Patent Description:
Intravenous administration of a liquid, usually a solution, is commonly carried out by delivery from an IV bag using pressure resulting from gravity. To create and maintain pressure resulting from gravity, the IV bag is suspended at a level higher than the level range of the patient body, for instance from a pole projecting from a foot or mounted to a bed. Such a pole severely restricts the freedom of movement of the patient. IV administration of medication may be required for prolonged periods of time. Restricting mobility of a patient for a prolonged period of time is inconvenient for the patient, increases the need of nursery care and is particularly disadvantageous since it has been found that physical exercise and mobility has a positive effect on patient health, so that restricting patient mobility has an adverse effect on patient health and tends to lead to longer stays in hospital.

Delivery of an IV solution may be supported by a peristaltic or piston driven IV pump. Use of such pumps is generally indicated if a specific amount of a pharmacologic agent is to be administered and/or fluid overload is to be prevented. However, such pumps are not suitable to be worn on the patient body due to weight, size and certified use restrictions and usually mounted to an IV pole, so that no improvement regarding patient mobility is achieved. Furthermore, such IV pumps are costly.

<CIT> discloses that a metering apparatus for controlling the flow of fluid through a fluid infusion system at an operator-designed rate includes a single-use cassette having a syringe-type pump in the flow system.

<CIT> discloses that a cassette for use with an IV infusion pump has a housing with a first inlet, a second inlet, an outlet, and a port to the IV infusion pump.

<CIT> discloses apparatus, systems and methods of delivering medical fluid to patients. More particularly, infusion pumps, disposable cassettes and associated methods are disclosed.

It is an object of the invention to provide a pump for providing liquid to be delivered intravenously that is wearable and can be used safely, easily and economically in a health care environment. More in particular, it is an object to provide a pump that is compatible with conventional IV bags and which accurately delivers IV liquid at a predetermined flow rate, regardless the orientation of the pump.

According to the invention, this object is achieved by providing a device according to claim <NUM>. The invention can also be embodied in a disposable unit according to claim <NUM> for use in a base unit of such a pump.

In use of such a device, the parts of the pump that are in direct contact with infusion liquid, in particular the pump cylinders and the pump valve, and which need to be sterile at least when perfusion is started, are replaceable as a single disposable unit, which is replaceable very easily. The base unit of the pump, in particular the relatively costly pump drive and the valve actuators can be re-used many times, so that costs are saved and relatively little waste is produced.

Particular elaborations and embodiments of the invention are set forth in the dependent claims. Features of the dependent claims applying to the disposable unit can also be applied advantageously in a disposable unit according to claim <NUM>.

Further features, effects and details of the invention appear from the detailed description and the drawings.

In <FIG>, a first example of an infusion delivery pump <NUM> according to the invention is shown. The pump <NUM> has a pump housing <NUM> and two plungers <NUM>, <NUM>. The pump housing <NUM> and the plungers <NUM>, <NUM> bound pump chamber <NUM> and, respectively <NUM>. The plungers <NUM>, <NUM> are reciprocally movable inwardly and outwardly of the pump housing <NUM> thereby increasing and decreasing the volume of the pump chambers <NUM> and, respectively, <NUM>.

For driving displacement of the plungers relative <NUM>, <NUM> to the pump housing <NUM>, a plunger drive <NUM> is provided. The plunger drive <NUM> has a pinion wheel <NUM> in driving engagement with toothed racks <NUM>, <NUM> which are coupled to respective ones of the plungers <NUM>, <NUM>. The plunger drive <NUM> is further composed of a shaft <NUM> engaging a coupling member <NUM> of an electric motor <NUM>.

The pump <NUM> further has two supply conduit sections <NUM>, <NUM> merging into a common supply conduit section <NUM> which communicates with one of the pump chambers <NUM>, <NUM> for delivering infusion liquid into that pump chamber <NUM> or <NUM>.

In the operating condition shown in <FIG>, a delivery conduit <NUM> communicates with the other one of the pump chambers <NUM> or <NUM> for receiving and delivering infusion liquid from that pump chamber <NUM>, <NUM>.

