WO1994000239A1

WO1994000239A1 - Metering apparatus, and metering method

Info

Publication number: WO1994000239A1
Application number: PCT/NL1993/000134
Authority: WO
Inventors: Jan Gerber
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-06-26
Filing date: 1993-06-25
Publication date: 1994-01-06
Anticipated expiration: 1994-12-26
Also published as: NL9201147A; AU4589093A

Abstract

Metering apparatus, comprising a large number of holders (3) with different substances, from which holders substance can be dispensed as desired to an object to be brought into contact with the apparatus, such as a plaster (13) for dermatological tests, while the holders (3) each have a dispensing aperture (17) by means of which a substance can be applied from a holder to the object, and the holders (3) and the object (13) are movable relative to each other, for the purpose of positioning the dispensing aperture of a holder as desired relative to said object.

Description

Title: Metering apparatus, and metering method

The invention relates to a metering apparatus by means of which one or more substances from a large number of different substances can be dispensed as desired to an object. More particularly, although hot exclusively, the invention relates to a metering apparatus for applying substances as desired to a plaster for dermatological or contact allergy tests. The invention also relates to a metering method.

In order to determine the substances to which a patient is allergic, various substances are often applied to the patient's skin, and the reaction of the skin to one or more of said substances is awaited. For this purpose, a special plaster, the size of, for example, a hand, is currently provided with said substances in various areas and then stuck with the side to which said substances are applied on the patient's skin, generally on the patient's back. A plaster of this type is known, for example from Dutch Patent Application 9001667, also in the name of Applicants. This plaster contains ten separate areas, in two parallel rows of five, in which ten different test substances can be placed.

A dermatologist has about three hundred substances from which a selection can be made for determining the substance or group of substances to which a patient is allergic. As is customary in laboratories, these substances are stored individually in plastic hypodermic syringes with a capacity of, for example, 5 ml each, and in series of twenty holders with different substances collected in a tray, which trays must be taken several times daily out of a refrigerator by a technician, for the preparation of the plasters. This preparation of the plasters is completely manual, with the technician seated at a table and selecting ten in each case from the various trays with holders filled with the approximately three hundred different substances, and applying these to the appropriate regions on the plaster. A list is kept of which substance is applied to which point on the plaster. The individual hypodermic syringes also have to be replenished from time to time, and it will be clear that all this is fairly time-consuming. In addition to the preparation of the plasters, the administration is also carried out completely manually, with a correspondingly great risk of mistakes being made.

The object of the invention is to provide a metering apparatus with which it is possible to prepare, for example, plasters for allergic tests. With such an apparatus, manual work can be eliminated as far as possible, so that plasters can be prepared more cheaply and mistakes, both in the preparation of the plaster and in the administration of the data, can be minimised.

For this purpose, according to the invention provision is made for a metering apparatus comprising a large number of holders with different substances, from which holders substance can be dispensed to an object, such as a plaster for dermatological tests, to be brought into contact with the apparatus, the holders each having a dispensing aperture, by means of which a substance can be applied from a holder to the object, and the holders and the object being movable relative to each other for the purpose of positioning the dispensing aperture of a holder as desired relative to said object. In this way, the selection and dispensing of the substances can be fully automatic, with a minimum of mistakes and with minimal intervention of an "expensive" technician. Due to the fact that with the metering apparatus the holder with the substance to be dispensed is movable relative to the object, the apparatus can be designed efficiently, so that it can be made unsusceptible to faults. Since it is possible .both to select and to meter with the apparatus, the remaining stock of substance in each holder can be determined by means of a microprocessor, so that the replenishment of a holder can be greatly facilitated. For example, the microprocessor gives off a warning signal when a holder is almost empty, while at the same time indicating the holder to which the warning signal relates, and where said holder is situated.

According to one embodiment of the invention, the holder with the selected substance is taken by the metering apparatus into the dispensing position, following which the technician controls the dispensing of said substance. For example, the technician sucks a little substance with a pipette out of the holder in question. The metering apparatus preferably both takes the holder into the dispensing position and carries out the dispensing itself fully automatically. However, with an apparatus which takes a holder with the selected substance into the dispensing position most of the mistakes are already eliminated, and the administration of the data on the prepared plasters can already be carried out fully automatically. If the metering apparatus also carries out the dispensing of the substance, the metering can be very accurate, and the monitoring of the preparation of a plaster is guaranteed in the best way, as is the monitoring of the remaining quantity of substance in each holder, in addition to a great cost saving on personnel.

