WIRE HEATED TUBE WITH TEMPERATURE CONTROL SYSTEM FOR HUMIDIFIER FOR RESPIRATORY APPARATUS

摘要

A PAP system for delivering breathable gas to a patient includes a flow generator to generate a supply of breathable gas to be delivered to the patient; a humidifier including a heating plate to vaporize water and deliver water vapor to humidify the supply of breathable gas; a heated tube configured to heat and deliver the humidified supply of breathable gas to the patient; a power supply configured to supply power to the heating plate and the heated tube; and a controller configured to control the power supply to prevent overheating of the heating plate and the heated tube.

主权项

1. A sensing circuit for a heated conduit for use in a respiratory apparatus, the sensing circuit comprising:
a sensing wire coupled to a heating circuit for the heated conduit; a temperature sensor coupled to the sensing wire and configured to measure the temperature of the heated conduit; a sensing resistor coupled to the sensing wire and configured to provide an output to indicate the temperature measured by the temperature sensor; and a bias generator circuit configured to provide a reference voltage to the sensing resistor to allow determination of the output as a function of a voltage drop across the sensing resistor during both heating on and heating off cycles of the heating circuit,wherein the bias generator includes a track and hold circuit configured to measure a voltage of the sensing wire and provide the measured voltage to the bias generator circuit, wherein the bias generator circuit is configured to adjust the reference voltage as a function of the measured voltage.