Since I have very little previous experience with microcontrollers, I'm looking for an advice on which microcontroller to get that will be appropriate for Holter monitoring (ECG signals from external circuit with 3 channels)? It should be ass small as possible with low battery usage (because of for 24 h+ monitoring) and good enough performance for ECG application. As far as connectivity goes, I will use Bluetooth and maybe Wi-Fi, but Bluetooth is crucial for sure. Are there any suitable microcontrollers with Bluetooth integrated or would I have to pair it with external BT module? If that is the case, which combination would you then recommend to me?

Any advise would be greatly appreciated! Thanks

 

Answering such a question is extremely hard. Vague descriptions like "ass small as possible" and "low battery usage" are nearly useless in making even a rudimentary determination of whether what you are trying to do is even possible let alone achievable at reasonable cost. Let me recommend that you start with a block diagram of this system, fill in the blanks as you decide what sensors and communications you need, how much battery capacity this will require and come back with a more definite set of requirements.