JPS6050497B2 - Disposable centrifugal blood processing system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to devices for separating or fractionating whole blood into its various individual components, and more particularly to devices for use in such devices. of disposable centrifugal blood separators.

In-vivo blood processing devices, in which blood is drawn from a living donor, passed through the device, and then returned to the donor, have become widely used in recent years.

During passage through this device, the blood is separated or fractionated into its constituent components, namely plasma, red blood cells, and white blood cells or platelets, and the other parts are optionally stored in suitable storage means. Although retained, a portion of these fractions is returned to the donor. Various types of devices have been proposed for in-vivo processing of blood.

One type of device that is widely used is U.S. Pat.
No. 145 and No. 3655123.
The device consists of a centrifuge in the form of a bowl-shaped outer shell which is rotatably driven with a cylindrical center or packing piece suspended inside it to form a narrow sleeve-shaped separation chamber of very precise dimensions. Use separator elements. Fluid communication with the chamber is established by a rotary seal, the chamber having an axially aligned inlet at one end for receiving whole blood, and a centrifugal chamber at the other end. It has three collection ports for removing separated red blood cells, white blood cells, and plasma components. The construction and operation of a rotating seal for transporting whole blood into a chamber and transporting fractionated blood components from the chamber is described in US Pat. No. 3,519,201. The main drawback of this type of centrifugal processing unit was its high manufacturing cost. This fact is important primarily for achieving efficient separation of blood components during the very limited transit time that blood actually has within the processing chamber. This is due to the extremely narrow gap that must be maintained.

Typically, 1 for a typical transit time of approximately 3 minutes.
．． A gap of 0 to 1.57 T$L is required. If mixing of the collected fractions is to be avoided, this dimension must be maintained with a high degree of concentricity. As a result, the outer shell has heretofore been formed with thick sidewalls to prevent any change in the width dimension of the separation channel during operation of the device. The need for thick sidewalls has heretofore made the molding of the outer and inner shells impractical because they cannot be molded to the desired thickness with the necessary precision.

Such shells were then extruded and then individually machined, thereby making manufacturing costs too high for disposable, one-time use convenient to avoid contamination. . The present invention allows units to be economically manufactured from plastic by known molding techniques while maintaining process channel width dimensions of 1.5 wt or less with a high degree of concentricity. The present invention relates to a new and improved structure for a centrifuge chamber.

The present invention relates to a disposable continuous flow centrifugal separator for use in conjunction with a centrifugal device containing a rotationally driven casing for separating fractions from a whole fluid, such as blood.

The separator is rotatably locked to the casing and is disposed within the outer shell in spaced relation to a molded outer shell dimensioned to be received within the casing. and a molded inner shell. The inner and outer shells include walls between their inner surfaces that define a separation chamber radially spaced from the axis of rotation of the casing. The walls of the outer shell are relatively thin and flexible so that the shell deforms toward the inner shell when seated within the casing. At least one of the inner surfaces is provided with means in the form of a projection for establishing a predetermined spacing between the walls and thus a predetermined width dimension for the separation chamber. Means is provided including an inlet for supplying whole blood to the separation chamber, and means includes a plurality of collection ports each communicating with the separation chamber at respective radial distances from the axis of rotation, each from the separation chamber. is provided for taking out the separated fraction. The features of the invention that are believed to be novel are set forth in the claims. The invention, together with objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings. Identical elements in the several drawings are designated by the same reference numerals. In the drawings, FIG. 1 is a perspective view of a centrifugal blood separator constructed in accordance with the present invention, with a portion cut away to show the internal structure. FIG. 2 is an enlarged longitudinal sectional view of a blood separator incorporated in a rotary seal type centrifugal device.

