Patent Description:
An infusion device of this kind comprises a housing and a receptacle arranged on the housing for receiving a syringe. The syringe comprises a barrel for containing a medical fluid and a plunger movable relative to the barrel for delivering the medical fluid out of the barrel via an infusion line towards the patient. Herein, a pusher device is movable relative to the housing for moving the plunger relative to the barrel, the pusher device being driven by a drive mechanism such that during an infusion operation the medical fluid can be delivered from the barrel to the patient in a controlled fashion at a set infusion rate.

To set up an infusion procedure, a syringe is manually installed on the receptacle of the infusion device, and the pusher device is brought into operative connection with the plunger in order to enable the pusher device to push the plunger into the barrel for delivering the medical fluid from the barrel towards the patient. For installing the syringe on the receptacle, typically the pusher device is uncoupled from the drive mechanism such that the pusher device can freely be moved relative to the drive mechanism and in particular can be brought into engagement with the plunger for acting onto the plunger during an infusion operation. For the infusion operation, then, the pusher device is again coupled to the drive mechanism such that the drive mechanism can act onto the pusher device for moving the pusher device relative to the housing.

For coupling the drive mechanism with the pusher device, a coupling mechanism may be provided. The coupling mechanism, in a coupling state, establishes a coupling between the drive mechanism and the pusher device such that the pusher device can be driven by the drive mechanism and, in an uncoupling state, uncouples the drive mechanism from the pusher device such that the pusher device can freely be moved independent of the drive mechanism.

For actuating the coupling mechanism, an actuation mechanism is arranged on the pusher device, the actuation mechanism comprising an actuation element for actuating the coupling mechanism between the coupling state and the uncoupling state.

Another coupling mechanism may be provided which is used to couple the plunger to the pusher device such that, during an infusion operation, the plunger cannot be moved independently of the pusher device.

For example in a hospital environment, in particular in an intensive care unit of a hospital, a rather large number of infusion devices are arranged at the bedside of a patient. In modern systems herein infusion devices are arranged in a vertical column on one or multiple racks and are placed on a stand or the like in order to organize the infusion devices at the bedside of the patient. The more infusion devices herein are arranged in a stack, the smaller the available room for the individual infusion devices is and the more important it is that a user can conveniently access the individual infusion devices.

With such constraints it is desirable to provide an actuation mechanism which allows a user to actuate a coupling mechanism in an easy and comfortable way. The actuation of the coupling mechanism herein takes place for example during the set-up of an infusion procedure in order to manually install a syringe on an infusion device, for which first the pusher device must be uncoupled from the drive mechanism by actuating a suitable coupling mechanism and, after the syringe has been installed on the infusion device, the coupling must once more be established in order to move the pusher device together with the plunger to deliver a medical fluid from the barrel.

From <CIT> an infusion device in the shape of a syringe pump is known, in which a button acting onto a lever is arranged on a pusher device for actuating a coupling mechanism between a coupling state and an uncoupling state.

From <CIT> an infusion pump is known which comprises a snap-in holder to secure the syringe barrel and a pusher to advance the syringe plunger. The pusher is advanced to the syringe plunger during set-up by squeezing a finger tab and sliding the pusher forward. This simultaneously decouples the pusher from the internal drive and opens the antisiphon catch to allow a quick and easy set-up.

It is an object of the instant invention to provide an infusion device which in an easy and comfortable manner allows a user to actuate a coupling mechanism, in particular for installing a syringe on a receptacle of the infusion device.

This object is achieved with an infusion device comprising the features of claim <NUM>.

Namely, it is provided an infusion device for administering a medical fluid to a patient, comprising: a housing, a receptacle arranged on the housing for receiving a syringe, the syringe having a barrel for containing a medical fluid and a plunger movable relative to the barrel for delivering the medical fluid out of the barrel, a pusher device movable along a pushing direction relative to the housing for acting onto the plunger for moving the plunge relative to the barrel, a drive mechanism for driving the pusher device, characterized by a first coupling mechanism operative to couple the plunger to the pusher device and a second coupling mechanism operative to couple the pusher device to the drive mechanism, and a common actuation mechanism arranged on the pusher device and comprising an actuation element for actuating the first coupling mechanism and the second coupling mechanism between a coupling state and an uncoupling state, wherein the actuation mechanism comprises a first threaded element rotatable about a rotational axis and a second threaded element movable longitudinally along the first threaded element, the second threaded element being in threaded engagement with the first threaded element such that the first threaded element is rotated when the second threaded element is longitudinally moved along the first threaded element, wherein the actuation element is actuatable to move the second threaded element along the first threaded element, the first threaded element being operatively connected to the first and second coupling mechanisms, wherein the longitudinal movement of the second threaded element is translated into the rotational movement of the first threaded element, which is transferred to the first and second coupling mechanisms for moving the first and second coupling mechanisms between their coupling state and their uncoupling state.

