HK1069353B - Core for blood processing apparatus - Google Patents

Description

Core body of blood treatment equipment

Technical Field

The present invention relates to centrifuge spinnerets for separating blood and other biological fluids. More particularly, the present invention relates to centrifuge spinnerets having improved cores that aid in the separation and collection of various blood components from whole blood.

Technical Field

It is known in the art to transfuse blood with whole blood, but the current trend is to collect and infuse only those blood components or constituents that are required by a particular patient. Human blood consists mainly of three specialized cells-red blood cells, white blood cells and platelets-suspended in a complex aqueous solution of proteins and other chemical components called plasma. Current methods of using apheresis protect the available blood source and in many cases, would be more beneficial to the patient because the patient is no longer unnecessarily exposed to other blood components and thus does not have to worry about the risk of infection or adverse reactions that may result from the infusion of other blood components. The more common blood components in transfusions are red blood cells and plasma. For example, plasma transfusions are commonly used to replenish lost coagulation factors. Indeed, about two million plasma units are delivered annually in the united states alone. The collected plasma is also fractionated into its constituent components, including proteins such as factor VIII, albumin, immune serum globulin, and the like, for storage.

One method of separating whole blood into its constituent components, including plasma, is by "bag" centrifugation. According to this method, one or more units of anticoagulated whole blood are collected in a blood bag. The blood bag is then inserted into a laboratory centrifuge and spun at ultra high speed, subjecting the blood to many times the force of gravity. This results in the stratification of the various blood components by their density. In particular, components of higher density, such as red blood cells, are separated from components of lower density, such as white blood cells and plasma. The individual blood components can then be expressed from the blood bag and collected separately.

Another separation method is called rotor centrifugation. U.S. patent 4,983,158 "' 158," issued to Headley at 1, 8, 1991, discloses an eccentric rotor having a seamless rotor body and an inner core body that includes four peripheral grooves at the top of the core body. The centrifugal rotary head is inserted into the chuck, and the chuck rotates at a high speed. Centrifugation using this device is performed by drawing whole blood from a donor, mixing anticoagulant in the blood and pumping it into a rotating centrifuge bowl. The denser red blood cells are forced radially outward from the central axis of the rotor and collected along the inner wall of the rotor. The less dense plasma is forced out through the outlet of the rotor and collected separately.

The centrifugal rotor of the' 158 patent may also be used to perform apheresis. Apheresis is a process in which whole blood is drawn from a donor and the desired blood components are separated, collected and the other blood components returned to the donor. By returning certain blood components (e.g., red blood cells) to the donor, a large amount of other components (e.g., plasma) can generally be collected.

Despite the high separation efficiency of centrifugal systems in general, the collected plasma may contain some residual blood cells. For example, in the case of disposable kits using molded centrifuge spinners, the collected plasma typically contains 0.1 to 30 white blood cells and 5,000 to 50,000 platelets per microliter. This is due at least in part to the rotational speed limit of the rotor and the need to maintain the fill rate of the rotor above 60 milliliters per minute (mL/min) to shorten the collection time, thus causing some remixing of the blood components within the rotor.

Another method for separating whole blood into its various components is membrane filtration. The membrane filtration process typically contains either internal or external filtration media. Baxter U.S. patent 4,871,462 ("the' 464 patent") provides an example of a membrane filtration system using internal filtration. The device of the' 462 patent includes a filter having a stationary cylindrical container with a rotatable cylindrical filter membrane disposed therein. The container together with the membrane forms a narrow gap between the side wall of the container and the filter membrane. Whole blood is introduced into the narrow gap during apheresis. Rotating the inner filter membrane at a sufficient speed generates a so-called taylor vortex in the fluid. The presence of taylor vortices essentially causes shear forces that drive plasma across the membrane while sweeping red blood cells away.

Prior art membrane filtration devices often produce relatively pure blood products (e.g., plasma) with little residual cells (e.g., white blood cells). However, they typically contain many complex parts that can be costly, making them difficult and expensive to manufacture. In contrast, prior art centrifugation devices are typically inexpensive to manufacture because they are simple in design and require fewer parts and/or materials. These devices, however, are not capable of producing blood components of the same purity characteristics as the membrane filtration devices.

Centrifugation and membrane filtration can also be combined into a blood processing system. For example, FIG. 1 shows a rotor centrifugation system 100 that also includes an outer filter media 142. The system 100 includes a disposable harness 102 loaded onto a blood processing machine 104. The harness 102 includes a phlebotomy needle 106 for drawing blood from a donor's arm 108, an anticoagulant container 110, a temporary Red Blood Cell (RBC) storage bag 112, a centrifuge bowl 114, a primary plasma collection bag 116, and a finished plasma collection bag 118. An inlet line 120 connects the phlebotomy needle 106 to an inlet 122 of the hub 114, and an outlet line 124 connects an outlet 126 of the hub 114 to the primary collection bag 116. The filter 142 is disposed in a secondary outlet line 144 that connects the primary and product plasma collection bags 116 and 118. The blood processing machine 104 includes a controller 130, a motor 132, a centrifuge chuck 134, and two peristaltic pumps 136 and 138. The controller 130 is operatively connected to two pumps 136 and 138 and to the motor 132, which motor 132 in turn drives the chuck 134.

