CENTRIFUGE ROTOR

A centrifuge rotor includes tube retainers for holding two or more sample tubes at a 90 degree angle in a minimized configuration for effective separation of a blood sample using a mini centrifuge. The centrifuge rotor with sample tubes in place has an overall width that is less than two times the length of a sample tube.

FIELD

The present disclosure relates to the field of centrifuge rotors. More particularly, the present disclosure relates to a compact centrifuge rotor design arranged to reduce width, volume, and weight and capable of effectively separating biological fluid samples.

BACKGROUND

Accurate analysis of a blood sample obtained from a subject requires that the plasma and red blood cells (RBCs) of the blood sample are separated from the time of collection to analysis. Mixing of the red blood cells and plasma increases lysis of the red blood cells (i.e., hemolysis), thereby rendering RBC analysis of the blood sample inaccurate and possibly ineffective. Accordingly, effective separation of the blood sample upon collection is imperative. Centrifuges have been used for several hundred years to separate components in a sample based on the density of the components. Centrifuges for separating biological samples such as blood are known in the art. Currently, there are two primary types of centrifuges on the market, one of which has a fixed angle rotor (typically less than 45 degrees), and the other of which has a swing bucket rotor (at approximately 90 degrees when spinning at full speed). While the fixed angle rotor is compact, the resulting separation from a 45 degree tube angle renders an increase in the risk of red blood cells leaking into the separated serum. A swing bucket rotor can provide effective blood separation; however, both the design of the swing bucket rotor and the power requirement to produce the 90 degree rotation, requires a larger sized rotor for use in a high powered centrifuge, all of which results in higher cost and could not be easily transported.

It is desirable to provide a compact centrifuge rotor for use in a compact, portable centrifuge for effectively separating biological (e.g., blood) samples.

SUMMARY

In one embodiment, a centrifuge and tube assembly includes a centrifuge body and a centrifuge rotor that rotates with respect to the centrifuge body about a rotation axis. The centrifuge rotor includes a rotor body and a plurality of tube retainers. The tube retainers are configured to receive a plurality of tubes, with each of the plurality of tubes having a tube length. The plurality of tubes are positioned side-by-side and overlap at the rotation axis. The centrifuge rotor having tube retainers with sample tubes positioned therein, has an overall width that is less than twice the length of the sample tube.

Aspects of embodiments of the present invention also include a kit for remote collection of a blood sample, wherein the kit comprises a compact centrifuge rotor as disclosed herein for use with a lightweight mini centrifuge. In some embodiments, the kit includes the compact centrifuge rotor and at least two sample tubes. In other embodiments, the kit includes the compact centrifuge rotor, at least two sample tubes, and a mini portable centrifuge.

DETAILED DESCRIPTION

Centrifuge rotors of the present disclosure provide separation of a sample using a compact, easy-to-use, portable centrifuge assembly. The presently disclosed centrifuge rotors (tube retainers) hold the sample tubes in a configuration within the centrifuge that occupies minimal space (e.g., width or diameter), thereby allowing for the overall centrifuge assembly to be compact in size.

Collection of a blood sample to be analyzed that is collected at a remote location (i.e. not at a clinic) requires processing (separation) soon after it is collected. For example, the collected sample requires good separation using a centrifuge rotor that will effectively hold the sample tubes at an angle (e.g., 90 degrees) relative to a vertical rotational axis, wherein the centrifuge rotor is fabricated from a lightweight material and is minimized in size (e.g., width) such that the width of the centrifuge rotor when the samples tubes are inserted in the tube retainers is less than two times the length of a sample tube. Accordingly, the centrifuge rotor is minimized for size to hold at least two sample tubes, and the centrifuge rotor with the sample tubes therein are used in a small sized centrifuge. With an effective and minimized centrifuge rotor, samples tubes along with the centrifuge rotor can be easily transported (e.g., by U.S. mail or courier) to a subject at any location away from a clinic for blood collection and effective separation. Additionally, a kit for remote blood collection and separation, according to embodiments of the present invention, comprises at least two sample tubes and a centrifuge rotor as disclosed herein for holding the centrifuge rotor. In further embodiments, the kit comprises at least two sample tubes, a centrifuge rotor, and a minimized, lightweight centrifuge. A lightweight mini centrifuge according to the present disclosure includes, for example, the MC-700 from Abcbio™. A lightweight mini centrifuge for use with the centrifuge rotor according to embodiments of the present invention, may have a weight of about 0.10 kilogram (kg) to about 2.0 kg. The lighter weight allows for the centrifuge to be transported (e.g., mailed) with the centrifuge rotor. For example, the lightweight mini centrifuge may have a weight of about 0.10 kg to about 1.0 kg or about 0.20 kg to about 1.0 kg. In other exemplary embodiments, the weight of the centrifuge is about 0.20 kg up to about 0.80 kg. A centrifuge for use with the presently disclosed centrifuge rotors may have a speed up to 7000 rotations per minute (r/min). A suitable lightweight mini centrifuge is capable of sufficiently separating a sample using a centrifuge rotor as disclosed herein inFIGS.6A-9.

