Patent ID: 8740807

Claim:
A system for monitoring a patient's respiratory rate, comprising: a sensor unit configured to be mounted on the patient's torso and configured to measure thoracic electrical impedance indicative of respiration, comprising: a first connector operably connected to an impedance pneumography circuit and configured to connect directly to a first electrode attached to the patient; a first cable operably connected to the impedance pneumography circuit and configured to connect a second electrode attached to the patient; an impedance pneumography circuit configured to receive electrical signals from the first and second electrodes and process them to generate an impedance pneumography signal therefrom; a motion sensor configured to measure breathing-induced movements of the torso, and to generate a motion signal therefrom; a processing system configured to receive the impedance pneumography and motion signals and collectively process them to determine the patient's respiratory rate, the collective processing comprising (i) filtering the motion signal using filter parameters selected to remove noise components while retaining signal components indicative of respiration, (ii) filtering the impedance pneumography signal using filter parameters selected to remove noise components while retaining signal components indicative of respiration, (iii) derivatizing the filtered impedance pneumography signal, (iv) determining an initial respiratory rate from the derivatized impedance pneumography signal, (v) adaptively filtering the filtered motion signal using filter parameters determined from the initial respiratory rate, and (vi) determining a final respiratory rate from the adaptively filtered motion signal; and a transceiver system configured to receive a value for respiratory rate from the processing system and transmit it to a remote system.