Infusion Filter

Abstract

To provide a medical pressure indicator.SOLUTION: Regarding a medical pressure indicator 3a for infusion that can be combined with a liquid passing filter element via an infusion line 2, a pressure indicator can expand at least first-dimensionally in accordance with pressure in the liquid passing element, and the pressure indicator is formed as a liquid passing tube part. A medical pressure indicator 3a of an aseptic package to be connected to an outlet of a medical infusion filter that is composed of at least partially an elastic material that can expand relates to the use of the pressure indicator to be connected to the outlet of the medical infusion filter. The infusion line includes an infusion filter that includes the pressure indicator 3a of the aseptic package or the pressure indicator.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] The present invention relates to a medical pressure indicator that can be connected to a patient's access port and easily and effectively detects blockages, occlusions, or other flow disturbances within a medical infusion system using a specially designed pressure indicator.

[0002] The invention also relates to a pressure indicator in a sterile package for connection to an outlet of a medical infusion filter and to the use of said pressure indicator for connection to an outlet of a medical infusion filter.

[0003] Finally, the invention relates to an infusion line comprising an infusion filter comprising a pressure indicator according to the invention or a pressure indicator according to the invention. [Background technology]

[0004] In intensive medicine and critical care, there is always the problem of optimal treatment of various pathological conditions, but also the stability of medicinal products in solution, the chemical-physical compatibility (compatibility) of the administered infusion solutions, and finally the compatibility of medicines with disposable materials (lines, cock banks, etc.). According to literature data, in intensive care medicine, without infusion filters, about 10 million particles can enter the human body per patient within 24 hours. Infusion solutions can contain particles of different sizes, for example particles with a size of 50 μm or more that are visible to the naked eye, and particles with a size of less than 50 μm that are not visible to the naked eye.

[0005] Undissolved solids in the glass ampoules, the drug or the parenteral infusion solution or particle formation due to, for example, incompatibility between the drug and the carrier solution represent a particularly high risk of particle contamination of the infusion solution. In particular with the latter so-called mixed infusion solutions, the risk of particle contamination is particularly high. Mixed infusion solutions are prepared on demand, for example in pharmacies or hospitals, and the risk of particle contamination is particularly high in emergency situations.

[0006] Contaminating particles present in the intraluminal portion and not retained, for example, by a filter, can enter the patient's body directly and cause undesirable effects there. The risks of particle contamination include disturbance of the microcirculation, displacement of blood vessels, damage to various organs or phlebitis.

[0007] These issues not only harm patients, but can also lead to increased costs of care through prolonged hospital stays.

[0008] To avoid such disadvantages, it is recommended to use filter elements such as infusion filters. However, the use of infusion filters is not a standard practice, since the correct handling of them must first be mastered. This is especially a problem for nurses, who are generally responsible for administering infusions to patients. Thus, it is not uncommon for infusion filters, the use of which would bring considerable benefits, to be discontinued due to initial handling difficulties, at least to the disadvantage of the patient, who suffers from an increased risk of contamination.

[0009] One of the problems that may arise in handling infusion filters is that if the infusion solution does not reach the patient as intended, it is not easy to determine the cause. It is not easy to distinguish whether the infusion filter is clogged (closed or blocked), whether the patient's access port is clogged (clogged or blocked), for example, due to the infusion needle getting stuck against the wall of the tube, or whether there is a catheter blockage. Since there was no way to identify whether the infusion filter or the patient's access port was clogged, it was necessary to replace the infusion filter when the infusion solution did not pass through the patient, and therefore there was no confidence that the problem of the infusion solution being delivered to the patient at the desired flow rate would be solved.

