FIELD OF INVENTION

[0001] The present disclosure relates to the field of pipetting. More particularly, the disclosure relates to an apparatus for aspirating liquids into and dispensing liquids from a pipette. More particularly, the present disclosure relates to a pipette controller for facilitating accurate pipetting of liquids.

BACKGROUND OF THE INVENTION

[0002] For the operation of pipetting, one of the traditional ways is to take up the liquids into a pipette by suction with operator's mouth, wherein the liquid is kept therein by blocking one end of the pipette with operator's finger tip. Liquid inside the pipette is then delivered by removal or release of the blocking finger tip. It is readily seen that pipetting in such manner is quite inconvenient and unsuitable because the amount of liquid being taken up and/or being delivered cannot be well controlled and also the operation is not hygienic, especially, when the liquid to be pipetted is destructive to one's health or has an unpleasing odor.

[0003] To obviate the necessity of using the operator's mouth and finger tip, it has been proposed to provide mechanically and/or electronically operated pipette controllers. Some of such pipette controllers are discussed herein below.

[0004] US Pat. No. 3,963,061 discloses an apparatus for drawing liquids into and expelling liquids from a pipette including a housing comprising a hand-held pistol grip to which is connected a pipette-supporting portion. Valve means mounted on the pistol grip beneath two fingers of the user permit selective application of pressure or vacuum to one end of the pipette for drawing the liquid into, and expelling the liquid from, the pipette. The patent discloses a pipette gun having an adjustable valve for continuously variably controlling the pressure applied to the pipette from a constant pressure source and, thus, continuously variably controlling the liquid flow rate through the pipette. The operator controls the liquid flow rate through the pipette by limiting the extent to which the trigger on the gun is depressed. In this manner the operator can rapidly fill or void a major portion of the pipette by depressing the trigger fully and then slowly meter the pipette by depressing the trigger slightly. In the pipette gun disclosed in this US patent, the full range of liquid flow rates is achieved over the action path of the trigger. Due to the wide range of liquid flow rates and the limited action path of the trigger, however, slight deflections of the trigger produce significant changes in the liquid flow rate. Limiting the range of flow rates for a particular trigger path of action makes the trigger less sensitive but also limits the usefulness and efficiency of the pipette gun.

[0005J U.S. Pat. No. 4,527,437 discloses a pipette controller for facilitating the handling of liquids by a pipette. The pipette attaches to the pipette controller. The pipette controller has a handle which is proximate to the attached pipette and substantially parallel to the pipette. The user operates the pipette controller by working a thumb wheel on the handle which is mechanically coupled to a bellows which controls the liquid level in the attached pipette. When operating the pipette controller, the user grasps the hand below the thumb wheel at a position which is approximately medial to the length of a typical pipette. This is a manually operated pipette control system incorporating a thumb wheel operated mechanical system coupled with a bellows type pumping system. In addition, it is obvious that even if a user wishes to rapidly dispense all or substantially all of the contents of an attached pipette, then the user must repeatedly operate thumb wheel and other mechanical elements associated therewith, until such liquid is dispensed. It means device disclosed in this US patent is unable to efficiently accommodate a wide variety of volumes of liquid and therefore is limited to larger pipettes having specific volumetric capacities. Furthermore, these devices suffer from the inability to rapidly dispense large volumes of liquid.

[0006] U.S. Pat. No. 5,294,405 discloses a valve for use in a pipette gun for selectively providing different ranges of flow rates through a pipette cooperating with the pipette gun. The valve has a predetermined number of discrete settings, each of which provides a range of fluid flow rates between zero and a different maximum flow rate. The operator controls the flow rate by depressing the gun trigger a selected distance. To change the flow rate setting, the operator simply rotates the gun trigger to a. desired setting. The present valve also eliminates the "piston effect" of prior art valve elements by isolating the pipette chamber while the valve element operably slides in and out of engagement with a port thereby connecting the pipette with a fluid source either under pressure or at a vacuum. This patent mainly provides a valve for use in a pipette gun having several range settings for variably controlling the flow of liquid samples through a pipette. The gun has separate triggers for activating the flow of negative and positive pressure to the pipette. The pipet guns disclosed in this US patent facilitates pipetting at a variety of flow rates but cannot effectively be adjusted from one general flow rate to another during expulsion of the liquid from the pipet, due to the risk of leakage and thus, can result in inaccurate pipetting. Further, while the valve attempts to close off the chamber from venting to ambient air over the entire path of the trigger, an effective airtight seal is not established, since the valve and valve chamber are typically constructed of plastic materials, thus decreasing the efficiency of the pipet gun. Additionally, while progressively increasing flow rates over the path of the trigger are useful, there is no indication for the operator to determine when the flow rate increases beyond a desired flow rate threshold. Hence in summary in the pipette gun disclosed in thus US patent it is difficult to achieve exact volume of liquid in the pipette.

