Gas identification system and respiratory technologies volumetrically corrected gas delivery system
View Patent ↗A gas delivery system, having a gas identification, by which a gas supplied to the gas delivery system is identified, a blender, blending oxygen and the gas to provide a gas mixture with an oxygen flow rate set up by an operator, and at least one flow sensor, to measure a flow rate of the gas mixture. The blender is driven by an actuator motor to various blender positions with the blender positions being calibrated based on the specific heat ratio and the gas constant of the gas. The flow sensor can be installed at the inspiratory circuit, the proximal circuit and the expiratory circuit of the gas delivery system. The flow sensor output is corrected based on the actual conditions, including the temperature, pressure and humidity, and characteristics of the gas mixture.
1. A gas delivery system, comprising:
a gas identifier comprising:
a gas inlet, interlocking a gas source with the gas delivery system; and
an electrical circuit comprising a voltage divider, positioned fluidically adjacent the gas inlet, configured to measure a voltage drop across a resistor, the electrical circuit connected to the gas delivery system and configured to identify, via the voltage drop, a gas supplied from the gas source;
an actuator driving a blender into various blending positions according to a desired oxygen flow rate of a gas mixture comprised of the gas identified by the gas identifier, the blender located downstream from the voltage divider; and
a flow sensor located downstream from the blender, configured to detect a flow rate of the gas mixture, wherein a blending position of the various blending positions is configured to be adjusted by the actuator to achieve the desired oxygen flow rate based on:
Sp
=
[
(
FIO
2
GI
-
vf
GI
)
·
Fr
+
vf
Air
·
(
1
-
FIO
2
GI
)
(
FIO
2
GI
-
vf
GI
)
·
Fr
+
(
1
-
FIO
2
GI
)
-
vf
Air
]
·
S
max
·
1.266
wherein Sp is blending position in steps of the actuator, S max is maximum steps or total steps of the actuator, FIO 2 | G1 is the oxygen flow rate of the gas mixture, vf G1 is oxygen percentage of the gas identified, Fr is a flow correction factor represented as a volumetric flow ratio of (a) the gas identified to (b) air, and vf Air is oxygen percentage of the air.
2. The gas delivery system according to claim 1 , further comprising a lookup table in which a list of voltage drop values corresponding to various gases is stored.
3. The gas delivery system according to claim 1 , further comprising a display that communicates to a user the gas identified by the gas identifier.
4. The gas delivery system according to claim 1 , further comprising (i) a processor that receives an input from a user and (ii) an alarm that notifies the user when the gas identified by the gas identifier differs from a gas provided by the input.
5. The gas delivery system according to claim 4 , wherein supply of gas identified by the gas identifier is ceased when the gas identified by the gas identifier differs from a gas provided by the input.
6. The gas delivery system according to claim 1 , wherein the resistor comprises a different resistance value for each gas supplied to the gas inlet.