[0010] Thus, although the use of such filters is desirable and even encouraged, this difficulty among others often discourages the use of infusion filters. Summary of the Invention [Problem to be solved by the invention]

[0011] Therefore, an object of the present invention is to provide a medical pressure indicator that can relatively easily determine whether an infusion filter or a patient's access port is blocked, thereby enabling the use of an infusion filter more reliably than in the past. [Means for solving the problem]

[0012] According to the invention, this problem is solved by a medical pressure indicator according to claim 1. The invention therefore relates to a medical pressure indicator for infusions, combinable and preferably combined with a liquid-passing filter element via an infusion line, the pressure indicator being formed as a liquid-passing element downstream of the combinable liquid-passing filter element, the pressure indicator being capable of expanding or contracting in at least one dimension depending on the pressure at the liquid-passing element. In a particularly advantageous embodiment, the liquid-passing element, i.e. the pressure indicator, is a liquid-passing tube section that can expand and contract in at least one dimension relative to the pressure at the tube section. Such a pressure indicator that can expand and contract in at least one dimension can indicate both overpressure (positive pressure) and underpressure (negative pressure) continuously, reliably and in a simple manner. Even very low pressures and pressure changes can be detected and measured. Furthermore, the pressure indicator is of simple design with a minimum of structures that are adapted to the infusion tube, thereby making it possible to determine also in a simple manner whether and where an obstruction is present at the infusion filter or at the patient's access port. The above mentioned advantages are also important during patient use, since the risk of clogging and unintentional withdrawal of the infusion fluid is minimized. Thus, the configuration as a liquid-passing tube section not only allows a compact design, but also increases security due to the associated shape.

[0013] Further subject matter of the invention is a pressure indicator in a sterile package suitable for connection to an outlet of a medical infusion filter as described in claim 11, a pressure indicator according to the invention as described in claim 13 and the use of said pressure indicator for connection to an outlet of a medical infusion filter as described in claim 14, as well as an infusion line as described in claim 15 comprising said pressure indicator or said infusion filter.

[0014] According to the invention, the medical infusion filter can be combined with a pressure indicator, which is formed downstream of the filter element as a liquid-permeable element, the pressure indicator having the property that it can expand or contract in at least one dimension depending on the pressure at the liquid-permeable element.

[0015] The term "downstream" refers to the general direction of fluid flow, i.e., from the side of the infusion bag or infusion filter toward the side of the patient access port.

[0016] Unless otherwise stated, the term "pressure" typically refers to the infusion pressure prevailing in the infusion system in which the filter element is located, in particular the pressure prevailing between the filter element and the patient access port.

[0017] Medical infusion filters are able to remove or retain particles from infusion solutions. As a result, contamination of the patient to which the infusion solution is delivered with (micro)particles can at least be reduced, and in the best case even be completely avoided. Such infusion filters are known to the skilled artisan and are available, for example, from the German company B.Braun. Infusion filters are also described in the following publications: DE-A-3347374, EP-A-2567720, EP-A-0784988.

[0018] The term "medical grade" as used herein means that the type of material is suitable for passing infusion solvents and does not dissolve unacceptable / harmful substances. For patient use, medical infusion filters also need to be sterile, and as a result, the present invention preferably relates to a sterile packaged medical pressure indicator or a medical infusion filter with a pressure indicator.

[0019] The terms "expansion" and "contraction" as used herein each relate to a change in dimension or size of the pressure indicator to an extent that can be perceived by the naked eye or detected using a simple measuring device such as a scanner. In particular, such a change in dimension or size is perceptible by eye or easily detectable by a suitable device at pressures in the range of 1-70 mmHg. In particular, the terms refer to a change in dimension in the millimeter range or centimeter range, e.g., an expansion or contraction of at least 1 mm.

[0020] The pressure indicator may expand and contract in at least one dimension, for example radially relative to the direction of infusion solution flow.

[0021] The pressure indicator is located downstream after the filter element. During fluid administration, both the filter element, e.g., the filter membrane, and the patient access port can become occluded. Essentially, there are three states in the system during fluid administration:

[0022] State 1: This state exists when all the liquid passage parts are free of blockages or other disturbances of the liquid flow or pressure change situations. In this case, in the state connected to the patient, the pressure between the filter element (here also referred to simply as "filter", e.g. the filter membrane of an infusion filter) and the patient's access port corresponds to the static pressure due to the infusion solution minus the venous static pressure and the dynamic pressure of the infusion solution and blood flow. In this case, the pressure indicator is in an intermediate state or at normal tension. For example, this can be seen by the line section formed correspondingly between the filter element and the patient's access port having a normal cross-sectional diameter or cross-sectional area. This means that the pressure indicator does not show a change in dimension or size, but still has the ability or property to expand or contract in response to changes in pressure. Thus, in this state, i.e. when all the liquid passage parts are free of blockages or other disturbances and therefore the infusion solution can be delivered to the patient without hindrance, the pressure indicator does not expand or contract. This state is illustrated in FIG. 1A.

[0023] In this condition ("normal condition"), the diameter of the liquid-passing element of the pressure indicator is at least 2 mm in normal conditions.

[0024] State 2: This state exists when the patient access port is clogged or partially clogged. In the case of complete occlusion, the pressure between the filter element and the patient access port corresponds to the static pressure due to the infusion solution. The pressure indicator is at maximum tension. That is, in this state, the pressure indicator is maximally expanded. This state is illustrated in FIG. 1B. For example, this can be seen by the fact that the correspondingly formed, in particular elastic, expandable line portion between the filter element and the patient access port has a larger cross-sectional diameter or cross-sectional area than in the normal state (i.e. compared to the state shown in FIG. 1A).

[0025] In this state (the "expanded state"), the diameter of the liquid-passing element of the pressure indicator is at least 3 mm.

[0026] State 3: This state exists when the filter element (e.g. the filter membrane of an infusion filter) is clogged or partially clogged, so that the infusion pressure acting upstream of the filter element no longer reaches the pressure indicator. In the case of a complete blockage, the pressure downstream of the filter element, i.e. between the filter element and the patient's access port, corresponds to the venous pressure minus the dynamic pressure of the blood flow. The pressure indicator is relaxed, i.e. in this state, the pressure indicator is contracted. This state is illustrated in FIG. 1C. For example, this can be seen by the fact that the correspondingly formed, in particular elastic, expandable line portion between the filter element and the patient's access port has a smaller cross-sectional diameter or a smaller cross-sectional area than in the normal state (i.e. compared to the state shown in FIG. 1A).

[0027] In this state (the "contracted state"), the diameter of the liquid-passing element of the pressure indicator is at least 1 mm.

[0028] As is apparent from the above description, the degree of dimensional or size change that can be detected by the pressure indicator corresponds to the degree of pressure change or degree of clogging and can be between the two extremes of "free" or "trouble-free" on the one hand and "completely clogged" on the other.

[0029] The state of the pressure indicator can therefore be used to quickly identify the cause and location of the interruption or malfunction of the infusion solvent fluid flow. Depending on whether the pressure indicator is inflated (stretched) or deflated, it can be easily and reliably detected whether the patient access port or the filter element is at least partially blocked (occluded). If the filter element is at least partially blocked, the pressure indicator is in a more or less deflated state. If the patient access port is at least partially blocked, the pressure indicator is in a more or less inflated state. Depending on where the occlusion is present, appropriate measures can be taken to remove it. For example, the at least partially blocked filter element can be replaced. Since the medical infusion filter according to the invention with a pressure indicator can be used to detect in a simple manner relatively quickly and reliably where the occlusion is located (patient access port or filter element) and can also be removed, the invention can make the use of infusion filters more widely accepted. Furthermore, the solution proposed here is relatively inexpensive.

[0030] In one possible embodiment, the pressure indicator contracts by at least 1 mm when the filter element is fully occluded at a standard infusion medium pressure of 5 mmHg upstream of the filter. In a further possible embodiment, the pressure indicator expands by at least 3 mm when the filter element is fully occluded at the patient's access port at a standard infusion medium pressure of 70 mmHg upstream of the filter (preferably indicating a non-inflated state, referring to a normal pressure of 1.013 bar and 20° C., e.g. a state in which the tube is filled with air and the same pressure prevails inside and outside).

[0031] In a preferred embodiment, the pressure indicator is configured as a liquid-passing element, most conveniently and most simply, this liquid-passing element being a line section arranged downstream of the filter element, in particular a line section of an infusion tube or an infusion system between the filter and the patient's access port.

[0032] In a preferred embodiment, the pressure indicator, or at least a portion of the liquid passing element described above, is at least partially made of a flexible material, such as an elastic or inelastic material, and is shaped to expand or contract. An example of a flexible inelastic material is LDPE ("low density polyethylene").

[0033] For example, the pressure indicator may be formed as an elastic tube section, which preferably expands from a pressure in the line higher than 30 mmHg, preferably higher than 40 mmHg, and / or contracts from a pressure lower than 20 mmHg, preferably lower than 10 mmHg. On the other hand, good and easy visibility of the pressure indicator is given, while other parts of the tube do not expand at said high pressure values ​​or contract at said low pressure values. This part of the hose serves as a reference for dimensional changes of the elastic section, which can then be more easily detected by an observer. The tube section is made of an elastic material, such as silicone, PVC (polyvinyl chloride), in particular plasticizer-free PVC or PVC containing the plasticizer DEHT (diethylhexyl phthalate). PVC containing DEHT as the only plasticizer is preferred.

[0034] In a further embodiment, the pressure indicator of the medical infusion filter can also be formed as a line section with folds, which can expand in a longitudinal direction from the folded normal state when the pressure increases, and can, if necessary, contract (even more) from the folded normal state along this longitudinal direction when the pressure is reduced. Such an embodiment is shown, for example, in FIG. 2.

[0035] In a further embodiment, the pressure indicator of the medical infusion filter can be used in an easy way if it is made partly of an elastic material and partly of a non-elastic hard material. For example, the pressure indicator can be in the form of a membrane. The membrane can expand in a first direction due to the elastic material forming the membrane in response to an increase in pressure, representing an increase in pressure in the fluid system due to at least a partial blockage at the patient's access port. An example of this is shown in FIG. 3, which shows how the elastic membrane expands outwardly ("first direction"). Alternatively, due to the elastic material forming the membrane, the membrane can also expand in a second direction opposite to the first direction in response to a decrease in pressure, representing a decrease in pressure in the fluid system due to at least a partial blockage of the filter. Although this is not explicitly shown in FIG. 3, it is readily apparent from this that the elastic membrane can expand inwardly ("second direction").

[0036] The expansion and contraction of the pressure indicator, preferably the elastic portion of the pressure indicator, preferably occurs radially relative to the flow direction of the infusion solution, however, the expansion and contraction may occur in the flow direction of the infusion solution.

[0037] In one embodiment, the elastic material of the pressure indicator may be a membrane. This membrane may be opposed to a non-elastic (rigid) component so that the pressure indicator can only expand or contract on the side of the membrane. An example of such an embodiment is shown in FIG.

[0038] The term "membrane" as used herein in connection with the elastic material of the pressure indicator refers to a fluid-impermeable thin "skin" of the line section or pressure indicator that can expand or contract, rather than a semi-permeable membrane or filter membrane.

[0039] In a further embodiment, or in addition to the embodiments described herein, the filter may be a capillary membrane.

[0040] In the case of a capillary membrane, the infusion solution is preferably filtered from the inside out, and the outer skin of the line section surrounding the capillary membrane may contain the elastic material of the pressure indicator and may expand or contract. Here again, the elastic material is located "downstream" of the filter element, since the filtered infusion solution that comes into contact with the elastic material has already passed through the capillary membrane.

[0041] The medical infusion filter may be formed in one piece, two pieces, or multiple pieces. In the two-piece or multiple piece configuration, the infusion filter may be spatially separated from the pressure indicator, both of which function as line parts and are connected to each other, for example, by an infusion tube.

[0042] Depending on whether the filter is fully or partially clogged or whether the patient's access port is fully or partially clogged, the pressure indicator expands or contracts to such an extent that a change in the pressure indicator is visually detectable. This expansion or contraction of the pressure indicator occurs, for example, at pressures in the range of 0-70 mmHg. Preferably, the pressure indicator, which may be formed, for example, as a tube section, expands from a pressure of 30 mmHg or more, preferably 40 mmHg or more, and / or contracts from a pressure of 20 mmHg or less, preferably 10 mmHg or less.

