The VCCA and VREFs and all those circuit are powering up this EKG/EMG circuit:
![](https://imagizer.imageshack.com/img923/2706/60RmAU.jpg)
complete schematic:
![](https://imagizer.imageshack.com/img923/4605/TvZMwr.jpg)
Now do all those capacitors justify it because it is powering the EKG/EMG?
I didn't share it before because people got nervous about medical electronics and afraid the newbie may use it at hospital. But don't worry. I follow the warning note by Olimex by heart which is:
"This evaluation board/kit is intended for use for engineering development, demonstration, or evaluation purposes
only and is not considered by OLIMEX to be a finished end-product fit for general consumer use. Persons
handling the product must have electronics training and observe good engineering practice standards. As such,
the goods being provided are not intended to be complete in terms of required design-, marketing-, and/or
manufacturing-related protective considerations, including product safety and environmental measures typically
found in end products that incorporate such semiconductor components or circuit boards."
Where are you supposed to add the Isolator? It's connected to laptop usb and battery powered only anyway. Do you know of other schematic like it but medical grade? I'm just curious how it differs to $10,000 EMG. What chips are used in the latter?
About the Electrode:
![](https://imagizer.imageshack.com/v2/1024x768q70/922/w9mLYm.jpg)
"**The cable features three electrodes – two data electrodes (1 channel) and DLR electrode
(feedback). If you use more than one SHIELD-EKG-EMG you can use cables without DLR
for every shield after the first."
So VREF is connected to the right foot as part of DLR feedback. Are all the VCCA, VREF design justified? Or do you still consider them poor design?
Again I don't use it as medical device so don't worry. Heck I don't even use it as ECG/EMG because after you try it once. You are tired of it. I'm just curious how it compares to $10,000 version. Is there such that uses superconductor as detector element?