METHOD FOR MANUFACTURING A DRIP CHAMBER, DRIP CHAMBER, INFUSION OR TRANSFUSION SYSTEM

Description

[0001] In human and veterinary medicine, infusions and transfusions are performed for therapeutic purposes. For example, infusions are used to administer liquid medications (solutions of active ingredients, etc.). An infusion or transfusion system is a system used to administer a medical infusion or to perform a medical transfusion. This can include, in particular, an infusion set (also known as an "infusion set").

[0002] An infusion or transfusion system typically consists of tubing and a drip chamber. Optionally, the infusion or transfusion system may include additional components, such as a flow regulator to control the fluid flow rate, like a roller clamp. The fluid to be administered during an infusion or transfusion is supplied in a container. This container could be, for example, an infusion bottle, an infusion bag, a blood product, etc.

[0003] The drip chamber is connected to the container via a container connection, allowing liquid to flow from the container into the drip chamber. This container connection can be, for example, a piercing device such as a hollow spike that pierces a septum sealing the container and typically has several channels inside. Such a piercing device is commonly referred to as a "spike." Other systems are also known for connecting the drip chamber to the container, such as coupling systems that prevent the drip chamber and container from being separated once connected. The drip chamber is in fluid communication with one end of the hose, allowing liquid to flow from the drip chamber into the hose.In this sense, the drip chamber is a fluid transfer system, as the fluid is transferred from the container through the drip chamber into the tubing. The tubing has a connection at the other end for patient access (e.g., a venous cannula or venous catheter). The patient access can optionally also be considered part of the infusion set.

[0004] As described, the drip chamber connects the hose to the container. The devices that ensure the container's ventilation are typically integrated into the drip chamber. For this purpose, the drip chamber usually features a ventilation device with a manually operated or automatic vent valve. A ventilation channel allows air to enter the container. To prevent contamination when ambient air flows through the vent valve, the ventilation device typically includes a ventilation filter. To reliably prevent liquid from reaching the ventilation filter, saturating it, and thus rendering it impermeable to air, a sealing mechanism is often incorporated into the ventilation channel.Various embodiments of the ventilation device based on different valve types, with and without ventilation filters and closure mechanisms, are known in the prior art. Examples include manual ventilation devices with a manually operated flap as a ventilation valve and automatic ventilation valves with a check valve as a ventilation valve. The present invention is compatible with both manual and automatic ventilation devices.

[0005] To begin an infusion, i.e., to allow fluid to flow through the tubing, the drip chamber is first connected to the container via the container connector. Then, the flow of fluid must be initiated. This is usually done by manually squeezing the drip chamber, which is made of an elastic material at least in its lower section (for example, between the thumb and a finger). This, for instance, when using a drip chamber with a spike, pumps air through one of the spike's channels into the infusion container. The resulting overpressure in the infusion container initiates the flow of fluid, causing it to drip into the drip chamber.The vent valve ensures the necessary pressure equalization for the liquid to continue dripping into the drip chamber by allowing air to enter through one of the channels of the piercing device (vent channel), while the liquid flows from the container into the drip chamber through another channel. After the force is applied to initiate the liquid flow, the drip chamber returns to its original shape. Alternatively or additionally, pressure can be applied to the container. However, since this is only possible with flexible containers, most commercially available drip chambers have a flexible and therefore pumpable lower section.

[0006] Inside the drip chamber is a droplet former that causes the liquid from the container to enter the chamber in the form of standardized-sized drops. In gravity infusion, the flow rate is adjusted by the drip rate, i.e., the number of drops per unit of time. The operator determines the drip rate by visually observing the dripping process. For some applications where an infusion pump is used to deliver the liquid, a droplet sensor is employed to optically measure the drip rate. The infusion pump is then controlled based on this measurement. For both visual observation and optical sensing, the wall of the drip chamber must be sufficiently transparent, at least in the upper section where the droplet former is located.

[0007] The dimensions of a drip chamber are partly specified in the relevant standards (e.g. DIN ISO 8536-4, Part 4).

[0008] Some commercially available infusion fluid containers allow for the addition of other medications (so-called "pharmacy admixture"). This is done, for example, by injecting the medication through a port provided on the container. This port is usually located near the port connecting the drip chamber's inlet to the container. The drip chamber must be designed so that the infusion port is easily accessible to the operator when the inlet is connected. In particular, the drip chamber must be sufficiently long and narrow to allow for this.

