Patent Publication Number: US-2022218931-A1

Title: Mask for mechanical ventilator

Description:
This application is based upon and claims the benefit of priority from Japanese patent application No. 2019-44108, filed on Mar. 11, 2019, the disclosure of which is incorporated herein in us entirety by reference. 
     TECHNICAL FIELD 
     The present invention relates to a mask for a mechanical ventilator. 
     BACKGROUND ART 
     In the above technical field, patent literature 1 discloses a mask attachment using a bellows configured to reduce an unpleasant feeling when attaching or pain caused by compression. 
     CITATION LIST 
     Patent Literature 
     Patent literature 1: Japanese Patent Laid-Open No. 2018-102349 
     SUMMARY OF THE INVENTION 
     Technical Problem 
     However, in the technique described in the above literature, since the mask cannot sufficiently follow the skin of the user, the attaching feeling is poor. 
     The present invention enables to provide a technique of solving the above-described problem. 
     Solution to Problem 
     One example aspect of the invention provides a mask for an mechanical ventilator, comprising 
     a first opening portion that takes in inspired air from the mechanical ventilator, 
     a second opening portion that has an edge abutting against a skin of a user to send the inspired air to at least one of a nose and a mouth of the user, and 
     a bellows portion that is formed on at least a part of the edge of the second opening portion, forms a space for temporarily storing the inspired air and expired air of the user between the first opening portion and the second opening portion, and deforms following a shape of a face of the user. 
     Advantageous Effects of Invention 
     According to the present invention, it is possible to provide a mask for a mechanical ventilator, which has excellent attaching feeling. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a view showing the use state of a mask according to the first example embodiment of the present invention; 
         FIG. 2  is a view showing the shape of the bellows portion of the mask according to the first example embodiment of the present invention; 
         FIG. 3  is a view showing the shape of the bellows portion of the mask according to the first example embodiment of the present invention; 
         FIG. 4  is a view showing the configuration of the bellows portion of the mask according to the first example embodiment of the present invention; 
         FIG. 5  is a view showing the use state of a mask according to the second example embodiment of the present invention; 
         FIG. 6  is a view showing the shape of the bellows portion of the mask according to the second example embodiment of the present invention; 
         FIG. 7  is a view showing the shape of the bellows portion of the mask according to the second example embodiment of the present invention; 
         FIG. 8  is a view showing the shape of the bellows portion of the mask according to the second example embodiment of the present invention; 
         FIG. 9  is a view showing the use state of the mask according to the second example embodiment of the present invention; 
         FIG. 10  is a view showing the use state of a mask according to the third example embodiment of the present invention; 
         FIG. 11  is a view showing the use state of the mask according to the third example embodiment of the present invention; 
         FIG. 12  is a view showing the use state of a mask according to the fourth example embodiment of the present invention; 
         FIG. 13  is a view showing the use state of the mask according to the fourth example embodiment of the present invention; 
         FIG. 14  is a view showing the shape of the bellows portion of the mask according to the fourth example embodiment of the present invention; 
         FIG. 15  is a view showing an example of the mask according to the fourth example embodiment of the present invention; 
         FIG. 16  is a view showing the use state of a mask according to another example embodiment of the present invention; 
         FIG. 17  is a view showing the use state of a mask according to still other example embodiment of the present invention; and 
         FIG. 18  is a view showing the use state of a mask according to still other example embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EXAMPLE EMBODIMENTS 
     Example embodiments of the present invention will now be described in detail with reference to the drawings. It should be noted that the relative arrangement of the components, the numerical expressions and numerical values set forth in these example embodiments do not limit the scope of the present invention unless it is specifically stated otherwise. 
     First Example Embodiment 
     A mask  100  for a noninvasive mechanical ventilator according to the first example embodiment of the present invention will be described with reference to  FIG. 1 .  FIG. 1  is a view for explaining the use state of the mask  100 . 
     In general, the object of a mechanical ventilator is to support inspiration, maintain an appropriate ventilation amount of a user, reduce the work of breathing, and improve oxygenation. However since long-time attachment of the mask may cause pressure ulcers in the skin of the user, it is important to control the pressure applied to the skin. 
     Taking this into consideration, the mask  100  according to this example embodiment includes opening portions  101  and  102 , and a bellows portion  103 , as shown in  FIG. 1 . 
