MXPA06010314A - Hand-held pipette comprising at least one track and one brush for displaying a volume value to be sampled - Google Patents

Abstract

- at least one track (80, 82) having increments (84, 86);and - at least one brush. It also comprises a register area (94) independent of the or each track, and arranged so as to come into contact with the or each brush after it has travelled a predetermined number of increments.

Description

MANUAL PIPET THAT COMPRISES AT LEAST ONE CHANNEL AND A BRUSH FOR DEPLOYING A VOLUME VALUE FOR SAMPLING FIELD OF THE INVENTION The invention relates to pipettes, in particular to portable pipettes.

BACKGROUND OF THE INVENTION It is known, in particular in document FR-2 807 558, a manually operated pipette to move a plunger in the pipette with a view to sample a liquid, and subsequently, eject this liquid. The pipette comprises means for adjusting the value of the volume of liquid to be sampled and an electronic display for displaying this value. It is possible to calibrate this pipette by registering in the pipette control microprocessor a calibration value corresponding to a predetermined mechanical configuration for the adjustment means. The pipette comprises one or more brushes that travel through one or more channels that have magnifications and that are connected to the volume adjustment means. When the user modifies the volume setting to be sampled, the brush or brush traverses the increases in the channels and the microprocessor counts the number of increases traveled, which allows the new volume value corresponding to the obtained adjustment to be properly displayed. However, there is a drawback, if the user modifies the volume setting when no power is supplied to the electronic part of the pipette (the pipette being disconnected or the power supply has been turned off), the pipette loses account of the increases tours. When the pipette is energized again, it is then that it is not in the position to display a correct value corresponding to the volume adjustment obtained. One of the objects of the invention is to mitigate this drawback by making it possible to display a correct volume value to be sampled, even when the adjustment means were manipulated at the moment that the pipette did not have any power supply.

SUMMARY OF THE INVENTION For this purpose, according to the invention, there is provided a manual pipette comprising: at least one channel that has increases; at least one brush, the pipette also comprising a separate recording area for each of the channels, and adjusted to make contact with each of the brushes after having traversed a predetermined number of increases. The independent registration area has many applications. In this way, it is possible to readjust the microprocessor with a display to display a correct volume value, even if the volume adjustment means are manipulated while the pipette is off. For example, in a preference mode, it is detected that the adjustment means have a predetermined configuration, for example, in a lower mechanical abutment. Subsequently, a volume adjustment is modified so that the brush has contact with the registration area. The microprocessor detects this contact, which constitutes the first contact after the predetermined configuration has been affected. Therefore, the microprocessor recognizes once more the exact mechanical configuration of the adjustment means. By counting the number of increases of this contact and using a predetermined reference value, it is therefore possible, at any time of deployment once more, to correctly adjust the volume value. In another application, the registration area constitutes security with respect to the increment counting by means of the microprocessor. This is because, in a preference mode, it is possible to ensure that the microprocessor measures the number of increases traveled on the channel by means of the brush between two contacts of the brush with the recording area. Accordingly, the microprocessor compares the measured number with a value that was previously stored in the microprocessor and corresponds to the actual number of increases. If these two numbers are different, this means that there is an abnormality. For example, it may be the case that an increase contains a bit of dirt, and therefore, can not make electrical contact with the brush when the latter passes over the increase. At the moment when such an abnormality exists, it is possible to perform a provisioning for the microprocessor to correct that the volume value is displayed by making contact with the registration area. The pipette, according to the invention, can also have, at least, any of the following characteristics: - independently of the contact area of each channel, means for detecting that the means of adjustment of the volume to be sampled, have a default configuration; - at least two channels, and the increases are placed so that the brush or brushes make contact with the channels in different successions along the direction of travel in the channels by means of the brushes; - the brush or brushes are adjusted to make contact simultaneously with the two channels; - the brush or brushes are adjusted to make contact with the channels, not simultaneously; - the brush or brushes are adjusted so that they can make contact with only one channel; - at least comprises two brushes associated with the respective channels; - at least comprises two brushes associated with each channel; - the brushes are electrically connected to each other permanently; - comprises a grounded channel the brush or brushes that are connected to the grounded channel permanently; and - at least comprises a support for the channel or brush, the support which is fixed in a rotatable manner and which is free to slide in a part of the pipette. According to the invention, a method for determining a value of a volume to be sampled is also provided by means of a manual pipette comprising at least one brush and at least one channel that has increases, a method in which: - it is detected that the adjustment means of the volume to be sampled, have a predetermined configuration; - a volume adjustment is modified; - a brush contact is detected with an independent recording area of each channel; and - a volume value is determined by means of a predetermined reference value. The determination method can also have at least any of the following characteristics: the predetermined configuration corresponds to one end of the volume value; - a value related to the position of the recording area with respect to the channel to be registered in the pipette; - a number of steps traveled by means of the brush as the contact is measured; and - a number of successive brush contacts are measured with the registration area. A method for controlling a manual pipette according to the invention is also provided, in which: - a number of steps traversed in a channel is measured by means of, at least, one brush between two contacts of the brush with an area of registry; and the measured number is compared to a predetermined number. The con-rol method that can also count, at least, with one of the following characteristics: - a display of a value of a volume of liquid to be sampled is demanded, considering the predetermined number; - an alert message is displayed if the measured number is different from the predetermined number; and - a succession of contacts of the brush or brushes is detected with the channels (the channels, which are at least two in number), and the detected sequence is compared with a predetermined sequence.BRIEF DESCRIPTION OF THE FIGURES Other features and advantages of the invention will arise from the following description of a preferred embodiment that is not intended to limit it and in which reference is made to the appended figures, in which: Figure 1 is a view in longitudinal axial section of a pipette according to a preferred embodiment of the invention. Figure 2 is a large-scale view of the middle part of the pipette of Figure 1. Figure 3 is a perspective view showing the screw, brush holder and channel holder of the pipette of Figure 1 Figure 4 is a perspective view in parts of the brushes and their support. Figure 5 is a detailed plan view of the channel support of Figure 3. Figure 6 is an illustrated diagram of the signals received by means of the microprocessor of Figure 1 when the brushes travel the channels.