[0043] The pressure indicator according to the invention is capable of continuously and reliably measuring negative and positive pressures, such as those defined herein, and is therefore also capable of measuring low pressures and therefore indicating even relatively small pressure changes.

[0044] In a preferred embodiment, it is only the elastic material of the pressure indicator that expands or contracts visually detectably at a given pressure.

[0045] In order to make the change in the pressure indicator (i.e. expansion or contraction) easier to visually detect, it is preferable to provide a color marking on the pressure indicator, preferably for detectability of the expansion or contraction, preferably change in expansion, of the flexible (preferably elastic) material of the pressure indicator.

[0046] The color markings of the pressure indicator of the medical infusion filter can create different color images depending on the state of inflation, which can further increase the visual perception of any change in the pressure indicator.

[0047] For example, an elastic material such as a membrane may be placed over the color markings which become more visible when the membrane is stretched more.

[0048] The diameter of the pressure indicator of the medical infusion filter in the relaxed state essentially depends on the shape of the pressure indicator. Thus, the pressure indicator may have any shape suitable for passing the infusion medium therethrough and indicating any pressure changes that may occur due to expansion or contraction in at least one dimension. For example, the pressure indicator may be tubular, accordion-shaped, circular, or spherical.

[0049] For example, if the pressure indicator is tubular, the diameter of the pressure indicator in its relaxed state (ambient pressure and no liquid) is approximately equal to the diameter of the infusion tube, for example 0.7 to 2 times the diameter of the infusion tube. In a preferred embodiment, the diameter of the pressure indicator in its relaxed state is 2 mm to 8 mm.

[0050] The pressure indicator according to the invention is therefore of a relatively simple construction, whereby the construction of the pressure indicator can be adapted, for example, to the size of the pressure indicator, to the infusion line to which it can be combined. This is for example beneficial in use on the patient, i.e. by maintaining the smallest possible size in combination with a design that is preferably adapted to the infusion tube, disadvantages in use can be avoided, for example, clogging of the pressure indicator with the result that infusion is drawn from the patient can be prevented. Thus, not only the simple design of the pressure indicator, which is preferably as small as possible, but also the shape of the pressure indicator, which is as simple as possible, contributes to an advantageous use on the patient.

[0051] The invention also relates to a pressure indicator in a sterile package for connection to an outlet of a medical infusion filter, the pressure indicator being formed as a line section for an infusion medium, the pressure indicator being able to expand or contract in at least one dimension depending on the infusion pressure in the line section. Advantageously, the pressure indicator in the sterile package is at least partially made of an elastic material that can expand and contract.

[0052] All features as described herein for the pressure indicator in connection with the medical infusion filter also apply to the pressure indicator in a sterile package for connection to the outlet of the medical infusion filter.

[0053] The present invention also relates to the use of a sterile packaged pressure indicator as described herein for connection to the outlet of a medical infusion filter.

[0054] Finally, the invention relates to an infusion line comprising a sterile packaged pressure indicator as described herein or an infusion filter having a pressure indicator as described herein. [Brief description of the drawings]

[0055] Exemplary embodiments of the present invention will now be described in more detail with reference to the drawings, which drawings and the following description are intended to illustrate the present invention in more detail without limiting the invention thereto.

[0056] [Figure 1A] 1 shows an example of a first embodiment according to the present invention. [Figure 1B] 1 shows an example of a first embodiment according to the present invention. [Figure 1C] 1 shows an example of a first embodiment according to the present invention. [Diagram 2] 2 shows an example of a second embodiment according to the present invention. [Diagram 3] 3 shows an example of a third embodiment according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0057] They each show a longitudinal section of a portion of a pressure indicator according to the invention connected in fluid communication with a medical infusion filter, the filter element of which itself and the patient access port are not explicitly shown, so any conventional or newly adapted filter element or any conventional or newly adapted form of patient access to the pressure element can be used.

[0058] Figure 1 shows a first embodiment and three possible states A), B) and C). In this figure, an infusion line 2 is shown downstream (upward arrow) of a filter element 1 (not shown) and leads with a downward arrow to a patient access port 5 (not shown). A line portion 3 of the infusion line 2 represents a pressure indicator 3, which here is exemplarily formed as an elastic tube 3a.