FIG.1AandFIG.1Bdepict an exemplary centrifuge with a fixed angle centrifuge rotor.

As shown inFIG.1A, centrifuge100includes body102and centrifuge rotor104. Body102contains electronics for operating centrifuge100, including a motor and power source. In this example the power source is an integral battery, but an external power source can be used. In another alternative embodiment, the power source includes one or more removable batteries.

The motor includes a motor shaft that rotates centrifuge rotor104about a rotation axis108when the motor is operating. Centrifuge rotor104includes rotor body106and tube retainer110. In the illustrated embodiment, the rotor body106is integral with the tube retainer110. Alternatively, the rotor body may be a separate component that is fastened to the tube retainer. Rotor body106is perpendicular to rotation axis108.

Tube retainer110includes first opening112and second opening114configured to hold a tube at angle120from rotation axis108, as can be seen inFIG.1B. In this example, the angle120is approximately 36 degrees. Angling at 36 degrees has several advantages including reducing the overall width of the centrifuge and improving aerodynamics. If the liquid separation is lopsided, however, such as in the case of blood gel separation, there is danger that the red blood cells can leak through the gel back into the serum, especially during transporting.

First retainer116is inserted into first opening112. Second retainer118is inserted into second opening114. First retainer116and second retainer118include a plurality of grips to secure a tube inserted into first opening112and second opening114, respectively. The first and second retainers116,118may be constructed of an elastomeric material. Tube200A and tube200B are inserted into first retainer116and second retainer118in the manner shown inFIG.1B.

FIG.2is a side view of an exemplary tube200for inserting into a centrifuge rotor. Tube200comprises first end202, tube head204, and second end206. In the illustrated embodiment, the tube200includes a large diameter portion adjacent to the tube head204, a small diameter portion adjacent to the second end206, and a transition portion that tapers from the large diameter portion to the small diameter portion. In other embodiments, the body of the tube has a single diameter.

In some embodiments, the openings of the tube retainer include a corresponding structure, to ensure that users insert the tube in the correct direction. Furthermore, the taper of the transition portion can assist users with properly securing the tube to the tub retainer by a friction fit, without the need for turning or twisting the tube.

Tube200has a length T. As shown inFIG.3,FIG.4, andFIG.5, the length T of tube200and arrangement of the plurality of tubes can contribute to the overall width W of a centrifuge rotor. It is advantageous to have a smaller overall width W, because it can reduce the spin time and weight of the centrifuge rotor, thereby significantly reducing the power to spin at given speeds. Minimizing power usage is especially relevant for battery-powered portable centrifuges where power is scarce. In addition, a reduced width W can result in cost savings related to shipping and packaging portable centrifuges.

Furthermore, the type and amount of material utilized to construct the centrifuge rotor can affect the overall weight. As shown inFIG.4andFIG.5, rotor body106is a disc shape that includes unused surface area that can be removed to reduce the weight of the centrifuge rotor. For example, the material used to separate tube200A and tube200B from contacting, can be removed by arranging the tubes to be positioned side-by-side, as discussed below in further details.

FIG.6AandFIG.6Bdepict an exemplary compact centrifuge rotor arranged to minimize width, volume, and weight. Such a compact centrifuge may be particularly useful as a mobile centrifuge. For example, a compact centrifuge may be shipped as part of a home blood test kit. After the user takes a blood sample, the user may place one or more test tubes of blood in a compact centrifuge and then ship the assembly to a testing center. It should be understood, however, that the compact centrifuge is not limited to mobile applications.

