An implantable device for monitoring physiological changes in a patient is provided. The device can include a vessel adapted to being implanted within a patient's body；a chamber having a cell layer and capable of being secured to the vessel； a light source for shining light onto the cell layer； and a reader for detecting and/or decoding signals from the cell layer to monitor physiological changes in the patient. The device is capable of engaging in a two-way communication with a second device through transmission of one or more electromagnetic signals through at least a portion of the patient's body.