FIG. 2a is an enlarged longitudinal cross-sectional view of the rotary seal assembly used in the apparatus shown in FIG. 2;

FIG. 3 is an enlarged longitudinal sectional view of the downstream end of the processing channel, illustrating the distribution of fractionated components in the processing channel. FIG. 4 is a schematic diagram of a liquid delivery system used in combination with the centrifugal blood separator of the present invention.

FIG. 5 is a longitudinal sectional view of a centrifugal blood separator incorporated in a sealless centrifugal device.

Referring to the drawings, and in particular to FIG. 1, a centrifugal blood separator 10 constructed in accordance with the present invention is shown to fit within a similar cavity in a rotationally driven casing, not shown in FIG. It includes a dimensioned bowl-shaped outer shell 11 .

A bowl-shaped inner shell 12 is disposed inside the outer shell and together with the outer shell forms a centrifugation chamber 13 within which whole blood fractionation takes place when the separator assembly is rotating. The edges of the two bowl-shaped shells are connected by bonded tongue and groove joints to four red blood cell (RBC) collection ports 15 disposed in the first ring and concentric with the first ring. However, it is joined to a flat bar member 14 containing four equally spaced white blood cell (WBC) sampling ports 16 in a second ring having a smaller diameter. The cover member also has a plurality of openings 17 in its center for establishing fluid communication with a rotating seal (not shown in Figure 1) in a manner that will be described shortly. Each of the four sampling ports 15 is connected to a tube 18 extending through an opening 19 in the cover member 14 and into the interior of the bowl-shaped inner shell 12 . Similarly, each of the sampling ports 16 is connected to a tube 20 extending through an opening 21 and into the interior of the inner shell member. Referring to FIG. 2, which shows a centrifuge in combination with a rotary seal centrifuge, the outer shell 11 of the separator is seated in a rotationally driven casing.

The outer shell 11 includes a thin upright cylindrical side wall 23;
The shell begins outwardly at the upper or downstream end;
It then terminates in an upwardly directed edge 24 and in a corner 25 which merges with a flat bottom wall 26 at the lower or upstream end. Similarly, the inner shell 12 includes a thin upright cylindrical side wall 27, a downstream portion 28 that points first inwardly and then upwardly, and a corner 29 that merges with a flat bottom wall 30. There is. Side wall portions 23 and 27
The inner surface of the separation channel 3 in the processing chamber 13
1, when whole blood flows through the channel under the influence of a centrifugal field, red blood cells, white blood cells and plasma components are separated from the whole blood within the channel. Edges 24 and 28 together define an area of widened chamber 13 in which blood components separated in channel 31 are collected before being removed from collection ports 15 and 16. It will be done. Another collection port 32 is provided in the edge 28 of the inner shell 12 for the purpose of removing plasma as it accumulates in the chamber 13.

This sampling port is connected by a tube 33 to the passage 17a of the top plate 14. Similarly, the tube 18 is connected to the passage 17 in the top plate 14.
b, and the tube 20 connects to the passage 17c. In order to provide a means for introducing whole blood into the separation channel 31, the inner shell 12 is provided with an inlet 34 along the axis of rotation of the casing 22. This inlet/outlet is connected to the passage 17d of the cover member 14 by a pipe 35. Additional openings 36 are provided through the bottom wall portions 26 and 30 of the inner and outer shells to facilitate mounting of the separator 10 in a sealless centrifugal device in accordance with the embodiments hereinafter described. A rotating seal assembly 40 is provided on the top plate 14 along the axis of rotation of the casing 22 to provide fluid communication between the non-rotating portions of the liquid delivery system associated with the inlet, collection port, and separator.

The seal assembly may be conventional in construction and operation and is secured to the top plate by suitable fasteners such as bolts 41.
It is placed on 4. Referring to FIG. 2a, the rotating seal assembly is comprised of a rotating member 43 having a plurality of annular recesses 44 therein and a stationary member 45 having a plurality of communicating annular recesses 46 therein. Lands 47 are provided between each recess for fluid isolation, and additional flushing and/or lubricating flow systems may be provided to improve operation in a manner well known to those skilled in the art. In practice, two passages are provided in the top plate 14 for each annular recess associated with each fractionated component, and each of these passages is fitted with a suitable Y-connector and a connecting tube of suitable length. can be connected to one of each of the four collection ports for the fractionation.