DETAILED DESCRIPTION OF THE INVENTION A preferred embodiment of the pipette according to the invention will be described with reference to figures 1 and 2. This pipette is essentially of the type described in WO 01/76747, WO 01/76748, WO 01/76749, WO 01/76750, WO 01/76751, WC / 0176752, WO 01/76753 and FR-2 807558. Therefore, only the features related to the invention and which are not described in these prior documents will be indicated in the present invention. In summary, the pipette 2 comprises a body 4, a control rod 6 provided at its upper end with an actuator knob 8, an adjusting nut 10, a liquid crystal display 12 for the display of information, in particular at a value of a volume to be sampled, an electronic circuit 14 for controlling the screen and the pipette, and a device 16 comprising a knob 18 that allows the ejection of a removable cone, not shown, fixed to a lower end 20 of the pipette in a known way. The bar 6 makes it possible to control a piston 21 for subtracting from the cone a sample of liquid to be taken or extracted therefrom. The pipette is a manual, hand-operated, non-motorized pipette. To use it, the user holds the body 4 in his hand and operates, as required, the lower part 8 or the lower part 18 by means of his fingers, for example, his thumb. The pipette comprises the already known means allowing the user to adjust the value of the volume to be sampled by means of the pipette. For this purpose, the screw 10 makes contact with a part 50 of the body forming a nut and thereby making a helical connection. The screw has a lower end 52 constituting an upper stop for a support of the bar 6 carrying the piston 21. Therefore, the position of the screw determines the volume value extracted by means of the piston. The user will maneuver the screw by means of the knob 8, rotating the bar about its longitudinal axis. The bar 6 which is coaxial with the screw 10 through which it extends and is fixed rotatably to the latter, the screw itself is also rotated. The user can also modify the adjustment by actuating the milled wheels accessible through the windows in the body 4, which are already known and which will not be described in the present invention. The pipette comprises a brush support plate 54 in the form of a washer, slid on the screw 10, as illustrated in figure 3. In the last figure, for ease, the screw is illustrated as if it were solid, but it should be understood that you count on that the bar 6 passes through it. The plate 54 has essentially a silver shape and extends in a general planar perpendicular to a longitudinal axis 56 of the screw. It has two lugs 58 each extending radially from an inner edge of a central hole 60 in the plate. The screw 10 has two slots 62 that are cut in the part of the screw 10. Each groove extending parallel to the axis 56. The plate 54 slides on the screw 10 such that the lugs 58 are received in the respective grooves 62. The plate 54 is also housed in the pipette without allowing its height to vary along the axis 56. The result of this assembly is that the plate 54 is fixed rotatably to the screw 10 during movement of the latter approximately on its axis 56. This adjustment results from the housing of the handles 58 on the screws 62. However, during the helical movement of the screw, the plate 54 remains at the same height in the body of the pipette in such a way that the screw moves slidably with respect to the plate 54 (and vice versa) when the volume adjustment is modified which will be sampled The pipette also comprises an encoder 64 set in this case in the form of a printed circuit. The encoder thus comprises a support 66 having the channels illustrated in detail in Figure 5. The encoder has a flat shape and also extends in a plane perpendicular to the axis 56. It is placed opposite the plate 54. with a circular body and a protrusion 67 extending radially from an outer edge of this body. The encoder is fixed rigidly to the body 4 of the pipette while sliding on the screw 10.