Alternatively, the first threaded element is a high helix screw.

In an alternative, the second threaded element is a high helix nut.

The second threaded element can movable relative to the first threaded element along an actuation direction extending in parallel to a pushing direction along which the pusher device is movable relative to the housing.

As an alternative, the actuation element is constituted as a lever pivotable about a pivot axis relative to the pusher device, the second threaded element being carried along with the actuation element when the actuation element is pivoted.

Possibly, the first threaded element carries a first gear wheel rotatable together with the first threaded element.

The first gear wheel can be in engagement with a second gear wheel, the second gear wheel being rotated upon rotation of the first gear wheel.

The second gear wheel can interact with a cam connected to a shaft, the cam being actuated for pivoting the shaft upon rotation of the second gear wheel.

The second gear wheel may interact with - a first cam connected to a first shaft, the first cam being actuated for pivoting the first shaft upon rotation of the second gear wheel, wherein the first shaft is constituted to actuate a first coupling mechanism, and - a second cam connected to a second shaft, the second cam being actuated for pivoting the second shaft upon rotation of the second gear wheel, wherein the second shaft is constituted to actuate a second coupling mechanism.

As an alternative, the first coupling mechanism comprises a coupling element pivotably arranged on the pusher device.

The idea underlying the invention shall subsequently be described in more detail with respect to the embodiments described in the figures.

<FIG> shows in a schematic drawing an arrangement of infusion devices <NUM> on one or multiple racks <NUM>. The infusion devices <NUM> may for example be constituted as syringe pumps or as volumetric (peristaltic) infusion devices and generally serve to administer medical fluids to a patient for example in a hospital environment, for example in an intensive care unit of a hospital. The infusion devices <NUM> herein are organized to form a vertical stack on the rack <NUM> and, via the rack <NUM>, are connected to a holding device <NUM> which for example is connected to the ceiling of the patient's bedroom.

The rack <NUM> serves as a communication link as well as a power supply for the infusion devices <NUM>. For this, connection lines <NUM>, <NUM> constituting a power supply line as well as one or multiple communication lines are connected to the rack <NUM>, the rack <NUM> providing for a data connection as well as for a power connection for the infusion devices <NUM> arranged on the rack <NUM>.

Another view of infusion devices <NUM> arranged on receptacles <NUM> of a rack <NUM> is shown in <FIG>. The infusion devices <NUM>, as said, generally may be constituted as syringe pumps or as volumetric (peristaltic) infusion pumps.

It is a desire to arrange a large number of infusion devices <NUM>, for example up to <NUM> infusion devices, at the bedside of a patient in order to be able to infuse a multiplicity of different medical solutions to the patient, such medical solutions including drugs, nutritional solutions, saline solutions or the like. Since the infusion devices <NUM> generally are arranged in a vertical stack on one or multiple racks <NUM>, in order to be able to increase the number of infusion devices <NUM> on rack <NUM> it is required to reduce the height of the infusion devices <NUM>, assuming that a maximum height of a rack <NUM> should not be exceeded to allow a convenient access to all infusion devices <NUM> placed on the rack <NUM>. This however comes with the drawback that the vertical space per infusion device <NUM> is reduced, thus reducing the available space a user has to access an individual infusion device <NUM>.

<FIG> shows a view of a single infusion device <NUM> in the shape of a syringe pump, the infusion device <NUM> having a housing <NUM>. On the front face of the housing <NUM> a receptacle <NUM> for receiving a syringe <NUM> is formed. A door <NUM> is pivotable about a pivot axis <NUM> with respect to the housing <NUM>, wherein the door <NUM> can be opened to access the receptacle <NUM> in order to place a syringe <NUM> on the receptacle <NUM> on to remove the syringe <NUM> from the receptacle <NUM> and can be closed to perform an infusion operation.

