Build a sensor with Bluetooth interface

Need to build a sensor that using two points could measure the variation of a small current flow (mili Amps) going through a material when affected by heat or pressure. Data must be send through a Bluetooth interface.. The device must accept some basic configuration and offer a simple protocol communication with the linked application through the Bluetooth interface. Even when the drawing shows a finished product layout, the prototyping could be done on any type of board.