Body-worn system for continuous, noninvasive measurement of cardiac output, stroke volume, cardiac power, and blood pressure

Abstract

The invention provides a system for measuring stroke volume (SV), cardiac output (CO), and cardiac power (CP) from a patient that features: 1) an impedance sensor connected to at least two body-worn electrodes and including an impedance circuit that processes analog signals from the electrodes to measure an impedance signal (e.g. a TBEV waveform); 2) an ECG sensor connected to at least two chest-worn electrodes and including an ECG circuit that processes analog signals from the electrodes to measure and ECG signal; 3) an optical sensor connected to a body-worn optical probe and including an optical circuit that processes signals from the probe to measure at least one optical signal (e.g. a PPG waveform) from the patient; 4) processing system, typically worn on the patient's wrist and connected through a wired interface to the optical sensor, and through either a wired or wireless interface to the TBEV and ECG sensors.

What is claimed is: 
     
         1 . A body-worn system for measuring a stroke volume value from a patient, comprising:
 a TBEV module worn on the patient's body and comprising: i) an electrical circuit configured to inject a current proximal to the patient's brachium; ii) a pair of electrical connectors located on a bottom portion of the module, the electrical connectors configured to snap into a pair of mated connectors comprised by a first electrode, with a first connector configured to inject the current into a first portion of the electrode, and a second connector configured to measure signals from a second portion of the electrode that relate to a voltage; iii) an analog circuit configured to process the signals from the second connector to generate a voltage value; and iv) a processor configured to convert the voltage value, or a value calculated therefrom, into a time-dependent resistance value, and then convert the time-dependent resistance value into a stroke volume value.