Abstract: An implantable container for housing a cardiovascular treatment device is disclosed with a window positioned in an external wall thereof for sensing a physiological parameter for the treatment device. The window is formed of an insulating material such as glass, a semiconductor material, or a membrane for sensing any one of a plurality of various physiological parameters. In one embodiment, the window material is glass on which a pair of electroptic devices are positioned on the interior surface thereof for emitting and receiving optical signals for sensing the physiological parameter. In another embodiment, the window comprises glass with a plurality of electrodes externally positioned thereon for measuring, for example, the electrical properties of the physiological parameter.