In operation, the inlet line 120 is fed by the first peristaltic pump 136 and a feed line 140 from the anticoagulant 110 connected to the inlet line 120 is fed into the chuck 134. Phlebotomy needle 106 is then inserted into donor's arm 108 and controller 130 activates peristaltic pumps 136 and 138 to mix the anticoagulant with the whole blood drawn from the donor and deliver the anticoagulated whole blood via input line 120 into centrifuge bowl 114. The controller 130 also activates the motor 132 to rotate the turret 114 at high speed via the chuck. Rotation of the rotor 114 causes the whole blood to separate into separate layers by density. Specifically, the denser red blood cells accumulate at the periphery of the bowl 114, while the less dense plasma forms an annular ring-shaped layer within the red blood cells. The plasma is forced out through an outlet port (not shown) of the rotor 114 and out an outlet port 126. From which plasma is delivered to the primary collection bag 116 by an outlet line 124.

When all of the plasma is removed and the bowl 114 is full of RBCs, it is common to shut down and reverse the first pump 136 to transfer RBCs from the bowl 114 to the temporary RBC collection bag 112. Once the rotor 114 is emptied, collection and separation of whole blood from the donor is resumed. At the end of the process, the RBCs in the turn 114 and temporary collection bag 112 are returned to the donor via the phlebotomy needle 106. The primary plasma collection bag 116, now filled with plasma, is then processed. Specifically, a valve (not shown) is opened to allow plasma to flow through the secondary outlet line 114, through the filter 142, and into the product plasma collection bag 118.

Although the binding system shown in fig. 1 can produce purer blood products compared to conventional centrifugation, the production costs are prohibitive.

Disclosure of Invention

Briefly, the present invention is directed to a centrifugal rotor with a rotating core of novel construction. The centrifugal rotor includes a rotating rotor body forming a primary separation chamber. A stationary head assembly is mounted on top of the bowl body via a rotary seal. The stationary head assembly includes an input port for receiving whole blood and an output port from which one or more blood components are removed. The input port is in fluid communication with a feed tube extending into the primary separation chamber. The output port is communicated with an outflow pipe extending into the rotary head body. The outflow conduit includes an inlet passage at a first radial position relative to the central axis of rotation of the swivel. A generally cylindrical core is also disposed within the rotor head and defines a secondary separation chamber therein. At least one partial core is arranged at a second radial position outwardly from the inlet channel to the outlet pipe and comprises one or more channels for providing a fluid connection between the primary and secondary separation chambers.

In accordance with the invention, the core has a seal at the upper edge relative to the connection point of the contra-rotation head of both the head assembly and the core. The sealing zone is free of any perforations, grooves or holes and extends substantially the axial length of the core, for example one quarter or more of the core length. Adjacent to the sealing region is a fluid transfer region which may extend the remainder of the length of the core, for example three quarters of the core length. One or more channels, which in one particular embodiment are circular holes, are located in the fluid-conveying region of the core. By incorporating an upper solid area without any perforations, slots or holes, the upper passageway through the core is remotely located relative to the connection point of the head assembly and core.

When in operation, the rotating head is rotated by the centrifugal chuck. Anticoagulated whole blood is fed into the input port and into the bowl body via the feed tube. The centrifugal force created in the separation chamber by the rotation of the rotor causes the whole blood to separate into its separate components in the primary separation chamber. In particular, the denser red blood cells form a first layer around the periphery of the rotor body, while the remaining components, which are less dense than the red blood cells and consist essentially of plasma, form an annular ring-shaped layer within the red blood cell layer. As more whole blood is fed into the bowl body, the annular plasma layer continues to close inside and eventually contacts the core. The plasma layer, which includes some non-plasma blood components, passes through the channels in the transport region of the core and then into the secondary separation chamber.

In the secondary separation chamber, the same centrifugal force created by the rotation of the rotor causes the plasma components to further separate from the non-plasma blood components within the core. The separated plasma in the secondary chamber is driven towards the inlet passage of the outlet tube where it is removed from the rotor. The combination of the sealing zone and the transfer zone helps to establish a more uniform flow pattern, thereby facilitating further separation of plasma in the secondary separation chamber. The non-plasma components that enter the secondary separation chamber are preferably remote from the outflow tube and may even be forced back into the primary separation chamber via additional channels in the transport region of the core. To collect other blood components than plasma, the rotor is rotated to allow the collection of platelets, white blood cells and/or red blood cells.

