Patent ID: 12251211

FIG.1relates to the prior art and has already been described at the beginning of this description.

InFIG.2, numeral1indicates—in its entirety—a combined filter and flowmeter device, entirely disposable, which can be used to carry out spirometry analyzes in order to evaluate the respiratory function of a user. A “disposable device” means a device intended to be used only once by a single user.

In the illustrated example, the device comprises a tubular body1, which defines a passage for the airflow. The tubular body1comprises an inlet end portion2A, for engaging the user's mouth, an outlet end portion3A and an intermediate portion100, shaped like a discoidal shell, having an enlarged diameter with respect to both the inlet and outlet end portions2A,3A (the terms “inlet” and “outlet” are used here with reference to the direction of airflow in an exhalation phase of the patient).

The inlet end portion2A has a cylindrical shape, or alternatively an oval shape, like a mouthpiece, for greater user comfort. The outlet end portion3A preferably has a cylindrical shape. The ratio between the outer diameter of the discoidal shell100and the largest dimension of the section of each of the two end portions2A and3A is at least equal to 2 and preferably is at least equal to 2.5.

In all the examples illustrated in the attached drawings, the discoidal shell100has an outer cylindrical wall4and two opposite bell-shaped portions2B,3B, which connect the cylindrical wall4with the end portions2A,3A.

In all the examples illustrated in the attached drawings, the body1of the device comprises a first element of plastic material2, which includes, in one piece, the inlet end portion2A and the bell portion2B, and a second element of plastic material3, which includes, in one piece, the outlet end portion3A and the bell-shaped portion3B

Only in the example ofFIGS.2-4, the outer cylindrical wall4is defined by two additional cylindrical annular elements of plastic material4A,4B (see in particularFIG.4), interposed between the outer peripheral edges of the two bell-shaped portions2B,3B and fitted in an annular seat10of the element4B. The aforesaid elements of plastic material4A,4B are rigidly connected to each other and to the two elements2,3, for example, by means of adhesive and/or ultrasonic welding, or with any other prior art suitable for the object.

In all the examples illustrated in the attached drawings, both an antimicrobial filtering membrane5and a pressure differential generator member6, in the form of a network of plastic material, are arranged inside the discoidal shell100.

According to a per se known technique, the filtering membrane5comprises antimicrobial material, preferably antibacterial and/or antiviral material, and is preferably an electrostatic membrane, where “electrostatic membrane” means a membrane comprising a polymeric mixture capable of inducing the formation of a stable electric charge on the membrane itself.

The filtering membrane5is in the form of a substantially circular disc having a thickness preferably between 1 and 5 millimeters. It is to be understood that the filtering membrane5may be of a different shape from that represented, for example, it can have an elliptical, square, rectangular or triangular shape In general, the filtering membrane5may have any shape suitable for insertion into the discoidal shell100of the body1of the device.

As already indicated, according to the present invention, the pressure differential generator member is a network6of plastic material arranged inside the discoidal shell100together with the filtering membrane5and parallel and spaced apart with respect to the filtering membrane5.

It should be understood that the expression “pressure differential generator member” as used herein refers to a member configured in such a way as to generate, following the passage of a flow of air through it, a pressure differential between the two sides upstream and downstream of the member.

In the illustrated examples, the network6for generating the pressure differential is in the form of a substantially circular disc.

In the embodiment illustrated inFIG.4, the network6(of whichFIG.7illustrates a front view) has an outer peripheral edge clamped between the two cylindrical annular elements4A,4B, in particular at the circumferential seat10of the annular element4B. Again in the case of this embodiment, the filtering membrane5is a circular disc with an outer peripheral edge rigidly connected (for example, by adhesive or by welding, for example, ultrasonic welding) to an annular lip L, coaxial with the cylindrical wall4and protruding from the inner surface of the bell-shaped element2B.

It is understood that both embodiments wherein the network6is entirely formed by meshes, and embodiments wherein the network6is only partially formed by meshes, fall under the scope of protection defined by the present description and, therefore, also includes portions wherein the surface is continuous and not perforated.