The plate 54 carries brushes which, in this case, are six and are adjusted in pairs. In that way, a pair of brushes 68, a pair of brushes 70 and a pair of brushes 72 can be observed. At this point, all the brushes are parallel to each other. Each pair of brushes is defined by means of a tongue, an extreme area of which is divided longitudinally to individualize the two brushes. These three languages are fixed to the same base 74. The consistent assembly of the base and tongues is formed in a single piece by cutting and forming a sheet of metal. This blade has three holes 76 which allow the base 74 to be fixed and fit in position on the plate 54 by means of three tacks extending to project from one face of the plate and attempting to pass through the holes 76. The configuration of the encoder 64 will now be described in detail with reference to Fig. 5. The encoder comprises two circular channels 80 and 82 or channel A and channel B. Each of these channels has a plurality of identical increments 84, 86 between yes and spaced regularly apart from each other in each channel. Thus, channel A in the present example 24 has increases 84, equal to channel B. In channel A, increases 84 are formed by means of rectangles connected at their outer edges by means of an electrical link 84 in a Arc of a circle. The same applies to channel B or channel 82 in which the increases 86 are connected to each other at their internal edges by means of a link 90. Channel A has the general configuration of an open circle such that its ends do not they are contiguous. The same applies to the channel B. With reference to the axis 56, the measurement of the angle separating two successive increases 84 of the channel 80 is equal to the measurement of the angles separating two successive increases 86 in the channel 82. However, the increases in the two channels they do not coincide from one channel to the other. In the present example, the increases are in a partial angular overlap with reference to the angular travel of the channels near the axis 56. The encoder 64 also comprises a grounded channel 92 having the general configuration of a closed circle so that its ends are contiguous. Finally, the encoder comprises a recording area or pipette revolution area 94 that extend at a smaller angle compared to the total angle covered by each of the channels A and B. In this case, the recording area 94 is extends in a part of an angle smaller than 90 ° and rests at this point between 5o and 10 °. In the present example, the recording area is formed by means of a rectangle with the same shape and dimensions as the rectangles that form poop increase 84 of channel A 80. In addition, this recording area is placed in equal distances of the two increases closest to the ends of this channel, in line with these extremes. Channel A 80, channel B 82, channel to ground 92 and the registration area 92 are each connected by means of a respective conductor to an output terminal that extends into the protrusion 67 of the encoder. In the present example, the two brushes 68 attempt to traverse the channel A and consequently, make contact with the increases 84 in this channel, and by themselves. The same applies to the two brushes 70 and the channel B with its increases 86. On the other hand, the two brushes 72 try to be in permanent contact, at least in one case, with the grounded channel 92. Additionally, once per revolution, the brushes 68 of the channel A make contact with the registration area 94. The six brushes that are produced from the same metal piece, are in permanent electrical contact with each other and in particular, directly or indirectly, with the grounded channel . Therefore, it will be understood that, during the movement of the screw, the brushes 68 and 70 cause the output of the grounded channels to come into contact sometimes with the output of the B-channel 82 and by itself, and finally sometimes in simultaneous connection with the output of channel A 80 and the output of channel B 82. Knowing that different electric voltages are applied in the pipette between, on the one hand, the output of channel A 80 and the output of the channel to ground, and on the other hand, the output of channel B 82 and the channel output to ground, the result is that several output signals are transmitted to the microprocessor according to the path of the increases by means of the brushes. These signals are shown, represented in the form of 0 and 1 in figure 6. The lower line corresponds to the signals emitted by virtue of the increases of channel B 82, and the average line of those emitted by virtue of increases in channel A 80. Knowing that these signals are established from one channel to another, the microprocessor can then distinguish four voltage states represented respectively by "00", "01", "11", "10". In each of these symbols, the first digit represents the state of channel B, while the second digit represents the state of channel A. These different states constitute the steps traveled by means of the brushes. With respect to the partial angular overlap of the A and B channel increases, the succession of the signals received by the microprocessor when the brushes travel the encoder in a first direction illustrated by the arrow 100 in FIG. 6 comprises the sequence 00, 01 , 11, 10. On the other hand, when the brushes travel the encoder in the opposite direction, this sequence comprises the sequence 10, 11, 01, 11 and the previous sequence does not exist. Therefore, this sequence is different from the previous sequence regardless of the starting point of the brushes. Therefore, the microprocessor is in a position at any time to detect the direction of rotation of the brushes in the encoder. Therefore, it can recognize whether these volume adjustment means are manipulated to increase the volume to be sampled, or on the contrary, that it will be reduced (for simplicity, the microprocessor can, for example, actually detect the volume). order of the two successive elements in the sequence, for example 10, 11 or 11, 10, to deduce the direction of rotation The microprocessor can count the number of steps traveled by the brushes Knowing that each step corresponds to the volume fraction The pipette can be continuously adjusted to the volume value displayed by the screen according to the new position of the adjustment means, as an example, it is assumed that the pipette has a total capacity of 1000 microliters and that the volume adjustment means comprise 100 steps per revolution, one step corresponding to 1 microliter.Each change in the voltage state ("00", "01", "10", "11") corresponds to one step so that the channels presented make it possible to distinguish the 99 steps. Additionally, once per revolution, the brushes 69 make contact with the registration area 94 as illustrated in FIG. 6. Therefore, if the adjustment means are manipulated to cause the brushes to travel more than one revolution in the encoder, the microprocessor detects, in each passage in the recording area, that a complete revolution has been made. On each occasion, the number of steps traveled from the previous contact with area 94 is compared with a predetermined number. This pre-registered number in the pipette corresponds to the number of steps per revolution. If the detected number is different from the registered number, this is a matter of an abnormality. Generally, the number of steps counted will then be less than the number recorded. The microprocessor then demands a correction to the display of the value on the screen so as not to consider the number of steps really counted, but the complete revolution that has taken place. In the present example, registration area 94 starts in line with channel 94, the number of steps to make a revolution is 100 steps. The number of steps between two pipettes provided by the registration area 94 should therefore be 99. According to the detected abnormalities and in particular their frequency and repetition, the microprocessor can be made to send one or more alert messages on the screen , or a maintenance message, or can be made to perform a systematic correction to the value display failure without having to make the aforementioned comparison of the detected and recorded numbers for a long time. In the absence of a registration area 94, if at least one increase does not make contact with the brushes in each revolution, the consecutive error accumulates from revolution to revolution, which may result in greater discrepancies between the sampled volume actually and the value of expanded volume .. It has been observed that each change of state of the channel corresponds to a known angular travel. This allows the microprocessor to convert the received signals into a liquid value to be sampled in the pipette. Considering this information, and knowing the direction of rotation of each movement of the adjustment means and the number of steps traveled, the microprocessor knows at all times the volume value that will be displayed on the screen, which corresponds to the current position of the means of adjustment.

