Pressure modulator for an artificial blood circuit

Claim 1

A PRESSURE MODULATOR FOR AN ARTIFICIAL BLOOD CIRCUIT, SAID MODULATOR COMPRISING, IN COMBINATION: A. AT LEAST ONE RESILIENT WALL DEFINING PART OF A BLOOD CHAMBER; B. AN INLET DUCT AND AN OUTLET DUCT FOR SAID BLOOD CHAMBER; C. A PAIR OF SUBSTANTIALLY RIGID PLATES ARRANGED ONE ON EITHER SIDE OF SAID BLOOD CHAMBER, AND FORMING PART OF SAID RIGID BLOOD EXCHANGER; D. AT LEAST ONE PULSATION CHAMBER DISPOSED ON THE SIDE OF AT LEAST ONE OF SAID PLATES REMOTE FROM SAID BLOOD CHAMBER; AND E. A FLUID PULSE GENERATOR CONNECTED TO SAID AT LEAST ONE PULSATION CHAMBER, EFFECTIVE TO CAUSE SLIGHT FLEXING OF SAID SUBSTANTIALLY RIGID PLATES AND THEREBY PULSING OF LIQUID IN SAID BLOOD CHAMBER, ACCORDING TO A TIME/PRESSURE CURVE WHICH IS VERY CLOSE TO THE PHYSIOLOGICAL CURVE AT A PERIPHERAL ARTERY.

Claim 7

A method of use of a fluid exchanger as a blood exchanger, disposed in an extracorporeal blood circuit, and comprising, in combination: a. a plurality of substantially rigid pairs of plates stacked in overlying relation to one another, each of said plates being substantially rectangular and symmetrical, and comprising a front face and a back face, with the front faces of a pair of plates being in facing relation; b. a pair of semi-permeable membranes between the front faces of each pair of plates, whereby each membrane has a plate adjacent thereto; c. means defining a first exchange zone between each membrane and its adjacent plate; d. means defining a blood exchange zone between the two membranes of a pair; e. means to feed a first liquid to and from the first exchange zone; f. means to feed blood to and from the blood exchange zone; g. at least one flexible wall chamber exerting a uniform controlled pressure on at least a portion of said plates, said flexible wall chamber defining a pulsation chamber; h. a plurality of longitudinal, parallel grooves separated by a plurality of longitudinal parallel ribs defined on said front faces, the ribs of a pair of plates being in register with one another; i. a depression on the back face of each plate of substantially constant cross-section; j. diagonally opposite ducts to feed said first liquid to and from said first exchange zone, said ducts being defined between the back faces of the plates of adjacent pairs and communicating with said depression; k. apertures defined in said plates and communicating said groove with said depression; l. recesses on the front face of said plates communicating with said grooves; and m. diagonally opposite passages, complementary to said ducts, to feed said blood to and from said blood exchange zone; said method comprising varying the pressure of the said at least one flexible wall chamber according to a time/blood pressure curve which is very close to the physiological curve at the level of a peripheral artery.

Claim 8

A method of use of a fluid exchanger as a blood exchanger, disposed in an extracorporeal blood circuit, and comprising, in combination: a. a plurality of substantially rigid pairs of plates stacked in overlying relation to one another, each of said plates being substantially rectangular and symmetrical, and comprising a front face and a back face, with the front faces of a pair of plates being in facing relation; b. a pair of semi-permeable membranes between the front faces of each pair of plates, whereby each membrane has a plate adjacent thereto; c. means defining a first exchange zone between each membrane and its adjacent plate; d. means defining a blood exchange zone between the two membranes of a pair; e. means to feed a first liquid to and from the first exchange zone; f. means to feed blood to and from the blood exchange zone; g. at least one flexible wall chamber exerting a uniform controlled pressure on at least a portion of said plates, said flexible wall chamber defining a pulsation chamber; h. a plurality of longitudinal, parallel grooves separated by a plurality of longitudinal parallel ribs defined on said front faces, the ribs of a pair of plates being in register with one another; i. a depression on the back face of each plate of substantially constant cross-section; j. diagonally opposite ducts to feed said first liquid to and from said first exchange zone, said ducts being defined between the back faces of the plates of adjacent pairs and communicating with said depression; k. apertures defined in said plates and communicating said groove with said depression; l. recesses on the front face of said plates communicating with said grooves; and m. diagonally opposite passages, complementary to said ducts, to feed said blood to and from said blood exchange zone; said method comprising varying the pressure of the said at least one flexible wall chamber according to a time/blood pressure curve which is very close to the physiological curve at the level of a peripheral artery.