DISPLACEMENT UNIT FOR A MEDICAL HOSE PUMP AND MEDICAL HOSE PUMP

Abstract

A displacement unit for a medical hose pump and a medical hose pump having such a displacement unit. The displacement unit has linearly movable displacers that can be actuated by a drive device of the displacement unit transversely to a conveying direction against a hose.

Claims

1. A displacement unit for a medical hose pump with linearly movable actuatable displacers, which are actuatable with a predetermined sequence by a drive device of the displacement unit for generating a peristaltic movement of a hose or hose portion transversely to the hose or hose portion and against the hose in order to squeeze the hose or hose portion, wherein the drive device has linear motors, each of which is coupled to one of the displacers and at least one of which is a piezoelectric linear motor.

2. The displacement unit according to claim 1, wherein the medical hose pump is an infusion device or an infusion pump or a hose pump for medical dosage or for extracorporeal blood treatment.

3. The displacement unit according to claim 1, wherein at least one of the linear motors is a piezoelectric stepper motor.

4. The displacement unit according to claim 1, wherein the linear motors are arranged and movable parallel to each other.

5. The displacement unit according to claim 1, wherein the linear motors are each arranged laterally to the displacers with respect to a direction of movement of the displacers.

6. The displacement unit according to claim 1, wherein the displacers each have a side edge, which is configured for friction fit and/or form fit with at least one actuator element of the linear motors.

7. The displacement unit according to claim 6, wherein the at least one actuator element of the linear motors is an amorphous bending actuator.

8. The displacement unit according to claim 6, wherein the side edge is flat.

9. The displacement unit according to claim 1, further comprising a carrying structure in or on which the displacers are mounted linearly movably, wherein at least one lateral rim of the displacers is configured as at least one guide rail which is guided longitudinally movable in or on the carrying structure.

10. The displacement unit according to claim 9, wherein the at least one lateral rim of the displacers is adjacent to the lateral edge.

11. The displacement unit according to claim 1, wherein the carrying structure forms at least one shaft in which the displacers are mounted in a linearly moveable manner and are spaced apart from each other.

12. The displacement unit according to claim 1, comprising a control unit via which a stroke or a force of at least one of the displacers can be controlled or regulated.

13. The displacement unit according to claim 1, comprising a housing or carrying structure in or on which the displacers are mounted linearly movable, and to which stators of the linear motors are fixed.

14. A medical hose pump with a housing with an externally accessible passage recess, into or via which a fluid-carrying or blood-carrying hose or hose portion is insertable or spannable, wherein a displacement unit configured in accordance with one of the preceding claims is accommodated in the housing, the displacers of which can be brought into operative engagement with the hose or hose portion through the passage recess or in the region of the passage recess in order to generate a peristaltic movement of the hose or hose portion.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The disclosure is explained in more detail below with reference to an exemplary, non-limiting embodiment shown in the figures.

[0025] FIG. 1 shows a medical hose pump according to a configuration example in a front view.

[0026] FIG. 2 shows the hose pump according to FIG. 1 in a perspective view from the front.

[0027] FIG. 3 shows a peristaltic displacement unit of the hose pump according to FIGS. 1 and 2 in a perspective view.

[0028] FIG. 4 shows a front view of the displacement unit according to FIG. 3.

[0029] FIG. 5 shows a displacer of the displacement unit according to FIGS. 3 and 4, exposed in a front view.

[0030] FIG. 6 shows the displacers according to FIG. 5 in a top view.

[0031] FIG. 7 shows the displacement unit according to FIG. 3, in a perspective view from behind.

[0032] FIG. 8 shows a contact zone of one of the displacers with an associated linear motor according to FIGS. 3 to 7, in a detailed perspective view.

DESCRIPTION

[0033] FIG. 1 shows a front view of a medical hose pump 1 configured as an infusion device. The infusion device or hose pump 1 has an essentially cuboid housing 2 with a front side 4, which is essentially divided into an upper operator panel 6 and a lower, lockable hose compartment 8. The latter is covered by a hinged hose compartment lid 10.

[0034] The operator panel 6 has a plurality of buttons for operating the infusion device 1 and includes, among other things, an on/off button 12 a display 14 for displaying selected operating parameters, current operating variables, and an operating menu, a button arrangement 16 for navigating the operating menu and changing operating parameters, and other buttons for operation.

[0035] FIG. 2 shows the infusion device 1 according to FIG. 1 in a perspective view from the front with the hose compartment 8 open, i.e. with the hose compartment lid 10 opened. According to FIG. 2, a hose or infusion hose 18 extends from the right, starting from an infusion container (not shown), into the hose compartment 8. The infusion hose 18 is not yet inserted as intended, but is shown in a raised position with respect to the operating state.

[0036] The hose compartment 8 has a hose inlet 20 in the area of a right side wall 22 from the operator's point of view, and a hose outlet 24 in the area of a left side wall 26.