It will now be explained how the volume value to be sampled is displayed at the time the adjustment means were modified while the pipette was off. A first step, usually carried out in the plant, consists of entering a reference value in the microprocessor memory of the pipette, which in this case is a calibration value. This is a case of an experimentally determined volume value (in a particular weighting) by measuring a volume of liquid actually sampled with the pipette and corresponding to a predetermined configuration of the adjustment means. It is assumed in the present invention that the calibration value corresponds to a value of 250 microliters and corresponds to two full revolutions plus steps after the registration area 94. It is now assumed that the position of the adjustment means is modified while the pipette is switched off For example, knob 8 is turned in such a way that the position of the screw near its axis is changed. Once the pipette is turned on again, the microprocessor will not have considered the steps traveled by the brushes when the pipette was turned off, so that the same value is displayed as previously displayed. Therefore, this value is wrong.

In such a way that, once the pipette is again in a position to display a correct value, the following operations are carried out. The user replaces the adjustment means in the lower contact position. In this way, the screw 10 is again placed in mechanical contact with its lower travel limit. The pipette is configured in a manner known per se, such that the microprocessor detects the contact by the electrical or electronic means independent of the encoder 64 and the brushes. By virtue of this detection, the microprocessor recognizes that the screw is at the lower end of the path. Again, the user modifies the volume setting to increase this volume. When the brushes 68 travel, for the first time, the registration area 94, this step is detected by means of the microprocessor as the first step since it was contacted. Therefore, the microprocessor knows, at this moment, the absolute position of the adjustment means with respect to the position corresponding to the calibration value, namely two revolutions plus steps and 250 microliters. Therefore, it can be calculated, based on the data and the number of steps traveled, at any time the volume value to be displayed.