[0059] FIG. 1A) shows state 1. This state 1 appears when the liquid-passing parts (filter element 1, patient access port 5) are free. In this case, the pressure between the filter element and the patient access port 5 corresponds to the venous pressure plus the pressure drop across the infusion cannula and the fluid path from the cannula to the filter element. In this case, the pressure indicator 3a is in an intermediate state or normal tension, which means that it can expand or contract depending on the pressure changes. Thus, in this state, i.e. when the liquid-passing parts (filter element 1, patient access port 5) are free and therefore the infusion medium can be delivered to the patient without hindrance, the pressure indicator 3a does not expand or contract.

[0060] In FIG. 1B) the patient access port 5 is at least partially blocked (clogged) (state 2). In the case of complete blockage, the pressure between the filter element 1 and the patient access port 5 corresponds to the static pressure due to the infusion solution. The pressure indicator 3a is under maximum tension, i.e. in this state the pressure indicator 3a is maximally expanded.

[0061] FIG. 1C) shows a state (state 3) in which the filter element 1 (e.g. the filter membrane of an infusion filter) is clogged or partially clogged, so that the infusion pressure applied upstream of the filter element 1 no longer reaches the pressure indicator. In case of complete blockage, the pressure downstream of the filter element 1, i.e. between the filter element 1 and the patient's access port 5, is equal to the venous pressure minus the dynamic pressure of the blood flow. The pressure indicator 3a is relaxed, i.e. in this state, the pressure indicator 3a is contracted. Since the venous pressure is very low, the pressure at the pressure indicator can reach negative values ​​depending on the height at which it is attached.

[0062] 2 shows a second embodiment. In this embodiment, an infusion line 2 can be seen, which is located downstream of a filter element 1 (not shown) and leads to a patient access port 5 (not shown). A line portion 3 of the infusion line 2 represents a pressure indicator 3. Here, the pressure indicator 3 is exemplarily formed as an accordion-shaped pressure indicator 3b.

