Need suggestions for using Arduino or Raspberry pi

  • I'm using STONE HMI display (from: https: //www.stoneitech.com/) for developing an open source medical device using a microcontroller (Arduino or Raspberry pi) with attached ECG, etc. circuits. I have not decided yet if I will make it:
    1) with Arduino, which means I will have to switch between the circuits manually.
    2) with Raspberry pi with LCD touch screen attached to switch between the multiple circuits electronically.
    The main goal of this project is developing an open source medical device such that the user can add circuits to the microcontroller following the specification that I will develop. The circuits will be built up on top of each other using assigned pins.
    If you have other suggestions than using Arduino or Raspberry pi please feel free to share.
    Thanks.