Medical fluid pump with drive head

Abstract

The invention relates to a medical fluid pump, in particular a syringe pump, comprising a housing (6), in which a syringe barrel (14) can be accommodated, fastening means for fastening a syringe piston rod (16) and / or the syringe barrel (14), and drive means for causing a controlled relative movement between the syringe barrel (14) and the syringe piston rod in the axial direction (A14) of the syringe barrel (14). In order to better fix the syringe piston rod (16), the fixing means are formed by a plurality of sheets (30), the lamellae (30) are grouped concentrically about a closure axis that can be oriented relative to the axis (A14) of the syringe barrel (14) according to the manner of a central or lamella closure (LV) known in camera technology and can be moved synchronously by means of driving means for fixing the syringe piston rod (16) in order to vary the central free space between the lamellae (30).

Description

Technical Field

[0001] The present disclosure relates to a medical fluid pump, in particular an infusion pump that can be equipped with a drive head. Background Art

[0002] The development of modern medicine, especially intensive medicine, has led to infusion therapy, which requires the targeted use and precise dosing of highly effective drugs through a fluid pump. In this context, a very common type of fluid pump structure is the so-called infusion pump. Infusion pumps are used in medicine to supply a defined dose of a drug from a syringe to a patient. Here, the syringe is automatically pressed out at a defined rate in order to supply a defined amount of the drug to the patient over a defined period of time. Such medical fluid pumps are known in various different designs. The common feature of these designs is that they have a housing for receiving the syringe barrel, a fixing device for fixing the syringe piston rod, and a drive device for causing a controlled relative movement between the syringe barrel and the syringe piston rod in the axial direction of the syringe barrel.

[0003] According to the variant of the drive of the syringe piston rod on the market, a filled syringe barrel is inserted into the infusion pump, and the free end of the pulled-out syringe piston rod is fixed by means of a drive head fastened to a holding arm / drive arm. The end section of the syringe piston rod must be held by a fixing device that can usually be driven motorically, which is usually achieved by a pivotable, angled clamp-like arm or jaw on the drive head. In addition, a device should be provided in the drive head by means of which the force exerted by the pump drive on the injection plunger via the drive arm and the drive head mounted on the drive arm can be measured. The purpose of this force monitoring is in particular to be able to quickly identify a blockage in the fluid path between the syringe and the patient. Infusion pumps are known, for example, from EP 0 566 825 A1 or EP 1 329 232 B1.

[0004] With this known jaw holder, syringes of different sizes can be fixed well. However, if a very small syringe with a correspondingly small syringe barrel 14 is to be fixed, the inaccuracy in the axis-precise fixing increases. Summary of the Invention

[0005] Therefore, the task of the present disclosure is to develop a medical fluid pump of the structure type described at the beginning such that the fixing device can better and more reliably fix fluid pumps or syringes in a wide size range.

[0006] This task is solved by a medical fluid pump, in particular an infusion pump, having the features of claim 1.

[0007] The fixing device is formed by a plurality of thin plates which are concentrically grouped around a closing axis parallel to the movement axis of the drive arm in the manner of a central or thin-plate closure or variable aperture known from camera technology and which can be moved synchronously by means of a manually or motor-operated drive device for changing the central free space between the thin plates. The opening remaining in the center between the thin plates can be varied in such a way and manner that, regardless of the size, the opening is always approximately circular and the center point remains unchanged. In the open state, i.e., in the state where the thin plates are moved radially outwards, the free end of the pulled-out injection plunger or syringe piston rod can be introduced into the drive head. By motor drive or manual drive or by the force of a spring, the thin plates can now be moved synchronously radially inwards until the thin plates abut against the contour of the syringe piston rod. Due to the structure of the thin-plate closure, the thin plates always remain of the same shape and are concentrically grouped around the closing axis, and the thin plates move radially inwards until the thin plates fix the smallest possible opening of the thin-plate closure, i.e., an opening that encloses the contour of the syringe piston rod or the piston disk carried by it by contact. This results in an improved, i.e., reliable, fixation over the entire circumference of the syringe piston rod or the syringe piston disk carried by it, and it is particularly advantageous that this fixation is independent of the size of the syringe inserted.