Drawings

The above features of the present invention can be understood readily by reference to the following detailed description when considered in connection with the accompanying drawings in which:

as discussed above, fig. 1 is a block diagram of a apheresis blood transfusion system;

FIG. 2 is a block diagram of a blood processing system according to the present invention;

FIG. 3 is a cross-sectional view of the centrifuge rotor shown in FIG. 2 illustrating one particular embodiment of the core of the present invention;

FIG. 4 is a partial cross-sectional view of the centrifuge rotor taken along line 4-4 of FIG. 3;

FIGS. 5-7 are side elevational views, partially in section, of alternate configurations of the core of the present invention;

FIG. 8 is a side elevational view, partially in section, of a second alternate configuration of the core of the present invention; and

figures 9 and 10 are side views, partially in section, of the alternative configuration of the core shown in figure 8.

Detailed description of the specific embodiments

In this specification and the appended claims, the following terms have the meanings indicated, unless the context requires otherwise:

fig. 2 is a block diagram of a blood processing system 200 according to the present invention. The system 200 includes a disposable collection kit 202 that may be loaded onto a blood processing machine 204. The collection kit 202 includes: a phlebotomy needle 206 for drawing blood from a donor's arm 208; an anticoagulant container 210, such AS AS-3 manufactured by MedSep, a division of Pall corporation; a temporary Red Blood Cell (RBC) storage bag 212 (optionally configured according to the collected blood components and the number of operations performed); a centrifugal rotor 214; and a finished plasma collection bag 216. An input line 218 connects the phlebotomy needle 206 to an inlet 220 of the bowl 214, and an output line 222 connects an outlet 224 of the centrifuge bowl 214 to the plasma collection bag 216. Feed line 225 connects anticoagulant 210 to input line 218. The blood processing machine 204 includes a controller 226, a motor 228, a centrifuge chuck 230, and two peristaltic pumps 232 and 234. The controller 226 is operably connected to two pumps 232 and 234 and to a motor 228, the motor 228 in turn driving a chuck 230.

An example of a blood processing machine suitable for use in the present invention is the PCS sold by Haemonetics Corporation of Braintree, Mass^®Provided is a system.

Structure of centrifugal rotor head of the invention

Fig. 3 is a side cross-sectional view of the eccentric rotor 214 of the present invention. The rotor 214 includes a generally cylindrical rotor body 302 that forms an enclosed primary separation chamber 304. The turret body 302 includes a base 306, an open top 308, and sidewalls 310. The swivel 214 also includes a head assembly or cap assembly 312 that is mounted to the top 308 of the swivel body 302 via an annular rotary seal. The head assembly 312 includes an input port 220 and an output port 224. Extending from head assembly 312 into separation chamber 304 is a feed tube 316 in fluid communication with inlet port 220. The feed tube 316 has an opening 318 that is preferably disposed proximate the base 306 of the turret body 302 when the head 312 is mounted on the turret body 302. The head assembly 312 also includes an output port, such as an outlet tube 320 disposed within the swivel 214. The outlet tube 320 may be placed proximate the top 308 of the turret body 302. In a particular embodiment, the outlet tube 320 is formed by a pair of spaced disks 322a and 322b, the pair of disks 322a and 322b forming a passage 324 with a generally circular inlet passage 326 at a first radial position R1 relative to the central axis of rotation a-a of the swivel 214.

One suitable head assembly and swivel body for use in the present invention is described in U.S. patent 4,983,158 ("the' 158 patent") issued to Headley, which is incorporated herein by reference in its entirety. It should be understood, however, that other swivel configurations may also be advantageously used with the present invention.

Disposed within the bowl body 302 is a core 328 that is a generally cylindrical outer wall 330, the outer wall 330 having an outer surface 325 and an inner surface 327 relative to the axis A-A. The outer wall 330 is alternatively at least partially preferably disposed at a second radial position R2 slightly outside of the first radial position R1, the first radial position R1 forming the inlet passage 326 of the passage 324, as described above. Core 328 may, but need not, include an inner wall 340 that can be bonded to inner surface 327 of outer wall 330 directly or through sleeve 342. The inner wall 340, including the first and second ends 343 and 344 opening into the receiving feed tube 316, may be of a conical configuration or may take the form of a truncated cone. As described in greater detail below, core 328 forms a secondary separation chamber 360 located within outer wall 330 relative to axis a-a. Secondary separation chamber 360 may be bounded by outer wall 330, sleeve 343, and inner wall 340.

Fig. 3A is an enlarged view of a portion of the rotor and core of fig. 3. As shown, the turret head 308 defines an opening 366 that receives the core 328 therein when the turret is assembled. The turret head 308 may also define a neck 380 that extends at least partially axially and defines an inner surface 380 a. The upper portion 382 of the core 328 matingly engages the inner surface 380a of the swivel neck 380 to provide a fluid seal therebetween. That is, the upper core portion 382 may fit against the inner surface 380a of the neck 380. As a result, core 328 has an overall axial length "L" and an effective axial length "U" defined as the portion of core 328 that extends into primary separation chamber 304. The effective length "U" is substantially equal to the total length "L" minus the axial length of the whip neck 380.