The invention will be explained in greater detail below with reference to a non-limiting example of an embodiment, taken in conjunction with the appended drawings, in which:

Fig. 1 shows a diagrammatic perspective view of a metering apparatus according to the present invention;

Fig. 2 shows a partially cut-away view in cross-section of the metering apparatus of Fig. 1 along the line II-II; Fig. 3 shows a perspective sketch of a detail of the metering apparatus of Fig. 1.

An apparatus 1 according to the present invention is shown w th reference to Figs. 1 and 2. It comprises an annular element 2, in which the holders 3 with various substances are placed (in Fig. 1 the top sides of the holders are shown only in a limited area, and very schematically). The holders 3 are in this case disposed in five concentric rings in the annular element 2. As can be seen in Fig. 1, the holders 3 of the various rings are aligned in the radial direction. The annular element 2 is rotatable about the centre thereof. A revolving tooth system 4 is provided on the outside of the annular element 2, for rotational driving thereof. A driving gear wheel 5 (Fig. 2) , which is accommodated in a manner not shown in any further detail in the central control housing 6 and is connected to an electric stepping motor (not showrl) , meshes with said tooth system. Fig. 2 also shows how the annular element 2 is rotatably supported by a roller 1. Three of these are provided, each disposed at an angle of 120° relative to the others along the circumference of the annular element 2. An accurate roller guide for the annular element 2 is achieved through the slanting position of the roller 7, the shape of the chamber 8 in the annular element 2 into which said roller 7 projects, and the edge 9 projecting into the chamber 8. A retention of the roller 7. and thus of the ring 2, is also achieved with the edge 9. with the result that the ring 2 is fixed in the axial direction. The edge 9 projecting from the side wall of the chamber 8 is interrupted at three points along the circumference of the annular element 2, each displaced 120° relative to the other along the circumference. Fig. 2 shows the position of the annular element in which such an interruption in the projecting edge 9 is exactly at each roller 7. In that position the roller 7 cannot prevent the annular element 2 from being removed in its axial direction from the apparatus 1. The apparatus 1 also comprises a console 11, containing the movable supporting plate 12 for a plaster 13 to be prepared, and also the metering means l-**.. The layout of the supporting plate 12 and the way in which it works will be explained in greater detail with reference to Fig. 3- As can be seen in Fig. 1, the metering means 14 are aligned radially, and there is one metering means for each ring of holders 3« The metering means 14 are also fixed on a bridge 15, which partially covers the annular element 2 when the metering apparatus 1 is in use. As can be seen in Fig. 2, this bridge 15, together with the metering means 1*-., can be swung up about hinge 16 from the lowered position shown by solid lines, in which the metering apparatus 1 is ready for use, to a position which is shown by dashed and dotted lines (partially shown) .

By rotating the annular element 2, a selected holder 3 iⁿ each concentric ring can be moved until .it is below the corresponding metering means 1*4, following which the substance can be dispensed from such a holder 3 to the plaster 13.

As can be seen in Fig. 1, the plaster 13 contains two columns, each with five dispensing points 18, to which a substance from a holder 3 can be applied. Due to the fact that the plaster 13 is movable in the radial direction relative to the annular element 2, and also the metering means 14, while the plaster 13 can also be moved laterally (as it were, tangentially) relative to the row of metering means 14, each of the ten individual points can be taken as desired below one of the five metering means 14, so that any desired substance can be applied to such a point from the holders 3 iⁿ the annular element 2.

Fig. 2 shows in greater detail how the metering apparatus 1 works during the metering. As can be seen, each holder is an elongated cylindrical shape. Each holder 3 is accommodated in a bore in the annular element 2. The lower end of each holder 3 shown in the drawing has an extension 17 with reduced diameter. The open end thereof forms the dispensing aperture of the holder 3- This end is slightly bevelled, in order to prevent substance from the holder 3 from adhering to the extension 17. This substance is generally mixed in vaseline here, and is thus liquidised. The holders 3 below the metering means 14a, d and e are shown in the retracted position. In that position the free end of the extension 17 is situated a good distance away from the plaster 13, which is shown in Fig. 2 by solid lines, in a position in which each of the dispensing points 18 (Figs. 1; 3) is taken directly below a holder 3- Iⁿ the drawing, the left and right edges of the plaster are shown schematically to the left and right thereof respectively by dashed and dotted lines, as two alternative extreme positions. In the extreme left position in the drawing, the dispensing point 18 furthest to the right will lie below the metering means l4a. In the position of the plaster 13 furthest to the right in the drawing, the dispensing point 18 furthest to the left will lie below the metering means l4e. Each dispensing point can thus be placed in a row below each metering means l4a, and thus below each holder 3-