For clarity, these connections are not shown in FIG. Upper non-rotating portion 45 of rotating seal assembly 40
is supported in a stationary, non-rotating position in compressive engagement with the lower rotating portion 43 by a retaining arm 48 mounted on the frame of the centrifuge.

The lower rotating portion of the seal is a polished ceramic disk attached to member 14 by a concentric silicone rubber O-ring that establishes fluid communication between the nozzle 44 and a corresponding one of the passageways 17. 5 can be formed from. The upper stationary part of the seal is made of stainless steel which is covered to ensure perfect contact with the ceramic disc.
Each of the annular recesses 46 is connected by a passageway to a canal in the top of the disc.
Referring to FIG. 4, the red blood cell outlet is located in tube 50.
The white blood cell outlet is connected to the piston pump 51 by the tube 5.
2 to a screw pump 53, and the plasma outlet is connected by a tube 54 to a screw pump 55. Whole blood is supplied by tube 56 to the inlet 4, to which citrate glucose (ACD) and hebalin are supplied to each tube 5.
7 and 58 as well as a piston pump 59.
For isolation purposes saline is supplied to the rotary seal through tube 60 and discharged through tube 61. Saline solution is supplied to the seal by tube 62 and pump 63 for lubrication purposes. The white blood cells, red blood cells, and plasma obtained by this system can be pumped into respective collection bags for storage or, if desired, return to the donor.

The system can be equipped with various safety devices to protect against air leakage, excessive temperature rise, or donor venous occlusion. A drive shaft 64 is mounted on the casing 22, and the shaft is rotationally driven by a motor 65.

In practice, this drive arrangement is designed and operated to provide a very high degree of concentricity to the rotation of the casing 22 in order to ensure efficient operation of the separation operation and efficient operation of the seal assembly 40. Ru. In operation, casing 22 is rotated at a speed of approximately 800 r'Pm to establish a centrifugal force field across separation chamber 31.

The channels are then filled with saline solution and any air bubbles are removed by backflowing the system through the leukocyte pulsation pump 53. The whole blood is then transferred to tube 56.
, through rotary seal assembly 40 and tube 35 and into inlet 34 . Whole blood flows radially outwardly within chamber 13 and upwardly through separation channel 31 . The centrifugation speed is adjusted to achieve separation of red blood cells, white blood cells and plasma components in the manner shown in FIG. Separation begins as the blood flows up the side of the pot toward the collection port, with the densest red blood cells in the outermost layer, the less dense white blood cells in the middle, and the least dense plasma. Separate into three concentric bands with the smallest diameter. Platelets are normally distributed across all three zones, but can be concentrated to some extent by varying the centrifugation speed. Collection ports 15, 16 and 32 remove components from processing chamber 13 for collection or return to the donor when desired. Typically, the flow rate of whole blood in chamber 13 is such that the blood residence time in the chamber is approximately 3 minutes. In order to ensure that the blood components are separated in a relatively short time, the width of the separation channel 31 must be very small, typically 1.5 Tr$t or less. be. For efficient separation of blood components, this dimension must be maintained with a high degree of concentricity so that the components flow upwardly toward the collection area at the upper end of chamber 13 when separated. In order to ensure the desired separation channel width dimensions with the desired degree of concentricity, the inner and/or outer shells are provided with a plurality of inwardly projecting, integrally molded spacing projections 60 in accordance with the invention. , these receive shell surfaces opposite them so as to maintain accurate spacing.