In one particular embodiment, the effective length "U" of the core 328 extends substantially along the axial length of the swivel body 302 (e.g., about 50% or more). The core 328 is preferably symmetrical about the axis of rotation. In other words, when core 328 is inserted into turret body 302, the axis of core 328 is aligned with the axis of rotation A-A. Core 328 has a top 364 that may be proximate to open top 308 of the turret body 302 when inserted into the turret body 302. According to the present invention, the outer wall 330 includes a sealing region 370 and a fluid transfer region 372. The sealing region 372 is free of any perforations, grooves or holes. Disposed within fluid delivery zone 372 of core 328 is at least one core passage, generally designated 332, extending from outer wall 330. Channel 332 allows fluid communication between primary separation chamber 304 and secondary separation chamber 360. Further, fluid may flow from the secondary separation chamber 360 to the outlet tube 320 (fig. 3), and thus be withdrawn from the swivel 214 via the outlet port 224 of the head assembly 312.

The sealing region 370 of the core 328 preferably extends over a substantial axial length "H" of the core 328. More specifically, the axial length "H" of the sealing region 370 is greater than about 15% of the effective length "U" of the core 328. Preferably, "H" is about 15-60%, and more preferably about 25-33%, of the effective length "U" of core 328. The fluid delivery zone 372 is configured for the remainder of the effective length "U" of the core 328. In other words, the length of the fluid transfer zone 372 is "U" minus "H". For a core 328 having an effective axial length "U" of about 75 millimeters (mm), the length "H" of the sealing region 370 is preferably in the range of about 11-45 mm. In a particular embodiment, the length "H" is about 20 mm.

In a particular embodiment, a plurality of channels are formed along the transport zone 372 of the outer wall 330 of the core 328, including at least one (and preferably two) lower core apertures 344a and 344b (FIG. 3) on opposite sides of the outer wall 330 relative to the turret base 306, and at least one (and preferably six) upper core apertures 335a-b, 336a-b, and 337a-b also generally formed on opposite sides of the outer wall 330 relative to the turret top 308. Although fig. 3 shows upper core apertures 335, 336, and 337 equally spaced axially along outer wall 330, it should be appreciated that the axial and circumferential spacing of upper core apertures 335, 336, and 337 from one another is immaterial. Because the sealing region 370 is devoid of any holes, channels, or apertures, the channels 325a-b uppermost in the core 328 relative to the crown 308 are spaced a distance away from the crown 308 and/or the head assembly 312.

In addition, at least some of the uppermost passageways 325a-b, 326a-b and 327a-b are also spaced a radial distance "D" inwardly relative to the opening 366 in the turret head 308. For an opening 366 having a diameter of 49mm, the distance "D" is preferably in the range of about 0-25mm or 0-63% of the opening 366 in the swivel body 302. In a particular embodiment, the distance "D" is about 0.5 to 15mm or 1.3 to 31%, and more particularly about 3.3mm or 8% of the diameter of the core 328.

Core passage configurations that may be used within the scope of the present invention include slots and/or round holes. When the core passage 332 is a slot, the size of the slot may vary. For example the axial length of the grooves may be 1 to 64 mm. When the core passage 332 is a circular hole, its diameter may be 0.25 to 10 mm. In a particular embodiment, core passage 332 is a hole having a diameter of about 0.5-4mm, more particularly, a diameter of 1.0 mm.

In addition to incorporating the sealing zone 370, the inner surface 327 of the outer wall 330 is preferably axially sloped rather than parallel to the axial direction. More specifically, the slope of inner surface 327 may be determined by an angle α extending from a line 366 parallel to axis of rotation A-A toward inner surface 327 of outer wall 330. The angle of inclination a of inner surface 327 may be between about +10 degrees and-10 degrees, i.e., inner surface 327 may have a reverse slope. In a particular embodiment, α is between about +2 degrees and-2 degrees, and more particularly about 10 degrees. The outer surface 325 of the outer wall 330 may also be an angle β extending from a line 374 parallel to the axis of rotation a-a to the outer surface 325 of the outer wall 330. The angle of inclination β of the outer surface 325 may be between about 0 degrees and 15 degrees. In a particular embodiment, there is no slope in the outer wall 325.

For an outer wall 330 of uniform thickness, the sloped inner surface 327 also results in the same slope imposed on the outer surface 325. Alternatively, outer wall 330 may be tapered in thickness so that outer surface 325 remains parallel to axis of rotation A-A while inner surface 327 is tilted. The outer wall 330 may also taper in thickness in a manner such that both the inner surface 327 and the outer surface 325 are inclined relative to the axis of rotation a-a.

The inner wall 340 may be slightly shorter in length than the outer wall 330 and may be of uniform thickness. Where inner wall 340 is provided, lower core apertures 334a-b are formed on outer wall 330 such that they provide fluid communication from primary separation chamber 304 into secondary separation chamber 360 proximate sleeve 342. The core 328 is preferably formed of a biocompatible material, such as high density polystyrene or polyvinyl chloride (PVC), and has a generally smooth surface.