In the annular element 2 each holder 3 rests, with the neck of the extension 17 as a transition to the extension 17, on a support 19, which is held in such a way that it can move up and down in the annular element. A spring 21, which rests on a base plate 22, presses the supporting element 19 upwards against a stop ^'in the bore for each holder 3. The extension 17 projects through the supporting element 19, the spring 21 and the retaining plate 22. The retaining plate 22 is screwed to the annular element 2 from the bottom side. In the area below the metering means l4a to l4e, the retaining plate 22 rests on a support 20 of the metering apparatus 1, in order to prevent any sagging of the retaining plate 22, and thus any inaccuracy in the metering. The support 20 spans the plaster 13 in such a way that the latter is not impeded in its lateral movement, and rests on either side of the apparatus 1, as shown. The holder 3 is forced by the spring 21 to the position in which the extension 17 is retracted relative to the plaster 13- The holders 3 can be moved into an extended position, with the extension 17 close to the plaster 13, in order to dispense substance thereto, as shown in the case of the holders situated below the metering means l4b and l4c in Fig. 2. This projection of the holder 3 and the subsequent metering are illustrated with reference to the metering means l4a to l4c. The metering means l4a shows the retracted position thereof. A hydraulic or pneumatic drive cylinder 23, from the bottom of which the piston rod 24 projects, can be seen. Said drive cylinder may, if desired, be replaced by, for example, an electric lead screw drive. A cup-shaped pressure element 25 grips around the end of said piston rod 24. Where the piston rod 24 projects through a hole in the centre of the body 25 thereof, said pressure element 25 is retained between the widened ram end 26 of the piston rod 24 and a spring 27. Ram 26 and spring 27 act here upon the body of the cup-shaped pressure element 25- In the retracted position, as shown for the metering means l4a, the cup-shaped pressure element 25 is forced against the action of the spring 27, by the ram end 26 of the piston rod 24, with its edge against a stop in the bore in the bridge 15- On extension of the piston rod 24, the cup-shaped pressure element 25 will be forced, under the action of the spring 27, to move along with the ram end 26 of the piston rod 24 and to go into engagement with the widened top edge of a holder 3- With continuing extension of the piston rod 24, the cup-shaped pressure element 25, under the action of spring 27, presses the holder 3 against the action of the (weaker) spring 21, into the position with the narrowed extension 17 extended (as in the case of the metering means l4b and l4c). In that position the holder 3 rests with the thickened part at the top edge thereof on a stop of the annular element 2. On further extension of the piston rod 24, the cup-shaped pressure element 25 remains stationary. The ram end 26 then comes into contact with a piston 28 in the holder 3. and on further extension of the piston rod 24 substance is driven out of the holder 3- The metering can be carried out very accurately here by giving the piston rod 24 a cumulative, fixed stroke. For retraction of the piston rod, the path can be followed from the metering means l4c, via metering means l4b to metering means 14a, as demonstrated in metering means l4b. During that retraction stroke of the piston rod 24, the cup-shaped pressure element 25 is taken along by the ram end 26 against the action of the spring 27 until it is against the stop at the bridge 15. The holder 3 then springs back up. This suspension and drive of each holder 3 specifically shown here ensures that any contact between moving and stationary parts of the metering apparatus is prevented during the rotation of the annular element 2, while the holders 3 can easily be changed individually in the annular element 2, and during the metering the dispensing aperture of the holder 2 is as close as possible to the plaster 13, in order to meter as accurately and reliably as possible. If the holder 2 is moved so far downwards during the metering that the dispensing aperture on the holder 2 essentially makes contact with the plaster, droplets will for the most part be prevented from remaining behind on the dispensing aperture, with the result that the metering is extremely reliable and accurate.