The supply conduit sections <NUM> or <NUM> and <NUM> communicate with one of the pump chambers via pump valve <NUM>, while the delivery conduit <NUM> is shut off from that one of the pump chambers <NUM>, if the pump valve <NUM> is in an infusion intake condition with regard to that pump chamber <NUM> as is shown in <FIG> and <FIG>. If the pump valve <NUM> is in an infusion delivery condition with regard to the pump chamber <NUM>, as is shown in <FIG>, the delivery conduit <NUM> communicates with the pump chamber <NUM>, while the supply conduit sections <NUM>-<NUM> are shut off from that pump chamber <NUM>. For operating the pump valve <NUM>, a pump valve actuator <NUM> is provided. The pump valve actuator <NUM> has a pump valve coupling member <NUM> for coupling the pump valve actuator <NUM> to the pump valve <NUM>, an electric pump valve motor <NUM> and a pump valve motor coupling member <NUM> coupling the pump valve coupling member <NUM> to the pump valve motor <NUM>.

A control unit <NUM> is arranged and connected for controlling the motor <NUM> of the plunger drive <NUM> and motor <NUM> of the pump valve actuator <NUM>.

The plunger drive <NUM>, the pump valve actuator <NUM> and the control unit <NUM> are part of a base unit <NUM> (shown separately in <FIG>), while the pump housing <NUM>, the plungers <NUM>, <NUM>, the supply conduit sections <NUM>-<NUM> and the delivery conduit <NUM> and the pump valve <NUM> are part of a disposable unit <NUM> (shown separately in <FIG>) which is removably attached to the base unit <NUM>. The coupling of the pump valve <NUM> to the pump valve actuator <NUM> and the coupling of the plungers <NUM>, <NUM> to the plunger drive <NUM> are releasable.

This allows the parts of the pump <NUM> that are in direct contact with infusion liquid, in particular the pump cylinders and the pump valve, and which need to be sterile at least when perfusion is started, to be replaceable as a single disposable unit, which can be mounted and dismounted very easily. The rest of the pump <NUM>, in particular the relatively costly plunger drive <NUM> and the valve actuators <NUM>, <NUM>, <NUM> can be re-used many times, so that costs are saved and relatively little waste is produced.

The base unit <NUM> has a lid <NUM> pivotably mounted to a main portion of the base unit <NUM>. The lid <NUM> shields the mounted disposable unit <NUM>, while a window <NUM> in the lid <NUM> allows visual inspection of the position of the plungers <NUM>, <NUM> and, if the pump housing <NUM> is transparent at least between the window <NUM> and the chambers <NUM>, <NUM>, visual inspection of the liquid in the pump chambers <NUM>, <NUM> in the housing <NUM>.

In the present example, the base unit <NUM> has a bottom portion <NUM> and a top portion <NUM>. In normal use, the bottom portion <NUM> remains attached to the top portion <NUM>, so that the coupling member <NUM> remains connected to the shaft <NUM> and the pump valve motor coupling member <NUM> remains coupled to the pump valve coupling member <NUM>. Only for repairs, such as exchanging a rechargeable battery <NUM>, the bottom portion <NUM> and the top portion <NUM> of the base unit <NUM> are dismounted from each other.

For showing an operating condition of the pump <NUM>, a display <NUM> connected to the control unit <NUM> is provided. For charging the battery <NUM> and for connecting the control unit <NUM> to an external device, a port <NUM> is provided, which may for instance be an USB-C port. This allows to display and control further features of operation and settings of the pump <NUM> via the external device. Data regarding operation and settings of the pump may also be monitored and/or registered by the external device, for instance to verify flow rates of liquid that have been administered to a patient during a given period of use. A transmitter/receiver for wireless communication between the control unit <NUM> and an external device may also be provided.

