The devices and methods generally relate to vibratable sensors for measuring ambient fluid pressure, in particular implantable sensors. The devices and methods are suited to implantation within the body to monitor physiological conditions, such as portal and/or hepatic venous blood pressure, and allow frequent, remote interrogation of venous pressure. The sensor devices are relatively small compared to conventional devices for measuring fluid pressure and can be implanted in the portohepatic venous system, whereas conventional devices are too large. The small size of the device is accomplished by using a thick sensor membrane, compared to conventional devices, and by limiting the size of additional elements of the device relative to the size of the sensor membrane. The thicker sensor member also obviates the need for multiple sensor arrays and maintains the accuracy and robustness of the sensor device. A data capture, processing, and display system provides a pressure measurement reading.