[0008] This solution can be used in a particularly advantageous manner in a medical fluid pump, where the housing is arranged to accommodate syringe barrels of different sizes, and where the fixing device is arranged in a drive head which can be moved linearly relative to the housing along the movement axis via a tubular or rod-shaped drive arm. In this case, it is particularly advantageous to design the assembly according to claim 2, i.e., to arrange the thin-plate closure such that the closing axis can be movably guided linearly and perpendicular to the movement axis of the drive arm in a plane spanned by the axes of syringe barrels of different diameters located in the housing without frictional or forced forces. Due to the frictional-force-free or forced-force-free movability of the closing axis and because the contour of the syringe piston rod is axially symmetric or rotationally symmetric, the closing axis aligns with the axis of the syringe piston rod during the closing movement of the thin-plate closure, whereby syringes of different sizes or circumferential contours can be fixed precisely and without tension in the medical fluid pump.

[0009] Advantageous design solutions are the subject of the further dependent claims.

[0010] The thin plates can be constituted by bodies of very different shapes, i.e., contours and thicknesses. If the body is configured in a plate shape, the thin-plate closure occupies advantageously little structural space.

[0011] Generally, the lamella closure is constructed in such a way that the lamellas can be rotated inwards or outwards together by means of a mechanism. Here, each lamella is supported on a shaft and all lamellas are respectively connected to a ring by means of a further shaft so that the lamellas move together. The more lamellas are inserted, the more circular the opening is. In order to keep the structure of the drive head as simple as possible, it is advantageous if the central or lamella closure consists of a module that can be accommodated in the drive head.

[0012] The linear mobility of the closure axis can be ensured in different ways and methods. If the module of the lamella closure is movably guided within the drive head, the mass of the movement remains relatively small.

[0013] On the other hand, if the central or lamella closure is fixedly accommodated in the drive head and the drive head is movably guided and connected to a drive arm, the structure of the drive head is simplified. A further advantage of this design is that in this case, the piston pressure sensor can also be arranged concentrically relative to the axis of the lamella closure fixedly behind the lamella closure.

[0014] It is also advantageous if the drive device consists of an adjuster ring that is rotatably supported. Such an adjuster ring can be easily accessible and accommodated within the drive head and can keep the driving force required to move the lamellas relatively small. This results in the following feasible solution, i.e., the lamellas are pre-tensioned into the closed position by means of a spring device with a small structural volume, and the lamellas can be manually brought from this closed position to the open position.

[0015] However, when the adjuster ring can be driven motorically, the operational-technical advantages of the medical fluid pump occur, where the drive motor is also accommodated in the drive head. Due to the small mass to be moved, such a motor can be constructed to be very small in volume so that the motor can be conveniently arranged in the housing of the drive head.

[0016] A particularly advantageous design of the syringe piston fixation is obtained by means of the improvement according to claim 6, according to which the lamellas respectively have inclined surfaces on the side of the lamellas facing away from the housing at least in the radially inner region, and the inclined surfaces can come into contact with the annular flange of the piston rod head when the syringe is inserted. With this design, the syringe piston can additionally be fixed axially without play, for example, in the drive head, whereby the measuring system for the force applied to the syringe piston can be more easily initialized and the control accuracy of the syringe piston can be increased. The resulting axial playlessness also contributes to ensuring a constant delivery in varying pressure situations (positive or negative overpressure due to changes in the relative height of the pump with respect to the patient).

[0017] In principle, the number of the thin sheets can vary within a wide range. These thin sheets can also overlap with each other. However, if the thin sheets are given the function of axially stabilizing the syringe piston, it is advantageous that the thin sheets are located in a common plane. This has the additional advantage that the thin sheets can be constructed thicker and thus more firmly.

[0018] Medical fluid pumps generally operate in an environment where liquid splashing cannot be kept away. The liquid given by using a syringe usually contains substances such as glucose, and the mechanism of, for example, an adhesive fixing device can be damaged by using this substance. To prevent such damage, it is advantageous that the thin sheets are provided with a liquid-repellent coating.

[0019] When the thin sheets are covered by an elastically stretchable sleeve, the mechanical components of the thin sheet closure can be protected particularly effectively.

[0020] If a medical fluid pump has a sensor through which the opening width of the thin sheet closure can be detected, the output signal of the sensor can be used to identify the type and / or size of the syringe inserted.