According to embodiments of the present invention, a compact centrifuge rotor having two tube retainers310has a width in a range from about 2.0 cm to about 5.0 cm. For example, the width of the centrifuge rotor having two tube retainers has a width in a range from 2.0 cm to 4.5 cm, 2.0 cm to 4.0 cm, 2.0 cm to 3.5 cm, 2.0 cm to 3.0 cm, or 2.0 cm to 2.5 cm. The centrifuge rotor having two tube retainers may have a width in a range from 2.5 to 5.0 cm, 3.0 cm to 5.0 cm, 3.5 cm to 5.0 cm, 4.0 cm to 5.0 cm, or 4.5 cm to 5.0 cm. In other embodiments of the present invention, the width of the centrifuge rotor having two tube retainers has a width in a range from 2.5 cm to 3.5 cm, 2.6 cm to 3.4 cm, 2.7 cm to 3.3 cm, 2.8 cm to 3.2 cm, 2.8 cm to 3.1 cm, 2.8 cm to 3.0 cm, or 2.8 cm to 2.9 cm.

The centrifuge rotor304having two tube retainers310, holds two or more sample tubes. For example, the centrifuge rotor304holds two sample tubes. The sample tubes have a length T of about 2.5 cm to 5.5 cm, 3.0 cm to 5.0 cm, 3.0 cm to 4.5 cm, 3.0 cm to 4.0 cm, or 3.0 cm to 3.5 cm. In other embodiments, sample tubes have a length T of about 3.5 cm to 5.5 cm, 4.0 to 5.5 cm, 4.5 cm to 5.5 cm, or 5.0 cm to 5.5 cm. In still other embodiments, the sample tubes have a length T of about 4.0 cm to 5.0 cm, 4.1 cm to 4.9 cm, 4.2 cm to 4.8 cm, 4.3 cm to 4.7 cm, 4.4 cm to 4.6 cm, or 4.4 cm to 4.5 cm.

As shown inFIG.6A, centrifuge300comprises body302, centrifuge rotor304, and lid306. Body302contains the electronics for operating centrifuge300, including a motor and power source. Body302is substantially similar to body102shown inFIG.1A. It should be understood, however that the diameter and length of the centrifuge body can be reduced as a result of the compact centrifuge rotor described in detail below. In this example the power source is an integral battery, but an external power source can be used. In exemplary embodiments of the present invention, the presently disclosed centrifuge rotor with sample tubes therein, can effectively separate a collected sample in one or both sample tubes using a centrifuge requiring 30 to 60 hertz (Hz) of power. In exemplary embodiments, a compatible and compact centrifuge for remote sample separation using the disclosed centrifuge rotor requires 45 to 55 Hz of power. In another alternative embodiment, a compatible centrifuge requires AC 220 volt. In other embodiments, the power source for a compatible and compact centrifuge for powering includes one or more removable batteries.

The motor comprises a motor shaft that rotates centrifuge rotor304about rotation axis308when the motor is operating. Centrifuge rotor304includes rotor body306and tube retainer310. Rotor body306is perpendicular to rotation axis308. Rotor body106and tube retainer110can be manufactured utilizing 3D printing, injection molding or CNC with materials, including but not limited to, plastic, light-weight metal, or wood-based materials. In exemplary embodiments, the centrifuge rotor is made of an elastomeric material (e.g., hard plastic, acrylonitrile butadiene styrene (ABS), or polylactic acid (PLA).

Tube retainer310comprises first opening312and second opening314. Tube200A and tube200B are shown inserted into first retainer316and second retainer318, respectively inFIG.6B. Tube200A and tube200B are positioned side-by-side such that tube head204A and tube head204B overlap at rotation axis308. Tube head204A and tube head204B face each other in the manner shown inFIG.6A. Tube200A and tube200B are positioned substantially perpendicular to the rotation axis308.

As can be seen inFIG.6B, the overall width of centrifuge300is reduced compared to the overall width of centrifuge100shown inFIG.1B. A tube angle of 90 degrees results in liquid separations that are flat instead of slanted in the tube. It has been found that such flat separation prevents the blood separation from leaking into the separated serum. It is estimated that the spin time of centrifuge rotor304is about 40% less than the spin time of centrifuge rotor104ofFIGS.1A and1Band achieve similar blood separation.

In an alternative embodiment, the tube retainer may hold the tubes at an angle other than 90 degrees with respect to the axis of rotation. For example, the tube retainer may hold the tubes at an angle between 36 degrees to 90 degrees without departing from the broad principals disclosed herein. In exemplary embodiments, the tube retainers hold the tubes at a 90 degree angle.

