BES-AFE-1: Bioelectric Signal Analog Front-end for ECGs

[trophosphere]

Hello everyone.

I have finally decided to hop onboard the crowd-funding campaign train and am very happy/proud to present a project I have been working on for about the past 3 months. Being that this is an engineering forum, and to make it worth more your time, I have included photos and specifications that are not available anywhere else at this time.

The campaign is on Crowd Supply if you wish to be on the mailing list for when the project launches which is planned for mid-January 2017.



What is it?
The BES-AFE-1 is a fully functional single lead electrocardiograph (ECG) analog front-end module designed for prototyping or for integration in user designs. It consists of input protection, amplification, right-leg drive feedback, reference generation, 60Hz notch filtering (configurable to 50Hz during purchase or by the user), anti-aliasing, and buffering for direct connection to an analog-to-digital converter (ADC) of the user’s choice. The module has been designed to offer the user a low noise, low offset, and low power solution in a compact easy-to-use form factor.

Target Audience

• Makers/Hobbyists
• Academic (Teaching lab and used by students as a component in their senior design/capstone project)

Overview of Specifications

• Voltage Range: Single or Bipolar supplies: 1.8v (±0.90) to +5.5v (±2.75v)
• Current Consumption: 180µA to 290uA over allowed voltage gamut
• Size: 2" by 0.6" (50.8mm by 15.24mm)
• Bandwidth: 100Hz with notch at 60Hz (A version) or 50Hz (B version)
• Filters: First order High-Pass at 0.8Hz and Fourth Order Low-Pass at 100Hz (Bessel). Secondary gain stage has a first-order low pass at ~96Hz
• Notch Depth: >20dB on the bench
• Virtual Ground: (Vdd-Vss)/2 This can be overridden by user input

Rewards a.k.a. Products
There are two tangible products planned. The first one is the module being presented which is further separated by two variants distinguished by either an A or B suffix in the name e.g. BES-AFE-A. The A-variant has its notch filter set at 60Hz while the B-variant has its notch filter set at 50Hz. The next product is a breakout board (for easy proto-typing) and, like the module above, has two variants – 60 or 50Hz versions.


Breakout Board

Cost
Planned costs for products will be 30USD for the module itself and 50USD for the break out board (which includes a module already mounted). This price includes domestic shipping in the United States. Shipping out of country to be determined but likely will be a few dollars more.

Pictures


Sine-wave (with noise) input {green} and output from module {yellow}


Simulated ECG (with noise) input {green} and output from module {yellow}


ECG signal through various stages of the BES-AFE-1 module


ECG from human being hooked up to module in Lead 2 configuration


Current consumption of module at 3.3v. Inputs are shorted to right-leg drive. 1M load on output


Example implementation of 2 modules in an application for a 6-lead EKG

Behind the scenes pictures


Test Setup for measuring various wave-forms


Test Setup for interfacing to human subject using the C/D variant of the module


All modules made will be tested with this apparatus

[trophosphere]

Update: I have attached a preliminary datasheet of the module to this post for anyone wanting more in-depth information.

[PlainName]

This is an interesting project for which I sadly don't have a use at the moment. But I just wanted to post so I can say it looks good, the (potential) price is great, and the professional datasheet is a quality touch 

[mtdoc]

Interesting project - I may purchase one.

You should consider offering a 5 module breakout board for a full 12 lead ECG!

[trophosphere]

@dunkemhigh: Thank you for the vote of approval. I borrowed some "creative" input from the organization of other data sheets such as those by Texas Instruments since I had to stare at them for quite a bit when designing this project.

@mtdoc: Thank you for your interest. The full 12-lead option is certainly an interesting suggestion. I will look into it.

[trophosphere]

Hello everyone. If you are interested in this project and am thinking about making a pledge then please head over to the campaign page as the campaign has started.

The datasheet for the module and breakout board is finished and available on my website.

[mtdoc]

Good job on the video.    It looks professional and is informative without being too "slick".

I'm looking forward to having some fun with one of these.

[trophosphere]

Good job on the video.    It looks professional and is informative without being too "slick".

I'm looking forward to having some fun with one of these.

Thank you for the complement.

[ez24]