[0009] The drip chambers known in the art and available on the market typically have a short, opaque upper section and a pumpable lower section. Some commercially available drip chambers also feature a grip ring formed on the outer wall of the chamber. This grip ring forms a ridge, which improves the handling of the drip chamber, as the operator can securely grasp it by hand. This grip ring is typically made of an opaque plastic and is molded onto the outer surface of the drip chamber using an injection molding process.

[0010] Depending on whether a handle ring is present or not, it is referred to as a "three-part construction" or a "two-part construction".

[0011] The handle ring is conventionally formed on the outer surface of the drip chamber in a separate step. This has disadvantages, particularly the very high cost of producing the three-part drip chambers, which are traditionally manufactured using the complex injection molding process. The injection molding process conventionally used to form the handle ring is very expensive to operate.

[0012] Conversely, omitting the grip ring would mean foregoing the ergonomic advantages described above. Furthermore, the grip ring has the advantage of concealing the joint of the drip chamber, so that, to the user, there are no externally visible seams. In addition, the grip ring material can be selected for its particularly grippy texture, further improving handling. It is also possible to color the grip ring material. A specific color can be used to individualize drip chambers of a particular type or from a specific manufacturer, thus preventing mix-ups in clinical practice.

[0013] In conventional drip chambers, the upper and lower parts are directly connected, for example, by gluing or welding. This, in addition to the already high manufacturing costs associated with conventional drip chambers, imposes significant limitations on the choice of materials for the upper and lower parts. These materials must be selected to ensure a secure and simple joining process. In other words, the materials must be compatible with each other. Furthermore, the materials must also meet the requirements of a drip chamber, such as the transparency of the upper part and the elasticity of the lower part required for pumping.

[0014] US 2017 / 0151385 A1 discloses a drip chamber for administering a medical fluid. The drip chamber comprises a chamber element forming a chamber, an inlet for introducing a medical fluid into the chamber, and a connector that is attached to the chamber element at an outlet of the drip chamber. The connector is integrally formed on the chamber element by injection molding. The chamber element is made of a first material, and the connector is made of a second material that differs from the first.

[0015] US 4,395,260, DE19931092A1 and GB768689A reveal further multi-part drip chambers.

[0016] EP 0 355 795 A1 describes an adapter for connecting enteral administration devices, such as a drip chamber, to bottles. The adapter has two coaxially arranged caps with different opening diameters, each of which can be placed on a corresponding bottle opening.

[0017] Starting from the above-mentioned situation, one object of the invention is to provide an improved system or method for a drip chamber for an infusion or transfusion system, an improved drip chamber for an infusion or transfusion system, and an improved infusion or transfusion system.

[0018] This problem is solved by a method according to claim 1, a drip chamber according to claim 2, and an infusion or transfusion system according to claim 11. Advantageous embodiments of the invention are particularly evident from the dependent claims. The features listed in the dependent claims and the subsequent description of the subject matter relating to an independent claim can also be used to advantageously enhance the subject matter relating to another claim of the same or a different claim category.

[0019] Due to the impossibility or difficulty of adapting the complex injection molding process for forming the handle ring to the production of a different type of handle ring made of a different material or with a different shape, it has proven very costly to design different drip chamber types rationally and economically using a modular system, due to the aforementioned material compatibility requirement. The term "modular system" refers to a concept for design and manufacturing in which differently designed top parts, bottom parts, and / or middle parts are used, but each top part, bottom part, and middle part can be used to manufacture a drip chamber. In this way, drip chambers of various types can be produced efficiently.This includes, for example, different tops with various droplet formers and / or different types of aeration devices. It also includes different tops with varying degrees of transparency or optical brilliance. For instance, lower transparency may be sufficient for visual observation of the droplet, while higher transparency may be required for the use of optical droplet sensors. This also applies to different bottoms, such as softer ones that are easier to pump and stiffer ones that are more stable. And more generally, it also applies to different sizes of tops and bottoms.

[0020] According to the inventive method, step D is carried out such that the upper and lower parts are not directly connected to each other, but rather via the middle part. That is, the upper and lower parts are not joined together, but are held together by the middle part. It is possible, but not necessary, for the upper and lower parts to touch each other in the finished drip chamber. According to this embodiment, the joining steps can be carried out in any order. It is therefore possible to join the upper part first and then the lower part, or the lower part first and then the upper part, to the middle part. Furthermore, it is also possible to join the upper and lower parts to the middle part, at least partially, simultaneously.For the individual steps A, B, C and D of the procedure, different sequences are possible, as long as it is ensured that the parts to be joined are provided in time to be joined together.

