Respiratory flow sensor
First Claim
1. A respiratory flow sensor comprising:
- a housing defining a flow space through which the respiratory flow flows;
substantially identical first wire and second wire arranged at spaced locations from one another in said housing flow space;
a power source for heating said first and second wires;
an air resistance body arranged in a vicinity of said second wire;
a measuring device;
a third wire connected to said measuring device as a temperature-dependent electric resistor and arranged in said housing at a spaced location from said first wire and from said second wire, said third wire for determining the temperature of the respiratory flow with said measuring device;
a central control and evaluating unit connected to the said power source and connected to said measuring device, said central control unit compensating a temperature change of the respiratory flow detected by said third wire based on a change in the heating current flowing through the said first and second wires to provide said first and second wires with an operating temperature that is above the temperature of the respiratory flow by a defined amount and said central control and evaluating unit determining an intensity and the direction of the respiratory flow flowing through said housing from the measured heating currents flowing through said first and second wires.
1 Assignment
0 Petitions
Accused Products
Abstract
A respiratory flow sensor is provided with two identical or substantially identical first and second wires arranged at spaced locations from one another in a housing through which the respiratory flow flows. The first and second wires can be heated by a respective associated power source. An air resistance body is arranged in the vicinity of the second wire. A third wire is arranged in the housing at a spaced location from the first and second wires and is used to determine the temperature of the respiratory flow via an associated measuring device for the temperature-dependent electric resistor. A central control and evaluating unit is connected to the power sources and to the measuring device and compensates a temperature change of the respiratory flow. The change is detected with the third wire by a change in the heating current flowing through the first and second wires, so that these wires have an operating temperature that is above the temperature of the respiratory flow by a defined amount. A central control and evaluating unit determines the intensity and the direction of the respiratory flow flowing through the housing from the measured heating currents flowing through the first and second wires.
12 Citations
10 Claims
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1. A respiratory flow sensor comprising:
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a housing defining a flow space through which the respiratory flow flows;
substantially identical first wire and second wire arranged at spaced locations from one another in said housing flow space;
a power source for heating said first and second wires;
an air resistance body arranged in a vicinity of said second wire;
a measuring device;
a third wire connected to said measuring device as a temperature-dependent electric resistor and arranged in said housing at a spaced location from said first wire and from said second wire, said third wire for determining the temperature of the respiratory flow with said measuring device;
a central control and evaluating unit connected to the said power source and connected to said measuring device, said central control unit compensating a temperature change of the respiratory flow detected by said third wire based on a change in the heating current flowing through the said first and second wires to provide said first and second wires with an operating temperature that is above the temperature of the respiratory flow by a defined amount and said central control and evaluating unit determining an intensity and the direction of the respiratory flow flowing through said housing from the measured heating currents flowing through said first and second wires. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification