STRAP MEMBER FOR A PATIENT INTERFACE

Abstract

The present invention relates to a strap member (28a-c) for use in a patient interface (10) for supplying a pressurized flow of breathable gas to an airway of a patient (12), wherein the strap member (28a-c) is configured to secure the patient interface (10) to the head of the patient (12) and comprises: —a strap portion (38) having (i) a first side (40) that is configured to contact the face of the patient (12) during use, (ii) an internal chamber forming a cavity (30), and (iii) a plurality of openings (44) which are fluidly connected to the cavity (30) and arranged at the first side (40); and —a connector (32) for fluidly connecting the cavity (30) to the pressurized flow of breathable gas supplied to the airway of the patient (12).

Claims

1. A strap member for use in a patient interface for supplying a pressurized flow of breathable gas to an airway of a patient, wherein the strap member is configured to secure the patient interface to the head of the patient and comprises: a strap portion having (i) a first side that is configured to contact the face of the patient during use, (ii) an internal chamber forming a cavity, and (iii) a plurality of openings (44) which are fluidly connected to the cavity and arranged at the first side; a flow restriction element for restricting and/or regulating an inflow of the pressurized flow of breathable gas into the cavity; and a connector for fluidly connecting the cavity to the pressurized flow of breathable gas supplied to the airway of the patient during use of the patient interface.

2. The strap member according to claim 1, wherein a second side of the strap portion opposite the first side comprises a substantially air-tight material.

3. The strap member according to claim 1, wherein the first side of the strap portion comprises a perforated material which comprises the plurality of openings.

4. The strap member according to claim 1, wherein the flow restriction element comprises a valve.

5. The strap member according to claim 4, wherein the valve is arranged at or near the connector.

6. The strap member according to claim 4, further comprising a pressure sensor for measuring a pressure within the cavity, and a controller for controlling the valve, wherein the controller is configured to control the valve depending on the pressure measured by the pressure sensor.

7. The strap member according to claim 4, further comprising a controller for controlling the valve, wherein the controller is configured to open the valve during predetermined time intervals.

8. The strap member according to claim 4, further comprising a humidity sensor for sensing a humidity at or near the first side, of the strap portion, and a controller for controlling the valve, wherein the controller is configured to control the valve depending on the humidity measured by the humidity sensor.

9. The strap member according to claim 4, further comprising a temperature sensor for sensing a temperature at or near the first side of the strap portion, and a controller for controlling the valve, wherein the controller is configured to control the valve depending on the temperature measured by the temperature sensor.

10. The strap member according to claim 1, wherein the connector comprises an inlet opening and a conical tube that is inserted into the inlet opening.

11. A patient interface for supplying a pressurized flow of breathable gas to an airway of a patient, comprising: a sealing arrangement for providing a substantially air-tight sealing connection with an airway opening of the patient; an inlet for receiving the pressurized flow of breathable gas which is fluidly connected to an interior of the sealing arrangement; and a headgear including a strap member as claimed in claim 1; wherein the interior of the sealing arrangement is fluidly connected to the cavity of the strap member by means of the connector.

12. The patient interface according to claim 11, wherein the inlet is arranged at the sealing arrangement.

13. The patient interface according to claim 11, wherein the inlet is arranged at the strap member.

14. A pressure support system comprising: a pressure generator for generating a pressurized flow of breathable gas; and a patient interface according to claim 11.

15. A strap member for use in a patient interface for supplying a pressurized flow of breathable gas to an airway of a patient, wherein the strap member is configured to secure the patient interface to the head of the patient and comprises: a strap portion having (i) a first side that is configured to contact the face of the patient during use, (ii) an internal chamber forming a cavity, and (iii) a plurality of openings which are fluidly connected to the cavity and arranged at the first side; an actuator for regulating an outflow of the pressurized flow of breathable gas through at least one of the plurality of openings out of the cavity by changing at least one of a size, a shape, a location, and a geometry of the at least one of the plurality of openings; and a connector for fluidly connecting the cavity to the pressurized flow of breathable gas supplied to the airway of the patient during use of the patient interface.

16. The strap member according to claim 15, wherein the actuator is arranged at or near the at least one of the plurality of openings.

17. The strap member according to claim 15, further comprising a pressure sensor for measuring a pressure within the cavity a, and a controller for controlling the actuator wherein the controller is configured to control the actuator depending on the pressure measured by the pressure sensor.

18. The strap member according to claim 15, further comprising a controller for controlling the actuator, wherein the controller is configured to control the actuator to change the outflow of the pressurized flow of breathable gas through the at least one of the plurality of openings during predetermined time intervals.

