A long-lasting, wireless, biocompatible pressure sensor device is integrated within a hydrocephalus shunt, either within the shunt's reservoir/anchor or as an inline or pigtailed connector. When integrated within a typical reservoir, the device can sit within the reservoir's hollow frustum area covered by the resilient silicone dome of the reservoir. When integrated as an inline connector, the device can sit at any point on the peritoneal catheter or ventricular catheter, including between the VP shut's valve and reservoir. The pressure sensor device includes electronics that can be powered wirelessly by a reader held to a patient's scalp, and so no battery may be required. The reader can transmit an ambient, atmospheric pressure reading from outside the skull to the implanted device so that its electronics can calculate a calibrated gauge pressure internally and then relay it to a patient's smart phone.