Mixing device, in particular designed for mixing bone cement

A mixing device, in particular for bone cement, in which at least two ampoules provided with a septum are pushed onto needles, in parallel to each other, for discharging the liquid.

FIELD OF THE INVENTION

The invention relates to a mixing device which is in particular configured for mixing bone cement.

BACKGROUND OF THE INVENTION

Mixing devices, in particular mixing devices for mixing components of medical products such as bone cement, for example, are known.

In a two-component system, two substances, in particular a liquid and a solid, are mixed together before being used, can be processed for a short period of time and will then cure.

In the medical field, in particular mixing devices for methyl methacrylate-based bone cement are known. Usually, a PMMA powder is mixed with a monomer component so that a curable paste is prepared. This paste is usually processed very well and is in particular used for cementing prostheses.

In this embodiment variant of a bone cement mixer, the monomer component is disposed on a handle of the mixing system. Before use, a monomer vial is pressed onto a needle. Due to a gas volume present in the monomer vial and due to a vacuum applied to the mixing chamber, the monomer flows into the mixing chamber.

Such a closed system is simple in design and safe in handling.

A drawback thereof is that highly volatile monomer components such as methyl methacrylate are only allowed to be transported in relatively small packages, depending on the applicable legal situation. In the case of the initially mentioned mixing device this might for some applications undesirably limit the quantity that can be mixed using the mixing device.

Furthermore, the aforementioned system is only configured for mixing together a liquid component and a solid component. The system is not intended for mixing two monomer components each one contained in a respective vial, which may moreover comprise a different liquid.

OBJECT OF THE INVENTION

Given this background, the object of the invention is to provide a mixing device, in particular a mixing device for bone cement, which is easier and even more safe in handling.

SUMMARY OF THE INVENTION

The object of the invention is already achieved by a mixing device in accordance with the illustrative embodiment of the present invention.

Firstly, the invention relates to a mixing device which is in particular configured for bone cement.

It comprises at least two ampoules filled with a liquid. Any suitable type of container can be used as an ampoule. In particular, the invention relates to glass ampoules in the form of vials provided with a septum that can be perforated.

According to the invention, two ampoules filled with a liquid can be perforated by means of needles and the liquid contained in the ampoules can be discharged through the needles, and the ampoules can be simultaneously pushed onto the needles using an ampoule holder.

Thus, according to the invention two ampoules are simultaneously pushed onto a respective needle so that the liquid from the two ampoules flows out simultaneously.

This has some advantages compared to a mixing device with only one ampoule. For example, the package size of the individual ampoules can be reduced, if necessary.

Furthermore, it is conceivable to mix two different liquids by means of the mixing device, by combining them during or after extraction.

Moreover, depending on the desired amount of bone cement to be mixed, it is conceivable to load the mixing device with only one or with two or more ampoules.

Preferably, the mixing device furthermore comprises a mixing chamber to which a vacuum can be applied. The liquid flows from the ampoules into the mixing chamber.

This may be accomplished, for example, by means of a tube which can additionally be used for pressing out the bone cement from the mixing chamber after mixing, by separating a housing containing the ampoules from the remaining mixing device, or for actuating a paddle arranged in the mixing chamber.

Preferably, the liquid flows out of the ampoules due to a gas volume included in the ampoules. However, it is also conceivable to ventilate the ampoules, for example via a diaphragm valve, or to provide needles in a thickness which permit air bubbles to ascend through the needles to enable pressure exchange in this way.

The use of at least two ampoules moreover offers the advantage that emptying occurs faster.

In one embodiment of the invention, the ampoule holder is arranged in a cap which can be slideably inserted into a housing that comprises the needle.

The cap may in particular be slideably latched in a housing, and the ampoule holder is accommodated in the cap as a separate component, for example also by being latched thereto.

However, a variant in which the ampoule holder is an integral component of the cap is also conceivable, so that the cap then supports the ampoules.

Preferably, the mixing device comprises a manifold. This manifold has passages in communication with the needles. Within the manifold, the liquids from the at least two ampoules are combined and can then be discharged via a channel, such as a tube.

The invention furthermore relates to a mixing device, in particular a mixing device as described above.

It comprises at least one ampoule filled with a liquid, which is opened by pushing the ampoule onto an opening means. The opening means is in particular provided in the form of a needle.

However, a different form is also conceivable, for example the form of a mandrel which does not have a passage but is adapted to open the ampoule so that the liquid can exit past the opening means.

According to the invention, an unlocking means must be actuated for being able to push the ampoule. This means that the ampoule holder can only be pushed in the direction of the opening means when the unlocking means are simultaneously actuated. In its engaged position on the opening means the ampoule is latched non-detachably.

In contrast to the prior art mentioned above, in which a safety bolt is removed, the unlocking means may thus constitute an integral part of the housing of the mixing device, and therefore the unlocking means will not produce any small parts which might present a potential danger in the operating room.

The at least one ampoule is preferably arranged in a cap, which is slideably accommodated in the housing and projects beyond the housing in its non-engaged position.

In the engaged and latched position, it is easy for the user to recognize that the mixing device was already used, given the compressed state of the housing.

