INFUSION DEVICE COMPRISING A WOBBLING DEVICE FOR ACTING ONTO A PUMP MODULE

Abstract

An infusion device (3) comprises a housing element (30) having a receptacle (301) for receiving a pump module (1), and a pump actuation mechanism (2) having a wobbling device (20) arranged on the housing element (30) and a drive shaft (21) being rotatable about a rotational axis (A). The wobbling device (20) is actuatable, by rotating the drive shaft (21) about the rotational axis (A), to perform a tumbling motion with respect to the receptacle (300) for acting onto the pump module (1) received in the receptacle (300) in order to pump a fluid through the pump module (1). Herein, the wobbling device (20) is displaceable along at least one direction (X, Y) transverse to the rotational axis (A) with respect to the receptacle (300). In this way an infusion device is provided which in an easy and cost-efficient manner allows for improving the positional accuracy of the pump module with respect to the wobbling device of the pump actuation mechanism upon arranging the pump module on the receptacle of the housing element.

Claims

1. An infusion device, comprising: a housing element having a receptacle for receiving a pump module, and a pump actuation mechanism having a wobbling device arranged on the housing element and a drive shaft being rotatable about a rotational axis, wherein the wobbling device is actuatable, by rotating the drive shaft about the rotational axis, to perform a tumbling motion about the rotational axis with respect to the receptacle for acting onto the pump module received in the receptacle in order to pump a fluid through the pump module, wherein the wobbling device is displaceable along at least one direction transverse to the rotational axis with respect to the receptacle.

2. The infusion device according to claim 1, wherein the wobbling device is displaceable along the rotational axis with respect to the receptacle and is elastically pretensioned with respect to the housing element along the rotational axis in a direction pointing towards the receptacle.

3. The infusion device according to claim 1, wherein the wobbling device is mounted on the drive shaft via a first bearing such that the wobbling device is actuated to perform a tumbling motion when rotating the drive shaft.

4. The infusion device according to claim 3, wherein the drive shaft is mounted on a carrier element via a second bearing such that the drive shaft is rotatable with respect to the carrier element about the rotational axis.

5. The infusion device according to claim 4, wherein the carrier element is mounted on the housing element such that the carrier element is displaceable along at least one direction transverse to the rotational axis with respect to the housing element.

6. The infusion device according to claim 4, wherein the carrier element is connected to the housing element via an elastically deformable connection element.

7. The infusion device according to claim 4, wherein the carrier element is elastically pretensioned with respect to the housing element along the rotational axis.

8. The infusion device according to claim 1, wherein the wobbling device comprises a wobbling disc extending along a plane transverse to a tumbling axis, wherein the tumbling axis is arranged at a skew angle with respect to the rotational axis and tumbles about the rotational axis when the wobbling device is driven by the drive shaft.

9. The infusion device according to claim 8, wherein the wobbling device comprises a protrusion protruding from the wobbling disc along the tumbling axis for acting onto the pump module.

10. The infusion device according to claim 1, wherein the wobbling device is constituted to self-align itself with respect to the pump module along at least one direction transverse to the rotational axis when acting onto the pump module during operation of the infusion device.

11. The infusion device according to claim 1, wherein the pump module comprises a housing part and a flexible wall section together forming a pump channel through which a fluid is to be pumped, wherein the wobbling device acts onto the flexible wall section for locally depressing the flexible wall section in order to pump a fluid through the pump channel.

12. The infusion device according to claim 11, wherein the pump channel is formed by a trench in the housing part of the pump module.

13. The infusion device according to claim 11, wherein the pump channel extends along an arc of a circle.

14. The infusion device according to claim 11, wherein the pump channel extends along a plane transverse to the rotational axis.

Description

[0027] The idea underlying the invention shall subsequently be described in more detail with regard to the embodiments shown in the figures. Herein,

[0028] FIG. 1 shows a schematic view of an infusion device in the shape of a peristaltic (volumetric) infusion pump;

[0029] FIG. 2 shows a top view of an embodiment of a disposable pump module;

[0030] FIG. 3A shows a sectional, explosive view of a pump module along line A-A according to FIG. 2, together with a wobbling device of a first type;

[0031] FIG. 3B shows a sectional, explosive view of the pump module along line A-A according to FIG. 2, together with a wobbling device of a second type;

[0032] FIG. 4A shows a sectional view of the pump module along line A-A according to FIG. 2 in interaction with the wobbling device of the first type;

[0033] FIG. 4B shows a sectional view of the pump module along line A-A according to FIG. 2 in interaction with the wobbling device of the second type;

[0034] FIG. 5A shows a sectional view of an embodiment of an infusion device, including a pump actuation mechanism for driving the wobbling device, along a sectional line corresponding to line B-B according to FIG. 2;

[0035] FIG. 5B shows a sectional view along the line C-C according to FIG. 5A;

[0036] FIG. 6 shows a view of another embodiment of a pump actuation mechanism;

[0037] FIG. 7A shows an example of a connection element for connecting a carrier element of the pump actuation mechanism with a housing element;

[0038] FIG. 7B shows a separate view of a connection element example;

[0039] FIG. 8 shows a top view of the pump actuation mechanism; and

[0040] FIG. 9 shows a schematic view of the connection of the wobbling device with a drive shaft of the pump actuation mechanism.