Removing a used disposable unit <NUM> from the base unit <NUM> and mounting a fresh disposable unit to the base unit <NUM> is made particularly easy, because the coupling of the pump valve <NUM> to the pump valve actuator <NUM> and the coupling of the plungers <NUM>, <NUM> to the plunger drive <NUM> are releasable in one common direction <NUM>. In the present example, this is achieved by providing couplings of the plungers <NUM>, <NUM> to the toothed racks <NUM>, <NUM> of the plunger drive <NUM> in the form of releasable ball joint connections <NUM>, <NUM> of which outer members <NUM>, <NUM> are open in the releasing direction <NUM> transverse to the direction in which plungers <NUM>, <NUM> are movable, so that ball members <NUM>, <NUM> can be moved out of engagement with the outer members <NUM>, <NUM>. Preferably, the opening of the outer members <NUM>, <NUM> in the releasing direction <NUM> is slightly smaller than the contour of the ball members <NUM>, <NUM>, so that a small resistance has to be overcome to mount and dismount the ball joint connections <NUM>, <NUM>. Other releasable connections, such as T-connections or pin-hole connections, are also conceivable.

An advantage of ball joint connections <NUM>, <NUM> is that during mounting, the disposable unit <NUM> can be oriented in a wide range of directions relative to the base unit <NUM> while the disposable unit <NUM> is connected to the base unit <NUM> only via one or both of the ball joint connections <NUM>, <NUM>. This facilitates mounting and dismounting of the disposable unit <NUM> and avoids damage to the coupling of the plungers <NUM>, <NUM> to the plunger drive <NUM> if the disposable unit <NUM> is rotated relative to the base unit <NUM> while not fully disconnected at the coupling of the plungers <NUM>, <NUM> to the plunger drive <NUM>.

The supply conduit sections <NUM>, <NUM> and the delivery conduit <NUM> have end portions <NUM>-<NUM> distally from the pump chambers <NUM>, <NUM> that are arranged for connection to infusion transfer tubing. In this example, the end portions are provided in the form of projections <NUM>-<NUM> insertable into ends of the tubing for frictional engagement with the tubing ends that are slightly expanded by the ends <NUM>-<NUM> inserted therein.

The two upstream supply conduit sections <NUM>, <NUM> in the disposable unit <NUM> are each provided with a connection <NUM>, <NUM> for infusion transfer tubing and merge into a downstream section <NUM>. A three-way source selector valve <NUM> is provided between the upstream supply conduit sections <NUM>, <NUM> and the downstream supply conduit section <NUM> for selectively causing a first or a second one of the upstream supply conduit sections <NUM>, <NUM> to communicate with the downstream supply conduit section <NUM>. The base unit <NUM> is provided with a source selector valve actuator <NUM> with a coupling <NUM> releasably coupled to the source selector valve <NUM>. Operating the source selector valve <NUM> allows switching between supply from a first source communicating with the supply conduit section <NUM> (see <FIG>) and supply from a second source communicating with the supply conduit section <NUM> (see <FIG>). The first source may for instance be an IV bag filled with standard IV solution while the second source may for instance be a container holding a liquid medicament. During filling of the pump chamber <NUM> or <NUM> by means of a given displacement of the plunger <NUM> or <NUM>, supplying from the second source during a predetermined portion of that displacement of the plunger <NUM> or <NUM> allows to mix in a predetermined dosage volume or concentration of the medicament to be administered into the total volume of liquid supplied into the pump chamber. In the pump chamber <NUM> or <NUM>, the medicament is then, at least to a certain extent, mixed with the IV solution and can subsequently be administered to the patient during delivery of the supplied liquid from the pump chamber <NUM> or <NUM> into which it has been supplied.

The source selector valve actuator <NUM> is also connected to the control unit <NUM> which is arranged for causing the source selector valve actuator <NUM> to be actuated in accordance with a dosage volume or mixing ratio setting and displacement of the plungers <NUM>, <NUM> during filling of the respective pump chambers <NUM>, <NUM>.

Because the source selector valve <NUM> is also included in the disposable unit <NUM> and releasably coupled to the source selector valve actuator <NUM> of the base unit <NUM>, also the coupling of the source selector valve <NUM> and the source selector valve actuator <NUM> is made and released as the disposable unit <NUM> is mounted or dismounted.