FIG.5illustrates an embodiment not forming part of the invention, wherein the pressure differential generator member is a membrane7, having a thickness preferably less than 5 millimeters and configured with an orifice8whose opening is controlled by a flexible fin9. In particular, the flexible fin9is designed to be deformed by the passage of the airflow, thus passing from a first operating condition wherein it is completely extended on the orifice8, visible inFIG.6A, to a second operating condition wherein it is raised so as to leave the orifice8, visible inFIG.6B, at least partially open. In the embodiment illustrated inFIGS.5and6A-6B, the membrane7comprises a single orifice8. However, the membrane7may comprise more than one single orifice8. Preferably, the membrane7is of biocompatible plastic and/or steel. In the embodiment shown inFIGS.6A-6B, the flexible fin9is connected at one end9A to a portion of the edge of the orifice8formed in the membrane7. However, it is to be understood that the flexible fin9may also be formed in one piece with the membrane7.

In all the illustrated examples, a single filtering membrane5and a single pressure differential generating network6are inserted inside the discoidal shell100. However, it is to be understood that embodiments also fall within the present invention wherein more than one filtering membrane5and/or more than one network6are arranged inside the discoidal shell of the device.

In all the illustrated examples, the tubular body1has two outlets11A,11B communicating, respectively, with two chambers13A,13B defined in the cavity of the body1, respectively, upstream and downstream of the network6for generating the pressure differential.

In all the examples illustrated, the two outlets11A,11B are intended to be connected, for example, by means of flexible tubes12(seeFIG.4) with a measuring instrument of any known type (which does not form part of the present invention) capable of detecting the flow rate of the airflow passing through the device based on a measurement of the aforesaid pressure differential.

During use of all the embodiments described here, a user whose respiratory function is to be assessed by means of a spirometry analysis places his mouth around the inlet end portion2A of the device. On the advice of a healthcare professional, the user performs one or more inhalations and/or exhalations of air. In the case wherein the user exhales, the exhaled air passes from the inlet end portion2A to the discoidal shell100, and then reaches the outlet end portion3A, and is expelled into the external environment, following the path exemplified by the arrows inFIGS.4-5. When the air passes through the discoidal shell100, it first passes through the filtering membrane5, and then through the network6, thus generating a pressure drop whose measurement is indicative of the flow rate of the exhaled air. The passage through the filtering membrane5, which comprises antimicrobial material, prevents the leakage of microbes into the external environment, for example, bacteria and/or viruses, which are possibly exhaled by the user, thus protecting the external environment and healthcare personnel from exposure to these microbes. Conversely, in the event that the user performs an inhalation, the air inhaled from the external environment passes into the outlet portion3A and from there it passes into the discoidal shell100, and then reaches the inlet portion2A and is thus inhaled by the user, thus following a path that is the reverse of that illustrated by the arrows inFIGS.4-5. When the air passes through the central portion4, it first passes through the network6, thus generating the pressure differential indicative of the flow rate of the inhaled airflow, and then through the filtering membrane5. In this way, the filtering membrane5prevents the user from inhaling any microbes coming from the external environment.

In the embodiment ofFIG.5, which does not form part of the invention, the pressure differential generator member is a membrane7with an orifice8whose opening is controlled by a flexible fin9. Before the passage of the airflow, the flexible fin9is not deformed and therefore completely covers the orifice8, which is, therefore, substantially closed (FIG.6A). As the airflow passes, the flexible fin9is stressed and deforms, flexing proportionally to the flow rate. The deformation of the fin9causes an opening of the orifice8, so that the air passes therethrough, and a pressure difference is generated between the two sides upstream and downstream of the membrane7, due to the pressure drop to which the airflow is subjected to.

FIGS.8-12and13-15illustrate two preferred embodiments of the present invention. In these figures, the parts common or corresponding to those ofFIGS.2-7are indicated by the same reference numbers. In the case of both these embodiments, the body1of the device consists solely of the two elements of plastic material2,3. The elements2,3have their respective bell-shaped portions2B,3B which have their outer peripheral edges directly connected to each other, for example by adhesive and/or by welding, for example, ultrasonic welding, in such a way as to define the outer peripheral wall of the discoidal shell100.