[0041] FIG. 1 shows in a schematic view an infusion device 3 in the shape of a peristaltic (volumetric) infusion pump. The infusion device 3 comprises a housing 30 having a front face 300 and a receptacle 301 arranged on the front face 300. The receptacle 301 is shaped as a reception opening and is constituted to receive a pump module 1.

[0042] Attached to the housing 30 is a door 31 which may be pivoted with respect to the housing 30 for accessing the front face 300 and the receptacle 301 arranged thereon. By pivoting the door 31 away from the front face 300, the receptacle 301 may be accessed for inserting a pump module 1 into the receptacle 301 or for removing the pump module 1 from the receptacle 301. During operation of the infusion device 3, the door 31 is closed such that the pump module 1 is securely held in the receptacle 301.

[0043] FIG. 2 shows a schematic top view of a disposable pump module 1 which may be part of an infusion set to be attached to the infusion device 3. The pump module 1 comprises a housing 10 having an inlet 100 and an outlet 101. The inlet 100 and the outlet 101 may be connected to a suitable tubing forming an infusion line such that an upstream flow U may enter the pump module 1 at the inlet 100 and a downstream flow D may exit the pump module 1 through the outlet 101.

[0044] Within the pump module 1 a flow path L is defined through which fluid may pass the pump module 1. Along the flow path L, as viewed from the inlet 100, a fluid flow first passes a pressure sensing location 11, then through an end 120A enters a pump channel 121 and exits the pump channel 121 through an end 120B, and flows through another pressure sensing location 13.

[0045] At the pressure sensing locations 11, 13 thin, flexible wall sections on the housing 10 may be provided such that pressure sensors of the infusion device 3 are enabled to sense the pressure at the pressure sensing locations 11, 13 on the flow path L.

[0046] In the embodiment of the pump module 1 according to FIG. 2, the pump channel 121 has the shape of an arch of a circle. The circle is not circumferentially closed such that the ends 120A, 120B of the pump channel 121 are separated from one another.

[0047] As visible from FIG. 3A, 3B and FIG. 4A, 4B, the pump channel 121 is formed by a trench in a housing part 103 of the housing 10 of the pump module 1. The pump channel 121, towards the outside, is covered by a flexible wall section 12 in the shape of a membrane, which is held between the housing part 103 and another, top housing part 102. The flexible wall section 12 may be glued or welded to the housing part 103 or may be held in-between the housing parts 102, 103 in a clamping fashion. The flexible wall section 12 may alternatively be formed in one piece together with the housing parts 102, 130 using for example a two-component molding technology.

[0048] Whereas the flexible wall section 12 is elastic such that it may locally be depressed in order to perform a pump action, the housing parts 102, 103 are formed as rigid pieces for example from plastics.

[0049] FIG. 3A, 4A and FIG. 3B, 4B show the pump module 1 in interaction with different types of wobbling devices 20 of a pump actuation mechanism 2. The wobbling devices 20 comprise a wobbling disc 200 and an arched projection 201 projecting from the wobbling disc 200 through an opening 104 in the top housing part 102 towards the flexible wall section 12 and, along the pump channel length, forming an arch similar in shape to the arch of the pump channel 121.

[0050] In an operational state of the infusion device, as shown in FIGS. 4A and 4B, each wobbling device 20 is in abutment with a projecting rim 122 of the flexible wall section 12 of the pump module 1. The wobbling device 20 herein is pretensioned towards the flexible wall section 12. This leads to a preloading of the flexible wall section 12, causing the wobbling device 20 to be in abutment with the flexible wall section 12 along the entire channel length of the pump channel 121 such that the flexible wall section 12 is preloaded along the channel length of the pump channel 121.

[0051] By means of the wobbling device 20 fluid may be pumped through the pump channel 121 between the inlet 100 and the outlet 101. The wobbling device 20, during operation of the infusion device 3, is driven to perform a wobbling action about a rotational axis A such that the wobbling device 20, by means of its projection 201, locally depresses the flexible wall section 120 at a depression location, the depression location revolving in a tumbling direction R about the rotational axis A along the channel length of the pump channel 121. By the local depression of the flexible section 120, the pump channel 121 is locally squeezed off, and by the revolving action of the wobbling device 20 fluid is peristaltically pumped through the pump channel 121 in the tumbling direction R.

