High pressure gas exchanger

Abstract

An apparatus 10 and method for delivering a high partial pressure of a gas into a liquid. The apparatus has a gas transfer device 12 with a housing 14 that includes upstream 16 and downstream 18 regions, between which there is located a gas-liquid contacting region 20 with contacting members 22, such as hollow microporous fibers. A reservoir 36 of gas supplies the gas at a high pressure (P) to a flask 38 of gas-depleted liquid and to the gas transfer device 12. The reservoir 36 of gas provides hydrostatic pressure for urging the liquid through the contacting members 22 and propelling the gas around the contacting members 22 so that the gas does not diffuse across the contacting members 22 . The gas-enriched liquid is then ducted to a high resistance delivery channel 44 for administration to a site of interest without effervescence, bubble formation, or significant disruption of laminar flow.

I claim:  
     
       1. An apparatus for delivering a high partial pressure of a gas into a liquid, comprising: 
       a gas transfer device having  
       a housing including an upstream region, a downstream region, and a gas-liquid contacting region with contacting members located intermediate the upstream and downstream regions;  
       a liquid inlet port defined in the upstream region for receiving gas-depleted liquid;  
       a liquid outlet port defined in the downstream region for delivering gas-enriched liquid;  
       a gas inlet port defined in the housing for receiving the gas before contact with the liquid in the contacting region;  
       a gas outlet port defined in the housing for returning gas which is undissolved in the liquid;  
       a reservoir of gas for supplying the gas at a high pressure (P); and  
       a flask of gas-depleted liquid in gaseous communication with the reservoir, the flask being in liquid communication with the liquid inlet port and in gaseous communication at a pressure (p), where p is less than P, with the gas inlet port of the gas transfer device;  
       whereby the reservoir of gas provides hydrostatic pressure for urging the liquid through the contacting members and the gas around the contacting members of the contacting region so that the gas does not diffuse across the members thereof.  
     
     
       2. The apparatus of claim  1  further comprising: 
       a first regulator located between the reservoir of gas and the flask of liquid.  
     
     
       3. The apparatus of claim  1  further comprising: 
       a second regulator situated between the flask of liquid and the gas inlet port of the gas transfer device.  
     
     
       4. The apparatus of claim  1  further comprising: 
       a first regulator located between the reservoir of gas and the flask of liquid; and  
       a second regulator located between the flask of liquid and the gas transfer device.  
     
     
       5. The apparatus of claim  1  wherein the flask of gas-depleted liquid includes: 
       a liquid conduit having an open end located below a meniscus of liquid contained within the flask in order to promote delivery of a relatively bubble-free liquid to the liquid inlet port of the gas transfer device.  
     
     
       6. The apparatus of claim  1  further comprising: 
       a high resistance delivery channel in communication with the liquid outlet port, the high resistance delivery channel serving to supply a gas-enriched, bubble-free liquid to a desired site.  
     
     
       7. The apparatus of claim  1  wherein (P)-(p) is within a range of about 5 p.s.i. to about 20 p.s.i. 
     
     
       8. The apparatus of claim  1  wherein the gas comprises oxygen and the liquid comprises blood. 
     
     
       9. The apparatus of claim  1  wherein the gas comprises oxygen and the liquid comprises water. 
     
     
       10. The apparatus of claim  1  wherein the gas comprises air and the liquid comprises water. 
     
     
       11. The apparatus of claim  1  wherein the gas comprises air and the liquid comprises gasoline. 
     
     
       12. The apparatus of claim  1  wherein the gas comprises carbon dioxide and the liquid comprises water. 
     
     
       13. The apparatus of claim  1  wherein the gas comprises nitrogen and the liquid comprises water. 
     
     
       14. A method for delivering a high partial pressure of a gas into a liquid, comprising: 
       providing a gas transfer device having contacting members with a gas-liquid contacting region;  
       supplying a gas under pressure to a flask of gas-depleted liquid for expelling the liquid therefrom and to the gas transfer device;  
       ducting the gas-depleted liquid to the gas transfer device; and  
       regulating a pressure differential within the contacting region between the gas-depleted liquid and the gas whereby the liquid is urged through the contacting members and the gas flows around the contacting members so that the gas does not bubble across the members.  
     
