Disposable Homogenizer kit
The present invention relates to a disposable device kit for homogenizing material, including biological materials (human or animal tissue, plants) and non-biological material, in particular for performing laboratory tests for various purposes.
There are many applications requiring the testing of biological or non biological materials where a sample is placed in a mixer and is cut into small pieces. The mixing may be performed in the presence of a solvent, or a solvent may be added to the material sample after it has been cut into small pieces in order to extract the substances from the material, depending on the application. For example, the sample may be animal or human tissue that is used for testing DNA, blood analytes and other substances within the tissue. Commonly, a sample of material is placed in a mixing unit, possibly with the addition of a solvent or other treatment liquid, and then cut into small pieces in the mixer. After mixing, the homogenized substance is transferred into a vial, where it may be mixed with a treatment liquid such as solvent, and then filtered to remove solid particles. In order to avoid contamination of samples in subsequent testing, the mixing container needs to be cleaned and sterilized and great care must be taken during the transfer of liquid from the mixer to the vial in which the sample is filtered or stored after filtering for further processing and testing. Each transfer also leads to loss of a certain amount of the liquid due to the residue left on the container walls.
It is known to provide homogenizing devices as described for example in US2006/0078474, US 2005/0139704, US 2006/0245298, US 2003/0077838, and US 2006/045816. An object of this invention is to provide a homogenizer kit for testing of biological or non biological material samples, that is economical yet easy and safe to use with a low risk of contamination. It is advantageous to provide a homogenizer kit that has a high recovery yield of sample material.
It is advantageous to provide a homogenizer kit that is easy to use. Objects of the invention have been achieved by providing a disposable single- use homogenizer kit according to claim 1 .
Objects of the invention have been achieved by providing a homogenizer kit according to claim 2.
Objects of the invention have been achieved by providing a homogenizer kit according to claim 3.
Disclosed herein is a homogenizer kit comprising a vial, a mixing unit comprising a cap and a mixing device for homogenizing material within the vial, the mixing device configured to be removably mounted to an open end of the vial, and an outlet cap configured to be removably mounted at an open end of the vial for extraction of homogenizing material. The vial comprises a pre- assembled movable piston or stopper forming an end wall of the vial, the piston sealingly engaging a side wall of the vial and configured to be movable towards the vial open end for expelling homogenized material from the vial.
The outlet cap comprises a cap body, a nozzle and optionally a filter positioned across an inner side of the nozzle to filter particulate material in the vial. The outlet cap advantageously comprises a pre-filter chamber portion or spacing with a shoulder or a radial wall presenting a stop for the piston such that the chamber portion forms a buffer volume to contain particles that are retained by the filter.
The piston of the vial may comprise an essentially disk shaped body and one or more flexible sealing lips therearound engaging the vial side wall.
The mixing unit cap may advantageously comprise a chamber that provides a separation of the bearing passages for guide stability of the shaft, and further serves as a buffer volume to prevent matter in the vial from escaping out of the cap through the bearings. The cap of the mixing unit may further comprise positioning protrusions engaging an annular shoulder of the shaft for axial positioning of the shaft. The protrusions also advantageously reduce the surface area to reduce friction and limit the heat generated during rotation. The mixing device may comprise blades having one or more tangential extensions positioned at a small gap distance from the vial side-wall, configured to stabilize and guide the blades.
The mixing device comprises a coupling portion at an upper end of the shaft configured to couple without fixed attachment or locking with a complementary coupling portion of the rotor of a motor detachably positioned over the mixing device coupling portion and intended to drive the shaft in rotation.
According to an embodiment of the invention, the mixing device is configured to be mounted to the motor so that the axis of rotation of the shaft and blades is at an angle between the vertical and horizontal positions, for example between 30° and 60° with respect to the vertical position. This assists in homogenizing very small quantities of substance placed in the vial. According to an embodiment of the invention, the mixing device may comprise a plurality of blades, positioned along the shaft at various heights, which allows to homogenize the substance in uniform manner. At high rotational speed the content is either thrown out or drawn in due to centripetal and centrifugal force, whereby multiple blades handle all the content. Advantageously, the homogenizer kit according to the invention allows a high recovery of samples treated and avoids the transfer of samples from one vial to another thus significantly reducing the risk of contamination and increasing safety of use. Moreover, the single use disposable components of the homogenizer kit according to the invention are very economical to produce and does not require cleaning of components. The homogenizer kit according to the invention is also very economical to use because of the low number of manipulations required.