[0007] U.S. Pat. No. 6,253,628 discloses a pipette gun for drawing liquids into and dispensing liquids from a pipette which includes a variable flow valve assembly. The valve assembly includes a valve which is capable of accommodating a plurality of flow rates, and which is progressively adjustable during pipetting between a first air flow rate and a second air flow rate which is in excess of the first flow rate and which is non-progressively adjustable during pipetting to a third air flow rate which is substantially greater than the second air flow rate. The valve assembly further includes a threshold detector in the form of a spring detent, which provides an indication to the operator that the pipet gun is operating at the increased fluid rate, i.e., the "express mode" of operation. In the pipette gun disclosed in this US patent it is difficult to achieve exact volume in pipette as the user has to vary the finger pressure on aspiration and dispensing knob to achieve exact volume, which too is possible only after few trial and errors. It is time consuming and tedious process.

[0008] US Pat. No. 6,090,348 discloses a method for programming an electronic pipetter to provide more precise measurement and dispensing is provided, as well as an improved display for displaying clearly and in details the programming steps and options to the user thereof. The electronic pipetter may be operated in one of five modes, including a manual mode, a quick-shot mode, a multi-dispense mode, a sequential-dispense mode and a hands-free mode. This patent provides electronic pipette having an advanced programming methodology and an easy-to-understand display so that the user can more exactly and quickly control the electronic pipetter, which in turn provides more precise, repeatable measuring and dispensing of fluids. In this US patent, programming is the only way to achieve exact volume of the liquid. It is time consuming and not user friendly to program for such simple application.

[0009] After studying foregoing pipette controllers, it is clear that in existing pipette controllers, while aspirating or dispensing, adjusting the pipette a particular amount of liquid is a cumbersome task, more particularly when user aspirates- dispenses at a high speed. To adjust at particular volume, the user has to change the speed of the motor by stopping aspiration-dispensing. This is very tedious time consuming. Such adjustment also affects the sensitivity and accuracy of aspiration-dispensing activities. Overall working efficiency and performance of the pipette controller goes down and there is therefore a need to provide a new pipette controller which can take care of such aforementioned problems which are associated with the existing pipette controller.

OBJECTS OF THE INVENTION

[00010] It is an object of the invention to provide a pipette controller which is free from all problems and deficiencies associated with existing pipette controllers.

[00011] It is an object of the invention to provide an apparatus for aspiration and dispensation of liquid in a pipette that facilitates volumetric accuracy of pipetting of liquids.

[00012] It is an object of the invention to provide an apparatus for aspirating liquids into and dispensing liquids from a pipette that provides better sensitivity and accuracy even in low volume of the liquid.

[00013] It is an object of the invention to provide an apparatus for aspirating liquids into and dispensing liquids from a pipette which is time efficient.

[00014] It is an object of the invention to provide an apparatus for aspirating liquids into and dispensing liquids from a pipette that provides maximum working efficiency and performance even with large pipetting volumes.

[00015] It is an object pf the invention to provide an apparatus for aspirating liquids into and dispensing liquids from a pipette that is light in weight and simple in construction.

[00016] It is an object of the invention to provide an apparatus for aspirating liquids into and dispensing liquids from a pipette that is fully user controlled and easy to handle.

[00017] It is an object of the invention to provide an apparatus for aspirating liquids into and dispensing liquids from a pipette that is having a controlled speed operation.

[00018] It is an object of the invention to provide an apparatus for aspirating liquids into and dispensing liquids from a pipette that can work with both glass as well as plastic pipettes. SUMMARY OF THE INVENTION

[00019] The present invention provides an apparatus for aspirating liquids into and dispensing liquids from a pipette, wherein the apparatus comprises of a pipette connecting means adapted to operatively connect the pipette to the apparatus; a dispensation knob for dispensing liquid from the pipette at a first defined speed; an aspiration knob for aspiring liquid into the pipette at a second defined speed; and a control switch for controlling speed of aspiration and dispensation of the liquid, wherein the control switch changes speed of aspiration and dispensation from the first defined speed and the second defined speed to a minimum speed.

BRIEF DESCRIPTION OF THE DRAWINGS

[00019] The detailed description is set forth with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items.

[00020] Fig. 1 illustrates a pipette controller for dispensing liquids from and aspirating liquids into a pipette according to an embodiment of the present invention.

[00021] Fig. 2 illustrates the pipette controller in liquid dispensing mode.

[00022] Fig. 3 illustrates the pipette controller in liquid aspiration mode.