The syringe <NUM> comprises a barrel <NUM> and a plunger <NUM> movable relative to the barrel <NUM>. The barrel <NUM> contains a medical solution to be delivered to the patient, the plunger <NUM> being pushable into the barrel <NUM> in order to deliver a medical solution from the barrel <NUM> via an infusion line <NUM> connected to the barrel <NUM> to the patient.

The infusion device <NUM> comprises a pusher device <NUM> being movable along a pushing direction P relative to the housing <NUM> and being constituted to act onto the plunger <NUM> in order to move the plunger <NUM> into the barrel <NUM>. The pusher device <NUM> is connected to a drive mechanism such that the pusher device <NUM> during operation of the infusion device <NUM> can electrically be pushed in the pushing direction P to move the plunger <NUM> into the barrel <NUM> in order to infuse the medical solution from the barrel <NUM> to the patient at for example a constant dose rate.

To prepare the infusion device <NUM> for an infusion operation, the barrel <NUM> is arranged on the receptacle <NUM> such that a flange <NUM> of the barrel <NUM> comes to rest in between stops <NUM>, <NUM> of the housing <NUM>. In this way the barrel <NUM> is axially held in position along the pushing direction P with respect to the housing <NUM>, and by pivoting a barrel holder <NUM> in the shape of a clamp towards the barrel <NUM> the barrel <NUM> is fixed on the receptacle <NUM>.

When installing the syringe <NUM> on the infusion device <NUM>, the pusher device <NUM> must be brought into abutment with a flange <NUM> at an end of the plunger <NUM> remote from the barrel <NUM>. For this, the pusher device <NUM> can be unclutched from the drive mechanism, as shall be explained in detail below, and can be freely moved along the pushing direction P relative to the housing <NUM> such that it can be brought into abutment with the plunger <NUM>. After the pusher device <NUM> has been moved towards the plunger <NUM>, a coupling element <NUM> (also denoted as antisiphon arm) can be pivoted with respect to the pusher device <NUM> and can be made to engage with the flange <NUM> such that the plunger <NUM> is secured relative to the pusher device <NUM> and in particular cannot be moved in the pushing direction P independent of the pusher device <NUM>.

To establish the coupling of the pusher device <NUM> with the plunger <NUM> a first coupling mechanism <NUM> is provided, and to establish the coupling of the pusher device <NUM> to the drive mechanism a second coupling mechanism <NUM> is provided, as is shown in <FIG>, <FIG> and <FIG>. The coupling mechanisms <NUM>, <NUM> can be actuated via a common actuation element <NUM> accessible from the front of the infusion device <NUM> and being placed on the pusher device <NUM>, as visible in <FIG>.

To actuate the coupling mechanisms <NUM>, <NUM>, a common actuation mechanism is used which is substantially enclosed in the pusher device <NUM> and during operation of the infusion device <NUM> is moved along with the pusher device <NUM>. Herein, the actuation element <NUM> is constituted as a lever which is, via a lever arm <NUM>, pivotable about a pivot axis <NUM> relative to the pusher device <NUM>. In particular, for transferring the coupling mechanisms <NUM>, <NUM> into an uncoupling state (in which the first coupling mechanism <NUM> does not couple the plunger <NUM> to the pusher device <NUM> and the second coupling mechanism <NUM> uncouples the pusher device <NUM> from the drive mechanism) the actuation element <NUM> is actuated in an actuation direction A and hence is pivoted with respect to the pusher device <NUM>. The pivot axis <NUM> herein is locationally fixed on the pusher device <NUM>, such that the actuation element <NUM> is actuated with respect to the pusher device <NUM>, but during operation of the infusion device <NUM> is moved together with the pusher device <NUM>.

As the actuation element <NUM> is actuated in the actuation direction A, the lever arm <NUM>, which is coupled with a threaded element <NUM> in the shape of a high helix nut, carries the threaded element <NUM> along and moves it longitudinally along another threaded element <NUM> in the shape of a high helix screw having an outer screw thread via which the threaded element <NUM> in the shape of the high helix nut engages with the threaded element <NUM> in the shape of the high helix screw. As the threaded element <NUM> in the shape of the high helix nut is moved along the threaded element <NUM> in the shape of the high helix screw, the threaded element <NUM> in the shape of the high helix screw is rotated about its longitudinal axis <NUM>, thus rotating a gear wheel <NUM> at a far end of the threaded element <NUM> in the shape of the high helix screw.

