A patient ventilator system for automatically weaning a patient from a ventilator. In one embodiment, the apparatus includes a panel configured to display an image; a glass window covering the panel; and a polarizing film attached on a surface of the glass window, wherein the polarizing film is configured to prevent the scatter of broken pieces when the glass window breaks and also prevent reflection of an external light. The monitor is configured to function only when the key is in communications with the locked sensor port, and the memory reader is able to retrieve predetermined data from the memory element.