A variant of the system of holders 2 and metering means shown in Fig. 2 is as follows: The piston 28 in the holder 2 is accommodated in a fixed position therein. Said piston 28 is in this case designed as a bellows-shaped element, which is compressed in the direction of the nozzle 17 when a pressure force is exerted by the ram 26, as a result of which excess pressure is formed inside the holder 2. Consequently, any contents will be dispensed from the holder 2 through the nozzle 17. When the ram 26 is then removed, the bellows 28 will resume the original position, while forming a vacuum inside the holder 2. Air will consequently flow out of the environment through the nozzle 17 into the holder 2. The bellows-shaped piston 28 may be perforated if desired, in such a way that on contact with the ram 26 said perforations are covered thereby in an airtight way. When the ram 26 is removed, with the piston 28 springing back, air from the environment can flow into the holder 2 through said perforations. For example, the piston 28 is provided for this purpose with a central hole, coaxial with the longitudinal axis of the holder 2. This design of the holder 2 prevents the stroke of the ram from being adapted to the contents of the holder 2, for example when the piston 28 is pushed a little further each time in the direction of the plaster 13. Continuing on the "squeeze bottle" principle of the holder 2, the latter can be provided with a to some extent compressible, possibly perforated bottom facing the ram 26. If the ram 26 is pressed against said bottom, in which case said ram 26 shuts off any perforation in an airtight manner, said bottom is compressed, with the result that excess pressure develops again in the holder 2, and the contents thereof are consequently metered. In this embodiment of the holder 2 also, the vertical movement of the holder 2 towards the plaster 13 is maintained during the metering.

Fig. 3 shows in detail the control of the plaster, which is only partially shown here. Said plaster 13 is situated on a supporting plate 12, which can be moved in various directions. For this purpose, the supporting plate 12 is supported in a rolling manner on a base plate 29, which has a slanting extension 31• The supporting plate 12 can be moved in the lengthwise direction of the base plate 29 and the extension 31- For this purpose, provision is made for an endless belt 32, which runs around return pulleys 33 at the beginning and end of the base plate 29- One of these return pulleys 33 is disposed on a drive shaft 34- The mobile supporting plate 12 is connected to the belt 32 at 35- For accurately positioning the supporting plate 12 in stages, said plate has on the underside thereof a spring-loaded lobe 36, which can snap into a recess 37. a series of which recesses is disposed accurately positioned in the base plate 29. The supporting plate 12 can also be moved on the slanting extension 31. and then takes up the position shown in Fig. 1. In that position a plaster can be placed on the supporting plate 12 and positioned by means of positioning strips 38. The slanting position of the extension 31 ensures easy operation. It is also possible to move the base plate 2 laterally. For this purpose, the base plate 29 is fitted on two parallel slide rods 39. which run at right angles to the lengthwise direction of the base plate 29. With a piston-cylinder combination 40, the base plate 29 can thus be moved laterally to and fro over the slide rods 39- The supporting plate 12 then, of course, moves with it, so that one of the two columns of dispensing points 18 on the plaster 13 can be aligned with the metering means 14 if desired. The extension 31 is stationary, so that the supporting plate 12 can be moved between the extension 31 and the base plate 29 only in one position of the base plate 29.

As can be seen in Fig. 1, the central control housing 6 is connected by means of a connection 42 to a microprocessor (not shown in any further detail). Due to the fact that the annular element 2 can be removed in only one way from the metering apparatus 1, the position of the holders 3 in the metering apparatus 1 is clearly fixed. This means that the microprocessor can reliably take full control of the metering apparatus 1. For this purpose, an operator feeds the data concerning the desired substances (in this case 10) into the microprocessor. The microprocessor then drives the annular element 2 into the plaster 13, in such a way that the holder with the appropriate substance is in register with the metering means belonging to the appropriate ring of holders 3 and a(n) (empty) dispensing point 18 on the plaster 13. The microprocessor then automatically establishes which substance is dispensed at which point on the plaster, and also the quantity if, for example, a quantity which differs from a fixed standard is selected. This alignment and metering process is repeated until all ten dispensing positions 18 on the plaster 13 are provided with the desired substance. The supporting plate 12, with the plaster 13 thereon is then moved onto the extension 31. ready to be removed and subsequently applied to a patient's skin, or to be stored for later use, and so on. A new plaster can then be placed in that position of the supporting plate 12.

