Blood collection and centrifugal separation device including a valve
AssigneeEastman Kodak Company
InventorsRichard L. Columbus, Harvey J. Palmer
Life of this patent
Estimating the term…
Abstract
A device is disclosed that causes phase separation of whole blood, using much lower centrifugal forces. As a result, lymphocytes are separated from blood cells having specific gravities of 1.08 g/ml or higher. The device features a separation chamber arranged so that its long dimension or axis is parallel, not perpendicular, to the spin axis, and a valve that allows automatic removal of the lighter phase(s). The valve is constructed to respond only to the head of liquid pressure generated by an increased centrifugal force, and not to that increased force alone.
Claims14
In a liquid phase separation device suitable for phase separation by centrifuging, comprising a chamber with a predetermined volume V, a longest dimension l, and at least one shorter dimension d;
- said chamber having at least a heavier phase-collecting portion and a lighter phase-collecting portion;
- means permitting liquid introduction into said chamber;
- and removing means for removing separated lighter phase out of said chamber after separation without decreasing the centrifugal force used to separate the two-phases;
- the improvement wherein said heavier phase-collecting portion and said lighter phase-collecting portion are disposed so that said longest dimension of said chamber is generally equal to the length of at least one of said collecting portions, and said dimension "d" extends from the lighter phase-collecting portion into said heavier phase-collecting portion,
- and wherein said removing means include valve means for passing said separated lighter phase out of said chamber only in response to a liquid head of pressure created by centrifugal force,
- whereby phase separation for a liquid volume of 500 .mu.L can occur for a spin radius of about 2.5 cm, in less than 2 minutes using a centrifuging force no greater than about 30 g's.
In a two-phase liquid separation device suitable for phase separation by centrifuging, comprising at least one chamber with a predetermined volume V, said chamber having a heavier phase-collecting portion, and a lighter phase-collecting portion;
- inlet means permitting liquid introduction into said chamber;
- and means for removing separated lighter phase out of said chamber including a valve constructed to open at centrifugal forces in excess of those used to separate the lighter phase from the heavier phase;
- the improvement wherein said device further includes means for opening and maintaining said valve open only in response to a liquid head of pressure created by said excess centrifugal forces.
In a two-phase liquid separation device suitable for phase separation by centrifuging, comprising at least one chamber with a predetermined volume V, said chamber having a heavier phase-collecting portion, and a lighter phase-collecting portion;
- inlet means permitting liquid introduction into said chamber;
- and means for removing separated lighter phase out of said chamber including a valve constructed to open at centrifugal forces in excess of those used to separate the lighter phase from the heavier phase;
- the improvement wherein said device further includes means for opening and maintaining said valve open only in response to a liquid head of pressure and further including a second chamber having a heavier phase-collecting portion and a lighter phase collecting portion, said at least one chamber and said second chamber being disposed adjacent to each other, said chambers having a proximal end and a distal end, said chambers being fluidly connected in common to a) said inlet means at said proximal end and b) said removing means at said distal end, so that said chambers act in parallel.
Dependencies are inferred from the claim text.