[0021] The advantage of the thin sheet closure used according to the present invention also lies in that generally a small adjustment force is sufficient for the synchronous movement of the thin sheets, so that a feasible solution for using a motor drive for the thin sheet closure by means of magnetic force coupling can even be obtained. Description of the Drawings

[0022] The embodiments of the present invention will be explained in more detail below with the aid of schematic diagrams. Shown are:

[0023] Figure 1 A perspective view of a medical fluid pump in the form of an injection pump having a closed lid or front cover according to a first embodiment of the present disclosure;

[0024] Figure 2 Shown in Figure 1 A perspective view of the injection pump shown, wherein the front cover is in an open position;

[0025] Figure 3a And Figure 3b A partial schematic view of a first embodiment of a medical fluid pump having syringes of different sizes inserted;

[0026] Figure 4a And Figure 4b A partial schematic view of a second embodiment of a medical fluid pump having syringes of different sizes inserted;

[0027] Figure 5a And 5b A perspective view of a fixing device for a syringe piston rod in a design of a thin sheet closure, showing syringes of different sizes;

[0028] Figures 6a to 6c Schematic diagram showing components of a thin - film closure used in a medical fluid pump according to the present invention;

[0029] Figures 7 to 9 Schematic diagram showing a variant of a thin - film closure with a thin - film applied to a medical fluid pump;

[0030] Figure 10 Cross - sectional perspective view showing another embodiment of a thin - film closure with a fixed syringe piston head;

[0031] Figure 11 Showing when the thin - films are joined together according to Figure 10 An enlarged view of the thin - film closure;

[0032] Figure 11a and Figure 11b Showing a perspective view of the thin - film in a thin - film closure according to Figure 10 and Figure 11 ;

[0033] Figure 12 Showing Figure 10 and Figure 11 A schematic diagram of a thin - film closure with a drive motor as shown in

[0034] Figure 13a and Figure 13b Showing a partial perspective view of a medical fluid pump according to Figure 3a and Figure 3b to show the linear mobility of the thin - film axis according to a variant;

[0035] Figure 14a and Figure 14b Showing a partial perspective view of a medical fluid pump according to Figure 4a and Figure 4b to show the linear mobility of the thin - film axis according to an altered variant;

[0036] Figure 15 Showing in an enlarged scale a cross - sectional perspective view of the details of Figure 14a for explaining the linear guidance of the thin - film closure in the drive head;

[0037] Figure 16a and Figure 16b Showing in an enlarged scale a view of a medical fluid pump according to Figure 13a 、 Figure 13b in the viewing direction along the axis of the syringe barrel;

[0038] Figure 17a and Figure 17bShown at an enlarged scale is a view of a medical fluid pump according to Figure 14a and Figure 14b in the direction of observation along the axis of the syringe barrel;

[0039] Figure 18a and 18b A schematic view of a drive head housing showing an embodiment for explaining further modifications of the fixing means for the syringe piston rod;

[0040] Figures 19a to 19c A schematic view showing the principle of a slide guide which can be used for the linear mobility of a sheet closure axis;

[0041] Figure 20 and 21 A schematic view of a drive head housing showing two further modified embodiments of the fixing means for the syringe piston rod; and

[0042] Figures 22A and 22B show an enlarged perspective view of a modified sheet closure constructed on the sheet closure LV according to Figure 10 shown. DETAILED DESCRIPTION

[0043] Figure 1 and Figure 2 show a perspective view of a medical fluid pump in the form of an injection pump, which is implemented in the structural type of a motor-driven drive head. However, it has been emphasized here that the solution according to the present application is applicable to all types of medical fluid pumps, which have a housing for accommodating a syringe barrel, a fixing means for fixing a syringe piston rod, and a drive means by which a controlled relative movement in the axial direction of the syringe barrel between the syringe barrel and the syringe piston rod can be caused.

[0044] In Figure 1 a medical fluid pump 2 with a front cover 4 in the closed position is shown. The front cover 4 usually has a display 5 on the outside. In Figure 2 a device 2 is shown which has a front cover 4 in the open position.

[0045] The medical fluid pump 2 has a housing body 6 which is substantially cuboid. A front cover 4 which can close the accommodation area 8 is arranged on the long side of the housing body 6 facing the user in the use position of the medical fluid pump 2. The front cover 4 is pivotally connected to the long edge of the body 6 via a hinge device 11. On the inner side of the front cover 4, a spring clip 13 is provided on the long edge opposite the hinge device 11, by means of which the front cover 4 is clamped to the body 6 in the closed position. A magnet can also be used instead of the spring clip.

[0046] On the side of the display 5, a drive head 10 is provided on the side wall of the housing body 6, which is arranged substantially perpendicular to the side wall of the housing body 6 and can be moved in and out substantially perpendicular to the side wall of the housing body 6 by means of a holding arm / drive arm 18 that is invisible in Figure 1 and Figure 2 but shown in FIGS. 3 and 4.

[0047] The receiving area 8, also referred to as the syringe slot, is configured to laterally and fixedly receive (not shown) syringe barrels 14 of different sizes, as schematically shown in FIGS. 3 and 4, such that the associated syringe pistons can be moved by means of a syringe piston rod 16 with the aid of the drive head 10 that serves as a stop for the injection plunger. For this purpose, the drive head 10 is moved by means of a drive integrated in the housing body 6 via a tubular or rod-shaped drive arm 18, i.e., linearly along the movement axis A18. To simplify the accommodation of the syringe, a button 12 can be provided on the drive head 10, which releases the drive head 10 from the drive in the pressed state such that the drive head can be moved manually. Instead of a button, a syringe holder for fixing the syringe barrel in the syringe slot can also be provided. Such a syringe holder can be pulled out and flipped 90 degrees laterally when the drive head extends.

[0048] To put the injection pump 2 into operation, first the front cover 4 is opened and a syringe (not shown) with a filled syringe barrel 14 is inserted into the receiving area with the axis A14, as schematically shown in FIG. 3. The housing 6 of the medical fluid pump 2 is only schematically shown in FIGS. 3 and 4. During insertion, the shoulder section 20 of the syringe barrel 14 abuts against the housing body 6 and brings the syringe barrel 14 into abutting contact with the inner wall of the receiving area 8. By means of a holding device (not shown) or by closing the front cover 4, the syringe barrel 14 is positioned in the housing body 6 as shown in FIGS. 3 and 4. In the case where the drive arm 18 extends, the free end of the pulled-out syringe piston rod 16 must now be fixed in the drive head 10. The fixing device developed for this purpose is described in more detail below with reference to FIG. 5 et seq.

[0049] As can be seen from the illustrations according to FIGS. 3 and 4, when positioning syringes of different sizes, the plane spanned by the axis A14 of the syringe barrel 14 and the movement axis A18 of the drive arm 18 does not change. Only the lateral distance between the syringe piston rod 16 and the drive arm 18, i.e., the lateral distance between the axes A14 and A18, changes, and specifically at the value AG (FIGS. 3A, 4A) for the largest syringe and the value AK for the smallest syringe to be inserted ( Figure 3b 、 Figure 4b) varies therebetween. Accordingly, the fixing device for the free end of the syringe piston rod 16 to be pulled out must likewise be able to move linearly relative to the drive arm 18 in the plane spanned by the axes A14 and A18, such that the syringe piston rod 16 can be moved by the drive head 10 without bending forces. Here, the linear movability is preferably designed such that as little frictional force as possible occurs and the fixing device can be oriented as force-free as possible.

[0050] Variant embodiments are shown in FIGS. 3A and 3B, in which this movability is provided by connecting the drive head 10 linearly and perpendicularly to the axes A14, A16 to the drive arm 18. This linear movability is indicated in FIGS. 3A and 3B by a solid double arrow LB and this linear movability lies in the plane E, which is spanned by the axis A14 of the syringe barrel 14 of different diameters positioned in the housing.

[0051] According to an alternative variant embodiment shown in Figure 4a , 4b , the drive head 10 is fixedly arranged on the drive arm 18. The fixing device for the free end of the syringe piston rod 16 to be pulled out obtains its linear movability perpendicular to the axes A14 and A18 due to its movably guided accommodation within the drive head 10. This movability is indicated in Figure 4a , 4b by a dashed double arrow LB.

[0052] The structure of the fixing device will be described in more detail below with reference to FIG. 5 et seq.

[0053] As shown in FIGS. 5A and 5B, the fixing device consists of a plurality of plate-shaped laminae 30, which are grouped concentrically around a closing axis A30 parallel to the movement axis A18 of the drive arm 18 (not shown in FIG. 5) in the manner of a central or lamina closure LV known from cinematography and are moved synchronously by means of drive means to be described further below for changing the central free space between the laminae 30. Here, the laminae 30 abut centrally on the circumference against the contour of the syringe piston rod 16, which has a cross shape in the illustrated embodiment, and the closing axis A30 is oriented essentially force-free with respect to the axes A14 of the syringe barrel 14 and the syringe piston rod 16 due to the linear movability LB in the plane E. The syringe is thus fixed by the drive head 10 such that no bending stress occurs on the syringe piston rod. In this position, the drive head 10 can be driven by the drive arm 18 to empty the syringe barrel 14, such that the propelling force acts precisely centrally on the syringe piston rod 16. The metering of the active substance accommodated in the syringe barrel 14 is thus controlled with the greatest possible precision.

