Patent ID: 8239010

Claim:
A system for characterizing a patient comprising: a vital sign monitor, attached to the patient and configured to interface to a hemodialysis machine, comprising: a sensor configured to be worn on the patient's finger, the sensor comprising an optical sensor comprising a light source and a photodetector for measuring an optical waveform from the patient; a first electrode, configured to be worn on the patient's body and to measure a first electrical signal from the patient; a second electrode, configured to be worn on the patient's body and to measure a second electrical signal from the patient; an electrical circuit configured to receive the first and second electrical signals and amplify and process them to generate an electrical waveform; a processing module configured to process: i) the optical waveform and the electrical waveform to determine a time difference between features in these waveforms; and ii) a blood pressure calibration and the time difference to determine a blood pressure value; a first transmission system for transmitting blood pressure values to the hemodialysis machine when the patient is connected to the hemodialysis machine; and a second transmission system for transmitting information to a remote receiver when the patient is disconnected from the hemodialysis machine.