For example, if the counter has registered that 10 steps have been taken after the last contact with the registration area 94, it recognizes that the volume to be displayed is 250-35 + 10-100, ie 125 microliters. Of course, various modifications to the invention can be made without departing from the scope thereof. The online registration area can be placed anywhere with one of the channels. It may have a different configuration than that of an increase. It can be extended by an angular value greater than or equal to two magnifications. The predetermined configuration corresponding to the reference value can be a different configuration from that of a screw travel stop end.

Claims (20)

NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following is claimed as a priority: CLAIMS

1. - A manual pipette (2) comprising: at least one channel (80, 82) that has increases (84, 86); and at least one brush (68), characterized in that it further comprises a registration area (94) independent of each channel, and adjusted to make contact with each brush after it has traveled a predetermined number of increases (84).

2. A pipette according to the preceding claim, characterized in that it comprises the means, regardless of the contact area and each channel, to detect that the adjustment means (10) of the volume to be sampled, have a configuration default

3. A pipette according to any of the preceding claims, characterized in that the channels (80, 82) are at least two in number and the increments (84, 86) are placed in such a way that the brush or brush (68). , 70) are able to make contact with the channels in different sequences in the direction of the path in the channels by means of the brushes.

4. - A pipette according to the preceding claim, characterized in that the brush or brushes (68, 70) are adjusted to make contact simultaneously with the two channels (80, 82).

5. A pipette according to any of claims 3 or 4, characterized in that the brush or brushes (68, 70) is adjusted to make contact with the channels (80, 82) in a non-simultaneous manner.

6. A pipette according to any of claims 3-5, characterized in that each of the brushes (68, 70) is adjusted to make contact with only one channel (80, 82).

7. A pipette according to any of claims 3-6, characterized in that it comprises at least two brushes (68, 70) associated with the respective channels (80, 82).

8. A pipette according to any of claims 3-7, characterized in that it comprises at least two brushes (68, 70) associated with each channel (80, 82).

9.- A pipette of; according to any of claims 7 or 8, characterized in that the brushes (68, 70) are electrically connected together permanently.

10. A pipette according to any of the preceding claims, characterized in that it also comprises a grounded channel (92), each of the brushes (68, 70) to be electrically connected to the grounded channel on a permanent basis .

11. A pipette according to any of the preceding claims, characterized in that it comprises at least one support (54) for the channel (80, 82) or the brush (68), the support that is fixed in a rotating manner and is free to slide in one piece (10) of the pipette.

12. A method for determining a value of a volume to be sampled by means of a manual pipette (2) comprises at least one brush (68) and at least one channel (80, 82) that has increases (84, 86), a method characterized in that: - it is detected that the means (10) for adjusting the volume to be sampled have a predetermined configuration; - a volume adjustment is modified; - a contact of the brush (68) with a recording area (94) independent of each channel (80, 82) is detected; and - a volume value is determined by means of a predetermined reference value.

13. A method according to the preceding claim, characterized in that the predetermined configuration corresponds to one end of the volume value.

14. A method according to any of claims 12-13, characterized in that a value related to the position of the registration area (94) with respect to the channel (80, 82) in the pipette is recorded.

15. A method according to any of claims 12-14, characterized in that a number of steps traveled by the brush (68) from which it makes contact is measured.

16. A method according to any of claims 12-15, characterized in that a number of successive contacts of the brush (68) are measured with the registration area (94).

17. A method for controlling a manual pipette, characterized in that: - a number of steps traversed in a channel (80) is measured by means of at least one brush (68) between two contacts of the brush with an area of registry. ; and the measured number is compared to a predetermined number.

18. - A control method according to the preceding claim, characterized in that a screen of a value of a volume of liquid to be sampled is demanded, considering the predetermined number.

19. A control method according to any of claims 17-18, characterized in that, in case the measured number is different from the predetermined number, an alert message is displayed.

20. A control method according to any of claims 17-19, characterized in that at least two brushes (80, 82), and: - a succession of contacts of the brush or brushes (68, 70) is detected. ) with the channels (80, 82); and - the detected sequence is compared with a predetermined sequence.