To ensure that these protrusions actually determine the spacing between the elements, the side walls of the outer shell are deformed slightly inwardly when the separator unit 10 is seated within the casing 22. The dimensions of the outer shell 11 are determined. This deformation is sufficient to bring the spacing projections 60 into engagement with their opposing wall surfaces and ensure that the desired spacing is created and maintained. To facilitate insertion of the separation unit into the casing 22, the outer shell is typically desirably tapered slightly inwardly, and the inner wall of the casing 22 is adapted to this. It is formed into a taper. Preferably, the inner and outer shells are molded from a polycarbonate resin such as LEXAN® (GENERAL, Plastics Inc.) by conventional molding techniques. The side walls 23 and 27 of these shells can have a thickness of 0.3175 cm to obtain the desired inward deformation when seating the separator within the casing 22. In a typical application, separator 10 is formed with an outer diameter of approximately 15.24 cm and a height of approximately 10.16 cm. The processing flow path 31 has a width of 1.5T0fL, and the processing chamber 13
has a volume of approximately 140nI1.

After the various lengths of tubing have been installed during fabrication of the separator unit 10, the volume surrounded by the inner shell 12 is filled with foam material to prevent a significant amount of fluid from accumulating within the process chamber. prevent.

This is a safety feature to ensure that leaks are readily apparent to operators and do not accumulate within the rotating pot assembly. Referring to FIG. 5, the centrifugal separator unit of the present invention is disclosed in Japanese Patent Application No. 51-30743 (1983) filed by the present applicant.
It can also be used in combination with a centrifugal device without a seal such as that described in Japanese Patent Publication No. 58-370-2).

Basically, the centrifugal device includes a rotor drive assembly 70 that supports a rotor assembly 71 by a hollow support shaft 72.
including. Rotor drive assembly 70 is journalled to stationary hub assembly 73 by vertical drive shaft 74 and includes a guide sleeve 75 . The centrifuge chamber 10 of the present invention is seated on a rotor assembly 71. extending along the axis of rotation of the separator unit from a central position downwardly through the center of the drive shaft 72 and then radially outwardly through the guide sleeve 75 and further defined by the support arm 77. Same as that shown in FIG. 4 except that the separator unit rotates with the rotor assembly 71 by means of cables 76 to the four flow passages extending axially in a straight line to a fixed position, and the rotary seal member 40 is omitted. Liquid communication is established between the non-rotating portion of the liquid flow system. As described in the aforementioned Japanese Patent Application No. 51-30743 (Japanese Patent Application No. 58-370), this path of the umbilical cable 76 connects the rotor assembly 71 driven in the same direction at a speed ratio of 2:1. and rotor drive assembly 70 to establish fluid communication with centrifuge unit 10 without heating the cables. Instead, as the rotor assembly 71 rotates, the umbilical cable is merely bent or repeatedly partially twisted about its axis through an angular range not exceeding 180 degrees. To obtain the desired 2:1 speed ratio between the rotor and the rotor drive assembly, the rotor drive assembly 70 is equipped with two pairs of idler pulleys 1.
J78 is mounted. The drive belt 79 passes through these pulleys, at one end around a stationary ring pulley 80 mounted on the hub 73, and at the other end around the bottom end of the rotor drive shaft 72. It rotates around a rotor drive pulley 81 attached to the rotor drive pulley 81. Drive belt 79 imparts clockwise rotation to rotor assembly 71 as rotor drive assembly 70 is rotated clockwise by drive shaft 74 driven by a motor (not shown). Assuming that the stationary pulley IJ8O and the rotor drive pulley 81 have the same diameter, the rotor assembly 7
1 rotational speed due to the direct 1:1 drive relationship established by pulleys 80 and ) 81 and the rotor assembly 71.
The rotor drive assembly 7
This is exactly twice the rotation speed of 0. To seat the centrifuge unit 10 on the rotor assembly 71, the collection port 1 is
Tubes 18, 20 and 33 connected to 5, 16 and 32
passes through the center of the separator unit and passes downwardly through openings 36 in the bottom walls of the inner and outer members.

