform. Even thought if it is, i hope we can get some decent output waveform. Now i am having INA326 with me. Can i use OP07D opamp for testing purpose? For quick check i am going to design a single side home made PCB with INA326 & OP07D with some through hole component. Can i proceed with this OPAMP or not????

regards

Udhay

Hi Udhay,

I do not think the OP07D is a good choice to replace the RRIO CMOS operational amplifiers used in the DAS/ECG demo application. The OP07D is intended for a minimum supply of +/-3 V (6 V) and +/-15 V typical. The DAS/ECG amplifiers are powered are all powered by a single +5 V supply that appears after the input regulator. Also, the OP07D common-mode input and output swing ranges are much restricted relative to the power supply rails when compared to what is achievable with the recommended RRIO CMOS amplifiers. That may result in limited performance even if you were to increase the OP07D supply voltage to the minimum.

I am not certain what capabilites are provided by TI in your country, but  in many countries free product samples are often available through the TI web site.

Regards, Thomas

PA - Linear Applications Engineering

Hi Thomas,

I am also working on a dry contact ECG system and would appreciate your help. Currently we have a biopotential amplifier circuit using discrete components and INA333 and OPA2333 that works well with leads placed on the chest, but not well with thumb leads. Although, a readable signal is possible.

To get a better signal and/or to reduce the component count, I am evaluating ADS1298and I have the ADS1298ECG-FE evaluation board with me. I get good results with an ECG simulator, but now when I test with my thumbs the signal is worse than our discrete circuit and also has a very strong baseline drift. Do you have any guidelines for finger leads with ADS1298? I am directly feeding the finger signals captured from an electrode to ADS1298, should I be doing some pre-processing?

I would also be interested in the dry contact circuit you have mentioned above, could you send me a copy of the presentation too? My email address is - govind at reka dot net.

Thanks in advance!

Govind

Hello Govind,

I will forward the DAS/ECG PowerPoint to the email address you provided. Also, I have contacted our data converter applications team to assist you with your questions regarding the ADS1298.

Regards, Thomas

PA - Linear Applications Engineering

Hi Thomas,

I am experimenting right foot feedback circuit from Webster's Medical Instrumentation book.

I would be very appreciate if you can send me the above mentioned circuit.  My email is [lionel.thiha @live.com]. thanks.

Hi Aung,

I will send the DAS/ECG PowerPoint file to the email address you have provided.

Best regards, Thomas

PA - Linear Applications Engineering

Hi Thomas,

I'm working with an eye movement detector and I guess it will be helpfull to take a look to the powerpoint you've mentioned.

I already built one with discrete Op. Amp. but now I'm looking for better performance, less consume and reduced size so I'm trying to find the better Inst. Amp. which fits with my requirements.

My email address is nelsonmigliacci@hotmail.com.

Thanks in advance!

Nelson

Hello Nelson,

I will send the DAS - ECG PowerPoint to the email address you provided.

Regards, Thomas

PA - Linear Applications Engineering

Hi Thomas,

I'm a student of electronic engineering and for my thesis I would be interested to see your ECG powerpoint, because I need to understand some of the basic principles about ECG, expecially with dry electrodes. Could you send me the ppt, if it is possible?

My email is beno82@yahoo.it

Thanks in advance

Alessandro

Hi Alessandro,

I will send the DAS_ECG PowerPoint to the email address you provided.

Regards, Thomas

PA - Linear Applications Engineering

Hi Thomas,

 I have the ADS1292fe kit and I would like to acquire data from dry contacts but I get a lot of noise. Could you send me the power point slides too?

My email is saeid.whb at gmail dot com

Hi Thomas

Would you forward the ECG presentation to my email address at zsolt.pardi@gmail.com please?

Thanks for your help in advance.

Regards,
Zsolt

Hi Thomas,

I'm a student of electronic engineering and for my industrial project I would be interested to see your ECG powerpoint. We need a circuit design for a 2 Lead Dry contact electrode ECG system.

Would you forward the ECG presentation to my email address at estelle.rutillet@gmail.com please?

Thanks for your help in advance.

Regards,
Estelle

Hi Estelle,

I am sending the ECG PowerPoint to the email address you provided.

Thank you for your interest.

Regards, Thomas

PA - Linear Applications Engineering

hi thomas

I'm design system 2 lead ecg please send me mentioned circuit : my email :hd.uni.pro@gmail.com

thx

Hi Thomas

Sorry for asking again and repeating my 20 January 2013 post (please see above), but is there any chance that you could send me as well the ECG Power Point presentation?

Best Regards,
Zsolt Pardi 

Hi Thomas,

Some of the TechDay presentations can be downloaded from ti.com, can't this ECG presentation be posted somewhere we can downloaded it from?

Thanks

Hello Saeed,

The DAS-ECG Tech Day PowerPoint has been sent to your email address.

Regards, Thomas

PA - Linear Applications Engineering

Hello Zsolt,

The DAS-ECG Tech Day PowerPoint has been sent to your email address.