In the present example, the source selector valve <NUM> is a three-way valve that can be switched between a first operating position providing open communication between the first supply conduit section <NUM> and the common supply conduit section <NUM> while blocking supply from the second supply conduit section <NUM> to the common supply conduit section <NUM> and a second operating position providing open communication between the second supply conduit section <NUM> and the common supply conduit section <NUM> while blocking supply from the first supply conduit section <NUM> to the common supply conduit section <NUM>. This allows controlling dosage volumes or concentration using a single valve. It is however also possible to provide separate valves for opening and closing the first and second supply conduit sections. Furthermore, it is also possible to provide three or more upstream supply conduit sections which associated tubing connections to allow mixing from three or more sources.

The disposable unit <NUM> is further provided with a three-way bleeding valve <NUM> in the delivery conduit <NUM>, a bleeding conduit <NUM> branching off from the delivery conduit <NUM> at the bleeding valve <NUM>, a bubble detector <NUM> and a bubble detector signal output port in the form of contact <NUM>. The base unit <NUM> is further provided with a bubble detector signal input port in the form of contact <NUM> in communication with the bubble detector signal output port <NUM> and a bleeding valve actuator <NUM> with a coupling <NUM> releasably coupled to the bleeding valve <NUM>. The control unit <NUM> is connected and arranged for operating bleeding valve actuator <NUM> for causing the bleeding valve <NUM> to switch, in response to a signal from the bubble detector <NUM> representing detection of presence of air in liquid being delivered from the pump chamber <NUM> or <NUM> through the delivery conduit <NUM>, from a position in which the delivery conduit <NUM> is open until its downstream end to a position in which the bleeding conduit <NUM> communicates via the bleeding valve <NUM> with the portion of the delivery conduit <NUM> upstream of the bleeding valve <NUM> and the one of the pump chambers <NUM>, <NUM> from which liquid is delivered. Thus, detected air is discharged via the bleeding conduit <NUM> together with a small amount of the liquid. If no further air is detected, first the piston <NUM> or <NUM> is displaced over a small further distance, to allow for displacement of the detected air from the bubble detector <NUM> until downstream of the bleeding valve <NUM>, and then the bleeding valve <NUM> is switched back to the position shown in <FIG> for resuming delivery of liquid via the delivery conduit <NUM>. Thus, bubbles can reliably be evacuated from the liquid to be administered.

In this example the bleeding conduit opens into the environment at a connection <NUM>. However, a tube for discharging liquid spilled during bleeding or a receptacle or an absorbing body for receiving such spilled liquid may be provided to avoid spilling of liquid outside of the pump.

During priming of the pump chamber <NUM>, the plunger <NUM> can first be moved outwardly with the pump valve in the position shown in <FIG>, in which the pump chamber <NUM> communicates with one of the supply conduit sections <NUM> and <NUM> and with the common supply conduit section <NUM>, so that the internal volume of the first pump chamber <NUM> is increased and liquid is supplied into the first pump chamber <NUM>. Then, the plunger <NUM> is stopped and the pump valve <NUM> is switched into the position shown in <FIG>, in which the pump chamber <NUM> communicates with the delivery conduit <NUM>. With the bleeding valve <NUM> in the position shown in <FIG>, in which the pump chamber <NUM> communicates with the bleeding conduit <NUM> and while holding the pump <NUM> in an orientation in which the transfer conduit <NUM> opens into an upper end of the pump chamber <NUM>, the plunger <NUM> is subsequently moved inwardly, so that the internal volume of the pump chamber <NUM> is reduced and air and priming liquid are expelled through the bleeding conduit <NUM>. The other pump chamber <NUM> can be primed in a corresponding manner.

Instead of by a bubble detection and diversion system, bubble evacuation may also be carried out passively, for instance as in a conventional drip chamber.