[0054] The number and shape of the sheets 30 used for the sheet closure can vary within wide limits. Figure 9 Some possible designs of applicable sheet closures are shown by way of example in FIG. A common feature of all designs is that, as shown in Figures 6a to 6c As schematically shown in FIG. 1 , the thin plates 30 are rotated inwardly or outwardly in a common and synchronous manner by a mechanism. To this end, for example, each thin plate 30 is supported on an axis 32 of a first ring 34, for example, which is fixed (see FIG. 1 ). Figure 6b ), and all the lamellae 30 are coupled to the rotatably mounted adjusting ring 36 via a further shaft 38, so that when the adjusting ring 36 is rotated, the lamellae can move together, while the shaft 38 moves in the guide slot 40 of the adjusting ring 36. Of course, the kinematics can also be reversed by exchanging the adjusting ring with the first ring.

[0055] From Figure 6 to Figure 9 It can be seen that the opening width of the lamella closure is always approximately circular during its change and the center point, i.e. the closure axis A30, remains constant. Furthermore, the more lamellae 30 are used, the more circular the opening width becomes. The adjusting ring 36 can be driven manually, by a spring mechanism or also mechanically, for example by coupling the adjusting ring 36 to a rack segment 42 that can be moved mechanically or by spring force or to a manually actuatable adjusting lever 44.

[0056] According to an advantageous embodiment, it can be provided, for example, that the foil closure is preloaded in the closed position by a spring device and that the foils 30 are moved apart by an adjustment rod for inserting the syringe piston rod 16. Alternatively, the foil closure can also be preloaded into the open position by spring force and into the fixed position by motorized drive of the adjustment ring.

[0057] See also Figure 10 and Figure 11 An advantageous embodiment of a foil closure is shown, by means of which the fixing of the syringe piston rod 16 is further improved. Figure 10 As shown in , the syringe piston rod 16 usually has a disk as a piston rod head 46 at its free end, which has an annular flange 48 on the edge side. The thin slice 30 has an inclined surface 50 on its side facing away from the housing body 6 at least in the radially built-in area, which can contact the annular flange 48 of the piston rod head 46 for fixing in the drive head 10 when the syringe is placed, that is, grip behind the annular flange 48 and squeeze the annular flange 51 axially against the abutment surface 51 in the drive head 10. In this way, the syringe piston rod 16 can be positioned in the drive head 10 to be axially immovable, that is, without clearance, so that when the syringe barrel 14 is emptied, the thrust acting on the syringe piston can be detected more accurately and therefore better controlled. For this reason, a pressure sensor can be installed behind the abutment surface 51.

[0058] In order to further improve the accuracy of the axial positioning of the piston rod head 46 in the drive head 10, in Figure 10 the illustrated embodiment, the thin plates 30 are arranged such that these thin plates do not overlap, but are located in a common plane and can move in this plane. Figure 11 、 Figure 11a and Figure 11b shows a design of the thin plate 30 on an enlarged scale. It can be seen that the thin plates 30 support each other in the circumferential direction and have a void in the radially inner region, and this void forms an inclined surface 50. In the remaining regions, the thin plates have the shape of a plate with a thickness of D30, and this thickness is in the range of mm. The thin layer 30 can be slidably guided in the thin plate closure past the plate surface. A metal material is selected, but plastic can also be used as the material for the thin plates 30.

[0059] Figure 12 schematically shows how the thin plate 30 of the thin plate closure can be motor-driven starting from the middle open position. For this purpose, the adjusting ring 36 (in which a guide chute 40 for the radial orientation of the pivot axis 38 is constructed) is provided with a toothed segment 142, and a gear 52 that can be driven by a worm gear 54 of a motor 56 meshes with this toothed segment. The motor 56 is mounted in the drive head 10 so that this motor moves together with the thin plate closure.

[0060] The motor 56 can be controlled via electrical contacts 58. However, it is also possible to drive the motor 56 by magnetic force coupling, thereby simplifying the positioning of the motor 56 in the drive head 10 and making it easier to meet the requirements regarding sealing and hygiene. It can also be provided that the gear 52 is movably supported, so that in order to allow the adjusting ring 36 to twist freely, the adjusting ring can be disengaged from the toothed segment 142.

[0061] Figure 13a 、 13b 、16a and 16b show a first variant of the centering orientation of the thin plate closure LV when using syringes or syringe barrels 14 of different sizes. In this variant, the thin plate closure LV is fixedly mounted in the drive head 10, and this drive head is supported in a guiding manner along an axis A58 on a carrier arm 58 that is fixedly connected to the drive arm 18. The axis A58 extends perpendicular to the axis A18 of the drive arm 18 and this axis lies in a plane E defined by the axes A14 of different-sized syringe barrels 14 inserted into the medical fluid pump 2. From Figure 13b as well as FIGS. 16A and Figure 16bAs can be seen, how syringes of different sizes affect the movement position of the thin - wall closure LV relative to the drive arm 18 is such that the center of the thin - wall closure LV can coincide with the axis A14 of the syringe barrel 14. It can be seen that this arrangement is carried out such that the receiving area 8 of the housing body 6 fixes the syringe barrel 14 such that the axis A14 of this syringe barrel is always located within the plane E. In this plane E, linear movability or mobility perpendicular to the axis A14 of the syringe barrel 14 is provided for the thin - wall closure LV (shown by the double - headed arrows in FIGS. 16A and 16B). For accommodating and fixing the syringes shown in Figure 16a and 16b a movement measure V of the thin - wall closure LV is sufficient.