[0021] In the inventive method, no central part in the form of a handle ring is molded onto the outer surface of the drip chamber using a complex injection molding process. Instead, a prefabricated central part is provided. This central part simply needs to be connected to the upper and / or lower part. This significantly reduces the manufacturing effort required to produce a three-part drip chamber. This reduction in manufacturing effort is particularly advantageous in this case, as infusion systems are mass-produced items manufactured in large quantities.

[0022] A further advantage of the method according to the invention is that the method can be very easily adapted to the production of a drip chamber with a different type of handle ring. For this purpose, only a different central part needs to be provided in step C. The complex conversion of a system in which the handle ring is formed by an injection molding process is eliminated.

[0023] In the process according to the invention, the connections between the individual parts are at least partially produced by solvent joining. This not only allows for further manufacturing advantages in terms of simplifying production, but also for improving the manufactured product.

[0024] In solvent joining, at least one of the parts to be joined is treated with a suitable organic solvent. The parts are then brought together and preferably moved against each other in a shearing motion. According to a non-restrictive theory, the molecules of the parts become entangled, forming a bond at the joint. Solvent joining is a particularly quick and easy process to implement, especially in automated manufacturing. Therefore, it is a cost-effective joining method. Solvent joining is also referred to as "solvent bonding," although it is not a bonding process in the strict sense, where an adhesive is used to create the bond between the parts.

[0025] The drip chamber according to the invention, which is particularly obtainable using the method according to the invention, comprises the upper part, the lower part, and the middle part. According to the invention, the middle part is prefabricated, i.e., subsequent application by injection molding is eliminated and avoided. In a first embodiment (a), the prefabricated middle part is configured to create a direct fluid-tight connection with both the upper part and the lower part by joining a lower end region of the upper part and an upper end region of the lower part to the middle part. In this embodiment, it is sufficient that these edges merely contact each other but are not joined together; the edges can simply be opposite each other or even just facing each other with a gap between them.

[0026] In a second embodiment (b), the prefabricated middle section is configured to provide a bridge between a lower end region of the upper section and an upper end region of the lower section, wherein the lower edge of the upper section and the upper edge of the lower section are directly joined together, and the middle section provides the bridge without injection molding, optionally but joined to a lower end region of the upper section and / or to an upper end region of the lower section. If, in this embodiment (b), the upper section and the lower section are not joined with the prefabricated middle section, the middle section can simply be held in a groove formed by a smaller diameter at the transition between the lower end region of the upper section and the upper end region of the lower section.

[0027] Fluid-tight joints are ensured by the prefabricated middle section, which provides either a direct fluid-tight connection to the upper and lower parts or indirectly bridges the gap between them. Furthermore, the use of a prefabricated middle section, which allows for solvent joining or welding, particularly ultrasonic welding, at the joints, guarantees both fluid tightness and a bridge between the upper and lower parts.

[0028] The drip chamber according to a particular embodiment of the invention is a drip chamber for an infusion or transfusion system, comprising an upper part with a first connection which is connected to a container or which is intended to be connected to a container, a lower part with a second connection which is connected to a hose or which is intended to be connected to a hose, and a middle part. The upper part and the lower part are each connected to the middle part in such a way that the upper part and the lower part are fluid-tightly connected to each other via the middle part.

[0029] In this embodiment, the upper and lower parts are not connected directly but fluid-tight via the middle section, allowing for considerable freedom in the selection of materials for both. This enables the materials to be optimally chosen for their respective functions. For example, a high-gloss plastic could be selected for the upper part, while the lower part could be made of a plastic with optimal pumping properties and sufficient robustness for transport and storage. The materials do not need to be specifically matched for easy and reliable direct joining. It is only necessary to select a material for the middle section that can be used with both the upper and lower parts.

[0030] In this embodiment, since the upper and lower parts are not directly connected but fluid-tight via the middle section, there is considerable freedom in the selection of joining techniques for connecting the individual parts. For example, it is possible to use a specific adhesive bonding technique even if the upper and lower parts cannot be joined using this technique, or only with great difficulty. It is only necessary to select a material for the middle section that can be bonded to both the upper and lower parts using this technique.

[0031] Since the central part, unlike the handle ring known in the prior art, does not need to be attached as a separate element in a separate manufacturing step, the production of the drip chambers according to the invention is particularly advantageous. This is especially true because a complex injection molding process can be avoided.

[0032] According to this embodiment, the advantages of the three-part design of the drip chamber, and thus the ergonomic and other advantages of a handle ring, can be optimally realized. These include, in particular, optimal ergonomic and intuitive handling, the possibility of marking different drip chamber types or other different products, the improved possibility of modular production, and therefore the simpler and more economical implementation of further or different functions.

