Extracorporeal blood circuit

Claim 2

An extracorporeal blood circuit comprising, in combination: a. a blood oxygenator; b. a first peristaltic pump including a variable tube means of a type having a capacity variable between maximum and minimum values in proportion to the pump inlet pressure, the maximum capacity being reached at an inlet pressure of atmospheric pressure + OR - 20 mm of mercury; c. an inlet of said first pump connectable to a patient''s blood circuit; d. an outlet of said pump connected in series with said oxygenator; e. a second peristaltic pump including a variable tube means of a type having a capacity variable between maximum and minimum values in proportion to the pump inlet pressure, the minimum capacity being reached at an inlet pressure of atmospheric pressure + OR - 20 mm of mercury; f. an inlet of said second pump connected in series with said blood oxygenator; and g. an outlet of said second pump connectable to said patient''s blood circuit.

Claim 3

A blood circuit as claimed in claim 1, and further comprising means for driving said first and second pumps synchronously.

Claim 4

A blood circuit as claimed in claim 1, wherein the capacity of said first pump reaches a maximum value for a liquid pressure at its inlet which is less than atmospheric pressure.

Claim 5

A blood circuit as claimed in claim 1, wherein the capacity of said second pump reaches a minimum value for a liquid pressure at its inlet which is greater than atmospheric pressure.

Claim 6

A blood circuit as claimed in claim 1, wherein the useful maximum flow rate capacity of said second pump is greater than the useful maximum flow rate capacity of said first pump.

Claim 7

A blood circuit as claimed in claim 1, wherein the useful minimum flow rate capacity of said second pump is less than the useful minimum flow rate capacity of said first pump.

Claim 8

A blood circuit as claimed in claim 1, wherein the two pumps further comprising an adjustable speed single motor, a common shaft driven by said motor and identical rotors of said peristaltic pumps mounted on said common shaft.

Claim 9

A blood circuit as claimed in claim 1, wherein, in the oxygenator, the blood is separated from the oxygenating gas stream by at least one microporous membrane.

Claim 10

A blood circuit as claimed in claim 8, in which the microporous membrane is water-repellent.

Claim 11

A blood circuit as claimed in claim 1, wherein the internal wall in contact with the blood of at least one component of the circuit carries a smooth organosilicon coating.

Claim 12

A blood circuit as claimed in claim 1, and further comprising at least one cannula connected to the inlet of the first pump for removing the venous blood and a non-occlusive enlargement near its end.

Claim 13

A blood circuit as claimed in claim 1, and further comprising a flared-out prosthesis, connected to the outlet of the second pump, and wherein said prosthesis can be stitched to a patient''s artery.

Claim 14

A blood circuit as claimed in claim 1, and further comprising means for reheating the blood and means for sensing the temperature of the blood located at the level of and downstream from the said means for reheating the blood.

Claim 15

A blood circuit as claimed in claim 1, and further comprising an auxiliary pump and at least one other source of blood or medicinal liquid connected to the inlet of said first pump by said auxiliary pump.

Claim 16

A blood circuit as claimed in claim 1, and further comprising a manometer upstream from said first pump.

Claim 17

A blood circuit as claimed in claim 15, wherein said manometer is of the type which measures the pressure across the wall of a flexible tube.

Claim 18

A blood circuit as claimed in claim 1, and further comprising a plurality of blood oxygenators connected in parallel and a further one of said first and second pumps connected in series on either side of each blood oxygenator.

Claim 19

An extracorporeal blood circuit comprising, in combination: a. a blood oxygenator; b. a first tubular variable membrane and valve pump of a type having a capacity variable between maximum and minimum values in proportion to the inlet pressure of the pump, the maximum capacity being reached at an inlet pressure of atmospheric pressure + or - 20 mm of mercury; c. an inlet of said first pump connectable to a patient''s blood circuit; d. an outlet of said pump connected in series with said oxygenator; e. a second tubular variable membrane and valve pump of a type having a capacity variable between maximum and minimum values in proportion to the inlet pressure, the minimum capacity being reached at an inlet pressure of atmospheric pressure + or -20 mm of mercury; f. an inlet of said second pump connected in series with said blood oxygenator; and g. an outlet of said second pump connectable to a patient''s blood circuit.