     The opening portion  101  opens to take inspired air from the outside and is connected to a mechanical ventilator  124  via a tube  123  or the like. Here, as the mechanical ventilator  124 , a mechanical ventilator for BIPAP (Bilevel Positive Airway Pressure), NIPPV (Noninvasive Positive Pressure Ventilation), or CPAP (Continuous Positive Airway Pressure) is shown. However, the mechanical ventilator according to the present invention is not limited to this and may be a hand pump, and a mask (BVM: Bag Valve Mask) connected to the hand pump and manually held is also included in the concept of the present invention. 
     A cover  104  provided in a gap between the edge of the periphery of the opening portion  101  and the end portion of the bellows portion is made of a transparent resin and configured such that the user&#39;s mouth (for example, the presence/absence to vomiting) can be confirmed even during attachment of the mask  100 . However, the present invention is not limited to this, and the cover  104  may be made of an opaque material. 
     The opening portion  102  is provided Placing the opening portion  101 , opens larger than the opening portion  101 , and sends the inspired air from the opening portion  101  to at least one of the nose and mouth of a user  110 . Here, the opening portion  101  and the opening portion  102  face each other. However, the present invention is not limited to this. The opening portions  101  and  102  may be formed at different angles without facing each other. The opening portion  101  may exist on the chin portion or on a portion between brows and open toward the chin. The opening portion may be provided on a base  134  or near a vertex portion  131  abutting against the nose bridge, or may be provided in the bellows portion  103 . 
     The bellows portion  103  is formed in at least a part of the edge of the opening portion  102 , forms a space to temporarily store the inspired air and expired air of the user  110  between the opening portion  101  and the opening portion  102 , contacts the skin of the face, and deforms following the shape of the face of the user  110 . The bellows portion  103  fits to the skin of the user  110  with a pressure of a predetermined value or less by its cushion property. The bellows portion  103  is preferably made of paper or a composite resin, particularly, silicone. However, the present invention is not limited to this. For example, plastic, rubber, a polymer material, an aluminum sheet, a spring material, or the like may be used. However, the materials are not limited to these, and new materials that implement this function in the future are also included. When viewed from the front of the user  110 , the bellows portion  103  includes the vertex portion  131  abutting against the nose root or the nose bridge of the user  110 , and vertex portions  132  and  133  abutting against cheeks  111 , and has a substantially isosceles triangular shape with a base  134  abutting against a chin  112 . Also, the bellows portion  103  has a height of a predetermined value (for example, 5 cm) or more from the cover  104  provided at the edge of the opening portion  101  to the opening portion  102 , and has a substantially triangular tubular shape as a whole. A sealed space is formed between the opening portion  101  and the nose and mouth of the user by the bellows portion  103  the cover  104  and the skin of the user  110 , and the inspired air from the mechanical ventilator is supplied to the nose or mouth of the user without leaking. 
     The mask  100  is pressed against the face by a belt  141  wound around the head of the user  110 , and the bellows portion  103  is moderately folded upon receiving the pressing force. In other words, the tightening force of the belt  141  is adjusted such that a pressing force that moderately folds the bellows portion  103  with a margin is generated. 
       FIGS. 2 and 3  are views for explaining the detailed shape of the bellows portion  103 . When viewed from a direction A in  FIG. 1 , in the bellows portion  103 , a plurality of short mountain folds  201  and valley folds  202  longer than the mountain folds  201  are alternately formed, as shown in  FIG. 2 . The edge closest to the opening portion  102  is preferably the mountain fold  201 . When the final surface of the bellows is folded inside, the pressure in the internal space of the bellows portion  103  becomes the force of pressing the final surface downward in  FIG. 2 . Hence, the contact pressure to the skin of the user  110  becomes higher. 
     When viewed from the side of the mouth of the user  110  in  FIG. 1 , the bellows portion  103  has bellows in which the vertex portions  131 ,  132 , and  133  are folded inside, as shown in  FIG. 3 . As a result, the cross section of the bellows portion  103  in the horizontal direction forms a hexagon. 
     The bellows portion  103  fits to the nose root or the nose bridge of the user  110  with a pressure of a predetermined value (for example, 15 mmHg) or less by its cushion property, and also fits to the cheeks of the user with a pressure of a predetermined value (for example, 4 mmHg) or less by its restoring force. 
