Patent ID: 8770193

Claim:
An apparatus for sensing respiration and synchronizing a ventilator to the respiration of a patient, the apparatus comprising: at least three thermal breath sensors; wherein a first thermal breath sensor measures temperature in an airway of the patient, a second thermal breath sensor measures temperature at or near the opening of an airway of the patient, and a third thermal breath sensor measures ambient temperature; wherein signals from the first thermal breath sensor and the second thermal breath sensor are initially compared to a signal from the third thermal breath sensor to determine if inspired ambient air should be warmer or cooler than body temperature, and wherein the initial signal comparison defines an inspiratory phase and an expiratory phase associated with the signals from the first thermal breath sensor and the second thermal breath sensor; and wherein the signals from the first thermal breath sensor and the second thermal breath sensor are subsequently compared to each other to compensate for drift and artifacts, and wherein the subsequent signal comparison is used to determine true patterns, phases and timing of the patient's respiration.