[0062] In Figure 14a 、 14b 、15, 17a and 17b, variant forms of centering of the thin - wall closure LV are schematically shown. Here, the thin - wall closure LV is linearly movably supported in the housing of the drive head 10, which is fixedly connected to the drive arm 18. The linear movability of the thin - wall closure LV is achieved by a laterally recessed guide rail 60, into which a guide pin 62 of the fixing member of the thin - wall closure LV is form - fit engaged. The guide rail 60 allows the thin - wall closure LV to be movable along an axis corresponding to the axis A58 shown in FIG. 13A, i.e., along an axis perpendicular to the axis A18 of the drive arm 18 and lying in the plane E defined by the axes A14 of the syringe barrels 14 of different sizes inserted into the medical fluid pump 2. For accommodating and fixing the syringes shown in Figure 17a and 17b a movement measure V of the thin - wall closure LV is again sufficient.

[0063] In Figure 18a 、 18b additional variant schemes of the design of the fixing device for the syringe piston rod 16 for different - sized syringes are schematically shown. Figure 18a is a view of the housing of the drive head 10 from the side of the syringe barrel 14, and Figure 18b is a view of the back side of the housing of the drive head 10. The housing has a drive - head lower shell layer and a drive - head upper shell layer not shown in more detail. These housing shell layers can be made of plastic. Inside the drive head 10, a slide 70 is arranged, which either carries the thin - wall closure LV or is part of the non - movable components of the thin - wall closure LV. The slide 70 is supported on a guide rod 74 by a linear bearing 72, which can be formed by a sliding bearing or a ball - bearing bushing, and the guide rod extends along an axis A74, which is parallel to the above - mentioned plane E and perpendicular to the axis A14 of the syringe barrel 14.

[0064] The drive motor 56 for actuating the sheet of the sheet closure LV is arranged on the back side of the slide 70. The drive motor drives a first gear 52-1 via a worm gear 54, and the first gear drives a second gear 52-2 on the front side of the slide 70 via a shaft (not shown in more detail) that extends through the lead-through portion 76. The second gear 52-2 meshes with the tooth segment 142 of the adjustment ring 36 of the sheet closure LV.

[0065] This type of slide guidance allows the sheet closure LV to be oriented substantially frictionlessly in the plane E by the movement of the linear bearing 72 when closing around the syringe piston rod 16 or around the annular flange 48 of the syringe piston rod 16, such that the axis A30 of the sheet closure is aligned with the axis A14 of the syringe barrel 14 without exerting any forced force on the syringe piston and the syringe piston rod 16.

[0066] In this embodiment, a pressure measuring disk can also be arranged behind the sheet closure LV. In addition, Figure 18b The optionally provided spring device is indicated by a double arrow 78 in, and this spring device can be set to ensure the defined position of the aperture mechanism. This spring device can also be used additionally to minimize the external force acting on the sheet closure when closing the opening.

[0067] The slide guidance is also implemented according to the principle schematically shown in three views in, according to which the slide 70 is accommodated in the housing in a linearly guided and movable manner with as little friction as possible. In the slide guidance according to FIG. 19, the slide 70 is guided by four linear bearings 72-1 to 72-4, different from the embodiment according to FIG. 18. Figures 19a to 19c

[0068] Figure 20 In A variant of the embodiment according to FIG. 18 is schematically shown. Different from the design according to FIG. 18, the slide 70 carries the sheet closure LV and the drive motor 56 on the same side, so that the additional gear 52-2 can be omitted for driving the adjustment ring.

[0069] The reference numeral 176 denotes a lead-through portion for the electrical connection of the motor 56. If a contact strip or sliding contact is provided or the motor 56 is driven by a magnetic force coupling, this lead-through portion can be omitted.

