Components for medical circuits
An expiratory limb is provided that is configured to remove humidified gases from a patient and configured to provide improved drying performance by providing a tailored temperature profile along the limb. Limbs for providing humidified gases to and/or removing humidified gases from a patient are also provided, the limbs having improved gas residence time at constant volumetric flow rate. The improved residence time can be achieved by providing a limb comprising multiple lumens.
1. A multi-lumen breathable expiratory limb suitable for use in a medical circuit, the expiratory limb comprising a plurality of discrete conduits, each of the plurality of discrete conduits comprising a wall, the wall extending from an inlet end to an outlet end, the inlet end being configured to receive gas from a patient interface, the wall being formed of a foam material that comprises a void fraction of between 40% and 50%, and an overall pneumatic compliance of the expiratory limb being less than 10 mL/kPA/m.
2. The expiratory limb of claim 1 , wherein the inlet end is connected to an inlet port and the outlet end is connected to an outlet port.
3. The expiratory limb of claim 1 , wherein the plurality of discrete conduits comprises less than six discrete conduits.
4. The expiratory limb of claim 3 , wherein the plurality of discrete conduits consists of three discrete conduits.
5. The expiratory limb of claim 1 , wherein each of the plurality of discrete conduits comprises a corrugated wall.
6. The expiratory limb of claim 5 , wherein one or more of the plurality of discrete conduits comprises a maximum outside diameter of about 14.45 mm or about 15.15 mm.
7. The expiratory limb of claim 5 , wherein one or more of the plurality of discrete conduits comprises a minimum outside diameter of about 12.7 mm.
8. The expiratory limb of claim 5 , wherein one or more of the plurality of discrete conduits comprises a corrugation period of about 3.14 mm.
9. The expiratory limb of claim 5 , wherein one or more of the plurality of discrete conduits comprises a corrugation amplitude of about 1.7525 mm.
10. The expiratory limb of claim 5 , wherein one or more of the plurality of discrete conduits comprises a wall thickness that is within a range of about 0.5 mm to about 1.0 mm.
11. The expiratory limb of claim 10 , wherein the wall thickness is within a range of about 0.6 mm to about 0.9 mm.
12. The expiratory limb of claim 10 , wherein the wall thickness proximal a peak of the corrugated wall is within a range of about 0.5 mm and 0.65 mm.
13. The expiratory limb of claim 10 , wherein the wall thickness proximal a valley of the corrugated wall is within a range of about 0.8 mm and 1.0 mm.
14. The expiratory limb of claim 1 , wherein the wall of each of the plurality of discrete conduits do not comprise longitudinal reinforcing ribs.
15. The expiratory limb of claim 1 , wherein the foam material comprises a void fraction of about 45%.
16. The expiratory limb of claim 1 , wherein the plurality of discrete conduits are twisted or braided together.
17. The expiratory limb of claim 16 , wherein the plurality of discrete conduits are connected together through at least one securing mechanism, the at least one securing mechanism comprising a plurality of openings that correspond to the plurality of discrete conduits.
18. The expiratory limb of claim 1 , wherein the plurality of discrete conduits are formed of a breathable polyester thermoplastic elastomer.
19. The expiratory limb of claim 1 , wherein the wall of each of the plurality of discrete conduits comprise a breathable material.