A wearable sensor and method for providing a wearable sensor are disclosed. In a first aspect, the wearable sensor comprises at least one power source and a first module coupled to the at least one power source. The first module includes a first outer shell and a first printed circuit board (PCB) within the first outer shell. The wearable sensor further comprises a second module coupled to the first module. The second module includes a second outer shell and a second PCB within the second outer shell. One of the first and second modules is disposable and the other of the first and second modules is reusable.