Operation of the invention

The following discussion illustrates the operation of the present invention for collecting plasma from a whole blood sample. However, it should be recognized that plasma is only one blood component that can be separated using the centrifuge bowl and core of the present invention. It is also possible in the described manner to simply continue working to collect platelets and white blood cells after the plasma component has been removed. Given the relative densities of the blood components, it is also recognized that by continuing the operation of the present invention, platelets will be removed first, followed by white blood cells. It will also be appreciated that the present invention provides red blood cells that are purer than other centrifugation devices heretofore known in the art because the red blood cells remaining in the primary separation chamber after removal of other whole blood components will contain less residual whole blood elements. Thus, while the following discussion details the operation of the present invention, it is in no way limited in its application to the collection of plasma from whole blood alone.

In operation, a disposable collection set 202 (FIG. 2) is loaded onto a blood processing machine 204. Specifically, it is provided that input line 218 passes through first pump 232 and feed line 225 passes from anticoagulant container 210 through second pump 234. The eccentric rotor 214 is securely mounted to the chuck 230 while the head assembly 312 is stationary. The phlebotomy needle 206 is then inserted into the donor's arm 208. The controller 226 then activates the pumps 232 and 234 and the motor 228. Pumps 232 and 234 are operated to mix whole blood from a donor with anticoagulant from container 210 and deliver the mixture to input port 220 of turret 214. Operation of the motor 228 drives the chuck 230, and the chuck 230 rotates the turret 214. Anticoagulated whole blood flows out of feed tube 316 (fig. 3) and into primary separation chamber 304.

The centrifugal force generated within the rotating rotor 214 pushes the blood toward the side wall 310 of the primary separation chamber 304. Continued rotation of the rotor 214 causes the blood in the primary separation chamber 304 to separate into separate layers by density. Specifically, the densest RBC of whole blood forms a first layer 346 to the perimeter of the sidewall 310. RBC layer 346 has a surface 348. Within the RBC layer 346 relative to axis a-a, the layer 350 also has a surface 352. A buffy coat 354 containing white blood cells and platelets may also form between the RBC and plasma 346 and 350 layers.

As additional anticoagulated whole blood is delivered to the primary separation chamber 304 of the rotor 214, each layer 346, 350, and 354 "grows" and the surface 353 of the plasma layer 350 moves toward the central axis a-a. When sufficient whole blood is introduced into the primary separation chamber 304, the surface 352 of the plasma layer 350 contacts the cylindrical outer wall 330 of the core 328 and enters the secondary separation chamber 360 by passing through the core passage 332 (i.e., core apertures 334-337).

Despite the configuration of the channel 332, plasma entering the secondary separation chamber 360 may include residual blood components, such as white blood cells and platelets. However, once inside the secondary separation chamber 360, the plasma 350 undergoes a further rotation of the rotor 214 and core 328 for a secondary separation process and a second plasma layer 356 (fig. 4) is formed. The second plasma layer 356 is further purified from non-plasma components that may enter the secondary separation chamber 360 via the passage 332 in the same manner as the separation process that takes place in the primary separation chamber 304. That is, the same centrifugal force generated by the rotation of the turret 214 and core 328 that pushes the denser red blood cells away from the axis of rotation A-A and toward the turret wall 310 forces the non-plasma components in the secondary plasma layer 356 away from the axis of rotation A-A and toward the sloped inner surface 327 or outer wall 330.

As shown in fig. 4, the combined effect of the forces generated by the rotation of the swivel 214 and core 328, and the downward inclination of the inner surface 327 of the outer wall 330, causes the residual non-plasma components 354 to move toward the sleeve 342, away from the outflow tube 320, and enables the formation of a pure second plasma layer 356 within the secondary separation chamber 360. The non-plasma components may even exit the secondary separation chamber 360 uniformly through the lower core apertures 334a-b and return to the primary separation chamber 304. While the non-plasma components 354 are forced out of the secondary separation chamber 360, the relatively pure plasma layer 356 "climbs" the sloped inner surface 327 of the upper outer wall 330 until sufficient pressure head is generated to "push" the plasma into the inlet channel 326 of the inlet/outlet conduit 320 as indicated by arrow P (fig. 4). From there, plasma is removed from the bowl 214 via the outlet port 224 and carried into the plasma collection bag 216 via the outlet line 222 (fig. 2).

As additional anticoagulated whole blood is delivered to the bowl 214 and separated plasma is removed, the thickness of the RBC layer 346 will grow. When the surface 348 of the RBC layer 346 reaches the core 328, indicating that all of the plasma in the primary separation chamber 304 has been removed, the process is preferably paused.

The fact that the surface 348 of the RBC layer 346 reaches the core 328 can be optically detected. Specifically, outer wall 330 of core 328 may include one or more light detectors 358 (fig. 3), which may extend around the entire circumference of core 328. The reflector 358 may be generally triangular in cross-section and forms a reflective surface 358 a. Reflector 358 cooperates with a light emitter and detector (not shown) located in blood processing machine 204 to detect the presence of RBCs at preselected points relative to core 328, resulting in a corresponding signal being delivered to controller 226. The controller 226 suspends processing in response.

It should be understood that the optical components and controller 226 may be configured to suspend the rotaryhead filling under other conditions and/or upon detection of other blood components.

