Flat Profile Filter

This invention relates generally to filters for IV sets and the like for intravenous administration of fluids. More particularly, the present invention relates to a filter assembly in which a sub-micron filter element is utilized. Such filters require increased surface area in order to function with standard gravity IV sets. Large filters, however, are bulky and difficult to place near the site of injection. Moreover, in prior art filters for IV sets and the like which utilize sub-micron filter elements, air entrapment is a problem.

With the present invention, a flat profile filter is provided which lends itself to placement near the final section of IV tubing, or in other words, near the site of injection. Further, the present invention enables a much larger filter area to be used than in prior art devices, with a resultant increased flow rate. Additionally, the filter according to the present invention eliminates the problem of air entrapment, and in the present invention, incoming fluid pushes or channels the air ahead of it, pushing the air through the filter and into the housing or case, where it is easily dispersed by tapping or shaking the case or housing. Additionally, a filter in accordance with the present invention can have essentially twice the filtration area within the confines of the same size housing by simply providing a frame having both sides thereof open and sealing a filter element over each opening. Such a double filter assembly is desirable, for example, in situations where adequate flow rates cannot be obtained with a single filter, or when the volume of fluid to be infused exceeds the filtration capacity of the single filter. Further, the elongate flat housing near the injection site provides a gripping means to facilitate manipulation of a needle and the like.

Accordingly, it is an object of this invention to provide a flat profile filter for IV sets and the like whereby a substantially larger filter area can be provided in less space than is accomplished with prior art devices.

Another object of the invention is to provide a flat profile filter for IV sets and the like which lends itself to placement near the site of injection.

A still further object of the invention is to provide a filter for IV sets and the like in which air entrapment is prevented.

An even further object of the invention is to provide a filter for IV sets and the like wherein the filtration area can be doubled within the confines of the same size housing.

FIG. 1 is a perspective view, with portions broken away, of a flat profile filter in accordance with the invention.

FIG. 2 is a view in section on a reduced scale, taken along line 2--2 in FIG. 1.

FIG. 3 is a plan view of the filter supporting frame and filter according to the invention, with a portion of the housing shown in phantom lines.

FIG. 4 is a view in section taken along line 4--4 in FIG. 3, showing the filter and frame supported within the housing.

FIG. 5 is a perspective view on a reduced scale of a modified frame for double filter elements in accordance with the invention.

FIG. 6 is a view in section, with portions thereof broken away, of a filter and housing according to the modified form of the invention shown in FIG. 5.

FIG. 7 is an enlarged view in section, taken along line 7--7 in FIG. 6.

In the drawings, wherein like reference numerals indicate like parts throughout the several views, a first form of filter in accordance with the invention is indicated generally at F and comprises a frame 10 having an end wall 11 and an inlet fitting 12 projecting axially substantially from the center of the end wall 11.

The inlet fitting 12 has a bore 13 extending therethrough, and the end wall 11 has an axially forwardly facing shoulder or sealing surface 14 thereon.

The frame also includes an elongate, shallow, generally trough-shaped portion 15, having one open side 16 facing laterally thereof, and bounded by a flat, planar, peripheral filter attaching surface 17.

A filter element 18 of generally rectangular configuration is suitably secured at its peripheral edge to the peripheral surface 17 bounding the opening in the side of frame 10.

In a preferred construction, the filter element 18 comprises a sub-micron filter.

A generally rectangularly shaped housing 19 has an open end 20 thereof suitably secured and sealed to the frame at the end wall 11 thereof, and more specifically, at surface 14 on the forwardly facing portion of end wall 11, and has a tapered outlet fitting 21 on the other end thereof, such as a Luer adaptor or the like, for attachment thereto of a length of IV tubing or other device, as desired or necessary. The outlet fitting 21 has a bore 22 therethrough for flow of fluid from the housing 19.

Preferably, the frame and housing are made of Dural PVC and the frame has an overall length of approximately 2.37 inches and a width measured at the end wall 11 of about 0.75 inch and a depth or height measured at the end wall 11 of about 0.50 inch. Moreover, the filter attaching surface 17 bounds an opening having dimensions of approximately 1.6 inches by 0.375 inch. These dimensions are by way of example only, and are not to be considered limiting.

A modified filter F' is illustrated in FIGS. 5, 6 and 7, and comprises a modified frame 10' having a substantially stirrup-shaped, forwardly extending portion 23 defining two open sides bounded by filter attaching surfaces 24 and 25, respectively, and also having an end wall 11 and inlet fitting 12 as previously described.

A pair of substantially indentical filter elements 18a and 18b are secured to the respective surfaces 24 and 25, as indicated in FIG. 6, for obtaining substantially double the filtration area in the same size housing 19 as obtained with the single filter element 18 in the FIG. 2 embodiment.

In all other respects this form of the invention is substantially identical to that previously described, and the same materials and dimensions may be used in one specific example of the low profile filter.

The filter element or elements can be secured to the frame in any suitable, conventional manner, as by an adhesive or sonic weld or the like.

As this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the present embodiment is, therefore, illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the metes and bounds of the claims or that form their functional as well as conjointly cooperative equivalents are, therefore, intended to be embraced by those claims.