Zone heating for breathing circuits

Abstract

The present invention discloses a zoned heating of a breathing circuit. Some embodiments provide an inspiratory branch for a breathing circuit, the inspiratory branch comprising a first segment including a first heating wire circuit and a second segment including a second heating wire circuit. The inspiratory branch may include an intermediate connector, the intermediate connector comprising a connecting circuit that electrically connects the first heating wire circuit to the second heating wire circuit. The inspiratory branch may be configured to operate in two modes, wherein, in a first mode, electrical power is provided to the first heating wire circuit through the first electrical connection without providing power to the second heating wire circuit, and in a second mode, electrical power is provided to both the first heating wire circuit and the second heating wire circuit through the first electrical connection.

Claims

1. A respiratory humidification system, comprising: an inspiratory limb comprising a first segment having a first heating wire, a second segment having a second heating wire, and a temperature sensor, the first and second heating wires being configured to heat respiratory gas flowing through the inspiratory limb, the temperature sensor being positioned at or near a patient end of the second segment, wherein the first and second heating wires are electrically coupled, the first heating wire forming a first heater circuit, and the first and second wires together forming a second heater circuit; a control module comprising a hardware processor configured to be in electrical communication with the temperature sensor and the first and second heater wires, the hardware processor configured to execute software instructions that cause the processor to selectively control power provided to the first and second heater circuits, wherein the processor is configured to use: the first heater circuit to meet the power demand of the first heater circuit required to maintain the temperature profile of the intake branch; and / or the second heater circuit to meet a power demand of the second heater circuit required to reduce or eliminate a difference between the set point temperature and the patient end temperature measured by the temperature sensor, To control the heating of the breathing gas.

2. The respiratory humidification system according to claim 1, wherein: The processor is configured to determine a power requirement of the first heater circuit and to operate in an open loop control mode.

3. The respiratory humidification system according to claim 1, wherein: The power demand of the first heater circuit is set to a specific duty cycle for controlling the first heater circuit.

4. The respiratory humidification system of claim 3, comprising a flow sensor in a flow path of the system, and the processor is configured to measure the flow of the respiratory gas, wherein The specific duty cycle is a fixed duty cycle value determined at least in part by the flow of the respiratory gas measured by the flow sensor.

5. A respiratory humidification system according to claim 3 or 4, wherein: The specific duty cycle is determined using a model that is configured to apply to most situations.

6. The respiratory humidification system according to claim 1, wherein: The power requirement of the first heater circuit is independent of ambient conditions.

7. The respiratory humidification system according to claim 1, wherein: The power demand of the first heater circuit is configured to achieve a target temperature profile in the first segment.

8. The respiratory humidification system according to claim 7, wherein: The target temperature profile utilizes a greater amount of heating in the first heater circuit relative to the second heater circuit.

9. A respiratory humidification system according to claim 7 or 8, wherein: The target temperature curve in the first segment heats the breathing gas in the first segment to above the set point temperature.

10. The respiratory humidification system of claim 1, wherein: The power requirement of the first heater circuit is based at least in part on the power requirement of the second heater circuit.

11. The respiratory humidification system of claim 1, wherein: The power requirement of the first heater circuit takes into account the power requirement of the second heater circuit.

12. The respiratory humidification system of claim 1, wherein: The processor is configured to determine a power requirement of the second heater circuit and to operate in a closed loop control mode.

13. The respiratory humidification system of claim 1, wherein: The power requirement for this first heater circuit is: i) satisfied by heating by the first heater circuit; ii) is met partly by heating by the first heater circuit and partly by heating by the second heater circuit; or iii) is satisfied by heating by the second heater circuit.

14. The respiratory humidification system of claim 1, wherein: The processor is configured to use: the second heater circuit acts as the primary means for controlling heating in the intake branch; and The first heater circuit provides supplemental heating.

15. The respiratory humidification system of claim 1, comprising a temperature sensor located on a portion of the inspiratory limb and configured to measure a surface temperature of the inspiratory limb.

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