Regards, Thomas

PA - Linear Applications Engineering

Hello Johannes,

I am certain the DAS-ECG Tech Day information can be posted somewhere within the TI information structure. I am investigating where the best place would be for it and how to go about getting that accomplished.

The requests for that particular ECG information is non-stop and it needs to be readily available. Thanks for the suggestion.

Regards, Thomas

PA - Linear Applications Engineering

Hi all,

I work at contact less electrode (capacitive ) and I want design circuit same as you, is it possible to send it for me too.

thank you,

Hello Siyavash,

The DAS-ECG portable solution is actually a 3-lead ECG measurement. The information may be helpful to you anyway.

Please send me an email and I will send the PowerPoint to you. My email address is:

kuehl_tom@ti.com

Regards, Thomas

PA - Linear Applications Engineering

hi,

thanks for your replay. it is my mail: asadi.siyavash@gmail.com

I am ready for cooperation in this topic with every one that like this field.

best regards,

Siyavash Asadi

Thomas,

Would you be kind enough to also forward me a copy of the powerpoint and any additional information on the dry 2 lead EKG circuit?

Sincerely,

Philip Holan

pholan@hotmail.com

Hi Philip,

The DAS-ECG PowerPoint has been sent to the email address you provided.

Regards, Thomas

PA - Linear Applications Engineering

Hi Thomas,

I have just found this discussion and I'm interested, what do you propose in the field of ECG circuits. Most devices I have seen, are based on traditional and well-known solutions, thus I'm looking for newer approach. Could you share to me the DAS-ECG ppt, too? My email adress is: przemotronik@przemotronik.pl.

Thank you in advance.

Best regards,

Przemyslaw

Hello Przemyslaw,

I am sending the DAS-ECG PowerPoint to the email address you provided.

Regards, Thomas

PA - Linear Applications Engineering

Dear TI,

I am also interested in the kind of circuit you mention. It should have a two elctrodes and one common mode electrode for CMR. Can you please send me the ppt file?

My email ID is gregariousgargi@gmail.com

Hi Gargi,

The DAS-ECG PowerPoint has been sent to the email address you sent directly to me.

Best regards, Thomas

PA - Linear Applications Engineering

Thomas, Would you be so kind to send me the ppt?

Thanks in advance.

Best regards,

Alejandro

Hi Alejandro,

Please send an email to me so that I may send the DAS-ECG PowerPoint directly to you.

Regards, Thomas

PA - Linear Applications Engineering

Thomas,

My email is ale_a_t@yahoo.com.ar

Thanks a lot for your quick response

Alejandro,

The presentation can now be downloaded at this link:

ECG (Heart) Signal Acquisition

Regards, Bruce

Dear Thomas,

could you send me the DAS-ECG ppt to andcell at hotmail dot com, please?

thanks in advance,

Andrea

Hi Andrea,

The DAS-ECG PowerPoint has been sent to your email address.

Regards, Thomas

PA - Linear Applications Engineering

Thomas,

Would you be so kind to send me the ppt too? Thanks in advance.

Best regards,

areeb

areeb6@live.com

Hi Areeb,

I am sending the ECG ppt to your email address.

Regards, Thomas

PA - Linear Applications Engineering

Hi Thomas,

Can I please get a copy of this ECG ppt?

mousaa3@mcmaster.ca

Thank you,

Alireza Mousavi

Alireza,

I am sending the DAS-ECG PowerPoint to the email address you provided.

Regards, Thomas

PA - Linear Applications Engineering

hello 

please send me too :

hd.uni.pro@gmail.com

For this request :

I need a circuit design for a 2 Lead Dry contact electrode ECG system. I am selecting INAMP & OPAMP for the design. Please suggest me a very good working circuit & IC'S. Please I am not preferring ADSXXXX series.

My requirements are as fallows,

1. It is a handheld equipment with battery powered, so the power consumption should be less.

2. The production quantity is 2000 piece/month, so the cost of the chip & circuit should be very less.

3. The circuit should have very good reliability & repeatability.

3. The electrodes contact with thump [dry contact], so the sensitivity should be linear for all type of skins.

Please provide me necessary support to start my project....

Thanks & regards

Hello Saeed,

I have attached the DAS-ECG PowerPoint to this response so that you, and others, may access it. Be sure to view the presenter's notes. They provide explanations for the slide contents.

The ECG board was designed for dry contact. The circuit is essentially a 3-electrode measurement accomplished by grasping the PC board with both hands. There is a pad for the left and right thumbs on the top of the board, and a pad underneath for the right index finger.

The board was deigned about a decade ago and newer, high performance, low power operational and instrumentation amplifiers have been developed and may be adapted for use in the circuit. Take a look at the OPA330, OPA333 and INA333:

http://www.ti.com/product/opa330

http://www.ti.com/product/opa333

http://www.ti.com/product/INA333

The OPA333 and INA333 data sheets provide information about some ECG applications.

Regards, Thomas

PA - Linear Applications Engineering

hello 

thank you.but i want circuit without product and chip opa3330 and opa333 and ina 333 .

and i can't downdown PPT file ! why ?