In this example, the side-by-side positioning of the tubes allows for the material used for the first retainer and the second retainer to be reduced. First retainer316and second retainer318include at least one grip320and may include a plurality of grips320. The grip(s)320is/are positioned at the second side of the first opening and second opening. For example, a plurality of grips320are positioned radially around first opening312and second opening314and taper inwards, thereby securing an inserted tube. Furthermore, the inward taper of the plurality of grips320assists in preventing users from inserting the tubes in the wrong direction. The length of the grips320may range from 0.2 cm to 1.2 cm, 0.3 cm to 1.1 cm, 0.4 cm to 1.0 cm, 0.5 cm to 1.0 cm, 0.4 cm to 1.0 cm, 0.5 cm to 1.0 cm, 0.6 cm to 1.0 cm. 0.7 cm to 1.0 cm, 0.8 cm to 1.0 cm, or 0.8 cm to 0.9 cm. In exemplary embodiments, the length of the grips range from 0.7 cm to 0.9 cm.

FIG.7,FIG.8, andFIG.9depict an exemplary centrifuge rotor configuration. wherein a plurality of tubes are aligned side-by-side and perpendicular to the rotation axis to reduce the overall width of a centrifuge rotor.

FIG.7is a top view of centrifuge rotor400. Centrifuge rotor400includes rotor body402, rotation axis404, and tube retainer406. Tube retainer406includes first opening408and second opening410. Tube200A and tube200B are shown inserted into first opening408and second opening410, respectively. As shown inFIG.7andFIG.9, tube200A and tube200B are positioned side-by-side such that tube head204A and tube head2048overlap at rotation axis404. Furthermore, tube200A and tube200B are perpendicular to the rotation axis404. As a result, the overall width W of centrifuge rotor400is less than two times the length T of tube200. According to some embodiments, the overall width W of the centrifuge rotor with sample tubes therein is in a range from about 2.0 cm to about 8.0 cm. For example, the overall width includes 2.5 cm to 8.0 cm, 3.0 cm to 8.0 cm, 3.5 cm to 8.0 cm, 4.0 cm to 8.0 cm, 4.5 cm to 8.0 cm, 5.0 cm to 8.0 cm, 5.5 cm to 8.0 cm, 6.0 cm to 7.5 cm, or 6.5 cm to 7.5 cm. In addition, orienting the tubes in this manner results in liquid separations that are flat instead of slanted in the tube. Tube200A and tube200B are positioned coplanar in the manner shown inFIG.8.

FIG.10,FIG.11, andFIG.12depict another exemplary centrifuge rotor configuration, wherein a pair of centrifuge tubes200are positioned to reduce the overall width W of a centrifuge rotor.

FIG.10is a top view of centrifuge rotor500. Centrifuge rotor500includes rotor body502, rotation axis504, and tube retainer506. In this example, tube retainer506comprises first angled opening508and second angled opening510. Tube200A and tube200B are shown inserted into first angled opening508and second angled opening510, respectively. As shown inFIG.10andFIG.12, tube200A and tube2008are positioned side-by-side such that tube head204A and tube head204B overlap at rotation axis504. Furthermore, tube200A and tube200B are positioned at an angle512from rotation axis504. Angle512can be a fixed angle between 45 degrees and 90 degrees. As a result, the overall width W of centrifuge rotor500is less than two times the length T of tube200. Tube200A and tube200B are positioned on different planes in the manner shown inFIG.8.

FIG.13,FIG.14, andFIG.15depict yet another exemplary centrifuge rotor configuration, wherein a plurality of centrifuge tubes200are positioned to further reduce the overall width of a centrifuge rotor.

FIG.13is a top view of centrifuge rotor600. Centrifuge rotor600includes rotor body602, rotation axis604, and tube retainer606. Rotor body602includes first arm614, second arm616, and central portion618. In this example, first arm614and second arm616are perpendicular to central portion618in the manner shown inFIG.13.

Tube retainer606comprises first opening608and second opening610. Tube200A and tube200B are shown inserted into first opening608and second opening610, respectively. As shown inFIG.13andFIG.15, tube200A and tube2008are positioned side-by-side such that tube head204A and tube head204B substantially overlap at rotation axis604. Furthermore, tube200A and tube200B are positioned at angle612comprising 90 degrees from rotation axis604. As a result, the overall width W of centrifuge rotor400is significantly less than two times the length T of tube200. Tube200A and tube200B are positioned coplanar in the manner shown inFIG.14.

