The present invention provides sensor systems and methods of using the same. The sensor systems include implantable sensors and readers configured to communicate with the implantable sensors. The implantable sensors are attachable to catheters and work with the readers to determine the presence of fluid flow and to calculate an absolute measure of fluid flow rate within a catheter. The sensor systems are capable of monitoring the flow of CSF fluid within shunt catheters, such as hydrocephalus shunt catheters.