Of course, it is also possible to bring different holders in succession into register with the same dispensing point 18 on the plaster 13, so that a substance mixture is formed there in the end. Other variants of the invention described and illustrated here are also possible. For example, the object provided with samples can be something other than a plaster. The number of places provided with samples on the object can also be different. Moreover, instead of an annular element 2, a differently shaped element 2, such as a rectangular element can, of course, be used. What is important is that an apparatus is provided in which one holder from a number disposed in a fixed pattern is selected and the metering means, said holder and the dispensing point are then brought into register with each other on an object to be provided with the samples. As such, the example of an embodiment according to the figures will be able to operate satisfactorily with just one metering means 14, which is movable in the radial direction above the various concentric rings with holders 3-

Claims

1. Metering apparatus, comprising a large number of holders with different substances, from which holders substance can be dispensed as desired to an object to be brought into contact with the apparatus, such as a plaster for dermatological tests, in which the holders each have a dispensing aperture by means of which a substance can applied from a holder to the object, and in which the holders and the object are movable relative to each other, for the purpose of positioning the dispensing aperture of a holder as desired relative to said object.

2. Apparatus according to Claim 1, characterised in that it contains a support for the abovementioned object, and the position of said support is adjustable.

3. Apparatus according to Claim 1 or 2, characterised in that it is provided with at least one metering means in a fixed position which can if desired be brought into engagement with a holder.

4. Apparatus according to Claim 3. characterised in that the holders are disposed in two or more rows, and in that one metering means is provided for each row. - Apparatus according to Claim 4, characterised in that the abovementioned holders are arranged in annular concentric rows, which are rotatable in common about the centre point thereof.

6. Apparatus according to Claim 4 or 5. characterised in that the metering means are placed in line with each other, and in that the support is adjustable in the direction at right angles to said line.

7- Apparatus according to Claim 4 or 5. possibly in conjunction with Claim 6, characterised in that the metering means are placed in line with each other, and in that the support is adjustable in the direction parallel to said line. 8. Apparatus according to one of the preceding claims, characterised in that the holders are accommodated therein in an easily removable manner.

9. Apparatus according to one of the preceding claims, characterised in that the holders are accommodated in a part which is easily removable.

10. Apparatus according to one of the preceding claims, characterised in that the holders are an elongated cylindrical shape, having at one end thereof an extension with smaller diameter which bounds the dispensing aperture and is bevelled at the free end.

11. Apparatus according to Claim 10, characterised in that the holders are accommodated movably in the lengthwise direction thereof, and in that at the end with the extension the holders are resiliently supported and are movable from a retracted rest position against the action of a spring means into a working position for dispensing a substance to the object.

12. Apparatus according to one of the preceding claims, characterised in that the holders contain an element held movably therein which acts like a known piston.

13. Apparatus according to Claim 11 or 12, characterised in that the at least one metering means comprises a pressure element which is movable between a position interacting with a holder and a rest position, in the abovementioned interacting position the holder being forced by the pressure element against the action of the spring-loaded support thereof.

14. Apparatus according to Claim 13, characterised in that a spring means and a control element act upon said drive element, the control element being movable in the lengthwise direction of the holders, and the pressure element being movable against the action of the spring means from the interacting position to the rest position.

15. Apparatus according to Claim 14, characterised in that the control element can be inserted into a holder.

16. Apparatus according to one of the preceding claims, characterised in that the holders are situated between the metering means and the support for the object, and in that the metering means are hingedly fixed, in such a way that they can be swung away, following which the holders are freely accessible.

17. Apparatus according to one of the "preceding claims, characterised in that the support for the object can be moved until it is beyond the area in which the holders are situated, so that an object can be placed easily thereon.

18. Apparatus according to one of the preceding claims, characterised in that the support is accommodated in an elongated base, and is movable therein in the lengthwise direction of said base, and in that said elongated base is movable at right angles to the lengthwise direction thereof.

19. Apparatus according to Claim 18, characterised in that the elongated base is extended beyond the area of the holders by an extension which is immovable and slants relative to the abovementioned base. 20. Apparatus according to Claim 18 or 19, characterised in that the support is connected to an endless flexible pulling element which runs in the lengthwise direction of the elongated base between the ends thereof and is connected to drive means for moving the support to and fro.

21. Method for dispensing, by means of a metering means, a substance selected from a large number of substances to a predetermined application point on an object, in which each substance is in a separate holder and the holders are arranged in a pattern, possibly to be carried out with the apparatus according to one of the preceding claims, characterised in that while maintaining the abovementioned pattern the holder with the selected substance, the application point on the object and the metering means are brought into register with each other, following which the substance is dispensed.