Anesthesia gas delivery and monitoring system
Various implementations include a gas delivery and monitoring apparatus that can be used, for example, to deliver oxygen and monitor exhaled carbon dioxide in a subject while under anesthesia. One advantage of the disclosed apparatus is the ability to deliver oxygen directly to the back of the mouth instead of in front of the face. Another advantage of the disclosed apparatus over existing nasal cannulas is the ability to capture carbon dioxide exhaled from both the nose and mouth.
1. A gas delivery and monitoring apparatus, comprising:
(a) a support member having a longitudinal axis, a proximal end, and a distal end opposite and spaced apart from the proximal end;
(b) a bite block sized to be disposed within a mouth of a subject between at least one tooth of an upper jaw of the subject and at least one tooth of a lower jaw of the subject, the bite block having a proximal end and a distal end opposite and spaced apart from the proximal end,
(c) a first elongated conduit defining an exhalation capture flow path extending from a capture inlet at the distal end of the bite block and terminating in an outlet port;
(d) a second elongated conduit defining a gas delivery flow path extending from an inlet port into the bite block, and terminating in a gas delivery port at the distal end of the bite block such that both the gas delivery port and capture inlet are located in the mouth of the subject when the bite block is inserted in the mouth of the subject during use; and
(e) a bridge extending between the proximal end of the bite block and the proximal end of the support member, wherein the bridge has a curvature that extends the bridge around a corner of the mouth of the subject when the bite block is disposed within the mouth of the subject between the at least one tooth of the upper jaw of the subject and the at least one tooth of the lower jaw of the subject such that the distal end of the support member and the distal end of the bite block are simultaneously positioned on opposite sides of a cheek of the subject and posterior to the corner of the mouth of the subject,
wherein a portion of the first elongated conduit between the bite block and the support member and a portion of the second elongated conduit between the bite block and the support member follows the curvature of the bridge.
2. The apparatus of claim 1 , wherein the support member has a channel therewithin extending along the longitudinal axis from a proximal end of the channel to a distal end of the channel.
3. The apparatus of claim 2 , further comprising a third elongated conduit defining a nasal exhalation capture flow path extending from a secondary capture inlet, through the channel from the distal end to the proximal end and terminating in a secondary outlet port.
4. The apparatus of claim 3 , wherein the third elongated conduit is encased in a deformable sheath.
5. The apparatus of claim 3 , wherein a distance between the distal end of the channel and the secondary capture inlet is about 4 to 8 cm.
6. The apparatus of claim 3 , wherein the third elongated conduit has an inner diameter of about 2 to 4 mm.
7. The apparatus of claim 3 , wherein the third elongated conduit comprises a flexible elastomeric material that is not gas-permeable.
8. The apparatus of claim 2 , wherein the first elongated conduit extends through the channel from the proximal end to the distal end.
9. The apparatus of claim 2 , wherein the second elongated conduit extends through the channel from the proximal end to the distal end.
10. The apparatus of claim 1 , wherein the bridge extends away from the support member along a transverse plane perpendicular to the longitudinal axis.
11. The apparatus of claim 1 , wherein the bridge positions the bite block a first minimum distance from the support member, wherein the first minimum distance is 1 to 3 cm.
12. The apparatus of claim 11 , wherein the bridge is deformable to a second minimum distance from the support element.
13. The apparatus of claim 12 , wherein the second minimum distance is 1 to 3 cm.
14. The apparatus of claim 12 , wherein the bridge provides spring tension to secure the bite block within the mouth of the subject.
15. The apparatus of claim 1 , wherein the second elongated conduit extends through the bite block to terminate in the gas delivery port.
16. The apparatus of claim 1 , wherein the first elongated conduit comprises an elastomeric material that is not gas-permeable.
17. The apparatus of claim 1 , wherein the second elongated conduit comprises an elastomeric material that is not gas-permeable.
18. The apparatus of claim 1 , wherein the inlet port is fluidly-connectable to a source of pressurized oxygen.
19. The apparatus of claim 1 , wherein at least a portion of each of the support member, bite block, and bridge are integrally formed.
20. The apparatus of claim 1 , wherein the support member, bite block, and bridge are mechanically connected.
21. The apparatus of claim 1 , wherein the first elongated conduit has an inner diameter of about 2 to 4 mm.
22. The apparatus of claim 1 , wherein the second elongated conduit has an inner diameter of about 2 to 8 mm.