BES-AFE-1: Bioelectric Signal Analog Front-end for ECGs - Page 1
Forum section: electronics / general

author: trophosphere
author_rank: Frequent Contributor
timestamp: November 30, 2016, 01:06:16 am
content: 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.Thecampaign is on Crowd Supplyif 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 AudienceMakers/HobbyistsAcademic (Teaching lab and used by students as a component in their senior design/capstone project)Overview of SpecificationsVoltage Range: Single or Bipolar supplies: 1.8v (±0.90) to +5.5v (±2.75v)Current Consumption: 180µA to 290uA over allowed voltage gamutSize: 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 ~96HzNotch Depth: >20dB on the benchVirtual Ground: (Vdd-Vss)/2 This can be overridden by user inputRewards a.k.a. ProductsThere 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 BoardCostPlanned 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.PicturesSine-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 moduleECG from human being hooked up to module in Lead 2 configurationCurrent consumption of module at 3.3v. Inputs are shorted to right-leg drive. 1Mload on outputExample implementation of 2 modules in an application for a 6-lead EKGBehind the scenes picturesTest Setup for measuring various wave-formsTest Setup for interfacing to human subject using the C/D variant of the moduleAll modules made will be tested with this apparatus

author: trophosphere
author_rank: Frequent Contributor
timestamp: December 14, 2016, 10:26:26 pm
content: Update: I have attached a preliminary datasheet of the module to this post for anyone wanting more in-depth information.

author: PlainName
author_rank: Super Contributor
timestamp: December 19, 2016, 04:03:39 am
content: 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

author: mtdoc
author_rank: Super Contributor
timestamp: December 19, 2016, 04:25:23 am
content: Interesting project - I may purchase one.You should consider offering a 5 module breakout board for a full 12 lead ECG!

author: trophosphere
author_rank: Frequent Contributor
timestamp: December 19, 2016, 07:27:40 am
content: @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.

author: trophosphere
author_rank: Frequent Contributor
timestamp: January 12, 2017, 10:35:17 pm
content: Hello everyone. If you are interested in this project and am thinking about making a pledge then please head over to thecampaign pageas the campaign has started.The datasheet for the module and breakout board is finished and available on mywebsite.

author: mtdoc
author_rank: Super Contributor
timestamp: January 13, 2017, 02:09:55 am
content: 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.

author: trophosphere
author_rank: Frequent Contributor
timestamp: January 13, 2017, 02:47:05 am
content: Quote from: mtdoc on January 13, 2017, 02:09:55 amThank you for the complement.