     
       15. An apparatus for producing a gas- enriched liquid, comprising:    
       
         a gas transfer device comprising:  
       
         a housing having an upstream region, a downstream region, and a gas - liquid contacting region with contacting members located intermediate the upstream and downstream regions;    
       
         a liquid inlet port defined in the upstream region for receiving liquid;  
       
         a liquid outlet port defined in the downstream region for delivering gas - enriched liquid at a first pressure;    
       
         a gas inlet port defined in the housing for receiving the gas at a second pressure wherein the first pressure is greater than the second pressure; and  
       
       
         a gas outlet port defined in the housing for returning gas which is undissolved in the liquid. 
       
     
     
       16. The apparatus of claim  15 , comprising a reservoir containing the gas, the reservoir being operably coupled to the gas inlet port. 
     
     
       17. The apparatus of claim  16 , comprising a flask containing the liquid, the flask being operably coupled to the fluid inlet port and to the reservoir containing the gas. 
     
     
       18. The apparatus of claim  16  comprising: 
       
         a regulator located between a supply of the gas and the gas inlet port. 
       
     
     
       19. The apparatus of claim  17  comprising: 
       
         a first regulator located between the reservoir containing the gas and the flask; and  
       
       
         a second regulator located between the flask and the gas inlet port. 
       
     
     
       20. The apparatus of claim  15  wherein a relatively bubble- free liquid is supplied to the liquid inlet port of the gas transfer device.   
     
     
       21. The apparatus of claim  15  comprising: 
         a delivery channel in communication with the liquid outlet port, the delivery channel serving to supply a gas - enriched, bubble - free liquid to a desired site.   
     
     
       22. The apparatus of claim  15  wherein the pressure differential between the first pressure and the second pressure is within a range of about  5  p.s.i. to about  20  p.s.i. 
     
     
       23. The apparatus of claim  15  wherein the gas comprises oxygen and the liquid comprises blood. 
     
     
       24. The apparatus of claim  15  wherein the gas comprises oxygen and the liquid comprises water. 
     
     
       25. The apparatus of claim  15  wherein the gas comprises air and the liquid comprises water. 
     
     
       26. The apparatus of claim  15 , wherein the gas comprises air and the liquid comprises combustible fuel. 
     
     
       27. The apparatus of claim  15 , wherein the gas comprises carbon dioxide and the liquid comprises water. 
     
     
       28. The apparatus of claim  15  wherein the gas comprises nitrogen and the liquid comprises water. 
     
     
       29. The apparatus of claim  15  wherein the second pressure is greater than atmospheric pressure. 
     
     
       30. The apparatus of claim  22  wherein the second pressure is greater than atmospheric pressure. 
     
     
       31. A method for delivering a gas into a liquid, comprising: 
         providing a gas transfer device having contacting members with a gas - liquid contacting region;    
       
         supplying a gas under pressure to the gas transfer device;  
       
       
         ducting a liquid to the gas transfer device; and  
       
       
         regulating a pressure differential within the contacting region between the liquid and the gas so that the gas does not bubble across the members. 
       
     
     
       32. The method of claim  31  wherein the liquid within the contacting region is at a first pressure which is greater than  760  mm Hg, and wherein the gas within the contacting region is at a second pressure which is less than the first pressure. 
     
     
       33. The method of claim  32 , wherein a pressure differential between the first pressure and the second pressure is between about  5  p.s.i. and about  20  p.s.i. 
     
     
       34. An apparatus for oxygenating blood comprising: 
         a membrane oxygenator adapted to provide oxygen - enriched blood at a pO   2    greater than  760  mm Hg.   
     
     
       35. A method of oxygenating blood comprising: 
       
         providing a membrane oxygenator;  
       
       
         providing gas to the membrane oxygenator at a first pressure that is greater than  760  mm Hg; and  
       
         passing blood through the membrane oxygenator to form oxygen - enriched blood, wherein the pressure of the oxygen - enriched blood proximate the exit of the membrane oxygenator is greater than the first pressure, and wherein the blood remains within the membrane oxygenator for sufficient time to form oxygen - enriched blood with a pO   2    greater than  760  mm Hg.   
     
     
       36. The method of claim  35 , wherein the pO 2    of the oxygen - enriched blood equals about the first pressure.   
     
     
       37. An apparatus for oxygenating blood comprising: 
         a membrane oxygenator adapted to provide oxygen - enriched blood at a pO   2    greater than  760  mm Hg, wherein the membrane oxygenator is formed to operate as an equilibrium device.   
     
     
       38. An apparatus for oxygenating blood comprising: 
         a membrane oxygenator adapted to provide oxygen - enriched blood at a pO   2    greater than  760  mm Hg and to operate as an equilibrium device.