Apparatus and methods for reducing foaming during saliva collection

1. A saliva collector for attachment in a vacuum line which aspirates an air stream entrained with saliva, said saliva collector comprising:

a reservoir having a bottom, a top, and a sidewall which together define an interior volume, said reservoir further having an air inlet and an air outlet with an air flow path between the air inlet and the air outlet; and

a bubble barrier positioned within the interior of the reservoir so that all air on the flow path passes therethrough,

wherein the bubble barrier is positioned within the interior of the reservoir to separate the reservoir into an inner portion and an outer portion, the bubble barrier extending to the bottom of the reservoir and the air flow path crossing the inner and outer portions,

wherein the bubble barrier is cylindrical with the axial lumen aligned with the air inlet or the air outlet, and

wherein the bubble barrier is configured to disrupt bubbles and foam present in the air stream before such bubbles of foam can reach the air outlet such that the bubbles and foam coalesce and return to a liquid state to fall to the bottom of the reservoir away from the air inlet and the air outlet.

2. A saliva collector as in claim 1 , further comprising a membrane positioned within the interior of the reservoir on the flow path downstream of the bubble barrier so that all air passes therethrough before passing through the air outlet, wherein the membrane permits the flow of air but blocks the passage of saliva.

3. A saliva collector as in claim 2 , wherein the membrane has both hydrophobic and oleophobic properties with an air flow resistance less than 40 cmH 2 O at an airflow rate of 120 ml/min.

4. A saliva collector as in claim 3 , wherein the membrane is composed of a material selected from the group consisting of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyethersulfone (PES), optionally coated to enhance oleophobicity to hydrophobic materials or to enhance hydrophobicity in hydrophilic materials.

5. A saliva collector as in claim 1 , wherein the bubble barrier comprises a perforate barrier.

6. A saliva collector as in claim 5 , wherein the reservoir has a volume in the range from 10 cm 3 to 1000 cm 3 and the perforate barrier has an area in the range from 20 cm 2 to 200 cm 2 .

7. A saliva collector as in claim 1 , wherein the bubble barrier comprises a mesh.

8. A saliva collector as in claim 7 , wherein the cylindrical mesh has openings with an area from 0.5 mm 2 to 2 mm 2 .

9. A saliva collector as in claim 1 , wherein the sidewall is cylindrical.

10. A saliva collector as in claim 1 , further comprising an inlet valve at the air inlet and an outlet valve at the air outlet, wherein the valves each open when connected to a conduit and close when disconnected from a conduit.

11. A saliva collector as in claim 10 , wherein the valves are self-opening and closing.

12. A saliva collector as in claim 1 , wherein the air flow path travels upward toward the air outlet after the bubbles and foam have been disrupted by the bubble barrier.

13. A saliva collector as in claim 1 , wherein the air flow path travels laterally outward toward the air outlet after the bubbles and foam have been disrupted by the bubble barrier.

14. A saliva collector as in claim 1 , wherein the air flow path travels laterally inward toward the bubble barrier prior to the bubbles and foam being disrupted by the bubble barrier.

15. A saliva collector as in claim 1 , wherein the air flow path travels downward from the air inlet toward the bubble barrier prior to the bubbles and foam being disrupted by the bubble barrier.

16. A saliva collector as in claim 1 , wherein the outer portion of the reservoir is open to the air inlet and the inner portion of the reservoir is open to the air outlet.

17. A saliva collector as in claim 1 , wherein the air inlet is configured to draw the air stream from an oral appliance held at least partially in the patient's oral cavity with a bite structure of the oral appliance held between upper and lower teeth of the patient.

18. A saliva collector as in claim 1 , wherein the top of the reservoir comprises a removable top, the removable top comprising the air inlet and the air outlet.

19. A saliva collector for attachment in a vacuum line which aspirates an air stream entrained with saliva, said saliva collector comprising:

a reservoir having a bottom, a top, and a sidewall which together define an interior volume, said reservoir further having an air inlet and an air outlet with an air flow path between the air inlet and the air outlet; and

a bubble barrier positioned within the interior of the reservoir so that all air on the flow path passes therethrough,

wherein the bubble barrier is positioned within the interior of the reservoir to separate the reservoir into an inner portion and an outer portion, the bubble barrier extending to the bottom of the reservoir and the air flow path crossing the inner and outer portions,

wherein the bubble barrier is configured to disrupt bubbles and foam present in the air stream before such bubbles of foam can reach the air outlet such that the bubbles and foam coalesce and return to a liquid state to fall to the bottom of the reservoir away from the air inlet and the air outlet, and

wherein the air flow path travels laterally outward toward the air outlet after the bubbles and foam have been disrupted by the bubble barrier.

20. A saliva collector for attachment in a vacuum line which aspirates an air stream entrained with saliva, said saliva collector comprising:

a reservoir having a bottom, a top, and a sidewall which together define an interior volume, said reservoir further having an air inlet and an air outlet with an air flow path between the air inlet and the air outlet; and

a bubble barrier positioned within the interior of the reservoir so that all air on the flow path passes therethrough,

wherein the bubble barrier is positioned within the interior of the reservoir to separate the reservoir into an inner portion and an outer portion, the bubble barrier extending to the bottom of the reservoir and the air flow path crossing the inner and outer portions,

wherein the bubble barrier is configured to disrupt bubbles and foam present in the air stream before such bubbles of foam can reach the air outlet such that the bubbles and foam coalesce and return to a liquid state to fall to the bottom of the reservoir away from the air inlet and the air outlet, and

wherein the air flow path travels laterally inwards toward the bubble barrier prior to the bubbles and foam being disrupted by the bubble barrier.