Abstract: A plurality of flow sensors are fabricated on a single substrate. The substrate is laid out to provide the proper physical relationship of the individual sensors. The resulting multiple sensor structure may be effectively used as a respiration detector by positioning a different sensor element at each of the airflow orifices (i.e., two nostrils and mouth) of a patient. In the preferred embodiment, the sensors are thermoresistive elements, which are screened on the substrate using conductive ink. The change in temperature of the air flow in relation to the ambient at each orifice provides an indication of the flow and may be used to determine the extent of the flow. The substrate is packaged in a single piece adhesive strip which provides ease of proper attachment by the patient.

Abstract: An apparatus for and method of monitoring respiration of a patient using impedance changes of the body to indicate respiration events. The impedance changes are measured by applying a carrier signal across the thorax of the patient. The carrier is periodically interrupted to produce a quiet period. A first level detector assumes the presence of EMI if the signal present during the quiet period exceeds a predetermined threshold. A second level detector senses the presence of substantial high frequency EMI. At initial power up, a third level detector checks for presence of signal before the carrier drive is applied. A fourth test circuit checks for the hang up of the differential amplification circuit.

Abstract: A plurality of flow sensors are fabricated on a single substrate. The substrate is laid out to provide the proper physical relationship of the individual sensors. The resulting multiple sensor structure may be effectively used as respiration detector by positioning a different sensor element at each of the airflow orifices (i.e., two nostrils and mouth) of a patient. In the preferred embodiment, the sensors are thermoresistive elements, which are screened on the substrate using conductive ink. The change in temperature of the air flow in relation to the ambient at each orifice provides an indication of the flow and may be used to determine the extent of the flow. The substrate is packaged in a single piece adhesive strip which provides ease of proper attachment by the patient.