Devices and methods for respiratory variation monitoring by measurement of respiratory volumes, motion and variability

A device for assessing a patient, the device comprising:

• a sensor array comprised of a set of impedance measurement electrodes adapted to be placed in one or more tetrapolar configurations on the chest of the patient for acquiring a bioimpedance signal from the patient;
• a programmable element coupled to the sensor array and having acquisition circuitry;
• wherein the programmable element:
• determines a Respiratory Variation Monitoring (RVM) calibration coefficient based on the patient's bioimpedance signal and demographic information of the patient;
• adjusts the acquisition circuitry based on the calibration coefficient;
• determines signal variation in the bioimpedance signal;
• adjusts the acquisition circuitry for the signal variation;
• and
• analyzes the bioimpedance signal using the RVM calibration coefficient to determine a respiratory volume and/or respiratory flow parameter of the patient;
• and
• a visual and/or audible alarm coupled to the programmable element or a medical therapy system coupled to the programmable element, wherein the alarm or medical therapy system is activated upon the respiratory volume and/or respiratory flow parameter exceeding a predetermined threshold.