In the embodiment ofFIGS.8-12, the network6constituting the pressure differential generator member is a circular disc with a peripheral edge clamped between the two outer peripheral edges of the two bell-shaped portions2B,3B.

FIG.11shows the detail on an enlarged scale of an embodiment example of the outer peripheral edges of the bell-shaped portions2B,3B. These outer circumferential edges define the outer cylindrical wall4of the discoidal shell100and have a series of annular lips201,202and301,302,303in mutual engagement to define a labyrinth seal in which the outer peripheral edge of the network6is clamped. The filtering membrane5, on the other hand, is rigidly connected, for example, by adhesive or by welding, to the circumferential lip L which protrudes from the inner surface of the bell-shaped portion2B.

Still with reference to the embodiment ofFIGS.8-12, the bell-shaped portion2B is conical in shape, with a radially inner portion having a lower inclination with respect to the axis X-X of the device (FIG.10), and a radially outermost portion having a greater inclination angle, preferably between 50° and 90°.

Again with reference to the embodiment ofFIGS.8-12, the bell-shaped portion3B has a conical shape with a single inclination, preferably between 50° and 90°, with respect to the axis X-X. In the case of this embodiment, moreover, the outlet end portion3A has a larger diameter than the inlet end portion2A. As already indicated, the inlet end portion2A preferably has an oval configuration (not illustrated), like a mouthpiece, for a more comfortable engagement by the user's mouth.

With reference in particular toFIGS.10and12, the inner surface of the bell-shaped portion2B is provided with radial fins2C to guide the flow inside the device, avoiding turbulence.

The radial fins2C are also configured in such a way as to keep the filtering membrane in position, preventing it from inspiratory inflecting, due to an inhalation effect.

Again with reference toFIG.10, in this example, the bell-shaped portion3B is also provided on its inner surface with an annular lip L1, coaxial with the outer cylindrical wall4of the device, which has the object of limiting communication with the passage11B.

Again with reference to the embodiment ofFIGS.8-12, the two outlet passages11A,11B are respectively defined in the bell-shaped portions2B and3B and include tubular fittings14A,14B projecting from opposite sides, in a direction parallel to the axis X-X of the device, from the two bell-shaped portions2B,3B.

The embodiment ofFIGS.13-15differs from that ofFIGS.8-12mainly due to the fact that—in this case—the outer peripheral edge of the filtering membrane5is clamped between the two outer circumferential edges of the bell-shaped portions2B,3B, while the pressure differential generating network6is rigidly connected (for example, by ultrasonic welding) to a circumferential lip L obtained on the inner surface of the bell-shaped portion3B. In this case, the two outlets11A,11B are both formed in the bell-shaped portion3B and extend through a longitudinal flattened fin15, defined by the body of the device and protruding from the outer surface of the discoidal shell.

In all the embodiment examples described above, the predisposition, as a pressure differential generator member, of a network of plastic material, inserted into the discoidal portion100wherein the filtering membrane5is also inserted, allows obtainment of an adequate but not excessive resistance to flow, and a simple and reliable detection to be made possible, due to the fact that the pressure differential generated by the network6varies substantially linearly as the flow varies. Furthermore, the inner volume of the device and the dead space inside the device are reduced to a minimum.

Thanks to the volume reduction, the flow of inhaled/exhaled air by the user makes a relatively short path and, consequently, the risk of unwanted air leaks that could negatively affect the reliability of the measurement is considerably reduced. In addition to this, the dead space, i.e. the volume of air that remains trapped in the device and which is consequently breathed in again by the user during the analysis, is also significantly reduced.

The combined antimicrobial filter and flowmeter device according to the present invention, being entirely disposable, allows healthcare personnel to operate safely and to reduce the risk of coming into contact with the user's viruses and/or bacteria.

Tests and studies carried out by the Applicant have led to identifying the need for the network of plastic material6constituting the pressure differential generator member to have a resistance to the airflow that is neither too high nor too low. Preferably, the permeability to the airflow of the network6must be between 3000 liters/sec m2and 6600 liters/sec m2.

Of course, without prejudice to the principle of the invention, the details of construction and the embodiments may vary widely with respect to those described and illustrated purely by way of example, without departing from the scope of protection of the present invention, as defined by the attached claims.