DETAILED DESCRIPTION OF THE INVENTION

[00023] The systems and methods described herein may be used in many different and compatible operating environments. Multiple and varied implementations are described below. An exemplary environment that is suitable for practicing various implementations is discussed in the following section. While the systems and methods are described in the foregoing contexts, acts and operations described hereinafter is implemented in hardware or other forms of computing platforms. Even though most of the disclosure in the present embodiments discussed below discloses a pipette controller, all other compatible apparatus and modes of pipetting can be used for implementation of the proposed systems and methods.

[00023] The above, and the other objects, features & advantages of invention will become apparent from following description read in conjunction with the accompanying drawings.

[00024] Fig. 1 illustrates a pipette controller (1) for dispensing liquids from and aspirating liquids into a pipette according to an embodiment of the present invention. In an embodiment, the pipette controller (1) includes a micro pump (15) having a motor, a control unit (20), dispensation and aspiration knobs (4, 5) for dispensing and aspirating liquids respectively, a speed selection switch (6) for selecting a speed at which aspiration and dispensing operation will take place, and a control switch (1 1).

[00025] In another embodiment, the pipette controller (1) includes a nozzle (3), a safety valve (7), and a silicon adapter (8). The silicon adaptor (8) can provide a tight fit for glass and plastic pipettes. In an embodiment, the silicon adaptor (8) can be accommodated in nozzle (3). The silicon adaptor (8) can be spiral shaped and can connect the pipette to the safety valve (7) and help in aspiration and dispensation of the liquid by piston cylinder type mechanism. In the piston cylinder mechanism, a piston (22) can be used along with an O ring (17) to carry out the aspiration and dispensation function. The piston (22) and O ring (17) are shown as parts both the aspiration (5) and dispensation knob (4). In yet another embodiment, the safety valve (7) can be used to stop liquid from entering into the nozzle (3) so that the control unit (20) is not affected. The safety valve (7) can further block the liquid from entering inside the pipette controller 1 in case of overpipetting. The pipetting apparatus can be also equipped with a membrane filter (not shown) which is replaceable. The filter can protect the pipetting apparatus and the user from contamination by vapors of the liquids being drawn in the pipette. The filter can further be accommodated by a filter holder (19).

[00026] In an implementation, the pipette controller (1) can operate in two modes, namely the dispensing mode and the aspiration mode. The modes are selected by using push buttons (4, 5). Push button (4) is provided for carrying out operation of dispensing liquid from pipette while push button (5) is provided for carrying out operation of aspiration of liquid into the pipette. In an embodiment, both push buttons (4, 5) are connected to the micro pump (15) to allow motor of the micro pump (15) to operatively function based on finger pressure on the aspiration and dispensation knob (4,5). In another embodiment, the push buttons and/or the knobs 4, 5 are independent of the micro pump (15) for their respective functions. In an embodiment, the push buttons (4, 5) can include a piston cylinder mechanism (17 and 22). The pistons can move smoothly and can be operated with minimum efforts making it easy to adjust meniscus precisely at the desired point. The push buttons (4, 5) can be operatively connected to the control unit (20), also interchangeably referred to as electronic control unit (20). The control unit (20) can further be operative connected to the speed selection switch (6), which decides the speed at which aspiration and the dispensation of liquid would take place.

[00027] In an implementation, the speed of aspiration and dispensing can be controlled mechanically by changing the finger pressure on the push buttons (4, 5). In such an implementation using the mechanical pressure mode, speed of the motor of micro pump (15) does not change and the motor continues to work at the same speed which is set by the speed selection switch (6). Speed of aspiration and dispensing, in such a case, only changes by the variation in finger pressure. In an other implementation however, the push buttons (4, 5) are connected to the micro pump (15) to allow motor of the micro pump (15) to operatively function based on finger pressure on the aspiration and dispensation knob (4,5).

[00028] In another implementation, speed selection switch (6) can be used for controlling the speed of aspiration and dispensing. In this mode, a user can set the desired speed using the speed selection switch (6), which is operatively connected to the micro pump (15) motor through the control unit (20).

[00029] In an embodiment, the electronic control unit (20) may be an electronic circuit, microprocessor or a programmable chip. The main function of the electronic control unit (20) is to manage the overall operation of the pipette controller 1.