[0052] The wobbling disk 200 of the wobbling device 20 extends along a plane perpendicular to a tumbling axis A, which is arranged at a skew angle relative to the rotational axis A. During operation of the infusion device 3, the wobbling disk 200 performs a tumbling motion T, and the tumbling axis A revolves about the rotational axis A, wherein the rotational position of the tumbling device 20 remains stationary.

[0053] The tumbling device 20 of FIG. 3A, 4A and the tumbling device of FIG. 3B, 4B differ in the shape of the projection 201. The tumbling device 20 of FIG. 3A, 4A comprises a projection 201 having a rounded outer edge acting onto the rim 122 of the flexible wall section 120. The projection 201 of the wobbling device 20 of FIG. 3B, 4B, in contrast, is flat at its face pointing away from the wobbling disk 200, and via its flat circumferential face acts onto the rim 122 of the flexible wall section 120.

[0054] The embodiment of the wobbling device 20 of FIG. 3A, 4A is self-aligning in that it allows for a self-alignment of the lateral position of the wobbling device 20 with respect to the pump channel 121 formed in the pump module 1. When the wobbling device 20 by means of its projection 201 engages with the pump channel 121 as shown in FIG. 4A on the left, the wobbling device 20 will automatically find its position with respect to the pump module 1 such that an optimum depression of the flexible wall section 120 becomes possible.

[0055] The self-alignment of the wobble device 20 becomes possible when the wobble device 20, by at least some margin, is laterally displaceable with respect to the pump module 1, as will be described below with respect to the embodiment of FIGS. 6 to 8.

[0056] In contrast to the embodiment of FIG. 3A, 4A, the wobble device 20 of the embodiment of FIG. 3B, 4B is not self-aligning, because the flat face of the projection 201 does not cause a lateral alignment of the wobbling device 20 with respect to the pump module 1 as the projection 201, as visible from FIG. 4B, does not engage with the pump channel 121 (i.e., it does not reach into the pump channel 121).

[0057] The wobbling device 20in the embodiment of FIG. 3A, 4A or FIG. 3B, 4Bis part of a pump actuation mechanism 2, as it is shown in FIG. 5A.

[0058] The pump actuation mechanism 2 comprises a drive shaft 21 which is rotatably mounted about a rotational axis A on a carrier element 22. The drive shaft 21 is driven by a drive device 24 in the shape of an electric motor, wherein a suitable gearing in-between the drive device 24 and the drive shaft 21 may be provided for driving the drive shaft 21. The carrier element 22 is mounted on the housing 30 of the infusion device 3 in a pivotable fashion and for this is pivotable about a pivot axis P via an axis 220.

[0059] By pivoting the carrier element 22 about the pivot axis P, the longitudinal position of the wobbling device 20 along the rotational axis A can be adapted. The carrier element 22 herein is pretensioned by means of a spring element 23 in the shape of a tension spring in a vertical direction Z towards a pump module 1 placed in the receptacle 301 on the front face 300 of the housing 30. By means of the pre-tensioning, hence, the wobbling device 20 is brought into abutment with the flexible wall section 12 of the pump module 1 such that the flexible wall section 12 is elastically preloaded.

[0060] Because the distance between the pivot axis P and the rotational axis A is large, the wobbling device 20 is substantially displaceable along the vertical direction Z with respect to the pump module 1. Because the axis 220 is stiff, the wobbling device 20 herein is not displaceable in a direction transverse to the rotation axis A with respect to the receptacle 301 on the front face 300 of the housing 30.

[0061] An embodiment implementing the instant invention is shown in FIGS. 6 to 8. In this embodiment, the carrier element 22 is connected to the housing element 30 via a connection element 25 which is by at least some margin deformable such that the lateral position of the carrier element 22 is, to at least some degree, displaceable in a plane transverse to the rotational axis A, i.e. in a plane spanned by the horizontal directions X, Y.

[0062] The connection element 25 comprises a connection section 250 fixedly connected to the carrier element 22 and a connection section 252 fixedly connected to the housing element 30. The connection sections 250, 252 are integrally connected by means of elastic connecting webs 251, which are bendable to allow for a lateral displacement of the carrier element 22 along bending directions B2, B2 in the horizontal plane spanned by the horizontal directions X, Y, as shown in FIG. 8. In addition, the connection element 25 is bendable in a bending direction B1 as shown in FIG. 6 to allow for a vertical displacement of the wobbling device 20 along the vertical direction Z.