To receive the centrifuge unit, a rotating casing 82 is constructed, similar in all respects to the casing 22, except that a passage 83 is provided in the bottom wall for accommodating the connecting conduit section. mounted on the child assembly. As in the rotary seal embodiment described above, the walls of the outer shell are compressed by the casing 82 to obtain a separate channel 31 with a high degree of concentricity. After passing through the passageway 83, the individual connecting tube pieces connect to the umbilical cable 76.
merge into. When intended for use in an unsealed centrifuge device such as that seen in FIG. Dew.

To attach the unit to the device, the free end of the umbilical cable is pulled downwardly through the hollow rotor support shaft 72 and then supported radially outwardly and upwardly through the sleeve 75. It will be possible to pass through arm 77.

The free end of the cable is then pulled until the separator unit seats against the casing 82. After use, the entire assembly will be removed from the device and discarded. A centrifugal blood separator that provides efficient processing of blood components is illustrated and described. Ta. By means of known molding techniques, the present separator unit can be manufactured economically, and because of its low manufacturing cost, it is a disposable, single-use unit that completely eliminates the risk of donor contamination from previous use. Ideally suited for as long as 3 uses.

While particular embodiments of the invention have been illustrated and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the broader aspects of the invention, and therefore the scope of the claims Its role is to cover such changes and modifications as come within the true spirit and scope of the invention. As best seen in FIG. 3, a concentric tongue 16L is provided with an inner surface aligned with the outside of the leukocyte sampling port 16, and the adjacent bottom surface of the cover member 14 is provided with a helicoid therein. A concentric groove 16G in which 16 is open is provided.

This sparse formation of grooves and tongues resulted in experimentally proven better separation of red blood cells from collected white blood cells.
The pot only requires the use of four spacing units 60, and the spacer flanges between the inner and outer shells at 36 maintain horizontal wall spacing (top and bottom).
It has been found that it is useful to a considerable extent not only for fixing the sidewall spacing, but also for fixing the sidewall spacing.

In one embodiment, four-piece spacing strips 60 were successfully used. These spacing pieces were equidistantly spaced around the circumference of the unit and located near its top surface. One experimental pot constructed in accordance with the present invention was molded in four sections from polycarbonate resin and had an overall height of approximately 10.16 cm and a diameter of approximately ±15.56 cm.

This particular unit had a fluid capacity of only 143 ml, which is well suited to pots of this type according to known technology. Shells 11 and 12 had a thickness of ±0.3175c71 and maintained a spacing dimension of 0.127 cm.

Although the outer shell has considerable stiffness for handling purposes, it is slightly non-circular and will deform further under increased centrifugal force. however,
A perfect circular casing 22 made of stainless steel ensures that the outer shell assumes a perfect circular concentric shape upon insertion. It should be remembered that the four molded doorways of the two example pot bodies 10 shown in FIGS. 1-2 and 5 are the same and can be adapted to either configuration.

The present invention makes it possible to manufacture these doorways with greater tolerances while still achieving good results compared to prior art permanent pot bodies. The disposable pot body according to the present invention can be used as a CELLTRIFUGE separation unit manufactured by Instruments, Inc., a part of Travenol Laboratories, Inc., by attaching it with a suitable casing. It can be easily re-equipped into existing commercially available machines.

Of course, similar casings can also be used so that such machines under other trade names can be refitted as well. Although polycarbonate is currently the preferred plastic for making the outer shell and other blood contact ports,
Methyl methacrylate, styrene-acrylonitrile,
Other plastic materials such as acrylic, styrene or acrorylonitrile can also be used.