     On the other hand, if the mask  100  is pressed against the face such that a pressure of the predetermined value or more is applied to the skin of the user  110  by tightening of the belt  141 , the bellows portion  103  deforms, and it is therefore difficult to function as a mechanical ventilator. For example, if the bellows portion  103  is excessively folded, a nose tip  113  of the user  110  abuts against the inside of the transparent cover  104  of the opening portion  101 , and the user and an operator on the periphery can very clearly know that the belt  141  is tightened too much. Also, since the bellows portion  103  constitutes the most part of the mask  100 , medical staff can easily judge, by checking how the bellows portion  103  is folded, that the belt  141  is tightened too much. 
     Also, as shown in  FIG. 4 , the outer peripheral portion of the bellows portion  103  may be colored such that “◯” can clearly be visually recognized in a state  401  in which the bellows portion  103  is expanded without being greatly folded, and “x” can clearly be visually recognized in a state  402  in which the bellows portion  103  is largely folded and contracted to a predetermined value or less. For example, when coloring of elements that form the “x” is not performed in the valley folds, “x” looks light in the expanded state, and “x” looks dark and clear in the contracted state. An example in which symbols such as “◯” and “x” are drawn has been described here. However, the present invention is not limited to this, and contact pressures (the unit if mmHg) such as “5” and “10” may be written, or characters such as “tightened too much” may he visible. Also, as these notifications, information obtained from, for example, an electronic pressure sensor may be transmitted to an electronic device by Bluetooth®. As described above, since it is possible to clearly notify that the belt  141  is tightened too much, pressure ulcers in the skin of the user can be prevented. 
     According to the above-described configuration, the bellows portion  103  having elasticity deforms following the shape of the face of the user. Hence, since the mask  100  tightly contacts skin of the user  110  with such a moderate pressure that presses skin not too much and does not cause leakage of inspired air, the attaching feeling, for the user  110  can be improved. 
     Note that m this example embodiment, the bellows portion is formed on the entire edge of the opening portion  102 . However, the present invention is not limited to this. The bellows portion need only be formed on a part of the edge of the opening portion  102 , more specifically, on one of die nose root portion, the nose bridge portion, the cheek portion, and the lower jaw portion or a combination thereof. Also, a sheet-shaped cushion material may be provided on a surface of the bellows portion, which comes into contact with the skin of the user. 
     Second Example Embodiment 
     A mask  500  according to the second example embodiment of the present invention will be described next with reference to  FIG. 5 .  FIG. 5  is a view for explaining the use state of the mask  500 . The mask  500  according to this example embodiment is different from the above-described first example embodiment in that a bellows portion  503  has a taper such that its cross section in the horizontal direction becomes narrow from the side of an opening portion  101  to the side of an opening portion  502 , in the configuration of a cover  504 , and in that a belt  541  is provided on both sides of the nose. The rest of the components and operations is the same as in the first example embodiment. Hence, the same reference numerals denote the same components and operations, and a detailed description thereof will be omitted. 
     The bellows portion  503  includes a vertex portion  531  abutting against the nose root or the nose bridge of a user  110 , and vertex portions  532  and  533  abutting against cheeks of the user  110 , and has a substantially isosceles triangular shape with a base  534  abutting against a chin  112  of the user  110 , as in  FIG. 1 . The cover  504  on the periphery of the opening portion  101  is made of a transparent resin, and deforms by the tensile force of the belts  141  and  541 . 
       FIGS. 6 to 8  are views for explaining the shape of the bellows portion  503  before attachment. When viewed from a direction C in  FIG. 5 , in the bellows portion  503 , a plurality of short mountain folds  601  and valley folds  602  longer than the mountain folds  601  are alternately formed, as shown in  FIG. 6 . In an unattached state, as shown in  FIG. 6 , the bellows portion  503  has a side surface in a substantially isosceles trapezoid shape, and the cover  504  has a flat plate shape. However, the cover  504  is not limited to this, and a shape and a material which enable elastic deformation by the tensile force of the belts  141  and  541  suffice. 
     Because of the taper, the bellows portion  503  easily bends to both the left and right sides with respect to an abutting, position  603  to the chin located on the midline of a human as the center in an attached state, and the adhesion to the cheeks increases. 