[0037] The hose compartment lid 10, which is folded down as shown in FIG. 2, together with a base or bottom of the hose compartment 8 forms shaped sections, i.e. differently shaped sections adapted for contact with the infusion hose, into which the infusion hose 18 can be inserted in its operating state in a manner fixed to the housing. Closing the hose compartment lid 10 fixes the infusion hose 18 in this operating state.

[0038] With reference to the direction of conveyance from right to left according to FIGS. 1 and 2, a substantially rectangular recess 28 is provided in the housing 2 on the right side at the bottom of the hose compartment 8, in which an adapter portion 30 of the housing 2 is arranged. This recess 28 has a passage recess 32, rearward of which displacers 50 of a peristaltic displacement unit 46 are arranged, which will be explained in more detail in the following figures.

[0039] On both sides of the passage recess 32, in an extension direction of the infusion hose 18 when it is inserted into the hose pump 1 (i.e. in a longitudinal direction of the hose), a half-shell-shaped or half-cylindrical receptacle 34, 36 tapering in steps towards the passage recess 32 is provided for a coupling portion 38, 40 of the infusion hose 18. The passage recess 32 is spanned on the inside of the housing by a membrane 42, which separates an interior housing space of the infusion device 1 from the medical treatment space, or vice versa, protects the interior housing space against fluid, disinfectant or contamination penetrating from the outside.

[0040] According to FIG. 2, the coupling portions 38, 40 of the infusion hose 18 are insertable into the receptacles 34, 36, so that a hose portion or peristaltic portion 44 of the infusion hose 18 formed between the coupling portions 38, 40 is held in a linear/straight manner in the passage recess 32. The hose compartment lid 10 is closable by folding up. As a result, the infusion hose 18 is received in a form-fitting manner in the hose compartment 8 and clamped by the hose compartment lid 10 acting as a counter bearing. Displacers 50 of the hose pump (cf. following Figures) arranged behind the membrane 42 can then impress a peristaltic constriction of its cross-section on the infusion hose 18, or more precisely on the peristaltic portion 44 extending between the coupling portions 38, 40. As an alternative to the multi-piece hose/infusion hose 18 shown, the latter may be a single piece. In the first case, a specifically selected material of the hose portion to be loaded by the displacers, for example silicone, can be used to respond to mechanical requirements. The use of a one-piece hose, on the other hand, is simpler in terms of device technology.

[0041] FIG. 3 shows the displacement unit 46 of the infusion device 1 already mentioned in the description of FIG. 2. The displacement unit 46 has a carrying structure 48 and displacers 50 accommodated therein so as to be linearly movable parallel to each other. These are flat and have conically tapering and rounded operating edges facing the membrane 42 according to FIG. 2, which can be brought into contact with the membrane 42 and thus into operative engagement with the infusion hose 18 according to FIG. 2. The cross-section occupied by the operating edges is somewhat smaller than that of the passage recess 32 according to FIG. 2.

[0042] The carrying structure 48 is essentially cuboidal in shape. In the direction in which the infusion hose extends, i.e. from right to left in FIG. 3, two shafts 52 and 54 are provided side by side, in each of which six displacers 50 are arranged. The shafts 52, 54 are separated by a separation wall 56, from which a support element 57 protrudes, which in the case of a comparatively soft structure of the infusion hose 18 gives it a height guide. Above the two shafts 52, 54, an actuator space 58 is formed in the carrying structure 48, in which piezoelectric linear motors 60 are accommodated fixed to the housing. Each of the displacers 50 is coupled to one of the linear motors 60.

[0043] In the configuration example shown, the piezoelectric linear motors 60 are configured as stepper or walk-drive motor. Designs deviating from this are possible.

[0044] Fixing portions 62, via which the displacement unit 46 can be fixed in the housing 2 of the infusion device 1, project laterally from the carrying structure 48.

[0045] FIG. 3 clearly shows the comparatively small overall depth of the displacement unit 46. This is made possible by the fact that the displacers 50 are driven by linear motors according to the disclosureand thus directly in their desired direction of actuationso that there is no need for a gear device to convert a rotational movement of the displacers 50 into a linear movement.

[0046] FIG. 4 shows a front view of the displacement unit 46 according to FIG. 3, i.e. a front view of the hose compartment 8 according to FIG. 2 with the housing 2 removed. It can be clearly seen that the shafts 52, 54 each have an upper and a lower guide surface between which the displacers 50 are slidably mounted. Short guide lamellae or webs extend out of the guide surfaces, on or respectively between which the displacers 50 are laterally slidably guided.

[0047] FIG. 5 shows the units of displacers 50 and linear motors 60 exposed from the carrying structure 48 according to FIGS. 3 and 4, whereby a contact zone 64 of the respective linear motor 60 with its associated displacer 50 is visible.

