US Patent 11534080 Vital sign monitoring via touchscreen using bioelectric impedance

Methods and apparatus for detecting body vital signs through the use of a Bioelectric Impedance Spectroscopy (BIS), either by (a) direct contact with the person (such as through one or more of their fingers) or (b) measurement of reflections from a field projected into the person's body. The techniques may be implemented using the projected capacitive touch array in a device such as the screen of a smartphone or tablet computer, or the touchpad of a laptop computer.