The valves <NUM>, <NUM>, <NUM> are rotary valves each having a plug rotatable in the pump housing <NUM>, the plugs each have passages arranged for providing communication between an inlet one and an outlet one of ports in the pump housing that are facing the plug in selected rotary positions of the plug. The plugs have axes of rotation in the direction <NUM> in which the disposable part <NUM> is releasable from the base part <NUM>. This allows the valves <NUM>, <NUM> and <NUM> in the disposable unit <NUM> to be operated by and to be releasably coupled to the actuators <NUM>, <NUM> and <NUM> in the base unit <NUM> in a simple manner. In the present example, all valves are three-way or four-way versions of such rotary valves. It is however also possible to provide the disposable unit with only one or any other number of such valves and to provide one or more of these valves with a different number of ports, e.g. just two ports, for instance in the form of a stopcock valve, or a larger number of ports, for instance for bleeding directly from the pump valve.

To ensure that the position of the valve actuators <NUM>, <NUM> and <NUM> are associated to positions of the plugs of the valves <NUM>, <NUM> and, respectively, <NUM> in a one on one relationship only, the plugs and the valve actuators <NUM>, <NUM> and <NUM> coupled thereto have complementary shaped coupling faces, which are each non-rotation symmetrical about the axis of rotation of the respective plug. Thus, for each valve plug, there is only one relative rotational position in which the associated valve actuator coupling <NUM>, <NUM> and <NUM> can be coupled thereto. In the present example, the valve actuator couplings <NUM>, <NUM>, <NUM> each have a triangular projection of which the center is offset from the axis of rotation of the respective valve actuator coupling <NUM>, <NUM>, <NUM> and the plugs have matching triangular recesses in which the triangular projections only fit closely if the orientations of the valve actuator couplings <NUM>, <NUM>, <NUM> match the orientations of the plugs. The triangular projections visually resemble arrows, which facilitates checking whether the orientations of the valve actuator couplings <NUM>, <NUM>, <NUM> match the orientations of the plugs before mounting a disposable unit <NUM> to a base unit <NUM>.

Because the pump <NUM> according to the present example has two of the plungers <NUM>, <NUM> and the pump housing <NUM> and the plungers <NUM>, <NUM> bounds two pump chambers <NUM>, <NUM> and both plungers <NUM>, <NUM> are reciprocally movable inwardly and outwardly of the pump housing <NUM>, thereby increasing and decreasing the volume of the respective pump chamber <NUM>, <NUM> and the plunger drive <NUM> is arranged for simultaneously driving the plungers <NUM>, <NUM> in opposite directions, a single drive is sufficient for driving two plungers for supplying IV liquid to one of the pump chambers <NUM>, <NUM> and delivering IV liquid from the other one of the pump chambers <NUM>, <NUM>.

In the pump <NUM> according to the present example, the plungers <NUM>, <NUM> are coupled to each other for simultaneous movement in mutually opposite directions only. Thus, supplying IV liquid to one of the pump chambers <NUM>, <NUM> and simultaneously delivering IV liquid from the other one of the pump chambers <NUM>, <NUM> is achieved in a simple manner.

Because the pump valve <NUM> is four way valve in which ports are arranged for alternatingly causing one of the pump chambers <NUM>, <NUM> to communicate with the delivery conduit and causing the other one of the pump chambers <NUM>, <NUM> to communicate with the supply conduit and vice versa, operation of a single valve is sufficient for switching between supplying liquid to a first one of the pump chambers <NUM>, <NUM> while delivering liquid from a second one of the pump chambers <NUM>, <NUM> to supplying liquid to the second one of the pump chambers <NUM>, <NUM> while delivering liquid from the first one of the pump chambers <NUM>, <NUM>.

The pump valve <NUM> is arranged so that there is no direct communication between, on the one hand, the supply conduit sections <NUM> or <NUM> and <NUM> and, on the other hand, the delivery conduit <NUM> in any position of the pump valve <NUM>. Thus, uncontrolled supply of IV liquid bypassing the pump chambers <NUM>, <NUM> is avoided, even if for instance the disposable unit <NUM> is dismounted without disconnecting the patient from the pump <NUM> or pressure is exerted onto the IV bag (e.g. as a result of falling). This is particularly useful for avoiding inadvertent direct and undiluted administration of a medicament that has been mixed in.

In <FIG>, a second example of a pump <NUM> according to the invention is shown. Also this pump <NUM> is composed of a re-usable base unit <NUM> and a disposable unit <NUM>. In <FIG>, the re-usable base unit <NUM> is shown without the disposable unit <NUM> mounted thereto.

