Virus and bacteria filter with filter membrane support elements

Abstract

The invention relates to a filter (100) for filtering aerosol-bound viruses and bacteria from respiratory gases, comprising a housing with a first user-side housing shell (110) and a second machine-side housing shell (120), wherein the first housing shell (110) comprises a mouthpiece (111, 150) and the second housing shell (120) comprises a connection nozzle (121) for a medical device or measuring instrument, and a filter pad (130) arranged between the first housing shell (110) and the second housing shell (120), wherein the first or the second housing shell (110, 120) has spacer or clamping elements (140) which contact the filter pad (130), and wherein the spacer or clamping elements (140) are further configured as isolated pins (142).

Description

[0001] The invention relates to a virus and bacteria filter, in particular for lung function diagnostics, for example for filtering aerosol-bound viruses and bacteria from respiratory gases, comprising a housing with a first patient-side housing shell and a second device-side housing shell, wherein the first housing shell comprises a mouthpiece and the second housing shell comprises a connection piece for a medical device or measuring device. Furthermore, a filter membrane is inserted between the first and second housing shell.

[0002] The project involves optimizing a virus and bacteria filter, for example, for cardiopulmonary function diagnostics. Virus and bacteria filters are used in pulmonary function diagnostics, for example, to protect patients from cross-infection. For this purpose, filters are inserted between the patient and the measuring device in the respiratory flow to prevent both contamination of the device by the patient's breath and infection of the patient from contaminated device parts.

[0003] The filters used preferably consist of two plastic housing halves, between which a filter fleece is inserted, which then filters a flow of air or other gas mixture, especially the patient's exhaled air. The patient places one end of the filter in their mouth, and the other end is connected to the measuring device. Alternatively, the filter is placed between or on a hose or flow tube system of a measuring device.

[0004] The following aspects play a particularly important role in the design of the filters: - The flow resistance must be as low as possible - The filter volume must be as small as possible - Filtration of bacteria and viruses must be safe. - The virus and bacteria filter is generally a disposable product. Its material mass or volume should therefore be as small as possible to minimize costs and keep waste to a minimum. - The mouthpiece must be shaped to prevent leakage at the corners of the mouth.

[0005] According to the current state of the art, round filter discs are preferably used to achieve the largest possible fleece surface with the smallest possible filter volume. Since this flat fleece would bend at high flow velocities and press against the inner walls of the filter shells, thereby increasing flow resistance, elongated, radially extending webs are commonly incorporated into the filter housing half-shells for stabilization. However, these webs lead to an increase in material and reduce the active passage area of ​​the filter fleece.

[0006] It is therefore the object of the present invention to eliminate the disadvantages of the prior art and to provide a virus and bacteria filter which can be manufactured with reduced material consumption for the housing shells and has a reduced flow resistance.

[0007] This object is achieved by a filter according to claim 1. Advantageous embodiments are claimed in the (dependent) subclaims. A filter according to the invention for viruses and bacteria of the type described above is characterized in that the first or second housing shell has spacer or support elements that contact the filter pad, wherein the spacer or support elements extend with their respective longitudinal directions or longitudinal axes obliquely or perpendicularly to the respective inner wall surface of the housing shells.

[0008] Spacer and support elements between the housing shells generally prevent the filter membrane or filter pad from moving due to breathing resistance. The spacer and support elements also prevent the filter pad from contacting the inner walls of the housing shells, thereby reducing the free cross-section of the filter pad available for the flow of breathing air. This would otherwise lead to an undesirable increase in flow resistance.

[0009] According to an exemplary embodiment of the invention, projections in the form of needle-shaped pins, i.e., needle supports, are used as spacer or support elements. This allows for a reduction in material and cost requirements. Finally, the spacer and support projections according to the invention reduce the flow resistance of the filter compared to known elongated and web-like radially extending spacer and clamping elements.

[0010] It is advantageous if the first and second housing shells have spacer or clamping elements that contact the filter pad or filter fleece, wherein the spacer or clamping elements are designed as needles or pins. Preferably, a pin or other projection of a first housing shell is arranged coaxially or congruently with a pin or other projection of a second housing shell. This ensures that the filter pads or filter tiles are held and supported particularly stably.

[0011] To ensure cost-effective manufacturing, for example using plastic injection molding, the spacer and support projections are formed in one piece with the respective housing shell.

[0012] Optionally, some of the pins or other projections are arranged along imaginary radial lines on the inner sides of the shell. This ensures a regular arrangement of the pins and prevents movement of the filter pad or filter membrane across the entire surface.

[0013] Further details, features, feature (sub)combinations, advantages and effects based on the invention will become apparent from the following description of a preferred embodiment of the invention and the drawings. These show in Fig. 1 a perspective view of the patient-facing side of an exemplary filter housing according to the prior art, Fig. 2 a perspective view of the side of the exemplary filter housing according to the prior art associated with a measuring device or ventilator, Fig. 3 an exploded, partially perspective view of individual parts of the filter according to the prior art, Fig. 4 a first perspective view of a filter housing according to an exemplary embodiment of the invention, Fig. 5 a second perspective view of the filter housing according to the exemplary embodiment of the invention and in Fig. 6 is an exploded perspective view of individual parts of the filter according to the exemplary embodiment of the invention.

[0014] The figures are merely exemplary and serve only to clarify the invention. The same elements are designated by the same reference numerals.

[0015] The Fig. 1-3 show an exemplary embodiment of a filter 100 from the prior art. Unless explicitly stated otherwise, the features described below also apply to the embodiment according to the invention. The filter 100 has a symmetrical mouthpiece 111 with two axes of symmetry for the patient and a connection piece 121 for connection to a measuring device or a medical device (not shown). Between the mouthpiece 111 and the connection piece 121 is a filter pad 130 (see Fig. 3) is placed or can be placed, which is inserted into a filter pad holder 102 between a first flange 114 and a second flange 124. The mouthpiece 111 and the first flange 114 are part of a first or user-side housing shell 110, while the connecting piece 121 and the second flange 124 are part of a second or machine-side housing shell 120. In the variant shown, the symmetrical mouthpiece 111 has a conical extension 112 to offer the user resistance or haptic feedback in the oral cavity. In addition, for the haptic feeling, the opening of the mouthpiece 111 has an oval mouthpiece border 113. The base of the mouthpiece 111 is arranged on the first flange outer side 115. A flow channel 101 begins at the mouthpiece 111, which is available for both inhalation and exhalation. Corresponding arrows indicate the respiratory gas flows in the inhalation direction E and the exhalation direction A.

[0016] The machine-side connection piece 121 of the second housing shell 120 has, for example, a circular cross-section, i.e., the border 123 of the opening corresponds to a circular arc. The base of the connection piece 121 is arranged on the second flange outer side 125 of the second flange 124 of the housing shell 120. The flow channel 101 ends at the connection piece 121. Fig. 2 the filter pad 130 is not shown for the sake of clarity, the flange inner side 116 of the first housing shell 110 is visible through the connecting piece 121. Both the first flange inner side 116 and the second flange inner side 126 have spacers 140, which are designed and arranged as radial webs 141 (running in the radial direction). The filter pad 130 is clamped between these radial webs 141 so that it cannot rest against the flange inner sides 116, 126. The spacer and clamping elements 140 are designed as projections that are as short as possible so that the filter volume spanned by the filter holder 102 is as small as possible. The filter pad 130 is circular, i.e., formed with a circular pad geometry 132. The first and second flanges 114 and 124, respectively, are also circular and formed with a circular flange geometry.The diameter of the flanges 114, 124 is selected so that the filter pad 130 completely penetrates the flow channel 101 in the area of ​​the filter holder 102. This prevents leaks between the filter pad 130 and the housing shells 110, 120. This ensures complete filtration of the aerosols from the respiratory gases. According to . Fig. 3, the filter pad 130 is formed with a filter fleece 131 for adsorbing aerosols.