Further advantageous objects and features of the invention will be apparent from the claims and the description of embodiments of the invention hereafter in relation to the annexed drawings, in which:
- figures 1 a to 1 g are perspective views of parts of a homogenizer kit according to an embodiment of the invention, illustrating different steps of operating the homogenizer kit for obtaining substances extracted from a sample of material, where
- figure 1 a shows a sample placed in a vial and a mixing device about to be assembled to the vial,
- figure 1 b shows a motor connected to the homogenizer kit for cutting the sample in small pieces,
- figure 1 c shows the removal of the mixing device,
- figure 1 d shows the vial with an outlet cap,
- figure 1 e shows the vial in position in a plunger device,
- figure 1f shows the vial in the plunger device prior to extraction, and
- figure 1 g shows the vial in the plunger device with the plunger depressed and extraction of the sample from the outlet; Figure 2 is a cross-sectional view through a vial of an embodiment according to this invention; Figure 3 is a cross-sectional view through a mixing device according to an embodiment of this invention;
Figure 4 is a cross-sectional view through an outlet cap according to an embodiment of this invention;
Figure 5 is a bottom view of a mixing blade portion of a mixing device according to an embodiment of this invention;
Figure 6 is a perspective view of a vial and mixing unit with multiple blades according to another embodiment of the invention.
Referring to the figures, the homogenizer kit according to an embodiment of this invention comprises a vial 2, a mixing device 4, and an outlet cap 6. The vial, mixing device and outlet cap are single-use disposable parts. The homogenizer kit may optionally further include a plunger device 8, although the plunger device may also form part of an external unit and be reusable. The mixing device 4 is configured to be coupled to an external motor or drive unit 9.
The vial comprises a side wall 12 surrounding a chamber 13 within which a sample 3 of material to be tested may be placed, one end of the vial being closed by a movable end wall 10 in form of a piston or a stopper 10 sealingly engaging the side wall 12. An opposite end of the vial 14 is open and configured to receive a cap portion 16 of the mixing device 4, or the cap portion or body 50 of the outlet cap 6. The vial side wall may be made of glass or of a polymer, and preferably has a cylindrical tubular shape. The mixing unit comprises a cap 16 and a mixing device 18 rotatably mounted to the cap.
The mixing unit cap comprises disc portions 20a, 20b having a central bearing cavity 22a, 22b and a side sealing wall 24 that sealingly engages the side-wall of the vial. In the embodiment illustrated, the cap comprises an intermediate spacing or chamber 21 between two disc portions 20a and 20b and bounded by the side sealing wall. The spacing 21 on the one hand advantageously provides a separation of the bearing passages 20a, 20b for guide stability of the shaft 26, and on the other hand advantageously serves as a buffer volume to prevent matter in the vial from escaping out of the cap portion through the bearings. Any possible leakage of liquid through the space between the lower bearing passage 20b and the shaft 26 due to the projection of liquid during the mixing operation will collect in the chamber 21 . The mixing unit cap may comprise two or more parts assembled together, for example as illustrated the outer disc portion 20a may be separately formed and assembled to the integrally formed outer annular sealing wall and lower disc portion 20b. The two or more parts may be made of the same material, or of different materials, for instance the side sealing wall 24 may be made of a polymeric material with a certain elasticity configured for slight compression and sealing engagement with the vial side wall, whereas the outer disc portion 20a may be made of a less elastic polymer.
The mixing device comprises a shaft 26, a blade portion 28 at one end of the shaft 26, and a coupling portion 30 at an opposite end of the shaft, the coupling portion configured to engage a coupling portion 1 1 of an external motor 9 and the blade portion 28 configured to chop and mix a material sample 3 placed in the vial. The material samples 3 may be solid, semi-solid, liquid or a combination of the foregoing. The blade portion 28 comprises blades 27 and has the function of cutting the sample into smaller pieces and mixing, or simply cutting, or simply mixing, depending on the properties of the sample to be treated and the nature of the tests to be carried out. The shaft 26 of the mixing portion 18 has a bearing portion 32 supported in rotation against the bearing section 22a, 22b of the cap portion whereby the bearing portions may also be configured to sealingly engage each other in order to prevent liquid in the vial from leaking out or escaping during the mixing process or during transport and handling of the vial with the mixing unit coupled thereto. The blade portion end of the shaft may also be provided with a bearing, for example an end of the shaft engaging in a corresponding central cavity or depression (not shown) in the plunger or stopper 10.
As best seen in figure 5, in the embodiment illustrated, the outer periphery of the blade portion 28 may comprise tangential wings or extensions 29 configured to stabilize and guide the blade portion end 28 by enabling sliding engagement against the vial side walls. The tangential extensions are positioned a small gap distance from the vial side-wall. In the embodiment shown, each blade has a tangential extension, however in a variant the extensions could be joined such that they form a single continuous ring, in other words a single annular extension.
In a variant as shown in figure 6, a plurality of blade portions 27a, 27b, 27c, 27d may be positioned along the shaft within the chamber depending on the chopping or mixing function required, the application and the samples to be homogenized, and the length and diameter of the vial. The blade portion 27a positioned closest to the plunger or stopper is preferably spaced from the plunger by a predetermined minimum non-zero distance. The position of the blade portions 27a-d may be set by the length of the shaft and the position of the shaft relative to the cap 16 as in the embodiment illustrated. The plurality of blades positioned along the shaft at various heights helps to homogenize the substance in uniform manner. At high rotational speed the content is either thrown out or drawn in due to centripetal and centrifugal force, whereby multiple blades handle all the content. The cap 16 may advantageously comprise positioning protrusions 17 against which a disc or thrust portion 19 of the shaft 26 abuts, the thrust engagement of the disc portion 19 and the protrusions 17 also forming a thrust bearing for positioning the height of the blades within the chamber. In this configuration, the rotation of the blade portion 28 configured such that the pressure of the material on the blade biases the mixing device in a direction towards the end wall 10. The protrusions advantageously reduce the surface area of the thrust bearing to reduce friction and limit the heat generated during rotation.
