Patent Application
20250082225
The present invention relates to a method for allowing the filters for protecting against contamination during the passage of the air flow by the sensors in pulmonary function tests to manage the wrinkles on the mouthpieces during production.
One of the methods used during the pulmonary function tests performed with spirometers is the comparison of the flight times of the signals published and read by two reciprocally positioned transceivers, which are angled with an airway through which air flow takes place. Various spirometers operating according to this method are described in documents U.S. Pat. Nos. 5,419,326, 5,647,370, JP2013250254, US2010145213, and WO2019004966. Interchangeable mouthpieces extending along the airway are used to perform respiratory function tests between patients without contamination.
However, the closest patent application in the literature is a patent application numbered 2020/01739 and it is related to the method before this application. In the aforementioned application, the lens effect of wrinkling on the sound wave is mentioned.
During tests performed with spirometers or other pulmonary function test devices, there are windows on the wall of the airway corresponding to transceivers and acting permeably at ultrasonic frequencies so that the signals can interact with the air flow in a healthy way. During the tests, there are filters covering the windows to protect the transceivers from the risk of contamination. The filters have a structure that transmits ultrasonic signals, especially porous. The porous structure is preferably obtained by weaving micrometer-level yarns.
Woven filters can take random wrinkled forms if they are placed on a drawing material before pulling after being taken from the mold due to small changes in production conditions. These filters used on the mouthpieces of spirometers can change the air flow rate, shape, and cross- sectional area during respiratory function tests. As a result of these changes, the path traveled by the signal measuring the air flow rate in the mouthpiece may vary. When the shape/distribution of the filter wrinkle in each mouthpiece is uncontrolled, the measurements made with the mouthpieces produced in series will also differ.
In order to solve this problem, EP3403813A1 describes the tensioning of the filter by thermal processes after the production of the mouthpiece. However, the stretching process creates additional process time and cost.
The object of the present invention is to solve the problems caused by the shrinking of the filter aperture due to the shrinkage of the mouthpiece taken from the mold while cooling after the melting of the plastic raw material of a filter-containing mouthpiece that protects the transceivers from contamination.
The object of the invention is to ensure that wrinkle or corrugated characteristics of all mouthpieces produced in succession during mass production perform low deviating wrinkles without showing great differences. It is to prevent different mouthpieces from producing different measurement results or measurement errors by ensuring that all mouthpieces produced in succession during serial production show the same wrinkle characteristic in their filters. Measurement standards indicate that the measurement values taken from different mouthpieces may contain a maximum of 3% difference from each other or may measure the flowing air volume with a maximum of 50 ml error. Thanks to the support of the filters of the mouthpiece of the invention, it is aimed to double or even triple the sensitivity of these values.
The filter, which is shrunk/crumpled by the shrinking mouthpiece and placed plain at the beginning, will be positioned in the relatively smaller new aperture area by forming two basic forms. These forms are observed as follows:
The invention aims to control both the wavy wrinkled structure and the bump consisting of waves and to give repeatable results in mass production.
The figures and related descriptions used to better explain the crease-managed filter on the mouthpiece developed by this invention are as follows.
All elements that provide the wrinkle management developed by this invention are numbered to better explain the subject, and the corresponding of each number is given below.
The mouthpiece (1) of the invention is produced by pressing the plastic raw material in a female-male mold after it is brought to the melting temperature. Due to the production method and the nature of the raw material, the mouthpiece (1) shrinks, that is, pulls from all directions, depending on the temperature, cooling rate, wall thickness, and dimensions when it is taken from the mold while falling to room temperature. Filters (3) are placed on the apertures on the airway (2) of the mouthpiece (1). While the mouthpiece (1) is produced to adhere to the mouthpiece (1), the filters (3) adhere to the apertures on the airway (2) by contacting the edge points because they are larger in width and length.
Since the filters (3) themselves are cold and the melting mouthpiece raw material is hot during the joining, since the filters (3) do not shrink in the same way during the shrinking of the mouthpiece (1), wrinkle regions (6) are formed on the surface of the filter (3). These wrinkle regions (6) are formed in each production regardless of any order due to their chaotic structure. Therefore, the wrinkle region (6) pattern of the filter (3) on each mouthpiece (1) is different from each other.