[0063] Figure 3 shows embodiment 3. In this embodiment, an infusion line 2 can be seen, which is located downstream of a filter element 1 (not shown) and leads to a patient access port 5 (not shown). A line portion 3 of the infusion line 2 represents a pressure indicator 3. Here, the pressure indicator 3 is exemplarily formed as a pressure indicator comprising an elastic membrane on the opposite side of which is located a non-elastic component 3c. The features of the technology described in this specification are listed below. (Feature 1) A medical pressure indicator (3, 3a, 3b, 3c) for infusions, combinable with a liquid-passing filter element (1) via an infusion line (2), said pressure indicator (3, 3a, 3b, 3c) being formed as a liquid-passing tube section downstream of the combinable liquid-passing filter element (1), said pressure indicator (3, 3a, 3b, 3c) being capable of expanding and contracting in at least one dimension depending on the pressure in said tube section. (Feature 2) 2. The medical pressure indicator (3, 3a, 3b, 3c) according to feature 1, wherein the tube section is a line section arranged downstream of the liquid-passing filter element (1), in particular a line section of an infusion tube (2) or an infusion system. (Feature 3) 3. The medical pressure indicator (3, 3a, 3b, 3c) according to feature 1 or 2, wherein the tube portion of the pressure indicator, or at least a part of the tube portion, is at least partially made of an elastic or inelastic material that is configured to stretch. (Feature 4) 4. A medical pressure indicator (3, 3a, 3b, 3c) according to any one of features 1 to 3, wherein the tube portion expands from a pressure of 30 mmHg or more, preferably 40 mmHg or more, and contracts at a pressure of 20 mmHg or less, preferably 10 mmHg or less. (Feature 5) A medical pressure indicator (3, 3a, 3b, 3c) according to any one of features 1 to 4, wherein the tube portion is formed as a line portion having folds, and the tube portion is capable of expanding in the longitudinal direction when the pressure increases and contracting along the longitudinal direction when the pressure decreases. (Feature 6) A medical pressure indicator (3c) according to any one of features 1 to 3, wherein the tube portion is in the form of an elastic membrane, the membrane being capable of expanding in a first direction when pressure increases and in a second direction opposite the first direction when pressure decreases, or alternatively the membrane is opposed to a non-elastic component such that the pressure indicator can only expand on the side of the membrane. (Feature 7) 7. The medical pressure indicator (3, 3a, 3b, 3c) according to any one of features 1 to 6, wherein the filter is a capillary membrane. (Feature 8) The medical pressure indicator (3, 3a, 3b, 3c) according to any one of the preceding features, wherein the tube portion expands or contracts (relative to a non-inflated state) by at least 1 mm. (Feature 9) a color marking is provided on said tube portion and changes in response to said expansion or contraction of said tube portion of preferably elastic material of said pressure indicator; or 9. The medical pressure indicator (3, 3a, 3b, 3c) according to any one of the preceding features, wherein the colour features on the tube portions provide different colour images depending on the state of elongation. (Feature 10) 10. The medical pressure indicator (3, 3a, 3b, 3c) according to any one of features 1 to 9, wherein the diameter of the liquid passing tube portion is at least 2 mm in normal condition, at least 3 mm in inflated condition and at least 1 mm in deflated condition. (Feature 11) A pressure indicator (3, 3a, 3b, 3c) in a sterile package suitable for connection to the outlet of a medical infusion filter (1) or to a connection located further downstream of a medical infusion filter, said pressure indicator being adapted to be connected as a line section for an infusion medium at the connection to the outlet of the medical infusion filter or to a further downstream section of the medical infusion filter, said pressure indicator being at least partially made of an elastic material that can stretch, said pressure indicator being able to stretch in at least one dimension depending on the pressure in the line section. (Feature 12) 12. The pressure indicator (3, 3a, 3b, 3c) of a sterile package according to feature 11, wherein the elastic material is capable of expanding at an infusion pressure on the line higher than 30 mmHg, preferably higher than 40 mmHg, and contracting at an infusion pressure lower than 20 mmHg, preferably lower than 10 mmHg. (Feature 13) 11. The pressure indicator (3, 3a, 3b, 3c) according to any one of the preceding features, wherein the pressure indicator is combined with a liquid-passing filter element (1). (Feature 14) Use of a pressure indicator (3, 3a, 3b, 3c) of a sterile package according to any one of features 11 to 13 for connection to the outlet of a medical infusion filter. (Feature 15) An infusion line (2) comprising a sterile packaged pressure indicator (3, 3a, 3b, 3c) according to any one of features 11 to 13 or in combination with an infusion filter and a pressure indicator according to any one of features 1 to 10. [Explanation of symbols]

[0064] 1: Filter element 2: Infusion line / infusion tube 3: Line section / pressure indicator 3a: Elastic tube 3b: Accordion Shape Pressure Indicator 3c: Pressure indicator with an elastic membrane located opposite a non-elastic component 4: Membrane 5: Patient access port

Claims

1. 1. A medical pressure indicator for infusion fluids, which is combinable with a liquid-passing filter element via an infusion line, comprising: the pressure indicator is formed as a portion of a liquid-passing tube downstream of the matable liquid-passing filter element and upstream of a patient access port; the pressure indicator may expand and contract in at least one dimension in response to pressure in the tube portion; the pressure in the tube portion corresponds to the static pressure due to the infusion solution minus the venous static pressure and the dynamic pressure of the infusion solution and blood flow; if the liquid-passing filter element is completely or partially clogged, the pressure indicator will deflate to a degree that is visually perceptible by a user's eye; and and if the patient access port is completely or partially clogged, the pressure indicator inflates to a degree that is visually noticeable to the user. When the pressure between the liquid-passing filter element and the patient access port corresponds to a static pressure due to an infusion solution, the tube portion expands; when the pressure between the liquid passing filter element and the patient access port corresponds to the venous pressure minus the dynamic pressure of the blood flow, the tube portion contracts; The other portion of the tube does not expand at the static pressure value of the infusion solvent, and does not contract at the pressure value of the venous pressure minus the dynamic pressure of the blood flow. Medical pressure indicator.