[0070] Figure 21 In Figure 20 The motor is omitted in the variant shown. Here, the adjustment ring 36 is driven by a manually operable gear 52, which is indicated by a double arrow M. In other respects, this variant corresponds to the embodiment according to

[0071] ​​In order to protect the accessible components and structural elements of the above-mentioned medical fluid pump and in particular the fixing device for the syringe piston rod 16 accommodated in the drive head 10 from soiling and to ensure easier cleaning, they can be provided with a suitable coating, for example a liquid-repellent nano-coating. It is also advantageous to encapsulate the drive unit and to magnetically control the motor.

[0072] In Figure 22a and 22b exemplary and schematic variants for effectively shielding the flap mechanism are shown, which are constructed on the flap closure LV according to Figure 10 of. Figure 22a The flap closure LV is shown in the fully open state, while Figure 22b shows the state in which the flap 30 is in abutting contact radially inwards with the annular flange 48 of the syringe piston rod 16. The thin-walled, elastically stretchable sleeve 80 can be seen, which extends radially inwards from the front wall 82 of the flap closure to the abutment surface 51 of the disc 46 for the syringe piston rod 16 and thus shields the entire mechanism of the diaphragm closure outwards. When the flap 30 moves radially inwards, as shown in Figure 22b the sleeve 80 deforms and further effectively shields the interior of the flap closure LV from external influences.

[0073] Of course, deviations from the described design are possible without departing from the basic concept of the invention.

[0074] The above-mentioned flap closure can in principle be used for any type of medical fluid pump having a housing for accommodating a syringe barrel, a fixing device for fixing the syringe piston rod, and

[0075] a drive device by means of which a controlled relative movement between the syringe barrel and the syringe piston rod in the axial direction of the syringe barrel can be caused.

[0076] The described flap closure LV can also be used for gripping the syringe barrel 14 in order to fix the syringe barrel and / or to effect a relative movement between the syringe barrel 14 and the syringe piston 16.

[0077] Sensors can be provided on the flap closure, by means of which the opening width of the flap closure can be detected. This signal can thus be used for syringe identification.

[0078] When a motor drive of the flap closure is provided, a freewheel device can be provided in the transmission system in order to temporarily decouple the manual movement of the diaphragm from the motor. Devices can also be provided in order to axially movably support the gear 52 for the adjusting ring 36 for driving the flap closure LV in order to engage and disengage the gear with the worm gear 54 when required.

[0079] It is also possible to make the thin - walled closure in the drive head 10 movable in two axial directions, whereby the retention of the syringe barrel 14 in the housing body 6 can be simplified.

[0080] The drive concept for the thin - walled closure LV can also vary and a belt drive or an eccentric drive can also be used.

[0081] The linear mobility of the thin - walled closure LV in the drive head 10 can also be provided by a track geometry constructed in the drive head 10.

[0082] The described medical fluid pump 2 can also be an infusion pump.

[0083] Accordingly, the present invention provides a medical fluid pump, in particular an injection pump, having a housing in which a syringe barrel can be received,

[0084] fixing means for fixing the syringe piston rod and / or the syringe barrel, and drive means for causing a controlled relative movement between the syringe barrel and the syringe piston rod in the axial direction of the syringe barrel. To improve the fixing of the syringe piston rod and / or the syringe barrel, the fixing means is formed by a plurality of thin - walls which are concentrically grouped around a closure axis which can be oriented relative to the axis of the syringe barrel in the manner of a central or thin - walled closure known from cinematography and which can be moved synchronously by the drive means for fixing the syringe piston rod for changing the central free space between the thin - walls.

[0085] The fixing means can be used for all types of medical fluid pumps. Additional positive effects are obtained when the injection pump is configured to receive syringe barrels of different diameters and is equipped with a drive head (in which the fixing means is received) which is linearly movable relative to the housing along a movement axis via a tubular or rod - shaped drive arm. For the fixing to occur in such a way that the syringe piston rod is not subject to bending stress, the thin - walled closure is preferably arranged such that the closure axis is preferably linearly and movably guided in a plane spanned by the axes of the syringe barrels of different diameters located in the housing, without friction, and perpendicular to the movement axis of the drive arm.