19. The strap member according to claim 15, further comprising a humidity sensor for sensing a humidity at or near the first side of the strap portion, and a controller for controlling the actuator, wherein the controller is configured to control the actuator to change the outflow of the pressurized flow of breathable gas through the at least one of the plurality of openings depending on the humidity measured by the humidity sensor.

20. The strap member according to claim 15, further comprising a temperature sensor for sensing a temperature at or near the first side of the strap portion, and a controller for controlling the actuator, wherein the controller is configured to control the actuator to change the outflow of the pressurized flow of breathable gas through the at least one of the plurality of openings depending on the temperature measured by the temperature sensor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0070] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter. In the following drawings

[0071] FIG. 1 shows a schematic side view of a patient wearing a patient interface according to an embodiment of the present invention;

[0072] FIG. 2 shows a detail of FIG. 1, in particular a connection between the sealing arrangement of the patient interface and the headgear;

[0073] FIG. 3 shows a schematic cross-section of a strap member according to a first embodiment of the present invention;

[0074] FIG. 4 shows a schematic cross-section of the strap member according to a second embodiment of the present invention;

[0075] FIG. 5 shows a schematic cross-section of the strap member according to a third embodiment of the present invention;

[0076] FIG. 6 shows a schematic cross-section of the strap member according to a fourth embodiment of the present invention;

[0077] FIG. 7 shows a schematic cross-section of the strap member according to a fifth embodiment of the present invention;

[0078] FIG. 8 shows a schematic block diagram illustrating the connections between possible components of the strap member according to the second and third embodiment of the present invention; and

[0079] FIG. 9 shows a schematic block diagram illustrating the connections between possible components of the strap member according to the fourth and fifth embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0080] FIG. 1 shows an exemplary embodiment of a patient interface for supplying a pressurized flow of breathable gas to an airway of a patient. The patient interface is therein in its entirety denoted by reference numeral 10.

[0081] In this embodiment the patient interface 10 is designed as a full-face mask covering the mouth and the nose of a patient 12. It shall be noted that the patient interface 10 may alternatively be designed as a nose mask, a mouth mask or as a total face mask without leaving the scope of the present invention.

[0082] The patient interface 10 is part of a pressure support system that is indicated by reference numeral 100. The pressure support system 100 comprises, besides the patient interface 10, a pressure generator 14 for generating the pressurized flow of breathable gas. This pressure generator 14 is usually arranged remote from the patient interface 10, e.g. on a desk beside the bed of the patient 12. The pressure generator 14 usually comprises a ventilator or compressor for generating the pressurized flow of breathable gas and a controller for controlling the ventilator/compressor according to a predefined pressure cycle. The pressure generator 14 may either be configured to provide a constant flow rate (e.g. CPAP) or a flow rate that is varying over time (e.g. BiPAP).

[0083] According to the embodiment shown in FIG. 1, the patient interface 10 comprises a sealing arrangement 16 for providing a substantially air-tight sealing connection with an airway of the patient 12. In the shown example, this sealing arrangement 16 surrounds the nose and the mouth of the patient 12.

[0084] The sealing arrangement 16 comprises a cushion element 18 and a mask shell 20. The cushion element 18 is designed to contact the face of the patient 12 and to provide an air-tight seal at the interface between the patient's face and the patient interface 10. The cushion element 18 usually comprises a soft material, like silicon or any other rubber or suitable elastic material. The mask shell 20 provides a flexible, semi-rigid or rigid support structure for holding the cushion element 18. The mask shell 20 is usually connected to the backside of the cushion element 18, wherein the backside is meant to denote the side of the cushion element 18 opposite the side of the cushion element 18 contacting the patient's face during use. The mask shell 20 may be either releasably or fixedly connected to the cushion element 18. The cushion element 18 and the mask shell 20 together form a cavity for receiving the mouth and/or the nose of the patient 12 (in this case the mouth and the nose of the patient 12). It shall be noted that the cushion element 18 and the mask shell 20 may be also formed as one integral piece.

[0085] On the opposite side directing away from the patient's face, the mask shell 20 is connected to a hose 22 via which the pressurized flow of breathable gas is transmitted from the pressure generator 14 to the patient interface 10. The hose 22 is connected to an inlet 24 formed within the mask shell 20, such that the inlet 24 fluidly connects the interior of the sealing arrangement 16 to the hose 22 and the pressure generator 14.

