Abstract:
A plastic disruption and homogenization device. The device has rotor that is axially disposed within a stator. The stator and the rotor have several teeth to aid the disruption and homogenization process. The device consists of plastic material that allows the rotor to rotate smoothly without the use of bearings.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application is a continuation of U.S. patent application Ser. No. 07/859,844 filed Mar. 30, 1992 now abandoned, the entirety of which is hereby incorporated herein by reference for all purposes. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to the field of homogenizing devices for liquid substrates, and more particularly, to a single-use, two-part agitation device. 
   2. Description of Related Art 
   When compared with previous years, modern laboratory assays require relatively small quantities of sample to obtain accurate results. When utilizing a reduced quantity of sample, however, the importance of obtaining complete homogenization without the introduction of contaminants is increased to maintain accuracy of the sample reading. Preventing the introduction of contaminants with the disrupter device is crucial when working with contaminant-sensitive samples, such as DNA or RNA. Additionally, agitation of such minute quantities must be performed without damaging the device, the sample housing, or spillage of the sample. 
   Conventional laboratory mixers are well known in the art. Generally, these devices possess an outer shaft (stator), and a central inner shaft (rotor), each having disruptor teeth at the lower end. Ball bearings or other types of bearings are generally provided between the rotor and stator, allowing the rotor to rotate while allowing the outer stator to remain fixed in position. Activation of the rotor draws the liquid substrate upwards to the rotor and outwardly towards the teeth of the stator, subjecting the liquid to the shearing action of the teeth. Variations in the size and shape of the teeth may affect the homogenization of the substrate. 
   Past devices have generally incorporated an ultrasonic pressure field to increase the agitation of solid particulates and increase homogeneity of the sample. Usually, the rotor is activated to turn at a determined velocity, resulting in the ultrasonic pressure field. The pressure field disintegrates solid particulates in the liquid, causing a homogenized sample for analysis. 
   Since modem high-speed analysis requires numerous samples to be homogenized in a relatively short amount of time, decontamination of the disruptor device following each use becomes impractical. The increased surface area of the teeth and the channels formed by the interacting teeth increase the difficulty of ensuring decontamination of the device. Additionally, due to the increased economic costs of properly assembling and aligning the mixing teeth, ball bearings, stator, and rotor, applying such mixers to single-use applications is not feasible for many researchers in the biological sciences. 
   Thus, it has been found that needs exist for an improved disrupter device to adequately homogenize a sample while minimizing or eliminating the introduction of contaminants. Needs further exist for a simple and economically feasible disposable disruptor device. It is to these and other needs that the present invention is primarily directed. 
   SUMMARY OF THE INVENTION 
   Briefly described, in its preferred embodiments, the present invention relates generally to an improved disrupter device. In example embodiments, the disrupter device of the present invention achieves complete homogenization of the sample without introducing contaminants. In addition, example embodiments of the device utilize a low-cost, two-piece design for economical single-use application. 
   In one aspect, the present invention is a plastic single-use disruptor device. The device preferably includes a rotor having a first end and a second end. The first end of the rotor includes several spaced teeth. The second end of the rotor comprises a releasable coupling for attachment to a rotating mechanism. The disruptor device also includes a hollow stator having a first end and a second end. The stator cylindrically houses the rotor. The first end of the stator includes several spaced teeth adjacent to the teeth on the first end of the stator, when assembled. The rotor rests within the stator and freely rotates without need of any bearings or other interposed components. Because the device is plastic and consists of only two parts, it is readily sterilized, but also economically feasible for single-use disposability. 
   In another aspect, the invention is an adapter for coupling a disrupter device to a rotational drive means. The adaptor preferably has a substantially hollow bore, which receives the stator through the use of locking pins. The hollow bore further preferably includes compression springs and a compression spring washer that receive the stator. 
   In yet another aspect, the invention is a disrupter device comprising a stator having a first end and a second end. The first end preferably includes at least one tooth, and the stator preferably defines a bore extending axially therethrough. The bore is preferably stepped to form a bearing surface facing the second end of the stator. The rotor preferably has a first end and a second end, with the first end of the rotor preferably comprising at least one tooth. The rotor preferably further comprises a flange having an expanded dimension, wherein the rotor is rotationally mounted within the bore of the stator with the flange of the rotor directly contacting the bearing surface of the stator without any interposed components. 
   In yet another aspect, the invention is a disruptor device comprising a stator having a first end and a second end. A bore preferably extends through the stator from the first end to the second end, and the second end preferably comprises at least one slot. The rotor is preferably rotationally mounted within the bore of the stator without any bearing components interposed between the rotor and the stator. The device preferably further includes adaptor coupling with a bore extending therethrough and at least one locking pin for engagement with the slot in the second end of the stator. 
   These and other features and advantages of representative embodiments of the present invention are described herein with reference to the drawing figures. 

   
     BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       FIG. 1  shows a disruptor device according to an example embodiment of the present invention, in partial cross-section to show the rotor. 
       FIG. 2  is a cross-sectional view of an adapter for coupling a disruptor device to a drive means, according to an example embodiment of the present invention. 