[0033] The infusion or transfusion system according to the invention is an infusion or transfusion system comprising a drip chamber according to the invention. This provides an infusion or transfusion system that possesses the advantageous properties of the drip chamber according to the invention.

[0034] Further features, advantages and benefits of the invention are described below with reference to exemplary embodiments and the accompanying drawing figures. Fig. 1 shows a flowchart of an exemplary embodiment of the method according to the invention. Fig. 2 shows a schematic perspective view of a drip chamber according to a first embodiment. Fig. 3 Figure 1 shows a schematic exploded view of the drip chamber according to the first embodiment. Fig. 4 Figure 1 shows a schematic view of the drip chamber according to a second embodiment in an exploded view.

[0035] In Fig. 1 Figure 1 shows a flowchart of an embodiment of the inventive method for manufacturing a drip chamber. The individual parts of the drip chamber are described in more detail below in the description of exemplary embodiments of the drip chamber. The inventive method is not limited to the manufacture of drip chambers according to these embodiments.

[0036] In step A, an upper part is provided. The upper part has a first connection, which is intended to be connected to a container.

[0037] In the following step B, a lower part is provided. The lower part has a second connection which is connected to a hose or which is intended to be connected to a hose.

[0038] In the subsequent step C, a central part is provided. This central part provides a grip ring in the finished drip chamber, i.e., a raised structure located on the outside of the drip chamber.

[0039] In the following step D, the upper part, the lower part and the middle part are joined together.

[0040] According to a first embodiment of the method according to the invention, step D is carried out such that the upper and lower parts are not directly connected to each other, but rather via the middle part. That is, the upper and lower parts are not joined together, but are held together by the middle part. According to this embodiment, the joining steps can be carried out in any order. It is therefore possible to first join the upper part and then the lower part, or first the lower part and then the upper part to the middle part. Furthermore, it is also possible to join the upper and lower parts to the middle part at least partially simultaneously.

[0041] According to another embodiment of the method according to the invention, step D is carried out such that the upper part and the lower part are directly connected to each other. The middle part is then not required to hold the upper part and the lower part together. Instead, the middle part is arranged on the outside of the hollow body consisting of the upper part and the lower part. According to this embodiment, the joining steps can be carried out in any order. It is therefore possible to first join the upper part to the middle part and then the lower part to the upper part, or first the lower part to the middle part and then the upper part to the lower part. It is also possible to first join the upper part and the lower part together and then to join the middle part to the upper part, the lower part, or to the upper part and lower part. Furthermore, it is also possible to carry out all joining steps at least partially simultaneously.

[0042] In alternative embodiments not shown in the drawings, the same steps are carried out in different sequences. Various sequences are possible as long as it is ensured that the parts to be joined are available in time for joining.

[0043] In alternative embodiments, the middle part in the finished drip chamber does not provide a handle ring, but serves, for example, merely as a connecting element that holds the upper and lower parts together.

[0044] In the inventive method, no central part in the form of a handle ring is molded onto the outer surface of the drip chamber using a complex injection molding process. Instead, a prefabricated central part is used, which only needs to be connected to the upper and / or lower part during the process, thus significantly reducing the manufacturing effort required to produce a three-part drip chamber. This reduction in manufacturing effort is particularly advantageous in this case, as infusion systems are mass-produced items manufactured in large quantities.

[0045] In the method according to the invention, either the upper part and the lower part are each joined to the middle part or directly joined to each other. In preferred embodiments of the invention, the joining is carried out by solvent bonding.

[0046] As an alternative to the described solvent joining method, other joining methods are possible in other embodiments, depending on the properties of the materials. These include, for example, bonding using an adhesive, preferably UV bonding, especially with acrylate adhesives, or welding such as mirror welding, torsion welding, or preferably ultrasonic welding. In many cases, welding processes are preferred because they do not require an additional material component.

[0047] The aforementioned joining methods (solvent joining, welding, bonding) require less manufacturing effort than the conventional injection molding process used to form the handle ring. In one described embodiment, the upper part can be joined to the middle part using the same joining method as the lower part to the middle part. However, the upper part can also be joined to the middle part using a different joining method than the lower part to the middle part. In the other described embodiment, the middle part can be joined to the upper part and / or the lower part using the same joining method as the lower part to the upper part. However, the middle part can also be joined to the upper part and / or the lower part using a different joining method than the lower part to the upper part.