[0048] In order to generate the necessary peristaltic movement of the infusion hose 18, a roughly sinusoidal peristaltic movement pattern is alternately impressed on the displacers 50 via the linear motors 60 assigned to them in a predetermined sequence, which is shown at a time tin FIG. 6.

[0049] The hose pump 1 has a control unit 70 from which the linear motors 60 are drivable via signal line 72, in particular as a function of the parameters specified via the operator panel 6. The parameters stored in the control unit are a sequence of actuation of the displacer 50, its stroke, stroke speed and/or stroke force. These parameters can be changed using the buttons on the operator panel 6.

[0050] FIG. 7 shows a perspective view of the displacement unit 46 from the rear, which again illustrates its comparatively small overall depth and the small installation space it occupies.

[0051] FIG. 8 shows in a schematic view a detailed view of the contact zone 64 between one of the displacers 50 and the piezoelectric linear motor 60 coupled to it. The latter is configured as a stepper motor and has a stator with a stator housing 66. For its driving and supply with electrical drive energy, the linear motor is electrically connected to the control unit of the hose pump via a contact lug (not shown). In the piezoelectric stepping motor embodiment, a plurality of bimorph bending actuators 68 project from the stator housing 66 and are deformable in and against the direction of actuation of the displacer 50 (along the double arrow) and are liftable transversely thereto. In the present example, the bending actuators 68 are deformable in such a way that their free ends, which are configured for frictional contact with the displacer 50, can be folded through a certain angle depending on energization of the bending actuators 68.

[0052] In addition to the linear motors 60 shown in FIG. 8, which are arranged on only one upper side of the displacer 50, they can of course also be arranged on an additional side of the displacer 50, for example its underside. The arrangement may be a mirror image.

[0053] At the time shown in FIG. 8, the direction of actuation towards the infusion hose is assumed to be from left to right. By applying the appropriate energization, two bending actuators 68 are lifted off and two other bending actuators 68 are deformed with the maximum possible return stroke (i.e. a maximum position set back against the direction of actuation), against the direction of actuation, and are placed on the displacer 50.

[0054] When the driving is changed, the latter two bending actuators 68 remain seated on the displacer 50 and are deformed to the right in FIG. 8 in this way, i.e. brought into a maximum possible pre-stroke. This causes a linear movement of the displacer 50 in FIG. 8 to the right, towards the infusion hose 18, via the frictional force transmitted to the displacer 50.

[0055] Once they have reached their maximum possible stroke in the actuating direction (pre-stroke), the two bending actuators 68 remain seated and the other two 68 are deformed in the lifted position to their maximum possible return stroke, against the actuating direction, and are then seated.

[0056] In this state, all bending actuators 68 and 68 are briefly seated, the first-mentioned bending actuators 68 with maximum possible stroke in the actuating direction, the other bending actuators 68 with maximum possible stroke against the actuating direction. In this way, the displacer 50 is transferred from one bending actuator 68 to the other bending actuators 68.

[0057] The one bending actuators 68 are lifted off and deformed against the direction of actuation from right to left, and the other bending actuators 68 are deformed in the direction of actuation from left to right.

[0058] The described driving is performed for all linear motors 60 in a sequence stored in the control unit for execution depending on at least one of the parameters of stroke, stroke speed and stroke force. In particular, the control unit is configured to determine the parameters from a volume flow specified by the operator.

[0059] The described use of the piezoelectric linear motors 60 makes it possible to implement the principle of displacers 50 arranged side by side, which perform a peristaltic movement or respectively imprint it on the infusion hose 18. The respective bending actuators 68 of the respective piezoelectric linear motor 60 run on the associated displacer 50 and move it back and forth in the direction of actuation, depending on the time-related driving via the control unit.

[0060] A significant advantage of the design of the displacement unit 46 described is its reliability and durability. The design of the piezoelectric linear motor 60 based on crystalline structures is subject to little or no significant wear. A space requirement of the linear motor 60, in particular its overall installation height and/or width, is small, and its controllability has high-resolution and may be, for example, in the nanometer range. In this way, the position of the displacer 50 relative to the (infusion) hose 18 can be controlled in the nanometer range. As a result, the force exerted by the displacer 50 on the hose 18, and consequently the pressure in the hose 18, can also be influenced extremely precisely. The achievable speeds are also high. For example, linear movements at 500 mm/sec are possible. In principle, one advantage of this design is a low energy requirement due to fewer components and friction. Since fewer components are required for the same function as in the prior art, this also results in a smaller installation space required as well as a lower weight, both of the displacement unit 46 and of the hose pump 1 in which the displacement unit 46 is inserted. Another advantage is a lower assembly effort resulting from the reduced number of components.

[0061] In summary, disclosed is a peristaltic displacement unit for a medical hose pump having a plurality of linear motors for generating a peristaltic motion of a fluid-carrying hose so that the hose is kneaded in an intended direction and thus conveys the fluid.