   

   DETAILED DESCRIPTION 
   Referring now to the drawing figures, in which like reference numbers refer to like parts throughout, preferred forms of the present invention will now be described by way of example embodiments. It is to be understood that the embodiments described and depicted herein are only selected examples of the many and various forms that the present invention may take, and that these examples are not intended to be exhaustive or limiting of the claimed invention. Also, as used in the specification including the appended claims, the singular forms “a,” “an,” and “the” include the plural unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. 
   With particular reference now to  FIG. 1 , a disruptor device  10  according to an example embodiment of the present invention includes a rotor  12  preferably formed substantially of engineering plastics such as for example polyetherimide (for example, Ultem® polyetherimide, commercially available from TexLoc, Ltd. Manufacturing, Forth Worth, Tex.), or polycarbonate (for example, LEXAN® polycarbonate, commercially available from Polymer Plastics. Mountain View, Calif.). The rotor  12  consists of a first end and a second end. The first end of the rotor  12  preferably comprises a plurality of spaced teeth  14 . The second end of the rotor  12  preferably includes a flange  15  having an increased diameter relative to the body of the rotor. The second end of the rotor  12  preferably further comprises at least one fin  20  for engagement with an adaptor or drive means. The drive means can be, for example, a motor drive, forced compressed air, vacuum, a mechanized crank, or adaptors for use thereof. 
   The disruptor device  10  further comprises a stator  16 , which preferably is a hollow, generally cylindrical tube formed substantially of plastic (such as for example polyetherimide or polycarbonate), having a first end and second end. The first end of the stator  16  preferably comprises a plurality of teeth  18  located adjacent to the teeth  14  on the first end of the rotor  12  when the device is assembled. The second end of the stator  16  preferably defines a bore  22  having a larger diameter than the lumen extending through the hollow stator, the bore  22  being configured to receive the flange  15  of the second end of the rotor  12 , whereby upon assembly, the rotor  12  is held within stator  16  to permit rotation of rotor  12 . 
   The shaft of the rotor  12  is received within the lumen extending through the stator  16  until the flange  15  of the rotor abuts against the lower surface of the bore  22  in the stator  16 . Engagement of the flange  15  against the lower surface of the bore  22  in the stator  16  places the teeth  14  of the rotor  12  in substantial alignment with the teeth  18  of the stator  16 . The rotor  12  simply rests within the stator  16 , to permit free rotation of the rotor within the stator without the need for a separate bearing or other component(s) interposed therebetween. In this manner, a simple, inexpensive, two-piece assembly is provided, thereby enabling economically feasible single-use disposability. The stator  16  is preferably fabricated from a clear material such as polycarbonate, so that its interior is visible during use and cleaning, if desired. The rotor  12  is preferably fabricated from an opaque material such as polyetherimide, so that it may be observed through the clear material of the stator  16 . The use of these materials is further advantageous, as the polycarbonate provides a smooth, low-friction finished surface, and the polyetherimide provides lubricity, to enable smooth, low-friction, high-speed rotation of the rotor relative to the stator without the need for a separate bearing or other interposed components. The device  10  is preferably sterilized and packaged to retain sterility during shipping and until the device is ready to be used. 
   With reference now to  FIG. 2 , a coupling adapter  30  according to an example embodiment of the present invention is shown. The coupling  30  preferably comprises a body or housing  32  having a cylindrical bore or recess  34  extending therethrough. The bore  34  preferably comprises at least one locking pin  36  to engage the disrupter device  10  when inserted. The adaptor  30  preferably further comprises a compression spring  38  and a retaining washer  40  mounted in the bore  34 . The upper end of the rotor-stator assembly  10  can be inserted into the bore  34  of the coupling adaptor  30 , whereupon vertical portions of channels or slots  24  formed in the upper end of the stator  16  receive and engage the locking pins  36 . The top of the stator  16  contacts the spring retaining washer  40  and compresses the spring  38  as the rotor-stator assembly  10  is inserted into the coupling adaptor  30 . This compression causes a downward force to be applied by the spring  38  and washer  40  against the rotor-stator assembly  10 . When the rotor-stator assembly  10  is inserted far enough into the bore  34  of the coupling adaptor  30 , the locking pins  36  come into alignment with horizontal portions of the channels or slots  26  formed in the upper end of the stator  16 . The stator  16  can then be rotated, for example through about 90°, to a final position wherein downward pressure applied by the spring  38  engages the locking pins  36  with radiused detents in the stator channels or slots to lock the coupling adaptor to the stator, and lock the stator in position in the adaptor to resist relative rotation therebetween. This quarter-turn adaptor  30  enables the device  10  to be quickly and easily installed and removed from a drive mechanism without the risk of cross-threading the plastic material of the device  10 , as might occur if conventional screw-thread connection means were utilized. The adaptor also facilitates connecting the device  10  to a multiplicity of drive means, such as drive motors of various manufacturers, thereby making the device  10  suitable for economical use by a broad range of practitioners without the need for purchasing additional or specialized homogenizing equipment. 
   While the invention has been described in its preferred forms, it will be readily apparent to those of ordinary skill in the art that many additions, modifications and deletions can be made thereto without departing from the spirit and scope of the invention.