OXYGENATOR FIBER MEMBRANE WITH MODIFIED SURFACE PROPERTIES
A blood oxygenator includes a housing having a blood inlet, a blood outlet, a gas inlet, and a gas outlet; and a gas exchange medium having a plurality of hollow fibers in fluid communication with the gas inlet and the gas outlet. Each of the hollow fibers has a roughened outer surface configured to decrease a thickness of a boundary layer at an interface between blood and the roughened outer surface and increase a gas exchange rate at the interface.
1 . A blood oxygenator comprising:
a housing having a blood inlet, a blood outlet, a gas inlet, and a gas outlet; and
a gas exchange medium having a plurality of hollow fibers in fluid communication with the gas inlet and the gas outlet;
wherein each of the hollow fibers has a roughened outer surface configured to decrease a thickness of a boundary layer at an interface between blood and the roughened outer surface and increase a gas exchange rate at the interface relative to hollow fibers having a smooth outer surface.
2 . The blood oxygenator of claim 1 , wherein the roughened outer surface of the hollow fibers includes a plurality of raised protuberances.
3 . The blood oxygenator of claim 1 , wherein the roughened outer surface of the hollow fibers is corrugated and includes a series ridges and valleys separating the ridges.
4 . The blood oxygenator of claim 3 , wherein the ridges and valleys extend helically around each fiber.
5 . The blood oxygenator of claim 3 , wherein the ridges and valleys extend circumferentially around each fiber.
6 . The blood oxygenator of claim 1 , wherein an inner surface of each fiber is smooth.
7 . The blood oxygenator of claim 1 , wherein the plurality of hollow fibers are arranged in multiple rows.
8 . The blood oxygenator of claim 7 , wherein the rows of fibers are stacked on top of each other with each row angled relative to the rows in contact therewith.
9 . The blood oxygenator of claim 8 , wherein adjacent rows are oriented perpendicular to one another.
10 . The blood oxygenator of claim 7 , wherein the rows of hollow fibers are formed into a cylinder.
11 . A blood oxygenator comprising:
a housing having a blood inlet, a blood outlet disposed opposite the blood inlet, a gas inlet, and a gas outlet disposed opposite the gas outlet; and
a gas exchange medium having a plurality of elongate hollow fibers in fluid communication with the gas inlet and the gas outlet, wherein each of the hollow fibers has a roughened outer surface configured to decrease a thickness of a boundary layer at an interface between blood and the roughened outer surface and increase a gas exchange rate at the interface relative to a hollow fiber with a smooth outer surface;
wherein the plurality of hollow fibers are arranged in the housing such that a direction of blood flow between the blood inlet and the blood outlet extends in a plane perpendicular to a plane of any of the hollow fibers.
12 . The blood oxygenator of claim 11 , wherein the roughened outer surface of the hollow fibers includes a plurality of raised protuberances.
13 . The blood oxygenator of claim 11 , wherein the roughened outer surface of the hollow fibers includes a series ridges separated by valleys.
14 . The blood oxygenator of claim 13 , wherein the ridges and valleys extend circumferentially around each fiber.
15 . The blood oxygenator of claim 13 , wherein the ridges and valleys extend helically around each fiber.
16 . The blood oxygenator of claim 11 , wherein an inner surface of each fiber is smooth.
17 . The blood oxygenator of claim 11 , wherein the plurality of hollow fibers are arranged in multiple rows.
18 . The blood oxygenator of claim 17 , wherein the rows of fibers are stacked on top of each other with each row angled relative to the rows in contact therewith,
19 . The blood oxygenator of claim 17 , wherein adjacent rows are oriented perpendicular to one another.
20 . The blood oxygenator of claim 17 , wherein the rows of hollow fibers are formed into a cylinder.