The control unit is based on Arduino boards: a family of open-source, low-cost, electronics platforms that can receive analog and digital input and generate digital signals.

These boards can be programmed in C++ within the Arduino Integrated Development Environmental (IDE) to acquire inputs from a variety of switches and sensors and to control lights, motors, and other physical outputs [Arduino website].

The control unit contains an Arduino-Mega board that receives pressure data from two amplifiers connected to the commercial pressure transducers.

It controls the peristaltic pump unit through signals delivered by two Arduino-nano boards.

The desired functions of the control unit can be set by receiving analog inputs from two potentiometers,  digital inputs from five toggle switches, and one push button.

An LCD monitor can visualize the data of interest.

Digital inputs and outputs can be recorded on a PC using CoolTerm, a freeware serial port terminal application that establishes a connection between a computer and external devices to exchange and analyze data [CoolTerm website]

The elements of the control unit must be installed in a suitable housing after they have been designed, realized and tested. I used a  box  from a discarded blood glucose meter. The whole process was similar to solving a puzzle... The end result is quite confusing and I am sure it could be tweaked. Labeling the wires proved incredibly helpful!