Filter for infusion medical lines

A filter for infusion medical lines including a flattened box-like body provided inside which is a plate-shaped element formed on whose one or both of the opposite faces are respective ribs defining inner channels. Arranged on the ribs are respective filtering hydrophilic membranes which separate the channels from respective interspaces delimited by a pair of half-shells. The interspaces are placed in communication with the inlet connector, the channels are placed in communication with the outlet fitting and the interspaces are placed in communication with the outside through vent openings arranged on the end walls of the box-like body.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national stage filing under section 371 of International Application No. PCT/IB2019/052079, filed on Mar. 14, 2019, published in English on Nov. 14, 2019 as WO2019/215516A1 and which claims priority to Italian Application No. 102018000005165, filed on May 8, 2018, the entire disclosure of these applications being hereby incorporated herein by reference.

FIELD OF THE INVENTION

The present invention regards a filter for infusion medical lines and more in particular an IV filter.

Filters thus made conventionally comprise a flattened box-like body having a first end wall and a second end wall, a pair of greater lateral walls, and a pair of smaller lateral walls. Such filters are provided with an inlet connector for a liquid to be filtered and an outlet connector for the filtered liquid at the one and the other end wall. Arranged in the box-like body is a plate-shaped element formed on whose at least one of the opposite faces is a plurality of ribs defining parallel channels. Arranged on the or on each plurality of ribs is a respective filtering hydrophilic membrane which separates the channels from one or from respective interspaces delimited by the two greater walls. The or each interspace is placed in communication with the inlet connector and the channels are placed in communication with the outlet connector. Furthermore, the or each interspace is placed in communication with the external by means of openings with associated hydrophobic membranes for deaerating the liquid.

STATE OF THE PRIOR ART

Documents EP-1208857, EP-1421960, U.S. Pat. Nos. 4,525,182 and 5,439,587 disclose filters thus made, wherein the deaeration openings provided with hydrophobic membranes are provided on the pair of greater lateral walls of the box-like body. Such positioning of the deaeration openings entails the drawback that they can be inadvertently occluded when handling the filter, or they can be unintentionally obstructed by objects present in proximity of the place of use of the filter, with the unacceptable risk of the liquid not being deaerated effectively.

Document WO 95/28215 describes a medical filter with multiple compartment comprising one or more vents each provided with a porous membrane for separating the air from the liquid. The vents are arranged at the ends of the box-like body but they are oriented perpendicularly to the greater faces of the filter, i.e. they terminate thereon, revealing the same drawbacks described above.

Document CN 104083819 describes a filter for medical lines having vent holes with respective membranes arranged in an end wall of the filter in proximity of the outlet connector for the liquid. The vent holes are placed in communication with a chamber designed to collect the liquid after it has been filtered by the hydrophilic membrane. The air venting is thus carried out only after filtering the liquid and it could be incomplete, in particular if the filter is used in a vertical position.

SUMMARY OF THE INVENTION

The object of the present invention is to overcome the aforementioned drawback.

With the aim of achieving such object, the invention regards a filter for infusion medical lines of the type defined in the preamble of claim1whose primary characteristic lies in the fact that the deaeration openings are provided on the end walls of the box-like body and so that—in use—the infusion liquid initially touches at least one of said hydrophobic membranes and subsequently touches and flows through said at least one hydrophilic membrane.

The hydrophobic membranes are arranged at the ends of the greater lateral walls of the plate-shaped element at respective transverse manifolds which are in turn placed in communication with the deaeration openings.

The inlet and outlet connectors for the liquid are conveniently coaxial so that—in use—torsional moments are not generated in the inflow and outflow tubes of the medical liquid.

The inlet and outlet connectors for the liquid can be designed for tube-tube or luer-tube or tube-luer or luer-luer connections of said medical line.

The or each filtering hydrophilic membrane can also be obtained as a single piece with the respective hydrophobic membranes.

The invention also regards a method for filtering and deaerating an infusion liquid for medical lines which provides for the use of a filter as claimed herein.

DETAINED DESCRIPTION OF THE INVENTION

Initially with reference toFIGS.1-3, the infusion filter according to the invention is indicated in its entirety with1.

It comprises a flattened box-like body2formed by a pair of half-shells5,6. The box-like body2comprises a first and second end wall3,4, a pair of greater lateral walls25,26, and a pair of smaller lateral walls7,8. Arranged at the first end wall3is an inlet connector9of a liquid to be filtered and arranged at the second end wall4is an outlet connector10for the filtered liquid. A first vent opening, in the form of a hole11a, is provided for on the first end wall3in proximity of the inlet connector9and a second vent opening, in the form of a hole11b, is provided on the second end wall4in proximity of the outlet connector10.

Visible in the partial section ofFIG.2is a duct12which connects the hole11awith the internal of the box-like body2. A similar duct not visible in the drawings connects the hole11bwith the internal of the box-like body2.

Now, with reference toFIGS.4to8a plate-shaped element in the half-shells5,6formed on whose opposite faces are respective pluralities of ribs14which define channels15extending longitudinally between the connectors9,10is indicated with13. Provided in proximity of the ends of the channels15of each face and perpendicularly thereto are transverse manifolds22. The opposite manifolds22of each end of the plate-shaped element13are placed in communication with each other by means of respective passages of the plate-shaped element13, one of which is indicated with27inFIG.7, and furthermore they are placed in communication respectively with the vent hole11aand with the vent hole11b. Resting on each face of the plate-shaped element13is a respective hydrophilic membrane16which is welded to the plate-shaped element13. Two pairs of hydrophobic membranes24are arranged above the four manifolds22and for example fixed by means of welding. The two pairs of hydrophobic membranes24can also be integrated and obtained as a single piece respectively with the one and with the other hydrophilic membrane16.

The plate-shaped element13has a projecting perimeter edge17which is coupled with respective annular lips18of the half-shells5,6.

The inlet9and outlet10connectors for the liquid are coaxial to each other, are integrally joined to the plate-shaped element13and they can be configured for the tube-tube or luer-tube or tube-luer or luer-luer connections of the medical line.

FIGS.5-8show two interspaces23,23coplanar to the faces of the plate-shaped element13, separated by it by means of the respective hydrophilic membranes16,16and each externally delimited by the respective half-shell5,6. A passage19(FIG.5), provided on the plate-shaped element13at the end of the inlet connector9places both the interspaces23,23in communication with such connector9.

Referring more in detail withFIG.6, a passage21of the plate-shaped element13places the outlet connector10in communication with the plurality of channels15.

As clear from the above, the filter1according to the invention has a configuration that is compact and small in size.

During use, the infusion liquid—through the inlet connector9and the passage19—enters into the interspaces23,23initially touching the proximal hydrophobic membranes24,24which allow the air trapped in the liquid to flow out into the respective manifolds22before being dispersed outside the filter1through the duct12and the hole11a.

Subsequently, the fluid touches and flows through the filtering hydrophilic membrane16,16so as to be conveyed from the channels15towards the passage21and flow out through the outlet connector10.

The filter1according to the invention is normally used in a vertical portion of an infusion line, i.e. it is oriented so that the inlet connector9is positioned at the upper part with respect to the outlet connector10. After touching the proximal hydrophobic membranes24, should the liquid still contain air, for example due to the orientation of use different from the one described previously, the residual air can flow out through the distal membranes24and the respective manifolds22connected to the hole11b.

The arrangement of the hydrophobic membranes24upstream and downstream of the flow in the interspaces23of the filter1reveals the further advantage lying in the fact that, in particular during the priming, the air contained in the liquid accumulates in the end areas of the filter1so as not to occlude part of the filtering surfaces; in this manner, the air has more time to flow out with respect to the known solutions described previously.

Obviously, the construction details and the embodiments may widely vary with respect to what has been described and illustrated, without departing from the scope of protection of the present invention as defined in the claims that follow. Thus, for example, the filter could generally have a different shape with respect to the one represented in the drawings and it could also be provided with a single filtering hydrophilic membrane16arranged on ribs14formed on only one of the faces of the plate-shaped element13.