[0063] The position of the carrier element 22 hence is adjustable with two degrees of freedoms, namely by bending the connection element 25 in the bending direction B1 as indicated in FIG. 6 (to allow for a displacement of the wobbling device 22 along the vertical direction Z) and along the bending directions B2, B2 as indicated in FIG. 8 (to allow for a lateral displacement of the wobbling device 20 with respect to the vertical direction Z). The position of the wobbling device 20 with respect to the pump module, hence, is adjustable laterally within the plane of the front face 300 on which the receptacle 301 is arranged, namely along the plane spanned by the directions X, Y perpendicular to the vertical direction Z.

[0064] In particular, when the wobbling device 20 is self-aligning as in the embodiment of FIG. 3A, 4A, the wobbling device 20 hence may find its optimum position with respect to the pump module 1 automatically when inserting the pump module 1 into the receptacle 301. Once the wobbling device 20 by means of its projection 201 engages with the pump channel 121, the carrier element 22 is laterally displaced by deforming the connection element 25 (by subjecting the connection element 25 to torsion). Tolerances in the pump module 1 and in the pump actuation mechanism 2 hence may be overcome, and an optimum engagement of the wobbling device 20 with the pump channel 121 of the pump module 1 may be achieved, leading to an increased flow rate accuracy during operation of the infusion device 3.

[0065] FIG. 9 shows the mounting of the wobbling device 20 on the drive shaft 21 and the mounting of the drive shaft 21 on the carrier element 22. The wobbling device 20 is mounted on the drive shaft 21 by means of a first bearing 203 arranged between a pin 202 of the wobbling device 20 and a circumferential face of a bearing opening 211 provided in the drive shaft 21. By means of the bearing 203 the wobbling device 20 is rotatable about the tumbling axis A with respect to the drive shaft 21. The drive shaft 21 in turn is mounted via a bearing 210 on the carrier element 22 such that it is rotatable with respect to the carrier element 22 about the rotational axis A. When driving the drive shaft 21 via the drive device 24, the drive shaft 21 is rotated about the rotational axis A relative to the carrier element 22. This causes the bearing opening 211 to rotate about the rotational axis A such that the wobbling device 20 is forced into a tumbling motion T about the rotational axis A in that the tumbling axis A revolves about the rotational axis A. The wobbling device 20 herein remains rotationally fixed (and hence is not rotated), but performs a tumbling motion T and hence, in a revolving fashion, acts onto the flexible wall section 12 of the pump module 1 to peristaltically pump a fluid through the pump channel 121.

[0066] Because the wobbling device 20 is mounted on the drive shaft 21 and the drive shaft 21 is mounted on the carrier element 22, the wobbling device 20 is laterally displaced together with the carrier element 22. Upon engaging of the projection 201 with the pump channel 121, the lateral position of the wobbling device 20 hence is self-aligned with respect to the pump module 1, causing a deformation of the connection element 25 and hence an adjustment of the lateral position of the carrier element 22.

[0067] The idea underlying the invention is not limited to the embodiments described above, but may be implemented in an entirely different fashion.

[0068] In particular, the wobble device may have an entirely different shape. Likewise, the pump module may have a different structure and shape. Also, the structure and mechanics of the pump actuation mechanism may be implemented in a different fashion.

LIST OF REFERENCE NUMERALS

[0069] 1 Pump module [0070] 10 Housing [0071] 100 Inlet [0072] 101 Outlet [0073] 102, 103 Housing part [0074] 104 Opening [0075] 11 Pressure sensing location [0076] 12 Flexible wall section (membrane) [0077] 120A, 120B End [0078] 121 Pump channel [0079] 122 Rim [0080] 13 Pressure sensing location [0081] 2 Pump actuation mechanism [0082] 20 Wobbling device (wobbling device) [0083] 200 Wobbling disc [0084] 201, 201 Projection [0085] 202 Pin [0086] 203 Bearing [0087] 21 Drive shaft [0088] 210 Bearing [0089] 211 Bearing opening [0090] 22 Carrier element [0091] 220 Axis [0092] 23 Spring element [0093] 24 Drive motor [0094] 25 Connection element [0095] 250 Connection section [0096] 251 Connecting webs [0097] 252 Connection section [0098] 3 Infusion device [0099] 30 Housing element [0100] 300 Front face [0101] 301 Receptacle [0102] 31 Door [0103] A Rotational axis [0104] A Tumbling axis [0105] B1, B2, B2 Bending direction [0106] D Downstream flow [0107] L Flow path [0108] P Pivot axis [0109] R Tumbling direction [0110] T Tumbling movement [0111] U Upstream flow [0112] X, Y, Z Direction