One-way valve device

p0001The invention relates to a one-way valve device, in particular a low-pressure non-return valve for use for an infusion set, comprising a housing with a supply line and a discharge pipe, and with at least one seal located in a pressure chamber.

p0002Valve devices of the generic type for generating an idle stop are preferably used for infusion devices in hospitals, wherein the valve device is used for an immediate idle stop when an infusion liquid filled reservoir is idle to prevent air from flowing into the infusion liquid and towards the end of the inflow via the existing one Leads into the venous system of a patient. A valve device for use in an infusion set is, for example, from the German laid-open application<patcit id="pcit0001" dnum="DE2919343A1"><text>DE 29 19 343 A1</text></patcit> Which is equipped with a drip chamber and a float valve which prevents air from entering the infusion tube when the chamber is empty, a roller clamp being arranged at the outlet side in the flexible tube leading to the infusion needle. To prevent the entire line system of the dialyzer from being filled with air, a double-seat float valve with a float ball is used. Such float ball valves, however, are not always exact, so that air flow into the infusion hose can not be prevented in any case.

p0003A further no-load protection is disclosed in the German Offenlegungsschrift <patcit id="pcit0002" dnum="DE3632412A1"><text>DE 36 32 412 A1</text></patcit> In which an idle valve is arranged upstream of a dripping chamber in the flow direction. A float ball is located under friction when sealing against the channel wall and can not prevent air supply with absolute safety if the movement play is appropriate. Both solutions mentioned above are not suitable for excluding air supply into the human venous system.

p0004From the <patcit id="pcit0003" dnum="DE19749562A1"><text>DE 197 49 562 A1</text></patcit> An infusion set is known that consists of a highly suspended container for the infusion liquid, as well as a droplet which can be connected to a throttle container by means of a mandrel tube, a roller clamp which can be adjusted on a flexible feed line, and an injection needle located at the line end. In order to prevent the infiltration of air into the infusion fluid, in particular towards the end of the inflow of the infusion liquid, an idle stop is introduced into the flow upstream of the dripping chamber or at its inlet opening. This valve is dependent on a static pressure of the throughflow The infusion liquid can be stopped. However, in practical use it has been shown that an idle stop is not sufficient depending on the statically occurring pressure of the infusion liquid to prevent the penetration of air. In particular, if the possibility of interchanging the connections is given by carelessness and thus the function of the idling stop valve is no longer ensured. This becomes particularly dangerous when air penetrates into the system, which can lead to embolism in the patient if the air penetrate into the veins. It is therefore important that, together with the infusion liquid, no air is entrained which leads to the abovementioned disadvantage. A particular disadvantage is that the prior art valve can not prevent the ingress of air into the system in the event of the occurrence of a static overpressure.

p0005The object of the invention is to provide a novel check valve with low opening pressure, which can be used for an infusion set with gravitational pressure and / or pumping pressure, and prevents the penetration of air into the system of the infusion set with higher safety.

p0006According to the invention, it is provided for the purpose of solving the problem that an interruption of the flow takes place by means of a static negative pressure present at the supply and / or discharge pipe or an overpressure at the discharge pipe. According to the invention, the penetration of air into the system of the infusion set is advantageously avoided in the case of the occurrence of a static vacuum as well as an overpressure at the discharge pipe. A static negative pressure on the supply pipe can arise, for example, when a supply container of the infusion liquid has run out when an infusion pump is operating faultily or air has entered the system. An overpressure on the discharge pipe can occur, for example, in the event of a temporary closure of the arm veins of the patient, if a medicament pump is additionally connected in the manner of an outlet. An overpressure would cause the drug to be pumped into the gravity infusion set.

p0007The valve device according to the invention, however, ensures that, in the aforementioned cases, a further transport of the infusion fluid is reliably stopped and thus the penetration of air-enriched infusion fluid into the veins is prevented. In addition, the one-way valve ensures that the valve closes when an overpressure is exerted by an infusion or medicament pump on the outlet side, and thus the medicament does not enter the infusion set, thus preventing short-term overdosing. In order to seal the supply and discharge pipe, a seal is provided here which rests on a first sealing ring lip on one side of a pressure chamber and on the opposite side on a second sealing ring lip. Alternatively, there is the possibility that two pressure chambers, which communicate via a connecting channel, are formed in which at least one one-piece or two separate seals lie under tension on a first and second sealing ring lip, the two sealing ring lips being in turn arranged on either side of the seals or the connecting channel Is designed such that it opens once below and once above the seal. The seals are used to seal the sealing ring lips, which are in operative connection with the supply or discharge pipe and, in the event of a vacuum being applied, allow a seal against the sealing ring lips. Because of the alternating sealing of the sealing ring lips by at least one seal, it is ensured that, in the event of an overpressure on the discharge pipe, only an increase in the seal takes place on the sealing ring lip assigned to the discharge pipe, whereas the seal is pressed onto the second sealing ring lip due to the prevailing overpressure A closure of the supply pipe takes place.

