Methods for separating constituents of biologic liquid mixtures
AssigneeKensey Nash Corporation
InventorsJohn E. Nash, William T. Fisher
Life of this patent
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Abstract
Centrifuges are useful to, among other things, remove red blood cells from whole blood and retain platelets and other factors in a reduced volume of plasma. Platelet rich plasma (PRP) can be obtained rapidly and is ready for immediate injection into the host. Embodiments may include valves, operated manually or automatically, to open ports that discharge the excess red blood cells and the excess plasma while retaining the platelets and other factors. High speeds used allow simple and small embodiments to be used at the patient's side during surgical procedures. The embodiments can also be used for the separation of liquids or slurries in other fields such as, for example, the separation of pigments or lubricants.
Claims22
A centrifuge for selectively concentrating and collecting constituents of a biologic liquid mixture, said constituents having differing specific gravities and being stratifiable in a centrifugal field produced by said centrifuge, said centrifuge comprising:
- a) a chamber arranged to contain a liquid mixture and having a central longitudinal axis about which said chamber is arranged to be rotated to produce said centrifugal field, said chamber comprising:
- (i) a sidewall and an end wall, said side wall tapering radially inward toward said central longitudinal axis in a direction from said end wall;
- (ii) an inlet for adding the liquid mixture to said chamber;
- (iii) a first port in fluid communication with said chamber and located in said assembly at a first predetermined radius from said central longitudinal axis;
- and
- (iv) a second port in fluid communication with said chamber;
- and
- b) a motor to rotate said chamber about said central longitudinal axis to produce said centrifugal field, whereupon said constituents of said biologic liquid mixture in said chamber stratify into at least two concentric stratified constituent layers as a function of the differing specific gravities of said constituents, said at least two concentric stratified constituent layers forming at least one interface between immediately adjacent constituent layers thereof, said at least one interface being detectable in said chamber, and wherein a first of said at least two concentric stratified constituent layers is present at said first port, said first port being selectively openable to enable at least a portion of said first of said at least two concentric stratified constituent layers to be automatically ejected from said chamber through said first port as a result of pressure built up by said centrifugal field and wherein a second of said at least two concentric stratified constituent layers is present at said second port, said second port being selectively openable to enable at least a portion of said second of said at least two concentric stratified constituent layers to be automatically ejected out of said chamber through said second port by said centrifugal field.
A centrifuge for selectively concentrating and collecting constituents of a biologic liquid mixture, said constituents having differing specific gravities and being stratifiable in a centrifugal field produced by said centrifuge, said centrifuge comprising:
- a) a chamber arranged to contain the liquid mixture and having a central longitudinal axis about which said chamber is arranged to be rotated to produce said centrifugal field, said chamber comprising:
- (i) an assembly comprising a side wall and an end wall, each comprising a common central longitudinal axis, said side wall tapering radially inward toward said central longitudinal axis in a direction from said end wall;
- (ii) an inlet for adding the liquid mixture to said chamber;
- (iii) a first port in fluid communication with said chamber and located in said assembly at a first radial distance from said central longitudinal axis;
- and
- (iv) a second port in fluid communication with said chamber and located in said assembly at a second radial distance from said central longitudinal axis, said second radial distance being smaller than said first radial distance;
- b) a motor to rotate said chamber about said central longitudinal axis to produce said centrifugal field, whereupon said constituents of said biologic liquid mixture in said chamber stratify into at least two concentric stratified constituent layers as a function of the differing specific gravities of said constituents, said at least two concentric stratified constituent layers forming at least one interface between immediately adjacent constituent layers thereof, and wherein a first of said at least two concentric stratified constituent layers is present at said first port, said first port being selectively actuatable in response to a first signal, wherein opening of said first port enables at least a portion of said first of said at least two concentric stratified constituent layers to be automatically ejected from said chamber through said first port as a result of pressure built up by said centrifugal field, a second of said at least two concentric stratified constituent layers being present at said second port after opening of said first port, said second port being selectively openable after opening of said first port to enable at least a portion of said second of said at least two concentric stratified constituent layers to be automatically ejected from said chamber through said second port as a result of pressure built up by said centrifugal field;
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- c) a detector for detecting said at least one interface and for providing said first signal in response thereto.
Dependencies are inferred from the claim text.