[0048] In Fig. 2 and Fig. 3 A drip chamber 1 according to a first embodiment is shown. The drip chamber 1 is depicted in its operating position with a vertical longitudinal axis L. The position designations "top" and "bottom" refer to this operating position. This reference to the operating position is intended to simplify the subsequent description. The subject matter of the invention is not thereby limited to a specific orientation of the drip chamber 1.

[0049] The drip chamber 1 comprises a top part 2, a bottom part 3 and a middle part 4.

[0050] The upper part 2 is connected to the middle part 4 at its lower end region 21. In the illustrated embodiment, the middle part 4 is ring-shaped. To improve the connection between the upper part 2 and the middle part 4, joining structures 211 can be provided on the upper part 2 and / or on the middle part 4. An example is shown in Fig. 3 A ribbed structure 211 is shown in the area of ​​the lower end region 21 of the upper part 2, which enables optimal bonding.

[0051] The lower part 3 is connected to the middle part 4 at its upper end region 31. To improve the connection between the lower part 3 and the middle part 4, joining structures (not shown) can be provided on the lower part 3 and the middle part 4.

[0052] To improve the connection between upper part 2 or lower part 3 and middle part 4, grooves, beads, or other connecting structures (not shown) can be provided. Such connecting structures can, for example, enable a positive-locking connection and / or improve the joining surfaces for a possible connection by solvent joining, welding, or bonding.

[0053] By connecting the upper part 2 and the lower part 3 to the middle part 4, a fluid-tight connection is created between the upper part 2 and the lower part 3 via the middle part 4. This means that the drip chamber 1 forms a hollow body that is fluid-tight, with the exception of the connections and the venting device, which will be described below.

[0054] The inner wall of this hollow body is composed of several inner wall sections, namely at least a first inner wall section, which corresponds at least substantially to the inner wall of the upper part 2, and a second inner wall section, which corresponds at least substantially to the inner wall of the lower part 3. In addition, a third inner wall section may be present, formed by a section of the middle part 4. In other words, if the upper part 2 and the lower part 3 do not butt together when each is connected to the middle part 4, the middle part 4 contributes to the formation of the drip chamber wall.

[0055] At the upper end of the upper part 2, which is opposite the lower end region 21 of the upper part 2 in the vertical longitudinal direction L, a first connection 22 is provided. This first connection 22 is intended to be connected to a container (not shown in the drawing) for the fluid to be administered to the patient, so that the fluid can flow from the container into the drip chamber 1. In the illustration in Fig. 3 The first connection 22 is a hollow spike that can pierce a septum sealing the container. Such a hollow spike, which has several channels inside, is generally referred to as a "spike". It is preferred to manufacture the first connection 22 monolithically with the housing part of the upper part 2. Apart from the vent 6, the upper part 2 then consists of a single piece, which is advantageous from a manufacturing perspective and further ensures that the connection 22 is securely attached to the drip chamber 1.

[0056] In alternative embodiments not shown in the drawings, other systems are provided to connect the drip chamber 1 to the container, for example, coupling systems that prevent the drip chamber and container from being separated once connected. It is also possible that the connection at the upper end of the drip chamber 1 is permanently attached to the container or the container closure, for example, by solvent bonding, adhesive bonding, welding, or monolithic manufacturing.

[0057] A cover cap 5 may be provided to cover the first port 22 before and, if necessary, also after use of the drip chamber 1. Covering the port 22 protects it from contamination. Furthermore, a sufficiently tight cover increases workplace safety by protecting users and patients from puncture wounds caused by a spike.

[0058] A droplet former 23 is provided in the upper part 2 of the interior of the drip chamber 1. Liquid entering the drip chamber 1 from the container through the first connection 22 passes through the droplet former 23 into the interior of the drip chamber 1. The droplet former 23 is shaped such that the liquid enters the drip chamber 1 in the form of drops of a standardized size.

[0059] The drip chamber 1 has a ventilation device 6. The drawings show one variant in which the ventilation valve 61 is fitted into a ventilation nozzle 24 molded into the upper part 2. In alternative embodiments, instead of a nozzle, a flat opening is provided in the wall of the upper part 2, into which the ventilation device is fitted.

[0060] According to the present embodiment, the vent valve 61 is a check valve that allows air to enter the container for the fluid to be administered to the patient via a channel of the connection 22, but prevents fluid from escaping. The function of the vent valve 61 is, for example, that when the lower part 3 is compressed, air is pumped into the container. This pumping action initiates the flow of fluid from the container into the drip chamber. During pumping, the hose connected to the drip chamber is advantageously clamped, for example, by means of a roller clamp commonly used for this purpose.

