Closed hemapheresis system and method

A system for extracting lighter matter from a liquid suspension, comprising:

• a closed cell centrifugal separator comprising a fixed housing concentric with a central axis and having a fixed inlet port coupled to receive the liquid suspension, a fixed outlet port spaced apart along the axis from the inlet port, and a coaxial outlet port for the lighter matter, the centrifugal separator comprising rotating interior double shell rotor means within the housing having a centrifugation gap, the rotor being spaced by a flow gap from the housing and including spaced apart aperture means in the outer shell providing communication between the centrifugation gap and the ports in the housing;
• means coupled to the rotor means for rotating the rotor means without mechanical connection through the separator;
• and
• wherein the flow of liquid suspension is relatively unrestricted in the centrifugation gap in comparison to the flow gap.

The method of centrifuging separating constituents of blood with a stationary housing and internal rotor system and without exposure to the environment comprising the steps of:

• feeding whole blood into a limited substantially stationary first volume having a fixed outer periphery defined by the stationary housing and an inner periphery defined by the internal rotor system, the first volume being concentric about a central axis;
• feeding the whole blood from said first volume into a concentric rotating second volume that is defined by the rotor system within the first volume;
• passing heavier matter in the whole blood from the second volume through the first volume in one region;
• passing lighter matter in the whole blood from the second volume along the central axis through the first volume in a second region;
• and
• rotating the rotor system without mechanical connection through the housing.

A system for continuously centrifugally separating lighter constituents of whole blood into packed cells and plasma fractions, comprising:

• a stationary housing having an interior cavity defined principally by an inner wall concentric about a central axis and including a whole blood input port adjacent a first end thereof and a packed cell outlet port adjacent the second end thereof;
• rotor means disposed and rotatable within the interior cavity of the housing, the rotor means including spaced apart outer and inner walls concentric about the central axis, the outer wall being spaced apart from the inner housing wall and including first aperture means adjacent the first end thereof for passing blood to be centrifugally separated into the space between the outer wall and inner wall, the rotor means further including means defining a radial inward path from the space between the outer and inner walls to the central axis at the second end thereof, and a central passageway communicating with the radial inward path and concentric with the central axis, and the rotor means further including second aperture means in the outer wall at the second end thereof;
• means coupled to the rotor means for rotating the rotor means at centrifugation speed within the housing;
• plasma outlet port means in the housing in communication with the central passageway in the rotor means;
• means disposed along the spacing between the outer wall of the rotor means and the inner wall of the housing for restricting passage between the rotor means and housing of the whole blood fed into the inlet port in relation to passage of blood in the space between the rotor outer wall and inner wall;
• and
• wherein the residence time of the blood passing in the centrifugation gap between the inner and outer walls of the rotor means is sufficient relative to the rotational speed to provide a radial gradient between packed cells at the outer radius and platelet rich plasma at inner radii, at the second end thereof, such that packed cells move continuously through the second aperture means in the rotor means and platelet rich plasma moves continuously inwardly to the central passageway.

A system for continuously centrifugally separating platelet rich plasma from cellular matter as whole blood is fed in, comprising:

• double wall rotor means concentric with the vertical axis and the walls defining a vertically ascending centrifugation gap about a central axis, the rotor means including a central passageway concentric with the central axis and means providing a radially inward path from the upper region of the centrifugation gap to the central passageway, the rotor means further including, at the upper end thereof, means for permitting outward flow from the rotor of heavier matter as lighter weight matter moves radially inward to the central passageway;
• housing means disposed substantially concentrically about the rotor means and including a sealed inlet port for input blood adjacent the bottom end of the rotor means, a sealed outlet port for heavier constituents adjacent the upper end of the rotor means, and a sealed outlet port for separated lighter constituents adjacent the lower end of the rotor means and in communication with the central passageway therein;
• means for rotating the rotor means within the housing without external mechanical connection through the housing, at centrifugation speed;
• means in the rotor means for communicating input blood in the lower region of the housing into the centrifugation gap;
• and
• means associated with the outer wall of the rotor means and the housing for providing a differential flow impedance between the centrifugation gap and the spacing between the rotor means and the housing, such as to facilitate upward ascension of blood constituents in the centrifugation gap.

A continuous centrifugation system that is biologically closed and separates lighter from heavier fractions of a liquid input suspension, comprising:

• a stationary housing having a substantially cylindrical cavity disposed about a vertical central axis;
• the housing including a liquid suspension inlet port adjacent a first end thereof and a heavier fraction outlet port adjacent the second end thereof;
• rotor means rotatably mounted within the housing and having spaced apart inner and outer right circular cylindrical walls defining a centrifugation gap between the first and second ends, the rotor means including first aperture means in the outer wall adjacent the first end providing inlet flow into the centrifugation gap and second aperture means in the second end of the outer wall thereof providing outlet flow of heavier fractions;
• the system including means disposed along at least the mid region of the gap between the outer wall of the rotor and the housing for impeding flow of the liquid suspension between the first and second ends;
• means coupled to the rotor means for rotating the rotor means within the housing at centrifugation speeds;
• and
• the rotor means further including means providing central passageway means for lighter fractions moving radially inwardly from the second end of the centrifugation gap along the central axis of the rotor means and an outlet port for lighter fractions coupled to the housing and in communication with the central passageway means in the rotor means.

A system for centrifugal separation of selected constituents of blood without exposure of such constituents to external environment, comprising:

• a stationary housing having an outwardly diverging perimeter extending upwardly from a base portion containing an inlet port and a lower central outlet port, said housing including an upper central outlet port, said lower and upper outlet ports being disposed along the central axis of said housing, and upper and lower end bearings mounted on said central axis adjacent said upper and lower outlet ports, respectively, and including central apertures in said end bearings in communication with said upper and lower outlet ports, and a substantially flat upper end cap closing the upper portion of the housing;
• a rotor having an exterior periphery generally conforming to the periphery of the housing but smaller than said housing and positioned therein to form a first predetermined gap between said rotor and said housing, means mounting said rotor for rotation on the upper and lower end bearings and including a flat upper end cap closing the upper portion of the rotor at the periphery of greatest diameter thereof, an upper conduit in said end cap communicating between the interior of the rotor at the outer periphery of greatest diameter, the central aperture in said upper end bearing and the upper outlet port along the central axis, said rotor further including apertures in the base portion thereof communicating with said inlet port for feeding blood constituents into the interior of the rotor, and a deflector plate disposed in the region of greatest diameter of the rotor at the upper end thereof and disposed adjacent to and substantially parallel to the end cap thereof and defining a passage between the deflector plate and the end cap of the rotor communicating with the upper conduit, thereby to permit heavier matter in the blood constituents to pass from the interior of the rotor through the apertures in said deflector plate and through said last mentioned passage to the upper conduit;
• a core mounted within the rotor, the core having an exterior configuration generally conforming to the periphery of the rotor but smaller than said rotor and forming a second predetermined gap between the rotor and the core, the core having an upper portion spaced from said deflector plate and having a reentrant central conduit in communication with the aperture in said outer end bearing and means mounting said core for rotation on said rotor, the core rotating with the rotor such that lighter matter in the blood constituents within the second gap in the interior of the rotor moves radially inwardly through the passage between the upper portion of said core and said deflector plate, through the reentrant central conduit, the central aperture in said lower bearing and the lower output port, as heavier matter in the blood constituents in the second gap passes through the apertures in said deflector plate as aforesaid.