p0008In a further embodiment of the invention it is provided that the supply pipe opens into a prechamber in which the first sealing ring lip is formed with a closed trough on which a seal limiting the pressure space rests while the discharge pipe opens into the pressure chamber of the housing within the second sealing ring lip , Against which a seal, which delimits the pressure space, rests against the second sealing ring lip, a second pre-chamber delimiting the seal, which is subjected to atmospheric pressure through a housing opening. The infusion liquid can flow into the prechamber through the supply pipe and the seal which bears against the first sealing ring lip can be lifted into which, in a further embodiment of the invention, an opening is provided in the region of the first sealing ring lip which is centered and lying within the first sealing ring lip, Pressure chamber is sealed against the prechamber. The inflowing infusion liquid lifts this seal from the sealing ring lip and can flow through the existing opening into the pressure chamber of the housing, the existing one-piece or two-part seal being lifted off the second sealing ring lip due to the opposing arrangement of the sealing ring lip To the discharge pipe. This is the normal flow process of the infusion liquid in the event that a sufficient static overpressure is present on the supply pipe. If, on the other hand, a vacuum is applied to the supply pipe, the existing seal closes the first sealing ring lip by the suction effect and thus an interruption of the flow of flow is effected. This is also the case if a negative pressure should be present on the discharge pipe because the seal is subjected to atmospheric pressure in the area of ​​the first sealing ring lip due to an existing housing opening. In the event that an overpressure develops at the discharge pipe, the latter reaches only into the pressure chamber via the second sealing ring lip and the lifting seal, and thus presses the existing seal directly onto the first sealing ring lip to ensure a flow of flow from the supply pipe to the discharge pipe is prevented.

p0009In a further embodiment of the invention, it is provided that the surface enclosed by the first and second sealing ring lip is formed smaller than the remaining surface of the abutting seal and that the ratio of the enclosed surface within the sealing ring lip to the remaining surface of the adjacent seal of the opening or Closing pressure. A preferably one-part seal is provided for both pressure chambers formed. Alternatively, it is possible to use a second-part seal, which is used, for example, in two self-contained pressure chambers, the two pressure chambers being connected to one another by a connecting channel.

p0010In a further embodiment of the invention it is provided that the seal is provided on the edge with a preferably T-shaped shoulder which comes to rest in a recess of the housing and is formed in one piece with the seal. By means of the T-shaped projection, a simple fastening possibility of the one or possibly of both seals within the housing is made possible, the T-shaped projection being located in a correspondingly designed recess and thus a sufficient guarantee for a secure fit of the seals used . In order to improve the sealing seat, it is also provided that the seal in the region of the connecting channel has a reinforcement in the form of a web which is integrally formed on one or both sides and is matched in shape to the edge of the housing half or of the pressure chambers. The housing is preferably designed in two parts and is held together by means of a clamping tongue-and-groove connection, whereby a simple mounting possibility is provided by the formed seal and the second-part housing form. In this case, the supply or discharge pipes can be arranged perpendicular to the housing, but it is also possible that they are arranged almost parallel to the housing by means of a curvature and thus a suitable and compact housing shape can be provided.

p0011The particular advantage of the present invention is that in the case of the application of a negative pressure at the supply or discharge pipe or in the case of an overpressure at the discharge pipe, a secure stop of the infusion liquid is ensured. The basic concept of the invention includes, among other things, a simple installation possibility of the valve seal, in particular with the formation of a T-shaped projection, which comes to lie in a corresponding recess of the housing halves so that a durable and reliable function of the valve device is ensured.

p0012The invention is explained in more detail below with reference to the figures.