[0086] List of reference numerals

[0087] 2 Injection pump

[0088] 4 Front cover

[0089] 5 Display

[0090] 6 Housing body

[0091] 8 Receiving area

[0092] 10 Drive head

[0093] 11 Hinge device

[0094] 12 Button

[0095] 13 Spring clip

[0096] 14 Syringe barrel

[0097] A14 The axis of the 14

[0098] 16 Syringe piston rod

[0099] 18 Driving arm

[0100] A18 The axis of the 18

[0101] 20 Shoulder section

[0102] 30 Flake

[0103] D30 The thickness of the 30

[0104] A30 The axis of the 30

[0105] 32 Axis

[0106] 34 First ring

[0107] 36 Adjusting ring

[0108] 38 Another axis

[0109] 40 Guide chute

[0110] 42 Rack segment

[0111] 142 Tooth segment

[0112] 44 Adjusting rod

[0113] 46 Piston rod head / disk

[0114] 48 Annular flange

[0115] 50 Surface

[0116] 52 Gear

[0117] 54 Worm gear

[0118] 56 Motor

[0119] 58 Bearing arm

[0120] A58 The axis of the 58

[0121] 60 Guide rail

[0122] 62 Guide pin

[0123] 70 Slide

[0124] 72 Linear bearing

[0125] 74 Guide rod

[0126] A74 The axis of the 74

[0127] 76 Through hole

[0128] 176 Through hole

[0129] 78 Spring device

[0130] 80 Sleeve

[0131] E plane

[0132] AG Large distance

[0133] AK Small distance

[0134] LB Linear movability

[0135] LV Thin sheet closure

[0136] V Measure of movement

Claims

1. A medical fluid pump (2), in particular an injection pump, having a housing (6) in which a syringe barrel (14) can be received, fixing means for fixing a syringe piston rod (16) and / or a syringe barrel (14), and driving means for causing a controlled relative movement between the syringe barrel (14) and the syringe piston rod (16) in a direction pointing along the axial direction (A14) of the syringe barrel (14), characterized in that the fixing means is formed by a plurality of laminae (30) which are concentrically grouped around a closing axis (A30) which can be oriented relative to the axis (A14) of the syringe barrel (14) in the manner of a central or lamina closure (LV) known in camera technology and which can be moved synchronously by driving means (36) for fixing the syringe piston rod (16) and / or the syringe barrel (14) for changing the central free space between the laminae (30).

2. The medical fluid pump according to claim 1, wherein, The housing (6) is arranged to receive syringe barrels (14) of different sizes, and the fixing means is arranged in a drive head (10) which can be linearly moved relative to the housing (6) along a movement axis (A18) via a tubular or rod-shaped drive arm (18), wherein the lamina closure (LV) is arranged such that the closing axis (A30) is preferably linearly and frictionlessly or force-free movably guided in a plane (E) perpendicular to the movement axis (A18) of the drive arm (18), the plane being spanned by the axes (A14) of syringe barrels (14) of different diameters located in the housing.

3. The medical fluid pump according to claim 1 or 2, characterized in that, The laminae (30) are configured in a plate-like shape.

4. The medical fluid pump according to any one of claims 1 to 3, characterized in that, The central or lamina closure (LV) consists of modules.

5. The medical fluid pump according to any one of claims 2 to 4, characterized in that The central or lamina closure (LV) is received in the drive head (6) in a linearly movable and guiding manner.

6. The medical fluid pump according to any one of claims 2 to 4, characterized in that, The central or lamina closure (LV) is received in the drive head (10) in a position-fixed manner, and the drive head is movably and guidingly connected to the drive arm (18).

7. The medical fluid pump according to any one of claims 1 to 6, characterized in that, The driving means is formed by an adjuster ring (36) which is rotatably supported.

8. The medical fluid pump according to claim 7, wherein, The adjuster ring is motor-driven, wherein the drive motor (56) is preferably received in the drive head (10) according to claim 2.

9. The medical fluid pump according to any one of claims 1 to 8, characterized in that, The laminae (30) each have inclined surfaces (50) at least in a radially inner region on the side of the lamina facing away from the housing (4), and the inclined surfaces can come into contact with the annular flange (48) of the piston rod head (disc 46) when the syringe piston rod (16) is inserted.

10. The medical fluid pump according to any one of claims 1 to 9, characterized in that, The laminae (30) are located in a common plane.

11. The medical fluid pump according to any one of claims 1 to 8, characterized in that, The laminae (30) are provided with a coating, such as a nano-coating, which repels dirt, such as liquid.

12. The medical fluid pump according to any one of claims 1 to 11, characterized in that, The laminae (30) are covered by an elastically stretchable sleeve (80).

13. The medical fluid pump according to any one of claims 1 to 12, characterized in that A sensor by which the opening width of the lamina closure (LV) can be detected.

14. The medical fluid pump according to any one of claims 1 to 13, characterized in that, The driving means is motor-driven by magnetic force coupling.

15. The medical fluid pump according to any one of claims 1 to 14, characterized in that, The thin-walled closure (LV) is arranged to grasp the syringe barrel (14) in order to fix the syringe barrel and / or to effect a relative movement between the syringe barrel (14) and the syringe piston (16).

Images