According to an embodiment of the invention, the mixing device is configured to be mounted to the motor so that the axis of rotation of the shaft and blades is at an angle between the vertical and horizontal positions, for example between 30° and 60° with respect to the vertical position (not shown). This assists in homogenizing very small quantities of substance placed in the vial. The shaft may further comprise a locking protrusion 34, or a plurality of locking protrusions, that engage a bottom side of the cap 20b to retain the shaft to the cap 16. The locking protrusion 34 may be in the form of an elastic arm that is connected at one end to the shaft and that allows assembly of the shaft by insertion through the central cavities 22a, 22b of the cap disc portions 20a, 20b. The blade portion 28 may then be assembled to the shaft. The blade portion may be made of a polymeric material or if cutting and other operations on hard material are required the blade portion 28 may be in metal with two, three, four or more sharpened blades. The blade portion 28 may be attached mechanically to the shaft by elastic locking arms on the shaft tip inserted into a central orifice 39 provided in the blade portion, or by other fixing means. Alternatively, the blade portion 28 may be welded or bonded to the shaft. The blades may comprise a sharp cutting edge 37 and may also have a shape configured to induce recirculation flow of the liquid in the vial chamber 13 in order to perform a size reduction and mixing operation on the solid particles and liquids within the vial.
The coupling portion 30 of the mixing unit may have various shapes configured to couple with a complementary coupling portion 1 1 of the rotor of a motor intended to drive the shaft 26 and blade portion 28 in rotation. Preferably, the coupling portions 30, 1 1 are configured to allow positioning of the motor 9 over the mixing unit in a simple axial movement without attachment or locking. In the example illustrated, the mixing unit coupling portion 30 comprises a pair of arms 36 extending radially from the shaft 26, configured to engage in a corresponding slot 41 in the rotor shaft of the external motor.
The piston or stopper 10 may advantageously be made of a silicon rubber or other material having a certain elasticity, injected as an integral body with the sealing rings or lips 43 that engage the vial or side-wall and allow the piston to be pushed along the vial to extract the substances within the vial as will be described further on in more detail. The piston 10 may also be made (e.g. injected) as a dual component part with sealing rings 43 in a different material to the piston body. The vial may comprise an inwardly radial shoulder 44 to form a defined end position for the piston 10, and to prevent the piston from being pushed inadvertently out of the end of the vial, for instance when inserting material 3 to be tested in the chamber 13 and assembling the mixing unit 4 to the vial 2.
After the homogenizing and mixing operation as illustrated in figure 1 b, the mixing device 4 may be removed from the vial 2 as illustrated in figure 1 c and the outlet cap 6 positioned over the vial open end, as illustrated in figure 1 d, to close off the open end. The outlet cap 6 comprises a cap body 50 with a sealing side ring 51 engaging the vial side-wall, a nozzle 52 for extraction of the substance in the vial, and a filter 54 positioned proximate or against an inner side of the cap body across the nozzle 52 to prevent solid particles from being expulsed through the nozzle 52. The presence of the filter 54 and the particle retention size of the filter may be configured for the specific application and may vary from one nozzle to another. Within the scope of the invention, it is possible to provide more than one nozzle in a homogenizing kit with a selection of different filters or nozzle orifice diameters. As best seen in figure 4, the cap body 15 may be made of two parts 50a and 50b, with the filter 54 clamped between the two parts. The filter may also be bonded, welded or held by other means to the cap body, and the cap body may be made of only one part. The outlet cap may also comprise a pre-filter chamber portion or spacing 56 with a shoulder or a radial wall 58 having an orifice 57 to form a stop for the piston 10, whereby the chamber portion 56 forms a buffer volume to contain particles that are retained by the filter. The spacing 56 thus provides a certain volume for the particles held back and prevents the piston from being pressed too far towards the filter and potentially rupturing or breaking the filter.
As shown in figures 1 e to 1 g, the vial with the outlet cap may be positioned in a plunger device 8 that has a holder portion 60 in which the vial is positioned and a plunger shaft 62 that engages the piston 10 through the vial end wall, configured to press the piston towards the nozzle to expel the filtered homogenized substance out of the vial. The plunger device may be provided as part of the homogenizer kit, or may be separate from the homogenizer kit. The plunger device may be a multi-use device or a single use disposable device, for example made of plastic. The plunger device may also be incorporated in a laboratory machine or other device, for instance for distributing portions of homogenized substance into different testing units in an automated or semi- automated manner. As there is no transfer of substances from one vial to another, and since the vial end wall is formed by a piston with sealing rings that wipe along the inside surface of the vial chamber, a maximum amount of homogenized material is extracted from the vial, with a very low risk of contamination. The homogenizer kit as described above may also be made cost effectively for single-use application.