p0013It shows<dl id="dl0001"><dt>FIG</dt><dd>In a sectional side view, an embodiment of the valve device according to the invention, </dd><dt>FIG</dt><dd>A sectional side view of the first housing half,</dd><dt>FIG</dt><dd>12 a top view of the outer side of the housing half according to FIG <figref idrefs="f0002">FIG</figref>,</dd><dt>FIG</dt><dd>12 a top view of the inner side of the housing half according to FIG <figref idrefs="f0002">FIG</figref>,</dd><dt>FIG</dt><dd>In a sectional view a second housing half,</dd><dt>FIG</dt><dd>12 a top view of the outer side of the housing half according to FIG <figref idrefs="f0005">FIG</figref>,</dd><dt>FIG</dt><dd>12 a top view of the inner side of the housing half according to FIG <figref idrefs="f0005">FIG</figref> and</dd><dt>FIG</dt><dd>A plan view and a sectional side view of a single seal.</dd></dl>

p0014<figref idrefs="f0001">FIG</figref> Shows a valve device 1 according to the invention, consisting of a first housing half 2 and a second housing half 3, as well as a seal 4 between the housing halves 2, 3 in an assembled state. In this case, the seal 4 is clamped between the two housing halves 2, 3. The first housing half 2 has a supply pipe 5 with a mouth pipe 6, which opens into a first pre-chamber 8 of the housing half 2 via a breakthrough 7. The pre-chamber 8, which is round or elliptically shaped, for example, has a center-bearing sealing ring lip 9, which is integrally formed from the housing half 2 and has a depression 10 lying between the sealing ring lip 9. The seal 4 abutting against the sealing ring lip 9 has an opening 11 which is arranged centrally to the sealing ring lip 9 so that, in the event of the seal 4 being lifted off the sealing ring lip 9, a connection through the opening 11 to the pressure chamber 12 is made possible. According to the construction, the pressure chamber 12 can be a pressure chamber 12 extending over the housing halves 2, 3, or two pressure chambers 12a, 12b can be formed which are connected to each other by a connecting duct 40 so that an identical static pressure prevails. The seal 4 rests against a second sealing ring lip 13, which is assigned to the second housing half 3. The second housing half 3 has a discharge pipe 14 with an orifice pipe 15 which opens into the recess 17 formed by the sealing ring lip 13 via an opening 16, so that an opening to the pressure chamber 12 is produced in the event of the seal 4 being lifted off. Opposite the sealing ring lip 13 of the second housing half 3, a breakthrough is present in the first housing half 2, which makes it possible to apply the atmospheric pressure to the seal 4 via a second prechamber 19. The seal 4 is clamped between the two housing halves 2, 3 such that, in the unpressurized state, the seal 4 rests directly against the sealing ring lips 9, 13. In order to prevent slipping of the seal 4 within the housing halves 2, 3 and thus to ensure a more reliable functioning of the valve device 1, the seal 4 is designed as a single part in the exemplary embodiment shown and has a T-shaped projection 20 which is arranged in a corresponding recess 21 of the first and second housing halves 2, 3. Alternatively, it is possible to use a second-part seal or to provide another fastening possibility for the seal 4.

p0015The seal 4 is lifted from the first sealing ring lip 9 by a static pressure, for example, the inflowing infusion liquid from a higher-lying storage container into the mouth tube 6 through the opening 7 into the first pre-chamber 8, so that the infusion liquid flows through the opening 11 under the seal 4 Into the pressure chamber 12. Because of the rising pressure in the pressure chamber 12, the seal 4 is also slightly raised in the region of the second sealing ring lip 13, so that the infusion liquid can flow into the mouth pipe 15 via the trough 17 and opening 16. When the static pressure decreases due to the infusion liquid, for example, an emptying of the reservoir, the seal 4 immediately comes into contact with the sealing ring lip 9, so that a stop of the infusion liquid is ensured. In the event of a negative pressure at the mouth pipe 6, the seal 4 is also sucked against the sealing ring lip 9 and also leads to a stop of the flow. If a negative pressure is present opposite the discharge pipe or mouth pipe 15, the seal 4 is also sucked and pressed onto the second sealing ring lip 13, so that a further flow is stopped. In the event that an overpressure prevails on the discharge pipe or mouth pipe 15, the seal 4 can indeed be lifted off from the second sealing ring lip 13, but the seal 4 is pressed in the region of the first sealing ring lip 9 because of the overpressure and the pretension present Thus preventing inflow of the infusion liquid into the mouth tube 6. The valve device 1 thus permits a stop of the infusion liquid in the event that a negative pressure prevails on the supply tube 5 or a vacuum or overpressure on the discharge tube 14 so that an infiltration of air into the system of the Infusion equipment. A predetermined flow direction of the infusion medium is only possible in the event that a static overpressure is applied to the supply pipe 5 or the mouth pipe 6.