The gear wheel <NUM>, with an outer circumferential toothing, engages with a toothing of another gear wheel <NUM> and hence, when rotated, rotates the gear wheel <NUM> about its rotational axis <NUM>. The gear wheel <NUM> in turn engages with a first cam <NUM> of the first coupling mechanism <NUM> and with a second cam <NUM> of the second coupling mechanism <NUM>. The first cam <NUM> herein is connected to a shaft <NUM>, and the second cam <NUM> is connected to a shaft <NUM>, the shafts <NUM>, <NUM> being pivoted about their longitudinal axes <NUM>, <NUM> upon actuation by the gear wheel <NUM>.

The first cam <NUM> engages via a pin <NUM> with an engagement contour <NUM> on a side of the gear wheel <NUM> facing the first cam <NUM>, such that upon rotation of the gear wheel <NUM> the cam <NUM> is pivoted.

The second cam <NUM> in turn engages with cam <NUM> on the outer circumference of the gear wheel <NUM>, such that the cam <NUM> is pivoted upon rotation of the gear wheel <NUM>.

In particular, as the actuation element <NUM> is actuated in the actuation direction A, the threaded element <NUM> in the shape of the high helix screw is rotated in a rotational direction B0 as shown in <FIG>. This rotates the gear wheel <NUM> and causes a rotation of the gear wheel <NUM> in the rotational direction B1, which pivots the first cam <NUM> in the direction B3 and the second cam <NUM> in the direction B2.

By means of the engagement of the threaded element <NUM> in the shape of the high helix nut and the threaded element <NUM> in the shape of the high helix screw, hence, a longitudinal movement (of the threaded element <NUM>) is translated into a rotational movement (of the threaded element <NUM>), which is transferred to the coupling mechanisms <NUM>, <NUM> for moving the coupling mechanisms <NUM>, <NUM> between their coupling state and their uncoupling state.

The first cam <NUM>, via the shaft <NUM>, is connected to the coupling element <NUM> such that, when actuating the first cam <NUM> by means of the gear wheel <NUM>, the coupling element <NUM> can be moved relative to the pusher device <NUM> to couple the plunger <NUM> to the pusher device <NUM> or to uncouple the plunger <NUM> from the pusher device <NUM>.

When actuating the coupling mechanism <NUM>, in fact two movements take place. On the one hand, the coupling element <NUM> is rotated as described above. In addition, the coupling element <NUM> (together with the shaft <NUM>) is translated along the rotational axis <NUM>, due to the geometry of the engagement contour <NUM> formed on the gear wheel <NUM>. The translational movement herein is such that, when transferring the coupling mechanism from the uncoupling state into the coupling state, the coupling element <NUM> is rotated towards the plunger <NUM> and at the same time is moved to approach the pusher device <NUM> such that the plunger flange <NUM> is caught in between the coupling element <NUM> and the pusher device <NUM>. When transferring the coupling mechanism <NUM> from the coupling state to the uncoupling state (by pushing the actuation element <NUM> in the actuation direction A) an opposite movement takes place, i.e. the coupling element <NUM> is rotated away from the plunger <NUM> and at the same time is translationally moved away from the pusher device <NUM> to give room to release the plunger flange <NUM> from the pusher device <NUM>.

The second cam <NUM>, via the shaft <NUM>, is connected to an actuation system <NUM> and via the actuation system <NUM> to coupling elements <NUM> in the shape of half nuts, as schematically is shown in <FIG>. The half nuts are pivotably arranged on a drive element <NUM> and serve to engage with a spindle <NUM> of the drive mechanism <NUM> schematically illustrated in <FIG>. When engaged with the spindle <NUM>, a threaded engagement between the spindle <NUM> and the half nuts <NUM> is established, such that a rotational movement of the spindle <NUM> causes the drive element <NUM> to longitudinally move along the spindle <NUM>, thus driving the pusher device <NUM>. For this, the spindle <NUM> is operatively connected to a drive motor <NUM>, and the drive element <NUM> is connected via an arm <NUM> to the pusher device <NUM>.