The latching moreover ensures that the entire liquid is discharged, since the user can not stop the discharging of the liquid by retracting the ampoule.

The invention furthermore relates to a mixing device, in particular one as described above.

It comprises at least one ampoule filled with a liquid, which is opened by pushing the ampoule onto a needle in order to discharge the liquid.

According to the invention, the needle is made of plastics.

The plastic needle in particular constitutes an integral part of an insert which is inserted in a housing of the mixing device and which is connected to the housing of the mixing device, for example by welding or gluing.

It has been found that with such an insert a plastic needle which is sufficient for piercing a monomer vial that is provided with a septum can be provided as an integral component of the insert.

This has considerable advantages in terms of production technology, since a single injection-molded part can be used to provide the needle and the insert. In particular it is not necessary to fit a metal cannula in the injection mold, which makes manufacturing faster and cheaper.

The insert is in particular provided in the form of a manifold comprising at least two needles.

It is preferably formed of two pieces, consisting of a needle unit with the two plastic needles and a manifold which includes passages for combining the liquids from the two needles.

The invention further relates to a mixing device, in particular one as described above.

It comprises at least one ampoule filled with a liquid. The ampoule can be opened by being pushed onto an opening means, in particular a needle, for discharging the liquid.

According to the invention, the ampoule is accommodated in an ampoule holder which is arranged in a cap which in turn is slideably inserted in a housing. The housing comprises at least one opening means and a channel for discharging the liquid.

Thus, the casing for accommodating the ampoule comprises three main components, namely a housing which may be considered as a main housing and which, for example, comprises a tube for discharging the liquid and the opening means.

In contrast to the prior art mentioned above, the ampoule is not inserted directly into the cap, but is supported by an ampoule holder inserted into the cap.

This provides for simplified assembly on the one hand.

On the other hand, the ampoule holder is preferably configured so as to comprise at least one retaining member engaging the ampoule at a collar to hold it in a defined position.

The ampoule may in particular be snapped into the retaining member.

The retaining member ensures a defined position of the ampoule relative to the opening means.

The invention is based on the findings that for example for known ampoules provided with a septum, the septum or the cap by which the ampoule is sealed has small tolerances.

Irrespectively of whether the retaining member engages the cap itself or a collar of the ampoule preferably made of glass, a high degree of dimensional accuracy will always be achieved.

The length of conventional glass vials, by contrast, is subject to rather high tolerances which can not always be reliably compensated by the configuration of the mixing device if the position of the ampoule in the cap is determined by the rear end of the ampoule.

In a preferred embodiment of the invention, the ampoule holder and the cap are latched together, and the cap and housing are latched together as well.

The assembly of such a three-part casing for the ampoule is thus accomplished very easily.

DETAILED DESCRIPTION

The subject matter of the invention will now be explained in more detail with reference to an exemplary embodiment illustrated inFIGS. 1 to 14.

FIG. 1is a perspective view of a mixing device1.

Mixing device1comprises a housing2which in this exemplary embodiment is elongated and has a cross section that is substantially rectangular with rounded corners, or oval.

The shape of the housing different from a circular cylindrical shape allows to safely grip the housing, in particular when using the housing which accommodates the ampoules.

For actuating a mixer, the necessary push and pull movements with simultaneous rotation of the mixing paddle can be performed more easily.

A cap3is slideably accommodated in the housing2, which is depressed to discharge the liquid.

The housing2has a profiled surface area4which is intended to provide an even better grip. Such a profiled surface may be particularly advantageous when the housing illustrated herein is used for driving a paddle for mixing bone cement in a mixing chamber (not shown).

A unlocking means7in the form of a button or pushbutton can be seen, which is provided in mirror-symmetrical manner in this embodiment of the invention, that is to say also on the opposite side.

Furthermore, a first opening5and a second opening6can be seen in housing2.

In an actuated state, a snap projection of cap3is latched in opening5and prevents cap3from being retracted rearwards.

When the user now actuates the unlocking means7on both sides by depressing them, he or she can push the cap3further forward or press it deeper into the housing2, and a snap projection on cap3will then become latched in the opening6in an actuated state.

The liquid from the ampoules accommodated in housing2will then exit via tube8.

When used as a bone cement mixing device, tube8is connected to a mixing chamber (not illustrated) to which a vacuum is applied and in which a solid component is mixed with the liquid from the ampoules.

In this case, the housing2may be used to drive a mixing paddle. Subsequently, housing2can be severed at a predetermined breaking point (not illustrated) of tube8, for pressing out the bone cement. Moreover, the housing2illustrated herein, which is designed for accommodating the monomer ampoule, may furthermore be used as a handle to actuate a plunger to press out the bone cement (not illustrated).

FIG. 2illustrates the essential components of the mixing device ofFIG. 1in an exploded view.

Housing2can be seen, on which the tube8for discharging the liquid is mounted on an extension9which has a circular cylindrical shape in this case.

In this exemplary embodiment, the mixing device furthermore comprises two monomer vials10which are closed by a septum.

The ampoules10containing the monomer are first inserted into an ampoule holder11.

Furthermore, a needle unit12can be seen which comprises two needles.