p0016<figref idrefs="f0002">FIG</figref> Shows in a sectional side view the first housing half 2 with its feed pipe 5 and mouth pipe 6 as well as the integrally formed sealing ring lip 9 with its trough 10, as in particular FIG <figref idrefs="f0003">FIG</figref> and <figref idrefs="f0004">4</figref> Can be seen. The housing half 2 has an oval basic shape from which the supply pipe 5 protrudes perpendicularly. The entire housing half 2 is constructed in one piece and has on its outer surface 22 a depression 23 in the region of the first sealing ring lip 9 as well as further triangular shaped recesses 24 laterally offset to the mouth pipe 6. For accommodating the T-shaped projection 20 of the seal 4, a recess 21a is provided, which recesses step-like into a further recess 25. The recess 25 is delimited by a circumferential collar 26 and is provided for receiving a corresponding annular projection of the second housing half 3.

p0017<figref idrefs="f0003">FIG</figref> and <figref idrefs="f0004">4</figref> Show the first housing half 2 in an outer and inner plan view. In this case, the prechamber 8 or 19 is formed by an annular recess 28, 29.

p0018<figref idrefs="f0005">FIG</figref> Shows in a sectional side view the second housing half 3 with its discharge pipe or mouth pipe 15 and the second sealing ring lip 13 with its trough 17, into which the mouth pipe 15 opens through an opening. For accommodating the T-shaped projection 20 of the seal 4, a recess 21b is provided which, together with the recess 21a of the first housing half 2, accommodates the T-shaped projection 20. The basic shape of the second housing half 3 largely corresponds to the first housing half 2, as can be seen in particular from FIGS<figref idrefs="f0006">FIGS</figref> and <figref idrefs="f0007">7</figref> Can be seen. For the clamping connection with the first housing half 2, the second housing half 3 has a peripheral collar 30 which engages into the recess 25 of the first housing half 2. The collar 30 is formed by a recess 31 against the radial surface 32.

p0019<figref idrefs="f0006">FIG</figref> and <figref idrefs="f0007">7</figref> Show the inner and outer surfaces of the second housing half 3. In the outer housing half 3 approximately triangular recesses 33 are formed, while on the inside the pressure space 12 is formed by two annular recesses 34, 35 and the two recesses 34, 35 are connected to each other by an opening 36.

p0020<figref idrefs="f0008">FIG</figref> Shows in a top view and a sectional side view a seal 4, which is integrally formed with a circumferential T-shaped projection 20. After assembly, the extension 20 rests in a recess of the two housing halves. After the mounting, the existing opening 11 comes to lie centrally within the sealing ring lip 9. In order to avoid a distortion or a deformation of the seal 4, segment-like webs 41, 42 integrally formed are formed, which are adapted to the shape of the pressure spaces of the two housing halves and serve to facilitate assembly or to provide an additional seal against the housing halves 2, 3, Infusion liquid does not pass through the seal into another pressure chamber or an antechamber.

Reference list

p0021<dl id="dl0002" compact="compact"><dt>1</dt><dd>Valve arrangement</dd><dt>2</dt><dd>Housing half</dd><dt>3</dt><dd>Housing half</dd><dt>4</dt><dd>poetry</dd><dt>5</dt><dd>Supply pipe</dd><dt>6</dt><dd>Mouth pipe</dd><dt>7</dt><dd>breakthrough</dd><dt>8th</dt><dd>prechamber</dd><dt>9</dt><dd>Sealing ring lip</dd><dt>10</dt><dd>trough</dd><dt>11</dt><dd>opening</dd><dt>12</dt><dd>pressure chamber</dd><dt>13</dt><dd>Sealing ring lip</dd><dt>14</dt><dd>Discharge pipe</dd><dt>15</dt><dd>Mouth pipe</dd><dt>16</dt><dd>opening</dd><dt>17</dt><dd>trough</dd><dt>18</dt><dd>breakthrough</dd><dt>19</dt><dd>prechamber</dd><dt>20</dt><dd>approach</dd><dt>21</dt><dd>recess</dd><dt>22</dt><dd>outer surface</dd><dt>23</dt><dd>trough</dd><dt>24</dt><dd>trough</dd><dt>25</dt><dd>recess</dd><dt>26</dt><dd>collar</dd><dt>27</dt><dd>Ring neck</dd><dt>28</dt><dd>recess</dd><dt>29</dt><dd>recess</dd><dt>30</dt><dd>collar</dd><dt>31</dt><dd>return</dd><dt>32</dt><dd>radial surface</dd><dt>33</dt><dd>recess</dd><dt>34</dt><dd>recess</dd><dt>35</dt><dd>recess </dd><dt>36</dt><dd>opening</dd><dt>40</dt><dd>Connection channel</dd><dt>41</dt><dd>web</dd><dt>42</dt><dd>web</dd></dl>