By rotating the shaft <NUM> when actuating the second cam <NUM>, the half nuts <NUM> can be moved between their coupled and their uncoupled position. In particular, when actuating the actuation element <NUM> in the actuation direction A, the second cam <NUM> is pivoted and hence moves the shaft <NUM> to move the half nuts <NUM> to their uncoupled position (<FIG>) such that the pusher device <NUM> is uncoupled from the drive mechanism <NUM>. When uncoupled, the pusher device <NUM> can freely be moved with respect to the drive mechanism <NUM>, such that a syringe <NUM> may be installed on the infusion device <NUM>, or a syringe <NUM> may be uninstalled from the infusion device <NUM>.

The actuation of the coupling mechanisms <NUM>, <NUM> takes place together (synchronously or with a slight relative delay) by actuating the actuation element <NUM>, wherein the actuation direction A extends in parallel to the pushing direction P along which the pusher device <NUM> is movable. The actuation element <NUM> hence is actuated along a horizontal direction, which makes the actuation mechanism suitable also for infusion devices <NUM> having a low height.

When an actuation has taken place (by actuating the actuation element <NUM> in the actuation direction A) and the actuation element <NUM> is again released, it can be provided that the actuation element <NUM> and together with it the coupling mechanisms <NUM>, <NUM> are automatically reverted to their initial, coupling state. For this, the coupling mechanisms may each comprise a spring element for mechanically pretensioning the coupling mechanisms <NUM>, <NUM> towards their coupling state (<FIG>). Such spring elements (not shown in the figures) may for example act onto the shafts <NUM>, <NUM> of the coupling mechanisms <NUM>, <NUM>. In addition, a spring element may act for example onto the gear wheel <NUM> to provide a tensioning force towards the initial, non-actuated state.

By means of the actuation mechanism with its threaded elements <NUM>, <NUM>, a translational movement is transferred into a rotational movement. The actuation mechanism can generally be actuated with low force, hence being comfortable to use for a user.

The invention is not limited to the embodiments described above, but generally may be used also on entirely different infusion devices.

An actuation mechanism of the kind described above can be used also to actuate only a single coupling mechanism, wherein it may be beneficial to use the actuation mechanism to actuate multiple coupling mechanisms at the same time.

Claim 1:
Infusion device (<NUM>) for administering a medical fluid to a patient, comprising:
- a housing (<NUM>),
- a receptacle (<NUM>) arranged on the housing (<NUM>) for receiving a syringe (<NUM>), the syringe (<NUM>) having a barrel (<NUM>) for containing a medical fluid and a plunger (<NUM>) movable relative to the barrel (<NUM>) for delivering the medical fluid out of the barrel (<NUM>),
- a pusher device (<NUM>) movable along a pushing direction (P) relative to the housing (<NUM>) for acting onto the plunger (<NUM>) for moving the plunger (<NUM>) relative to the barrel (<NUM>),
- a drive mechanism (<NUM>) for driving the pusher device (<NUM>),
- a first coupling mechanism (<NUM>) operative to couple the plunger (<NUM>) to the pusher device (<NUM>) and a second coupling mechanism (<NUM>) operative to couple the pusher device (<NUM>) to the drive mechanism (<NUM>), and
- a common actuation mechanism arranged on the pusher device (<NUM>) and comprising an actuation element (<NUM>) for actuating the first coupling mechanism (<NUM>) and the second coupling mechanism (<NUM>) between a coupling state and an uncoupling state, wherein
the actuation mechanism comprises a first threaded element (<NUM>) rotatable about a rotational axis (<NUM>) and a second threaded element (<NUM>) movable longitudinally along the first threaded element (<NUM>), the second threaded element (<NUM>) being in threaded engagement with the first threaded element (<NUM>) wherein the actuation element (<NUM>) is actuatable to move the second threaded element (<NUM>) along the first threaded element (<NUM>), the first threaded element (<NUM>) being operatively connected to the first and second coupling mechanisms (<NUM>, <NUM>),
characterised in that
the longitudinal movement of the second threaded element (<NUM>) along the first threaded element (<NUM>) is translated into the rotational movement of the first threaded element (<NUM>), which is transferred to the first and second coupling mechanisms (<NUM>, <NUM>) for moving the first and second coupling mechanisms (<NUM>, <NUM>) between their coupling state and their uncoupling state.