Measuring multiple physiological parameters through blind signal processing of video parameters

A method of determining a circulatory patient characteristic corresponding to a patient supported on a patient support apparatus, the method comprising

• receiving image data from a camera,
• determining a pulse transit time (PTT) of an amount of time taken for an arterial pulse pressure wave to travel from the patient's aortic valve to a peripheral site and determining blood volume pulse information based on the image data using a controller of the patient support apparatus to perform blind signal processing image analysis, wherein the patient support apparatus is embodied as a patient bed having a touch screen display and user inputs spaced from the touch screen display, the controller being coupled to the touch screen display and to the user inputs, wherein the controller is also operable to control a motion system that is operable to reposition a patient supported on the patient bed and an air system that is operable to inflate and deflate at least one bladder of a mattress of the patient bed,
• determining with the controller a relative blood pressure value based on the blood volume pulse information corresponding to a face of the patient and to an extremity of the patient, and
• using the PTT to trigger a change in operational characteristics of the patient support apparatus, wherein the change in the operational characteristics includes repositioning the patient using the motion system and changing inflation of the at least one bladder using the air system.