Specifically, the controller 226 turns off the pumps 232 and 234 and the motor 228, thereby stopping the swivel 214. Without centrifugal force, the RBCs in layer 346 fall to the bottom of the bowl 214. That is, RBCs deposit onto the bottom of primary separation chamber 304 opposite head assembly 312, and the non-plasma components in secondary separation chamber 360 exit secondary separation chamber 360 and pass through lower core orifice 334 into bowl body 302.

After waiting for sufficient time for RBC to settle in the stopped bowl 214, the controller 226 reverses the start of the pump 232. This causes the RBCs in the lower portion of the turret 214 to be drawn up the feed tube 316 and out of the turret 214 through the input port 220. The RBCs are then transported via a transfer line 218 into a temporary RBC storage bag 212. It should be understood that one or more valves (not shown) may be operated to ensure that RBCs are delivered to bag 212. To facilitate emptying RBCs from the bowl 214, the configuration of the sleeve 342 preferably allows air from the plasma collection bag 216 to easily enter the primary separation chamber 304. That is, the sleeve 342 is spaced from the feed tube 316 such that it does not block the flow of air from the outlet tube 320 to the separation chamber 304. Air is not required to bridge the wet core 328 to empty the RBCs. It should be appreciated that such a sleeve 342 is constructed and arranged to also facilitate the emptying of air from the separation chamber 304 during the filling of the swivel.

After all the RBCs have been transferred from the bowl 214 to the temporary storage bag 212, the system 220 is ready to begin the next plasma collection session. Specifically, the controller 226 again activates the pumps 232 and 234 and the motor 228. To "clean" the core 328 prior to the next operation, the controller 226 preferably activates the pumps 232 and 234 and the motor 228 in such a manner (or in such a sequence) that the rotor 214 is rotated at its operating speed for a period of time before additional anticoagulated whole blood is allowed to reach the primary separation chamber 304. This rotation of the swivel 214 and core 328 forces residual blood cells that may adhere or be "trapped" in the secondary separation chamber 360 to flow down the chamber 360 and out of the core 328 through the lower core aperture 334. Thus effectively "cleaning" the residual blood cells that may have adhered to their surfaces in the previous operation, and then performing the plasma collection process as previously described.

Specifically, anticoagulated whole blood is separated into its constituent components in the primary separation chamber 304 of the bowl 214, while plasma is pumped through the core 328. The separated plasma is removed from the bowl 214 and transferred along outlet line 222 to plasma collection bag 216 where it is added to the plasma collected in the first session. When the primary separation chamber 304 of the turret 214 is again filled with RBCs (detected by the optical detector), the controller 226 stops the collection process. Specifically, the controller 226 turns off the pumps 232 and 234 and the motor 228. If the treatment is complete (i.e., the desired amount of plasma is donated), the system returns the RBCs to the donor. Specifically, the controller 226 reverses the activation of the pumps 232 and 234 to pump RBCs from the bowl 214 and from the temporary storage bag 212 through the input line 218. RBCs flow through venous blood collection needle 206 to return to the donor.

After returning the RBCs to the donor, the venous needle 206 can be removed and the donor removed. The plasma collection bag 216 now filled with separated plasma can be detached from the disposable collection set 202 and sealed. The remainder of the disposable set 202, including the needle, the bags 210, 212, and the swivel 214, can be discarded. The separated plasma is sent to a blood bank or hospital or a fractionation center for producing various components from the plasma.

In one embodiment, system 200 includes one or more devices for detecting whether core 328 is clogged. In particular, the blood processing machine 204 may include one or more conventional fluid flow sensors (not shown) coupled to the controller 226 for measuring the flow of anticoagulated whole blood into the bowl 214 and separating the flow of blood out of the bowl 214. The controller 226 preferably monitors the output of the flow sensor and if the flow of whole blood exceeds the flow of plasma for a period of time, the controller 226 preferably suspends the collection process. The system 220 may also include one or more conventional line sensors (not shown) that detect the presence of red blood cells in the output line 222. The presence of RBCs in outlet line 222 may indicate that blood components in separation chamber 304 overflow sleeve 342.

It should be understood that the core 328 of the present invention may have other configurations. Fig. 5-7 illustrate various other core configurations.

For example, fig. 5 is a side cross-sectional view of another core 500. In this embodiment, the core 500 has a generally cylindrical shape forming an outer wall 502, a first or upper open end 504, and a second or lower open end 506. The outer wall 502 includes three pairs of opposing upper core apertures 512 and a pair of opposing lower core apertures 526, the pair of lower core apertures 526 providing fluid communication through the outer wall 502, similar to the embodiment of fig. 3. Core 500 further includes an inner wall 530 and a sleeve 518 disposed between inner wall 520 and inner surface 524 of outer wall 502. In this embodiment, the inner wall 520, the sleeve 518, and the inner surface 524 of the outer wall 502 cooperate to form the second separation chamber 514.

The outer wall 502 also has an outer surface 508. Formed on the outer surface 508 are a plurality of spaced apart ribs 510. That is, the ribs 510 may extend circumferentially around all or a portion of the outer surface 508 of the wall 502. The spacing between adjacent ribs 510 preferably forms respective channels 516 leading into the apertures 512 and 526.