     When viewed from the side of the mouth of the user  110  in  FIG. 5 , the bellows portion  503  has a bellows in which the distance between the vertex portions  532  and  533  gradually becomes narrow, as shown in  FIG. 7 . As a result, the bellows portion  503  has a taper that is formed such that the cross section in the horizontal direction becomes narrow toward the side of the mouth of the user  110 .  FIG. 8  is a perspective view of the bellows portion  503 .  FIG. 8  shows a perspective view viewed from the side of the opening portion  502  to facilitate understanding. When the bellows portion  503  bends with respect to the abutting position  603  to the chin as the center, the vertex portions  532  and  533  readily come into tight contact with the cheeks of the user  110 . 
       FIG. 9  is a view showing the use state of the mask  500  when viewed, from the lower side (the direction C in  FIG. 5 ) of the chin  112  of the user  110 . As shown in  FIG. 9 , the base  534  of the bellows portion  503  abuts against the chin  112  and bends. Also, in  FIG. 9 , the cover  504  on the upper side of the bellows portion  503  also deforms into an arc shape projecting upward due to the tensile force of the belts  141  and  541 . Accordingly, the vertex portions  532  and  533  come into tight contact with the cheeks of the user  110 , and airtightness in the mask  500  improves, This is expected to have a great effect for a user with hollow cheeks. 
     As described above, according to this example embodiment, in addition to the first example embodiment, it is possible to improve the adhesion to the skin without losing the attaching feeling for the user, and also improve the airtightness of the mask  500  and maintain an appropriate ventilation amount of the user. 
     Third Example Embodiment 
     A mask  1000  according to the third example embodiment of the present invention will be described next with reference to  FIG. 10 .  FIG. 10  is a perspective view for explaining the use state of the mask  1000 . The mask  1000  according to this example embodiment is different from the above-described second example embodiment in that a taper is provided such that the cross section of a bellows portion  1003  in the horizontal direction becomes wide from the side of an opening portion  101  to the side of an opening portion  1002 . The rest of the components and operations is the same as in the second example embodiment. Hence, the same reference numerals denote the same components and operations, and a detailed description thereof will be omitted. 
       FIG. 11  is a view showing the use state of the mask  1000  when viewed from the lower side of a chin  112  of a user  110 . As shown in  FIG. 11 , a base  1034  of the bellows portion  1003  abuts against the chin  112  and bends. Accordingly, vertex portions  1032  and  1033  come into tight contact with cheeks  111  of the user  110 , and airtightness in the mask  1000  improves. This is expected to have a great effect for a user with bulging cheeks. 
     Fourth Example Embodiment 
     A mask  1200  according to the fourth example embodiment of the present invention will be described next with reference to  FIG. 12 .  FIG. 12  is a view for explaining the use slate of die mask  1200 . The mask  1200  according to this example embodiment is different from the above-described second example embodiment in that a reinforcing member  1231  is provided on each of a surface between a vertex portion  531  and a vertex portion  532  of a bellows portion  1203  and a surface between the vertex portion  531  and a vertex portion  533 . The rest of the components and operations is the same as in the second example embodiment. Hence, the same reference numerals denote the same components and operations, and a detailed description thereof will be omitted. 
     When the reinforcing members  1231  are provided, the elastic force (the repelling force or the force of returning to the original state) around the vertex portions  532  and  533  of the bellows portion  1203  increases, and the vertex portions  532  and  533  thus more firmly fit to cheeks  111  (for example, 4 mmHg or more). On the other hand, since the elastic force (the repelling force or the force of returning to the original state) becomes relatively small around the vertex portion  531 , it fits to the nose root or the nose bridge of a user  110  with a pressure of a predetermined value (for example, 15 mmHg) or less by its cushion property. The reinforcing members  1231  are preferably configured to be detachable. When medical staff attaches/detaches the reinforcing members in accordance with the shape of the face of the user, a mask with a high adhesion for any user can be implemented. 
     If the cheeks  111  of the user  110  are largely sunken, as shown in  FIG. 13 , a mask  1300  with additional reinforcing members  1331  may be formed.  FIG. 14  is a perspective view showing a bellows portion  1303  extracted from the mask  1300 , which is a perspective view viewed from the side of an opening portion  101 . As shown in  FIG. 14 , each of the reinforcing members  1231  and  1331  is a plate-shaped member such as a cardboard adhered in the direction from the opening portion  101  to an opening portion  502  on the outer peripheral surface of the bellows portion  1303 , and is mountain- and valley-folded along the bellows portion  1303 . 