[0061] The ventilation device 6 comprises, in addition to the ventilation valve 61, a ventilation filter 62 and a cap 63, which holds the ventilation valve 61 and the ventilation filter 62 around ventilation nozzle 24.

[0062] Preferably, and in contrast to the conventional design, the upper part 2 has an elongated shape, i.e., its length in the longitudinal direction L is greater than its width in the transverse direction. This improves the ergonomics of the drip chamber 1. In particular, the injection of medication is facilitated because the optional port of the infusion container is more easily accessible to the user when the drip chamber 1 has a slim shape in the area of ​​the upper part 2.

[0063] A second connection 32 is provided at the lower end of the lower part 3, which is opposite the upper end region 31 of the lower part 3 in the vertical longitudinal direction L. This first connection 32 is intended to be connected to a hose.

[0064] In the present embodiment, the middle part 4 is shaped such that, after connection with the upper part 2 and the lower part 3, it provides a bead 41 on the outer surface of the drip chamber 1. Viewed in the direction transverse to the longitudinal axis L, this bead 41 represents the widest point of the drip chamber 1. Therefore, the drip chamber 1 can be gripped particularly securely and comfortably at the bead 41, resulting in very ergonomic and safe handling of the drip chamber 1. The bead thus constitutes a grip ring.

[0065] In a further embodiment (b) of the drip chamber according to the invention, which is not shown specifically in the drawings but can be readily derived from them, the lower edge 21a of the upper part and the upper edge 31a of the lower part are directly joined together, for example by solvent joining, bonding, or welding. Here, the middle part 4 can be joined to a lower end region 21 of the upper part 2 and / or an upper end region 31 of the lower part 3, but this is not necessary to simplify manufacturing. Even without joining to the upper part 2 and / or lower part 3, the middle part 4 is held in the groove formed by the smaller diameter at the transition between the lower end region 21 of the upper part 2 and the upper end region 31 of the lower part 3.

[0066] The upper part 2 is preferably made, at least in the wall area, of an optically superior plastic that is highly transparent and exhibits high optical brilliance. A highly transparent plastic is understood to be one that allows at least a section of the wall of the upper part 2 to have a light transmission of at least 90% in the visible spectral range. This means that at least 90% of white light shone onto this section of the wall of the upper part 2 passes through it, and thus less than 10% is reflected and absorbed. A light transmission of at least 95% in the visible spectral range is preferred.

[0067] The use of highly transparent styrene-based plastic is preferred. This highly transparent styrene-based plastic is, for example, polystyrene or styrene-acrylonitrile copolymer (SAN). This allows for excellent observation of droplet formation at the droplet former 23 and droplet fall – either visually with the naked eye or automatically using an optical droplet sensor. In one specific embodiment, the upper part 2, with the exception of the venting device 6, consists of highly transparent polystyrene. In an alternative embodiment, the upper part 2, with the exception of the venting device 6, consists of highly transparent SAN.

[0068] The lower part 3 is preferably made of an elastic plastic, at least in the wall area. This ensures optimal performance of the pumping function of the drip chamber 1 described above. A styrene-based polymer material with a suitable degree of softness tailored to the desired elasticity is preferred. Styrene-butadiene copolymer (SBC) is particularly preferred. In the specific embodiment described, the lower part 3 is made of SBC.

[0069] The upper part 2 and the lower part 3 are each connected to the middle part 4. In preferred embodiments of the invention, the connection is provided by joining the components to one another by solvent bonding.

[0070] The material of the middle section 4 is selected to facilitate the simplest possible formation of a strong bond between the components. In the described embodiment, the middle section 3 consists of a styrene-based polymer material that can be securely bonded to both the highly transparent polystyrene of the upper section 2 and the elastic polystyrene of the lower section 3 using solvent bonding. The material of the middle section 4 is thus compatible with both the upper section 2 and the lower section 3. Preferably, the middle section should be made of a styrene-based polymer material with a suitable degree of softness that is tailored to the desired grip of the bead (grip ring). In particular, it is considered that the styrene-based polymer material of the middle section could also be SBC (styrene-based polymer).

[0071] Softer plastics generally do not meet the requirements for transparency and optical brilliance of the upper part 2 of a drip chamber 1. Highly transparent plastics generally do not meet the mechanical requirements for pumpability of the lower part 3 of a drip chamber 1. The invention enables a variety of material combinations for the upper part 2 and lower part 3, each well-suited with regard to its optical and mechanical properties, respectively, and fulfilling other requirements such as chemical resistance and durability.

