Abstract: A monitoring device includes an input port attachable for fluid communication with a catheter, the catheter for insertion in a body of a user, for receiving fluid from the body of the user, an output port, generally parallel to the input port, in fluid communication with a fluid reservoir, a fluid channel defining fluid communication between the input port and the output port, and a biosensor for continuously measuring bio-signal data of the fluid in the fluid channel, the biosensor including an electrode pair. The biosensor is in communication with a computing device for determining a condition of the user based at least in part on the bio-signal data.