[0017] The Fig. 4-6 show an exemplary embodiment of a filter 100 according to the invention. The filter 100 has an ergonomically optimized mouthpiece 150 with a symmetry axis 156 for the patient and a connection piece 121 for connection to a measuring device or a medical device (not shown). Between the mouthpiece 150 and the connection piece 121 is a filter pad 130 (see Fig. 6) with a hexagonal cross-sectional pad geometry 133 is placed, which is inserted into a correspondingly hexagonal filter pad receptacle 102 between a hexagonal first flange 114, i.e. with a hexagonal flange geometry, and a congruent hexagonal second flange 124. The ergonomically optimized mouthpiece 150 comprises an oval-curved upper palate wall 151 for contact with the palate of the oral cavity of the user or patient. The lower wall is designed as a substantially flat wall 152 for contact with the human tongue (tongue wall). Furthermore, the tongue wall 152 has a projection 153, which itself is provided with an oval curvature 155 at a free end 155. The projection 153 is designed as an extension of the tongue wall 152 in the flow direction or parallel to the flow path 101. The oval curved border 154 of the opening of the palatal wall 151 forms a plane.This plane forms an angle α of less than 90° with the plane of the essentially flat tongue wall 152. The border 154 of the opening of the palatal wall 151 is thus inclined and lies obliquely relative to the tongue wall 152.

[0018] The appliance-side connection piece 121 of the second housing shell 120 has a circular cross-section, i.e., the border 123 of the opening corresponds to a circular arc. Both the first flange inner side 116 and the second flange inner side 126 have spacers 140, which are designed and arranged as individual pins 142. The pins 142 represent needles, which run essentially perpendicular to the flange inner sides 116, 126. The filter pad 130 is clamped between these pins 142 so that it does not lie directly against the flange inner sides 116, 126. The pins 142 reduce the flow cross-section in the filter chamber 102 significantly less than the Fig.3 according to the prior art. This reduces flow resistance. To facilitate manufacturing changes, the arrangement of the pins 142 is based on the arrangement and orientation of the radial ridge 141 according to the prior art. The filter pad 130 is designed with a hexagonal pad geometry 132 or with a hexagonal outline. The flanges 114 and 124 are also designed with hexagonal pad geometries. The side edges of the flanges 114, 124 are selected such that the filter pad 130 completely penetrates the flow channel 101 in the area of ​​the filter holder 102, thus preventing leaks. List of reference symbols 100 (virus and bacteria) filters 101 Flow channel 102 filter holder 110 patient-side / user-side or first housing shell 111 oval mouthpiece 112 conical extension 113 Mouthpiece border 114 first flange 115 first flange outside 116 first flange inside 120 machine-side or second housing shell 121 connecting pieces 123 Connection border 124 second flange 125 second flange outside 126 second flange inside 130 filter pad 131 fleece 132 Circle pad geometry 133 hexagonal or hexagonal pad geometry 140 spacers or clamping elements 141 radial webs 142 pins 150 Ergonomic mouthpiece 151 upper wall or palatal wall 152 lower wall or tongue wall 153 overhang 154 Mouthpiece border 155 free end 156 axis of symmetry A Flow direction during inhalation E Flow direction when exhaling r radial direction z axial direction α angle

Claims

[1] Virus and bacteria filter (100) in particular for lung function diagnostics, comprising - a housing with a first housing shell (110) and a second housing shell (120), - wherein the first housing shell (110) comprises a mouthpiece (111, 150) for a person, and - the second housing shell (120) comprises a connection piece (121) for a medical device or measuring device or apparatus, - a filter membrane (130) arranged between the first and second housing shells (110, 120), and - one or more spacer or support elements (140) which project from the respective inner wall of the first or second housing shell (110, 120) in such a way that they contact and hold the filter membrane, characterized bythat the spacer or support element(s) (140) are arranged and aligned such that their respective longitudinal directions or longitudinal axes run obliquely or perpendicularly to the shell inner walls. [2] Filter (100) according to claim 1, characterized by that all or at least several of the spacer or support elements (140) are designed as projections (142) in needle, peg or tenon shape. [3] Filter (100) according to one of claims 1 or 2, characterized by that at least some of the support elements (140) taper conically towards the free end or are designed with one or more cross-sectional reductions. [4] Filter (100) according to one of the preceding claims, characterized by that in at least some of the support elements (140) the free end tapers to a needle-like point. [5] Filter (100) according to one of the preceding claims, characterized bythat at least some of the support elements (140) are arranged in one or more rows which run radially with respect to the respective housing shell geometry.

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