Fig. 6 is a side cross-sectional view of another core 600, which is a variation of the core construction 500 of fig. 5. The core 600 of this embodiment similarly includes an outer wall 602, an inner wall 620, and a sleeve 618 disposed between the inner wall 620 and an inner surface 624 of the outer wall 602. The inner wall 620, the sleeve 618, and the inner surface 624 of the outer wall 602 cooperate to form the second separation chamber 614. In this embodiment, the core 600 further includes a plurality of ribs 610 and a plurality of core holes 612 arranged substantially along the axial length of the outer wall 602 of the core 600. That is, rather than providing one or more upper core holes and one or more lower core holes, a series of core holes 612 are relatively evenly distributed along the axial length of core 600. However, the uppermost core hole, such as hole 612, is spaced from the first opening 620 in the core 600 in the manner described for core 500.

Fig. 7 is a side cross-sectional view of another core 700, which is another variation of the core configuration of fig. 5. In this embodiment, the core 700 includes an outer wall 702, an inner wall 706, and a sleeve 712 disposed between the inner wall 706 and an inner surface 716 of the outer wall 702. Inner wall 706, sleeve 712, and inner surface 716 of outer wall 702 cooperate to form a second separation chamber 714. A pair of lower core apertures 710 preferably extend through the outer wall 702 of the proximal sleeve 712. A pair of upper core apertures 708 preferably extend through the outer wall 702 in spaced relation relative to the first open end 720. As shown, the sleeve 712 is positioned higher in the core 700. The truncated cone formed by the inner wall 706 is thus disposed approximately in the upper third or half of the core 700, as opposed to extending substantially the axial length through the core in other embodiments.

Fig. 8-10 illustrate another configuration of the core. Fig. 8 is a side cross-sectional view of the core 800 and the rotor 830. More specifically, the core 800 includes an outer wall 804 forming an inner surface 810. A pair of upper core holes 806 are disposed on the core 800 adjacent to the sealing region 812. The inner surface 810 of the outer wall 802 is angled away from the head assembly 840. In operation, plasma passes through the second series of core holes 806 in the manner described above. Once inside the secondary separation chamber 808, the plasma is further separated by continuing to rotate the rotor 830 and core 800 to form a "purer" plasma layer. Also, the inclination of the inner surface 810 causes the remaining cells to move down the outer wall 804 and out through the lower core hole 802 in a manner similar to that described above. As shown, the core 800 does not include an inner wall.

It should be understood that only a single channel 806 may be formed in the core 804.

Fig. 9 is a side cross-sectional view of a core 900, which is a variation of the core construction 800 shown in fig. 8. In this embodiment, core 900 includes an outer wall 906 having an inner surface 908, the inner surface 908 forming a secondary separation chamber 909. A plurality of ribs 902 may be disposed around the outer wall 906 of the core 900. As with the core 600 of the embodiment of fig. 6, a series of core holes 904 are relatively evenly distributed along the axial length of the core 600.

FIG. 10 is a side cross-sectional view of yet another variation of the core body 900 shown in FIG. 9, wherein the core body 900 includes a sleeve 910 that forms a sleeve via 912. In this embodiment, core 900 does not include an inner wall. Also, the sleeve via 912 is designed, e.g., sized, to receive the feed tube from the head assembly. It is also sized to prevent whole blood from splashing back into the core.

One of ordinary skill in the art will appreciate that other configurations of the core are possible, so long as the plasma is forced through the core before it reaches the outlet port. For example, one of ordinary skill in the art will also recognize that the filter media may be wrapped or otherwise positioned around the outer wall of the core. Alternatively, one skilled in the art will recognize that the filter media is integrated or incorporated into the core structure. Those embodiments having ribs are particularly suitable for additional filtration media or membranes. A filter media may also be placed within the core to filter blood components entering the secondary separation chamber.

It will also be appreciated that the core of the present invention may be stationary relative to the rotatable turret body. That is, the core may also be secured to the head assembly rather than to the rotor body. It should also be understood that the core of the present invention may be incorporated into a build rotor having different geometric states, including the bell-shaped Latham series of build rotors available from Haemonetics corporation. Also, the core may be conically shaped (i.e., have a wall of uniform thickness, but shaped like an hourglass, for example). In addition, the outer wall of the core may have a slope opposite to that described herein.

The foregoing description has been directed to specific embodiments of this invention. It will be apparent that other variations and modifications may be made to the described embodiments, with the attainment of some or all of their advantages. Accordingly, the foregoing description is by way of example only and is not intended as limiting. It is intended that the appended claims cover all such variations and modifications as fall within the true spirit and scope of this present invention.