     However, the reinforcing member  1231  is not limited to this, and can have any configuration if a has a function of changing the elastic coefficient of the bellows depending on a place. For example, a spring configured to physically expand the two ends of the bellows portion may be attached. Alternatively, a spray or a liquid coating may be applied to control the stiffness of the material. In addition, the thickness, the hardness, or the material is preferably changed depending on a part to change the elastic force of the bellows (the thickness is increased on the cheeks to increase the elastic force, and the elastic force is decreased on the nose or chin). The number of folds of the bellows portion may be changed between a. portion that hits the nose of the user and portions that hit the cheeks. For example, the number of folds of the portion that hits the nose of the user may be made smaller than the number of folds of the portions that hit the cheeks. 
     As described above, since the elastic force (the repelling force or the reproducing force) changes between the portion that hits the nose root of the user  110  and the portions that hit the cheeks, the bellows portion  1203  or  1303  can contact the nose root or the nose bridge at a relatively small pressure and contact the cheeks at a sufficient pressure. Since the nose root or the nose bridge is harder than the cheeks, pressure ulcers readily occur upon receiving the pressure from the mask. However, according to the mask  1200  or  1300  of this example embodiment, it is possible to very effectively avoid such pressure ulcers. 
       FIG. 15  shows a result of specifically conducting experiments. Pressure sensors were arranged at six points of a face  1501  of a user, the mask  1300  was attached, a mechanical ventilator was connected, and a contact pressure at each point was measured while sending oxygen (CPAP 10 cm H2O, Leak 40 L/min). The result is shown in a table  1502 . The minimum value of the contact pressure was 4.5 mmHg, and the maximum value was 8 mmHg. The standard deviation was 1.5. As compared to a conventional product (Vivo50 available from Breas was used as an mechanical ventilator, and Simplus Masks available from Fisher &amp; Paykel was used as a mask), both the maximum value of the contact pressure and the standard deviation are ½ or less, and the mask contacts the skin at a suitable and even contact pressure, as can be seen. That is, the numerical values show that according to this example embodiment, the attaching feeling for the user improves. 
     Other Example Embodiments 
     Masks  1600 ,  1700 , and  1800  according to other example embodiments of the present invention will be described with reference to  FIGS. 16 to 18 .  FIGS. 16, 17, and 18  are views for explaining the use states of the masks  1600 ,  1700 , and  1800 . 
     The mask  1600  is different from the above-described example embodiments in that when viewed from the from of a user  110 , a bellows portion  1603  has a circular shape having, as a diameter, a line that connects a portion  1631  abutting against the nose root or the nose bridge of the user  110  and a portion  1632  abutting against a chin  112 . The rest of the components and operations is the same as in the second example embodiment. Hence, the same reference numerals denote the same components and operations, and a detailed description thereof will be omitted. 
     The mask  1700  is different from the above-described example embodiments in that when viewed from the front of a user  110 , a bellows portion  1703  has an elliptical shape having, as a long axis, a line that connects a portion  1731  abutting against the nose root or the nose bridge of the user  110  and a portion  1732  abutting against a chin  112 . The rest of the components and operations is the same as in the second example embodiment. Hence, the same reference numerals denote the same components and operations, and a detailed description thereof will be omitted. 
     The mask  1800  is different from the above-described example embodiments in that when viewed from the front of a user  110 , a bellows portion  1803  has a rhombic shape having, as a diagonal line, a line that connects a portion  1831  abutting against the nose root or the nose bridge of the user  110  and a portion  1832  abutting against a chin  112 . The rest of the components and operations is the same as in the second example embodiment. Hence, the same reference numerals denote the same components and operations, and a detailed description thereof will be omitted. 
     In addition, the bellows portion of the mask  1800  may have a rounded isosceles triangular shape, an equilateral triangular shape, a trapezoidal shape, a pentagonal shape, a hexagonal shape, other polygonal shapes, or a teardrop shape, or a combination thereof when viewed from the front of the user. 
     Other Example Embodiments 
     While the invention has been particularly shown and described with reference to example embodiments thereof, the invention is not limited to these example embodiments. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the claims. A system or apparatus including any combination of the individual features included in the respective example embodiments may be incorporated in the scope of the present invention.