[00030] While aspirating liquids into and dispensing liquids from a pipette, adjusting the liquid at particular level in the pipette is a tedious job. In existing devices, for adjusting a proper liquid volume, it is necessary to stop aspiration- dispensing activities or adjust speed by changing pressure on aspiration and/or dispensing knob. However, the present disclosure provides a motor control switch (11), also is interchangeably referred to as a control switch (11). The control switch (11) allows the user to change the speed of the motor (aspiration speed or dispensation speed) from existing speed to a minimum speed (drop wise aspiration and dispensation). In an embodiment, this speed conversion can happen immediately by pressing of the control switch (1 1) once. In an implementation, the control switch (11) further allows speed change from the minimum speed to a preselected/predefined speed without stopping aspiration-dispensing. In another implementation, the control switch (1 1) can also change the speed from the minimum speed to the aspiration/dispensation speed from which it was changed earlier to the minimum speed. In yet another embodiment, the control switch (11) can be operatively connected to the control unit (20) for controlling the operation of the motor of the micro pump (15).

[00031] In an embodiment, at the time of dispensing operation, motor of the micro pump (15) runs at the adjusted speed / highest speed decided by the user. When the user presses the motor control switch (11), pump (15) starts running at the slowest/minimum programmed speed. In an embodiment, this speed is already set/ programmed in the electronic control unit (20) which allows drop wise dispensing of the liquid. The minimum speed can also be configurable by the user at ran time. In another embodiment, a battery charging plug (10) can be provided for charging batteries whenever required.

[00032] In yet another embodiment, the pipette controller (1) can include an LCD (21) coupled with a Battery Cell (18) for improved display of the pipette controller 1 and parts thereof.

[00033] Fig. 2 and 3 illustrate the liquid dispensing 200 and aspiration mode 300 respectively. In working, a user can connect a pipette (14) to a pipette controller (1) using a pipette connector. The user can then select an operation to be performed and select a speed at which it is to be performed using the speed selection switch (6). Based on the selection of aspiration or dispensation function, the user can trigger push buttons (4, 5). The user can control the speed of motor of the micropump (15) by the electronic control unit (20) or by changing the finger pressure on the push buttons (4, 5) to ensure dispensing from or aspiration into the pipette of the desired quantity of liquid. In an embodiment, the electronic control unit (20) is operatively connected to the speed selection switch (6). In yet another embodiment, the electronic control unit (20) is operatively connected to the speed selection switch (6) and/or the control switch (1 1). The user can also change the speed of motor from existing speed to lowest/minimum speed once he/she aspirates liquid to a level from where desired/required level is close and from lowest speed to a predefine speed/or earlier aspiration/dispensation speed using motor control switch (11) once desired volume is achieved. In an embodiment, the apparatus can operate in two modes, namely the aspiration mode and the dispense mode. When a user presses the push button (5), motor of the micro pump (15) starts running according the electronically adjusted aspiration speed. In this mode, the liquid gets aspirated in the pipette (14) and remains intact after releasing the button. When user presses the push button (4), the motor starts running according the electronically adjusted dispensing speed. In this mode the liquid gets dispensed from the pipette. ADVANTAGES OF THE INVENTION

[00034] The present disclosure provides a pipette controller which is free from all problems and deficiencies associated with existing pipette controllers.

[00035] The present disclosure provides an apparatus for aspiration and dispensation of liquid in a pipette that facilitates volumetric accuracy of pipetting of liquids.

[00036] The present disclosure provides an apparatus for aspirating liquids into and dispensing liquids from a pipette that provides better sensitivity and accuracy even in low volume of the liquid.

[00037] The present disclosure provides an apparatus for aspirating liquids into and dispensing liquids from a pipette which is time efficient.

[00038] The present disclosure provides an apparatus for aspirating liquids into and dispensing liquids from a pipette that provides maximum working efficiency and performance even with large pipetting volumes.

[00039] The present disclosure provides an apparatus for aspirating liquids into and dispensing liquids from a pipette that is light in weight and simple in construction.

[00040] The present disclosure provides an apparatus for aspirating liquids into and dispensing liquids from a pipette that is fully user controlled and easy to handle.

[00041] The present disclosure provides an apparatus for aspirating liquids into and dispensing liquids from a pipette that is having a controlled speed operation.

[00042] The present disclosure provides an apparatus for aspirating liquids into and dispensing liquids from a pipette that can work with both glass as well as plastic pipettes.

[00043] The present apparatus works with all types of glass and plastic pipettes in the range of 1 ml to 200 ml.

[00044] The present apparatus allows changing the speed of motor from low to high and vice versa without stopping aspiration-dispensing operations. [00045] Control switch, of the present apparatus, along with aspiration- dispensing knob ensures fast dispensing of large volumes and precise measuring of small volumes.

[00046] The present apparatus is equipped with replaceable membrane filters that protect cross contamination. The filter also prevents contamination of the mechanism by reagent vapors.

[00047] Smooth push buttons of the present apparatus ensure effortless pipetting even during extensive use.

[00048] Batteries can be charged and changed very easily by the user.

[00049] The present apparatus allows a relaxed grip design having low weight and low resistance operation to minimize strain from prolonged pipetting.