The plungers <NUM>, <NUM> are coupled to a double arm <NUM> having an axis of rotation <NUM> extending centrally between the plungers <NUM>, <NUM>. Thus, the coupling of the plungers <NUM>, <NUM> to each other is achieved in a very simple manner and the plungers <NUM>, <NUM> are guided by the double arm <NUM> with very little friction.

The double arm <NUM> is a portion of a gear wheel <NUM> having a toothed gear rack <NUM> extending along at least a section of a circle concentric with the axis of rotation <NUM> of the double arm <NUM>. The plunger drive <NUM> further has pinions <NUM>, <NUM> coupled to an electric motor. The pinions <NUM>, <NUM> drivingly engaging the toothed gear rack <NUM>. Thus, pivoting of the double arm <NUM> about the axis of rotation, and thereby simultaneous movement of the plungers <NUM>, <NUM> in opposite directions is driven in a simple manner. A particular advantage of driving movement of the plungers via a double arm is that the pump <NUM> can be relatively short in longitudinal direction, because of the absence of a toothed rack projecting from the plungers in the direction of movement of the plungers.

To allow the orientations of the pump chambers to accommodate to the movement of ends of the plungers <NUM>, <NUM> along a circle segment, the pump housing <NUM> includes two pump housing parts <NUM>, <NUM> each bounding one of the pump chambers, that are pivotably suspended near ends <NUM>, <NUM> distally from the couplings <NUM>, <NUM> engaging the plungers <NUM>, <NUM>.

Also in this example, the couplings <NUM>, <NUM> of the plunger drive <NUM> to the plungers <NUM>, <NUM> are provided in the form of ball joints of which the balls <NUM>, <NUM> are releasable from outer coupling members <NUM>, <NUM>. In this example, a further advantage of the ball joints <NUM>, <NUM> is that angular movement at the couplings <NUM>, <NUM> during pivoting of the double arm <NUM> is also accommodated.

Claim 1:
An infusion delivery pump (<NUM>) comprising:
a pump housing (<NUM>);
a plunger (<NUM>), wherein the pump housing and the plunger bound a pump chamber (<NUM>), the plunger is reciprocally movable inwardly and outwardly of the pump housing thereby increasing and decreasing the volume of the pump chamber;
a plunger drive (<NUM>) for driving displacement of the plunger relative to the pump housing, the plunger drive being coupled to the plunger;
a supply conduit (<NUM>-<NUM>) communicating with the pump chamber for delivering infusion liquid from a reservoir, such as an IV bag, into the pump chamber;
a delivery conduit (<NUM>) communicating with the pump chamber for receiving and delivering infusion liquid from the pump chamber;
at least one pump valve (<NUM>) via which the supply conduit communicates with the pump chamber, while the delivery conduit is shut off from the pump chamber, if the pump valve is in an infusion intake condition and via which the delivery conduit communicates with the pump chamber, while the supply conduit is shut off from the pump chamber, if the pump valve is in an infusion delivery condition;
at least one pump valve actuator (<NUM>); and
a control unit (<NUM>) arranged and connected for controlling the plunger drive (<NUM>) and the pump valve actuator (<NUM>);
wherein the plunger drive (<NUM>), the pump valve actuator (<NUM>) and the control unit (<NUM>) are part of a base unit (<NUM>);
wherein the pump housing (<NUM>), the plunger (<NUM>), at least a downstream portion of the supply conduit and at least one upstream portion of the delivery conduit and the at least one pump valve are part of a disposable unit removably attached to the base unit, the coupling of the at least one pump valve to the at least one pump valve actuator and the coupling of the at least one plunger to the plunger drive being releasable,
characterized by:
a further plunger (<NUM>), wherein the pump housing (<NUM>) and the further plunger bound a further pump chamber (<NUM>), the further plunger is reciprocally movable inwardly and outwardly of the pump housing thereby increasing and decreasing the volume of the further pump chamber, and wherein the plunger drive (<NUM>) is arranged for simultaneously driving the plungers (<NUM>, <NUM>) in opposite directions.