Although molding is currently the preferred manufacturing method, it is also possible to fabricate the shell by vacuum forming or casting. Also, although the inner shell is preferably described as a hollow body and subsequently filled with a foamed material, the phrase "inner shell" is to be understood in the claims to also include solid units. Should.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a centrifugal blood separator constructed in accordance with the present invention, with a portion cut away to show the internal structure. FIG. 2 is an enlarged longitudinal sectional view of a blood separator incorporated in a rotary seal type centrifugal device. FIG. 2a is an enlarged longitudinal cross-sectional view of the rotary seal assembly used in the apparatus shown in FIG. 2; FIG. 3 is an enlarged longitudinal sectional view of the downstream end of the processing channel, illustrating the distribution of fractionated components in the processing channel. FIG. 4 is a schematic diagram of a liquid feeding system used in combination with the centrifugal blood separator of the present invention. FIG. 5 is a longitudinal sectional view of a centrifugal blood separator incorporated in a sealless centrifugal device. 10: Centrifugal separator, 14: Cover member, 40: Rotating seal assembly, 11: Bowl-shaped outer shell, 17: Opening,
22, 82: Casing, 12: Bowl-shaped inner shell, 19
: opening, 64: drive shaft, 13: centrifugal processing chamber, 18: tube,
60: Spacing projection, 15: Red blood cell collection port, 21: Opening, 75: Guide sleeve, 16: White blood cell collection port, 31: Separation flow. path, 76: umbilical cable, 48: holding arm, 48
: Annular recess, 65: Motor, 51, 53, 55: Motion pump, 70: Rotor drive assembly, 73: Stationary hub assembly 72: Drive shaft, 77: Support arm.

Claims (1)

[Scope of Claims] 1. A continuous flow centrifugal separator for use with a centrifugal device having a rigid casing driven in rotation highly concentric with a rotating shaft, the centrifugal separator being rotatably locked and housed within the casing. and an inner shell spaced within the outer shell, the inner and outer shells being radially spaced apart from the axis of rotation of the casing to form a separation chamber. between its inner surfaces, the wall portion of the outer shell being relatively thin and flexible so that it conforms substantially to the shape of the casing when the shell is seated therein. and the separator further includes means including a protrusion on at least one of the inner surfaces for ensuring a predetermined spacing between the walls, and for supplying the fluid to be treated to the separation chamber. an inlet means including an inlet for removing the separated fractions from the separation chamber, and from the rotating shaft for enabling the separation of the fractions from the total fluid. and outlet means comprising a plurality of sampling ports communicating with the separation chamber at respective radial distances. 2. The disposable centrifuge of claim 1, wherein said outer and inner shells are bowl-shaped, and said casing defines a bowl-shaped recess for accommodating the outer shell. 3. A disposable centrifugal separator according to claim 2, wherein said inlet is coaxial with the axis of rotation of the separator. 4. said outlet means each have a first
, first, second and third sampling ports spaced apart from each other in a second and third radial distance.
Disposable centrifuge. 5. A disposable centrifuge according to claim 2 or 4, wherein said total fluid is whole blood and said fractions are red blood cells, white blood cells and plasma, respectively. 6. The disposable centrifuge of claim 2, wherein the inner and outer shells have edges and a substantially flat top cover member is attached to the edges. 7. The disposable centrifuge of claim 6, wherein at least a portion of said collection port is located on said top cover. 8. said inner shell has an inwardly and upwardly facing edge at its upper end, and said outer shell has an outwardly and upwardly facing edge at its upper end, and said outer shell has an outwardly and upwardly facing edge at its upper end; 7. A disposable centrifugal separator as claimed in claim 6, wherein a separation chamber is formed having a radial width. 9. The disposable centrifuge of claim 2, wherein said outer shell is made from a relatively thin plastic material. 10. The disposable centrifuge of claim 2, wherein said inner and outer shells are thin polycarbonate plastic moldings. 11. The disposable centrifuge of claim 6, wherein said cover member includes at least one channel for establishing fluid communication with said collection port. 12. The disposable centrifuge of claim 1, wherein said protrusion comprises a protrusion extending inwardly on said inner surface of said shell.