In the assembled state, needle unit12is coupled with a manifold13which itself is inserted in the housing2together with needle unit12and is in particular connected thereto by being welded or glued thereto.

If now the cap3is pressed down, as already described with reference toFIG. 1, the ampoules10will simultaneously be pushed onto the needle unit12.

The liquid will then flow through the needles of needle unit12and through manifold13into the tube8, for example by virtue of a vacuum applied to tube8in conjunction with a gas volume in ampoules10, and will exit into a mixing chamber, for example.

FIG. 3shows a sectional view of a mixing device in the pre-assembled but not yet actuated state.

The two ampoules10can be seen, which are arranged in parallel and held on a collar15in a defined position.

Needles14of needle unit12can also be seen. Needle unit12is connected to manifold13which includes passages where the liquid from the two ampoules10is combined.

The system according to the invention may therefore also be used to mix two liquids with each other.

FIG. 4shows a perspective sectional view in which the housing, the housing cap and one ampoule are omitted.

It can be seen that the ampoule10has a collar15that is seated in a retaining member16of an ampoule holder.

Thus, the septum17is arranged directly opposite to the needle of needle unit12.

In addition to the better defined position of the ampoule10, the use of an ampoule holder provides for improved assembly.

FIG. 5is a perspective view of the cap.

The cap is formed for being slideably inserted into the housing (2inFIG. 1).

The cap has latching tabs18which protrude from an adjacent housing wall19.

Latching tabs18can be urged inwards by actuating the unlocking means (7inFIG. 1) in order to release the cap and hence the ampoules accommodated in the cap to be able to slideably displace them.

Furthermore, the cap has a latching projection21which in the pre-assembled but not yet actuated state is latched in the upper opening of the housing (5inFIG. 1) and which is latched in the lower opening (6inFIG. 1) in the actuated state.

A further opening20in the cap serves to latch the cap and the ampoule holder (11inFIG. 2) to each other.

FIG. 6shows a further perspective view of housing2. In particular the upper opening5for latching the cap illustrated inFIG. 5in the pre-assembled state and the opening6for latching in the actuated state can be seen.

The latching of the cap ensures that the cap can neither be remove nor retracted rearwards by the user in the actuated state without using a tool.

Furthermore, the unlocking means7in the form of pushbuttons can be seen, which are formed as an integral component of the housing2. For this purpose, the housing2has slots along the edges of unlocking means7, so that the profiled unlocking means7can be depressed like a button.

FIG. 7shows a perspective sectional view of the housing. In particular the underside of unlocking means7can be seen, where a projection22is provided which in the assembled state actuates the latching tabs (18inFIG. 5) when unlocking means7are depressed.

The housing furthermore has lateral openings28through which the content of the ampoules is visible for the user, for example.

Referring toFIGS. 8 and 9which are sectional views, the function of the various latching and locking means will be explained.

FIG. 8shows the mixing device in its pre-assembled but not yet actuated state.

The ampoules10are seated in cap3.

The cap has latching projections which are locked in an upper opening5of the housing and prevent the cap from being retracted.

The front position of cap3and hence of the ampoule10is delimited by latching tabs18which are spread forwardly resting on a collar23of the housing.

When the user now actuates the unlocking means7by depressing them, the latching tabs18will be pressed inwards and can be pushed forward past the collar when the cap is pressed.

The ampoule with the septum is then pressed onto the needle.

FIG. 9shows a sectional view in the actuated state.

Latching projections21are now locked in the lower opening6of the housing so that, again, the cap3can not be retracted.

The latching tabs18have moved past the collar23.

The front end position may be defined, for example, by abutment of the ampoule against the needle unit.

FIG. 10is a sectional view of the mixing device in the actuated state.

The ampoules10with their septum have been pushed onto the needle unit12. From the needles of needle unit12, the liquids from the ampoules10are flowing into the manifold13where they are combined to be discharged via tube8.

FIG. 11shows a perspective view of ampoule holder11.

In particular, the retaining members16can be seen, which extend laterally away from the elongated support and are in the form of ring segments into which the ampoules can be snapped.

The holder furthermore has a latching projection24which is slideably inserted into the cap, with the holder together with the ampoules.

The latching projection will then lock the holder together with the ampoules in an opening of the cap (20inFIG. 5).

In the present exemplary embodiment, manifold13and needle unit12are both made of plastics.

Manifold13has a well26into which the needle unit12is inserted. Needle unit12has a profiled surface25on its underside, for example in the form of circumferential webs adapted for bonding by ultrasonic welding.

Needles14together with the rest of needle unit12are formed as a one-piece injection molded component.

In the present exemplary embodiment, needles14have a tip and lateral slots extending rearwards of the tip. In this manner, a high flow rate is ensured despite of the use of a plastic component.

FIG. 14is a perspective bottom view of manifold13. The underside of manifold13also has a profiled surface27adapted for welding manifold13to the housing of the mixing device.

It will be understood that the subject matter of the invention is not limited to a combination of the features described above, but that a person skilled in the art will in particular combine the features described in conjunction with the drawings as far as technically appropriate.

LIST OF REFERENCE NUMERALS