[0072] In further embodiments of the invention, the handling and safety of the drip chamber 1 are further improved by the fact that the central part not only provides an exposed area, such as a ridge or similar feature, on the outer wall of the drip chamber 1, but is also made of a material that is particularly comfortable and secure to grip. Soft materials and / or materials with good grip, such as SBC, have proven particularly suitable for this purpose. It is not necessary for the entire central part 4 to be made of such a material. Rather, it is sufficient if the sections by which the drip chamber 1 is to be grasped and held are made of such a material.In specific embodiments of the invention, the middle part 4 is therefore composed of different materials, wherein at the points where the connection with the upper part 2 and the lower part 3 is made, a material optimized for a particularly easy-to-produce and / or particularly strong connection is used, and at the points where the drip chamber 1 is to be grasped and held, a material optimized for gripping is used. In particular, it is possible and advantageous if the middle part 4 has a soft, grippy material at the points where the drip chamber 1 is to be grasped and held, and otherwise consists of a harder material to give the drip chamber 1 additional mechanical stability.

[0073] As an alternative to the described solvent joining method, other joining methods are possible in other embodiments, depending on the properties of the materials. These include, for example, bonding using an adhesive, preferably UV bonding, particularly with acrylate adhesives, or welding such as mirror welding, torsion welding, or preferably ultrasonic welding. In many cases, welding processes are preferred because they do not require an additional material component. The material properties of the components to be joined must also be compatible for these alternative joining methods, so the invention is also advantageous in connection with these alternative methods. In particular, it is advantageous that the aforementioned joining methods involve less manufacturing effort than the injection molding process conventionally used to form the handle ring.The upper part 2 can be joined to the middle part 4 using the same joining method as the lower part 3 is joined to the middle part 4. Alternatively, the upper part 2 can be joined to the middle part 4 using a different joining method than the lower part 3 is joined to the middle part 4.

[0074] Fig. 4 Figure 1 shows a schematic exploded view of drip chamber 11 according to a second embodiment. Drip chamber 11 according to the second embodiment differs from drip chamber 1 according to the first embodiment only with respect to the ventilation device. The remaining elements are identical and are identified by the same reference numerals. A more detailed description of the remaining elements and their function is therefore unnecessary.

[0075] The ventilation device 60 of the drip chamber 11 according to the second embodiment comprises, in addition to the ventilation valve 601, a ventilation filter 602.

[0076] The ventilation valve 601 is a flap that can be opened and closed manually. The function of the ventilation device 60 (second embodiment) corresponds to the function of the ventilation device 6 (first embodiment) described above.

[0077] In the illustrated embodiments, the outer basic shape of the upper part is conical. In alternative embodiments not shown in the drawings, the upper part can also have a different basic shape, for example, cylindrical or dome-shaped.

[0078] In the illustrated embodiments, the outer basic shape of the lower part is cylindrical. In alternative embodiments not shown in the drawings, the lower part can also have a different basic shape, for example, a conical one.

[0079] In the illustrated embodiments, the drip chamber exhibits rotational symmetry with respect to rotation about the longitudinal axis L, apart from the ventilation device. In alternative embodiments not shown in the drawings, the drip chamber may also be non-rotationally symmetric, for example, having elliptical cross-sections.

[0080] The central part 4 of the drip chamber 1 according to the invention is designed as a sleeve, which ensures a fluid-tight connection between the upper part 2 and the lower part 3. It is possible for the upper part 2 and the lower part 3 to each be connected to the central part 4 such that the upper part 2, or rather its lower edge 21a, and the lower part 3, or rather its upper edge 31a, are abutted from each other, and, for example, a circumferential gap exists between the upper part 2 and the lower part 3. In this case, the central part 4, via which the upper part 2 and the lower part 3 are connected to each other, contributes to the formation of the inner wall of the drip chamber 1. However, the upper part 2 and the lower part 3 can also be arranged such that the lower edge 21a of the upper part 2 and the upper edge 31a of the lower part 3 are in a butt joint, i.e., the upper part 2 and the lower part 3 are then not spaced apart from each other but are in contact with each other.The middle section 4 then serves to hold the upper section 2 and the lower section 3 in this position relative to each other and, if necessary, to further seal the connection between the upper section 2 and the lower section 3. In this case, the middle section 4 does not contribute to the formation of the inner wall of the drip chamber 1.