2. The medical pressure indicator of claim 1 , wherein the tube portion is a line portion disposed downstream of the liquid-passing filter element.

3. The medical pressure indicator of claim 2 , wherein the tubing section is an infusion tubing or a line section of an infusion system.

4. 4. A medical pressure indicator as claimed in any one of claims 1 to 3, wherein the tube portion of the pressure indicator, or at least a portion of the tube portion, is at least partially formed from an elastic or inelastic material that is configured to stretch.

5. 5. A medical pressure indicator according to any one of claims 1 to 4, wherein the tube portion expands from a pressure of 30mmHg or more and contracts at a pressure of 20mmHg or less.

6. 6. The medical pressure indicator of claim 5, wherein the tube portion expands from a pressure of 40 mmHg or more and contracts at a pressure of 10 mmHg or less.

7. 7. A medical pressure indicator as claimed in any one of claims 1 to 6, wherein the tube portion is formed as a line portion with folds, and the tube portion is capable of expanding in a longitudinal direction when the pressure increases and contracting along the longitudinal direction when the pressure decreases.

8. 5. A medical pressure indicator as claimed in any one of claims 1 to 4, wherein the tube portion is in the form of an elastic membrane, the membrane being capable of expanding in a first direction when pressure increases and in a second direction opposite the first direction when pressure decreases, or alternatively the membrane is opposed to a non-elastic component such that the pressure indicator can only expand on the side of the membrane.

9. A medical pressure indicator according to any one of claims 1 to 8, wherein the filter is a capillary membrane.

10. 10. A medical pressure indicator according to any preceding claim, wherein the tube portion expands or contracts by at least 1 mm relative to an uninflated state.

11. a color marking is applied to the tube portion and changes in response to the expansion or contraction of the tube portion; or 11. A medical pressure indicator according to any one of claims 1 to 10, wherein colour features on the tube portions provide different colour images depending on the state of elongation.

12. 12. A medical pressure indicator according to any one of claims 1 to 11, wherein the diameter of the liquid passing tube portion is at least 2mm in normal condition, at least 3mm in inflated condition and at least 1mm in deflated condition.

13. 1. A pressure indicator in a sterile package suitable for connection to the outlet of a medical infusion filter or to a connection further downstream of said medical infusion filter, comprising: the pressure indicator is adapted to be connected as part of a line for an infusion solvent in a connection to the outlet of the medical infusion filter or in a connection further downstream of the medical infusion filter and upstream of a patient access port, the pressure indicator is made at least in part from a resilient material that is stretchable, the pressure indicator being stretchable in at least one dimension in response to pressure at the line portion; the pressure in the line corresponds to the static pressure due to the infusion solution minus the venous static pressure and the dynamic pressure of the infusion solution and blood flow, if the medical infusion filter is completely or partially clogged, the pressure indicator will deflate to a degree that is visually perceptible to a user's eye; and and if the patient access port is completely or partially clogged, the pressure indicator inflates to a degree that is visually noticeable to the user. When the pressure between the medical infusion filter and the patient access port corresponds to a static pressure due to an infusion solution, the line portion expands; when the pressure between the medical infusion filter and the patient access port corresponds to the venous pressure minus the dynamic pressure of the blood flow, the line segment contracts; The remaining portion of the line does not expand at the static pressure of the infusion solution, and does not contract at the venous pressure minus the dynamic pressure of the blood flow. Pressure indicator for sterile packaging.

14. 14. The sterile packaged pressure indicator of claim 13, wherein the elastic material is capable of expanding at infusion pressures on the line greater than 30 mmHg and contracting at infusion pressures less than 20 mmHg.

15. 15. The sterile packaged pressure indicator of claim 14, wherein the elastic material is capable of expanding at infusion pressures on the line greater than 40 mmHg and contracting at infusion pressures less than 10 mmHg.

16. A pressure indicator according to any one of claims 1 to 12, wherein the pressure indicator is combined with a liquid-passing filter element.

17. An infusion line comprising a sterile packaged pressure indicator according to any one of claims 13 to 15 or in combination with an infusion filter and a pressure indicator according to any one of claims 1 to 12.

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