Claims (19)

1. A blood processing centrifugation bowl (214) for separating whole blood into components, the bowl comprising:

a rotor body (302) rotatable about an axis, the rotor body having an open end (308) and a base (306) forming a primary separation chamber (304);

a head assembly (312) received within the open end of the swivel body;

an output port (224) disposed within the body for removing one or more blood components from the body; and

a core (328) disposed within the swivel body, the core forming a secondary separation chamber (360) and including an outer wall (330) at least a portion of which is external to the output port relative to the axis of rotation, the outer wall having a sealing region (370) disposed in an upper portion of the core relative to the head assembly and a fluid delivery region (372) contiguous with the sealing region, and

at least one core passage (332) extending through the outer wall within the fluid transfer region (372) for providing fluid communication between the primary separation chamber and the output port;

the sealing area (370) is free of any perforations, grooves or holes;

the core (328) has an effective axial length (U) projecting into the primary separation chamber, the seal region has an axial length (H), and the length of the seal region is 15-60% of the effective length of the core; and

the outer wall (330) of the core has an inner surface (327) relative to the axis of rotation and the inner surface is inclined to form an angle of inclination a relative to the axis of rotation, the angle of inclination a being in the range of +10 degrees to-10 degrees.

2. The blood processing centrifugation bowl of claim 1, wherein the core (328) has an effective axial length (U) that extends into the primary separation chamber, the sealing region has an axial length (H), and the length of the sealing region is 25-33% of the effective length of the core.

3. The blood processing centrifugation bowl of claim 1, wherein the angle of inclination α is between +2 and-2 degrees.

4. The blood processing centrifugation bowl of claim 2, wherein the angle of inclination α is 1 degree.

5. The blood processing centrifugation bowl of claim 4, wherein the core is mounted on a bowl body that rotates therewith.

6. The blood processing centrifugation bowl of claim 5, wherein the outlet port is an outlet tube including an inlet channel (326), and at least a portion of the core is located outside of the inlet channel relative to the axis of rotation.

7. The blood processing centrifugation bowl of claim 6, wherein the outer wall of the core is coaxially aligned about and disposed outside of the inlet channel of the outflow tube relative to the axis of rotation.

8. The blood processing centrifugation bowl of claim 1, wherein at least one core channel (332) abuts the sealing region.

9. The blood processing centrifugation bowl of claim 1 having a plurality of core channels (334b, 335b, 336b) formed in the fluid transfer region of the core.

10. The blood processing centrifugation bowl of claim 9, wherein at least some of the core channels (335b) abut the sealing region.

11. The blood processing centrifugation bowl of claim 10, wherein the outer wall includes at least two upper core apertures formed in an upper portion of the outer wall.

12. The blood processing centrifugation bowl of claim 9, wherein the core further includes an inner wall (340) relative to the axis of rotation, the inner wall being attached to the outer wall, extending axially within the outer wall, and being devoid of any perforations, slots, or holes.

13. The blood processing centrifugation bowl of claim 12, wherein the inner wall is cylindrically shaped having first and second open ends.

14. The blood processing centrifugation bowl of claim 13, wherein the core further includes at least one core channel (334b) disposed adjacent to an inner wall to outer wall junction.

15. The blood processing centrifugation bowl of claim 1, wherein the core further comprises an optical reflector (358).

16. The blood processing centrifugation bowl of claim 1, wherein the core further includes at least one rib (610) disposed about the outer wall.

17. The blood processing centrifugation bowl of claim 16, further comprising a filter media wrapped around an outer surface of the outer wall over the at least one rib.

18. A method of extracting one or more blood components from whole blood, the method comprising the steps of:

providing a blood processing centrifugation bowl (302), the bowl having a bowl body rotatable about an axis, the bowl body forming an enclosed primary separation chamber (304) having an open end (308), a head assembly (312) received within the open end of the bowl body, an outlet port (224) disposed within the bowl body, and a core (328) disposed within the bowl body and defining a secondary separation chamber (360) therein, the core including an outer wall (325) at least a portion of which is external to the outlet port relative to the axis of rotation, the outer wall having a sealing region (370) disposed on an upper portion of the core relative to the head assembly, a fluid transfer region (372) contiguous with the sealing region;

the core has at least one core passage (332) extending through the outer wall in the fluid transfer region (372) and an overall axial length (L), the seal region has an axial length (H), and the length of the seal region is 25-60% of the overall length of the core;

the sealing area (370) of the blood processing centrifugation bowl is free of any perforations, slots or holes;

the outer wall (330) of the core has an inner surface (327) relative to the axis of rotation and the inner surface is inclined to form an angle of inclination a relative to the axis of rotation, the angle of inclination a being in the range of +10 degrees to-10 degrees;

rotating the blood treatment centrifugal rotor;

supplying whole blood to the rotating centrifuge bowl;

separating the whole blood into components, including a lower density component, within the primary separation chamber (304);

forcing the lower density blood component through the rotating core into a secondary separation chamber (360) with at least some of the remaining cells;

further separating the lower density blood component from residual cells in a secondary separation chamber to produce a purer lower density blood component; and

a purer, less dense blood component is removed from the blood processing centrifuge bowl.

19. The method of claim 18, further comprising the steps of: the removal of relatively pure, less dense blood components from the blood processing centrifugation bowl (214) is stopped in response to the relatively dense blood components reaching the core by optical detection.