[0081] In summary, one embodiment of the invention can be described as follows: A method for manufacturing a drip chamber 1, comprising the steps of providing an upper part 2, a lower part 3, and a middle part (4), and of connecting the upper part 2, the lower part 3, and the middle part 4. The connection is made such that the upper part 2 and the lower part 3 are fluid-tightly connected to each other via the middle part 4, or such that the upper part 2 and the lower part 3 are directly fluid-tightly connected to each other and the middle part 4 is attached to the outside of the upper part 2 and / or the lower part 3.

[0082] According to the invention, for example, a drip chamber 1 is obtained which, in addition to the upper part 2 and the lower part 3, has a prefabricated middle part 4, which is arranged in such a way that it creates a direct fluid-tight connection with the upper part and with the lower part by joining a lower end region 21 of the upper part 2 and an upper end region 31 of the lower part 3 with the middle part 4, or which is arranged in such a way that it provides a bridging between a lower end region 21 of the upper part 2 and an upper end region 31 of the lower part 3, wherein the lower edge 21a of the upper part and the upper edge 31a of the lower part are joined directly to each other and the middle part 4 provides the bridging.

Claims

1. A method of manufacturing a drip chamber (1), comprising the steps of: A) providing an upper part (2) for the drip chamber (1) with a first connection intended to be connected to a container, B) providing a lower part (3) for the drip chamber (1) with a second connection (32) connected to a tube or intended to be connected to a tube, and C) providing a middle part (4) for the drip chamber (1), which part is designed as a sleeve, D) connecting the upper part (2), the lower part (3) and the sleeve, such that the upper part (2) and the lower part (3) are connected to each other in a fluid-tight manner via the sleeve, wherein the upper part (2) and the sleeve are connected to each other by solvent joining, and wherein the lower part (3) and the sleeve are connected to each other by solvent joining.

2. A drip chamber (1) for an infusion or transfusion system, in particular manufactured by a method according to claim 1, wherein the drip chamber (1) comprises: an upper part (2) with a first connection intended to be connected to a container, a lower part (3) with a second connection (32) connected to a tube or intended to be connected to a tube, and a prefabricated middle part (4), designed as a sleeve and configured to provide a direct fluid-tight connection with the upper part and with the lower part, respectively, by joining a lower end region (21) of the upper part (2) and an upper end region (31) of the lower part (3) to the middle part (4), respectively, wherein the upper part (2) and the middle part (4) are connected to each other by solvent joining, and wherein the lower part (3) and the middle part (4) are connected to each other by solvent joining.

3. The drip chamber (1) according to claim 2, wherein the upper part (2) comprises a polymer material, wherein the polymer material is preferably a styrene-based polymer material, wherein the styrene-based polymer material is more preferably a polystyrene material or a styrene-acrylonitrile copolymer material, in particular a highly transparent polystyrene material or a highly transparent styrene-acrylonitrile copolymer material.

4. The drip chamber (1) according to any one of claims 2 to 3, wherein the lower part (3) comprises a polymer material, wherein the polymer material is preferably a styrene-based polymer material, wherein the styrene-based polymer material is more preferably a styrenebutadiene copolymer material.

5. The drip chamber (1) according to any one of claims 2 to 4, wherein the middle part (4) comprises a polymer material, wherein the polymer material is preferably a styrene-based polymer material, wherein the styrene-based polymer material is more preferably a styrenebutadiene copolymer material.

6. The drip chamber (1) according to any one of claims 2 to 5, wherein at least a portion of a wall of the upper part (2) has a light transmission in the visible spectral range of at least 90%, preferably at least 95%.

7. The drip chamber (1) according to any one of claims 2 to 6, wherein the middle part (4) provides a protrusion (41) on an outer surface of the drip chamber (1).

8. The drip chamber (1) according to any one of claims 2 to 7, wherein the first connection (22) is formed as a piercing device, in particular as a hollow piercing device, for piercing the wall of a container for a liquid to be administered to a patient or of a septum provided at the container, and / or wherein the first connection (22) is non-detachably connected to the container or is non-detachably connectable to the container.

9. The drip chamber (1) according to any one of claims 2 to 8, wherein the second connection (32) is formed as a coupling device which may be connected to a complementary coupling device at the end of a tube such that a tight fluid connection exists between the interior of the drip chamber (1) and the tube, wherein the coupling devices are preferably closed in a dry manner when not connected to each other.

10. The drip chamber (1) according to any one of claims 2 to 9, wherein the upper part (2) has a first connection (22) connected to a container or intended to be connected to a container, and wherein the lower part (3) has a second connection connected to a tube or intended to be connected to a tube.

11. An infusion or transfusion system comprising a drip chamber (1) according to any one of claims 2 to 10.