The velocity of the air passing through the mouthpiece (1) is measured by means of sound waves moving in the space between the two filters (3) in the airway (2). If the wrinkle regions (6) of the filters (3) get closer to each other (forming a concave bump), the cross-sectional area in which the air moves is reduced, and otherwise (forming a convex bump) it grows. Therefore, even if the velocity of the air is the same, different measurement results can be obtained only due to the differences in the wrinkle regions (6).
By making the wrinkle region (6) predictable and reproducible, similar/slightly different wrinkles can be obtained as a result of the mass production of the whole mouthpiece. For this purpose, the filter (3) placed in the aperture will be divided by the support lines (4) produced from the same raw material as the plastic raw material used in the production of the mouthpiece (1) to control the wrinkle regions (6). Support lines (4) are formed by filling plastic raw material into gaps in different geometric shapes on the production molds so that they can be formed on the filters (3) during production.
It is expected that the support lines (4) will cool faster than the mouthpiece (1) body, depending on whether they are thick-thin, or flat-high. It is not technically possible for the support lines (4) to cool more slowly than the body of the mouthpiece (1). Since the support lines (4) showing the same or faster cooling will adhere to the filter (3), they will contribute to the formation of the wrinkle regions (6) and guide the distribution of the wrinkle regions (6) in the aperture. The support lines (4) will move by staying in the plane in a shrinking frame to ensure that they and the filter (3) do not separate from the plane where they were first placed during the shrinking of the aperture.
As explained above, the main cause of wrinkles is that the width (Xaperture) and length (Yaperture) of the filter decrease during the cooling time (Δt), and the width (Xfilter) and length (Yfilter) of the filter do not change over time despite the new width (X′aperture) and length (Y′aperture).
Δt=t2−t1
The most important object of the invention is to ensure that the placement of the said wrinkles in all wrinkle regions (6) remains the same in each production. The main cause of wrinkling is the Xfilter and Yfilter values that do not change over time (t) despite the change of Xaperture−X′aperture and Yaperture−Y′aperture values.
With the invention, it is aimed to manage the wrinkling of the filter (3) and especially not to form the bobbin. In order to prevent the wrinkle regions (6) from moving away from the aperture plane, the filter (3) will be actively crumpled in a controlled manner. To achieve this, the shape of the support lines (4) on the filter (3) will be used.
The support lines (4) are positioned to follow different angular and curvilinear paths instead of being positioned parallel to the edges of the filter (3) on the aperture. Thanks to these ways, if the width of the aperture is narrowed, it will pull the filter (3) towards it while on the other hand, it will allow the filter (3) to move away from itself. Two basic forms that enable this function to be performed are described below.
The single- or double-angle zigzag-shaped support line (4) contacts the two long sides of the filter (3) and its length, i.e. the length of the zigzag support line length (Xsupport-zigzag) is greater than the length of the width (Xfilter) between these two side surfaces.
Xsupport-zigzag>>Xfilter
The curvilinear support line (4), which is similar to the single-angle arrow shape, contacts the two long sides of the filter (3), and its length, that is, the length of the curvilinear support line (Xsupport-curvilinear), is greater than the length of the width (Xfilter) between these two edge surfaces.
Xsupport-curvilinear>>Xfilter
The length of the curvilinear support line (4) or zigzag support line (4) with a similar single-angle arrow support line (4) is between 1.01 and 1.5 times more than the width (Xfilter) of the filter (3). A support line (4) of this length contacts the two side walls of the aperture by contacting the filter (3) at 1 or 2 angles/slopes.
In the selection of filter (3) itself, a filter (3) with an open area between 10% and 50% can be used regardless of fiber thickness. In the preferred embodiment of the invention, a filter (3) with an open area between 20-25% will be used.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022/000477 | Jan 2022 | TR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/TR2022/051592 | 12/23/2022 | WO |