FIG.16,FIG.17, andFIG.18depict an exemplary centrifuge rotor configuration, wherein a plurality of centrifuge tubes200are positioned on different vertical planes.

FIG.16is a top view of centrifuge rotor700. Centrifuge rotor700includes rotor body702, rotation axis704, and tube retainer706. Rotor body702includes first arm714, second arm716, and central portion718. In this example, first arm714and second arm716are perpendicular to central portion718in the manner shown inFIG.16. First arm714defines a first horizontal plane and the second arm716defines a second horizontal plane above the first horizontal plane in the manner shown inFIG.18.

Tube retainer706comprises first opening708and second opening710. Tube200A and tube200B are shown inserted into first opening708and second opening710, respectively. As shown inFIG.16andFIG.18, tube200A and tube200B are positioned side-by-side such that tube200A and tube200B substantially overlap at rotation axis704. Furthermore, tube200A and tube200B are perpendicular to the rotation axis604. As a result, the overall width W of centrifuge rotor700is significantly less than two times the length T of tube200. Tube200A and tube200B on different vertical planes in the manner shown inFIG.14.

FIG.19,FIG.20, andFIG.21depict an exemplary centrifuge rotor configuration, wherein a plurality of centrifuge tubes200are positioned coplanar and stacked vertically.

FIG.19is a top view of centrifuge rotor800. Centrifuge rotor800comprises rotor body802, rotation axis804, and tube retainer806. In this example, tube retainer806comprises first opening808and second opening810stacked vertically. Tube200A and tube200B are shown inserted into first opening808and second opening810, respectively. As shown inFIG.19andFIG.20, tube200A and tube200B are positioned side-by-side such that tube head204A and tube head204B overlap at rotation axis804. Furthermore, tube200A and tube200B are positioned at angle812comprising 90 degrees from rotation axis804. As a result, the overall width W of centrifuge rotor800is less than two times the length T of tube200. Tube200A and tube200B are positioned coplanar in the manner shown inFIG.8.

With reference toFIG.22, the two tubes shown on the left were centrifuged using a fixed angled rotor at 36 degrees, and the two tubes shown on the right were centrifuged using a rotor (i.e., tube retainer)310as shown inFIGS.6A and6Bat 90 degrees. The sample separation gels centrifuged in the 36 degree rotor have thin, uneven, and lopsided separation. (The two tubes on the left inFIG.22.) Comparatively, the sample separation gels centrifuged in the tube retainer rotor310have even and straight separation. (The two tubes on the right inFIG.22.) The thin, uneven, and lopsided separation from the 36 degree rotor is less separation than the separation of the tube retainer rotor310.

Embodiments of the present invention also include kits comprising a centrifuge rotor as disclosed herein having two sample tube retainers and two sample tubes. The kit may be easily transported for delivery by vehicle and/or U.S. mail or courier for remote sample collection. The kit may also include a compact centrifuge for use after the collection of the blood sample. In an exemplary embodiment, a compact centrifuge for use with the disclosed centrifuge rotor includes the Mini Centrifuge. Model MC-700 manufactured by Ai Bi Sheng Biochemistry Technology.

As used in this specification and the appended claims, and unless otherwise specified, the terms “about” and “approximately,” when used in connection with various terms such as temperatures, doses, amounts, or weight percent of ingredients of a composition or a dosage form, mean e.g. a temperature, dose, amount, or weight percent that is recognized by those of ordinary skill in the art to provide an effect equivalent to that obtained from the specified temperature dose, amount, or weight percent. Specifically, the terms “about” and “approximately,” when used in this context, contemplate a temperature, dose, amount, or weight percent, etc. within 15%, within 10%, within 5%, within 4%, within 3%, within 2%, within 1%, or within 0.5% of the specified temperature, dose, amount, or weight percent, etc.

All publications and patent applications cited in this specification are herein incorporated by reference as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. While the claimed subject matter has been described in terms of various embodiments, the skilled artisan will appreciate that various modifications, substitutions, omissions, and changes may be made without departing from the spirit thereof. Accordingly, it is intended that the scope of the subject matter limited solely by the scope of the following claims, including equivalents thereof.