Claim 20

An extracorporeal blood circuit comprising, in combination: a. a blood oxygenator; b. a first tubular variable membrane and valve pump of a type having a capacity variable between maximum and minimum values in proportion to the inlet pressure of the pump, the maximum capacity being reached at an inlet pressure of atmospheric pressure + or - 20 mm of mercury; c. an inlet of said first pump connectable to a patient''s blood circuit; d. an outlet of said pump connected in series with said oxygenator; e. a second tubular variable membrane and valve pump of a type having a capacity variable between maximum and minimum values in proportion to the inlet pressure, the minimum capacity being reached at an inlet pressure of atmospheric pressure + or -20 mm of mercury; f. an inlet of said second pump connected in series with said blood oxygenator; and g. an outlet of said second pump connectable to a patient''s blood circuit.

Claim 21

An extracorporeal blood circuit comprising; in combination: a. a blood oxygenator; b. a first peristaltic pump of a type having a capacity which is variable in proportion to the pump inlet pressure and having a tube of circular cross-section at rest; c. an inlet of said first pump connectable to a patient''s blood circuit; d. an outlet of said pump connected in series with said oxygenator; e. a second peristaltic pump of a type having a capacity which is variable in proportion to the pump inlet pressure and having a tube of substantially ellipitical cross-section at rest, the internal perimeter of the tube of the second pump being greater than that of the tube of the first pump, so that the maximum capacity of the first pump and the minimum capacity of the second pump is reached at a pump inlet pressure Of atmospheric pressure + or - 20 mm of mercury; f. an inlet of said second pump connected in series with said blood oxygenator; and g. an outlet of said second pump connectable to said patient''s blood circuit.

Claim 22

An extracorporeal blood circuit comprising; in combination: a. a blood oxygenator; b. a first peristaltic pump of a type having a capacity which is variable in proportion to the pump inlet pressure and having a tube of circular cross-section at rest; c. an inlet of said first pump connectable to a patient''s blood circuit; d. an outlet of said pump connected in series with said oxygenator; e. a second peristaltic pump of a type having a capacity which is variable in proportion to the pump inlet pressure and having a tube of substantially ellipitical cross-section at rest, the internal perimeter of the tube of the second pump being greater than that of the tube of the first pump, so that the maximum capacity of the first pump and the minimum capacity of the second pump is reached at a pump inlet pressure Of atmospheric pressure + or - 20 mm of mercury; f. an inlet of said second pump connected in series with said blood oxygenator; and g. an outlet of said second pump connectable to said patient''s blood circuit.

Claim 23

An extracorporeal blood circuit comprising, in combination: a. a blood oxygenator; b. a first tubular membrane and valve pump of a type having a capacity which is variable in proportion to the pump inlet pressure and having a tubular membrane of circular cross-section at rest; c. an inlet of said first pump connectable to a patient''s blood circuit; d. an outlet of said pump connected in series with said oxygenator; e. a second tubular membrane and valve pump of a type having a capacity which is variable in proportion to the pump inlet pressure and the tubular membrane having a substantially elliptical cross-section at rest, the internal perimeter of the tube of the membrane of the second pump being greater than that of the tubular membrane of the first pump, so that the maximum capacity of the first pump and the minimum capacity of the second pump is reached at a pump inlet pressure of atmospheric pressure + or - 20 mm of mercury; f. an inlet of said second pump connected in series with said blood oxygenator; and g. an outlet of said second pump connectable to said patient''s blood circuit.

Claim 24

An extracorporeal blood circuit comprising, in combination: a. a blood oxygenator; b. a first tubular membrane and valve pump of a type having a capacity which is variable in proportion to the pump inlet pressure and having a tubular membrane of circular cross-section at rest; c. an inlet of said first pump connectable to a patient''s blood circuit; d. an outlet of said pump connected in series with said oxygenator; e. a second tubular membrane and valve pump of a type having a capacity which is variable in proportion to the pump inlet pressure and the tubular membrane having a substantially elliptical cross-section at rest, the internal perimeter of the tube of the membrane of the second pump being greater than that of the tubular membrane of the first pump, so that the maximum capacity of the first pump and the minimum capacity of the second pump is reached at a pump inlet pressure of atmospheric pressure + or - 20 mm of mercury; f. an inlet of said second pump connected in series with said blood oxygenator; and g. an outlet of said second pump connectable to said patient''s blood circuit.