[0086] The sealing arrangement 16 is furthermore connected to a headgear 26. The headgear 26 may comprise one or more strap members 28a-28c which may be used for donning the sealing arrangement 16 to the face of the patient 12. The strap members 28a-28c may be guided around the back and/or the top of the skull of the patient 12 in order to secure the patient interface 10 to the head of the patient 12. The strap members 28a-28c are herein also denoted as headgear straps.

[0087] One of the central features of the present invention is the fluidic connection between the interior of the sealing arrangement 16 and the interior of the headgear straps 28a-28c. The headgear straps 28a-28c comprise an internal chamber forming a cavity 30 in the interior of the headgear straps 28a-28c. The pressurized flow of breathable gas may thus be guided from the interior of the sealing arrangement 16 into the cavity 30 within the interior of the headgear straps 28a-28c.

[0088] FIG. 2 shows a schematic illustration of the connection between the sealing arrangement 16 and headgear strap 28a. As illustrated therein, the headgear strap 28a comprises a connector 32 for fluidly connecting the cavity 30 to the interior of the sealing arrangement 16. In the shown example the headgear strap 28a is connected to the mask shell 20 by means of the connector 32. FIG. 2 shows one exemplary example of such a connector 32. Therein the connector 32 comprises an inlet opening 34 and a conical tube 36 that is inserted into the inlet opening 34 of the headgear strap 28a. The conical tube 36 is arranged such that the side with the smaller diameter leads into the headgear strap 28a and the side with the larger diameter is facing towards the interior of the sealing arrangement 16. This ensures a mechanically stable connection between the sealing arrangement 16 and the headgear strap 28a, since the conical tube 36 will be automatically pressed into the cavity 30 by means of the pressure occurring within the interior of the sealing arrangement 16. However, it shall be noted that other types of connectors 32 may be used without leaving the scope of the present invention.

[0089] FIG. 3 shows a schematic cross-section of a strap portion 38 of the strap member 28a. The first side 40 of the strap portion 38 is configured to contact the face of the patient 12 during use. The opposite second side 42 of the strap portion 38 is facing away from the face of the patient 12 during use and so to say builds the outer side/top side of the headgear strap 28a shown in FIG. 1.

[0090] As it may be seen in FIG. 3, the strap portion 38 comprises a plurality of openings 44 which are arranged at the first side 40. These openings 44 are preferably realized as through holes which lead into the internal chamber 30. The internal chamber 30 is thus fluidly connected to the exterior of the headgear strap 28a by means of these openings 44. The flow of breathable gas generated by the pressure generator 14 is therefore not only supplied to the interior of the sealing arrangement 16, but also into the interior 30 of the headgear 26. As indicated by arrows 46 in FIG. 3, at least a part of the flow of breathable gas, which is guided through the headgear 26, leaves the headgear 26 through the openings 44 towards the face of the patient 12. The flow of breathable gas is therefore not only supplied to the airway of the patient 12, but (at least in part) also supplied to the areas of the patient's face that are covered by the headgear 26. In other words, the generated flow of breathable gas is not only used for ventilation purposes, but also for cooling and drying the areas underneath the headgear straps 28a-28c. This helps to reduce or prevent sweat and a red mark formation underneath the headgear straps 28a-28c.

[0091] The openings 44 arranged at the first side 40 of the strap portion 38 may, for example, be realized by means of a perforated material. The second side 42 of the strap portion 38 preferably comprises an air-tight material, such that gas is leaving the internal chamber 30 of the strap portion 38 only towards the patient's face, but not towards the top side of the headgear 26.

[0092] FIG. 4 shows a schematic cross-section of the strap member 28a according to a second embodiment of the present invention. The strap member 28a therein further comprises a flow restriction element 48 for restricting and/or regulating an inflow of the pressurized flow of breathable gas into the cavity 30 of the strap portion 38. This flow restriction element 48 may comprise a valve 48′. The valve 48′ helps to regulate the amount of flow guided through the headgear 26 in order to regulate the pressure occurring within the cavity 30. The pressure within the cavity 30 is preferably controlled to be lower than the pressure occurring within the interior of the sealing arrangement 16.

[0093] The valve 48′ may be either realized as a mechanical pressure relief valve or as an electronically actuated valve. According to the embodiment shown in FIG. 4 the strap member 28a also comprises a pressure sensor 50 for measuring the pressure within the cavity 30, and a controller 52 (see FIG. 8) for controlling the valve 48′. The controller 52 is configured to control the valve 48′ depending on the pressure measured by the pressure sensor 50. This arrangement may help to regulate the amount of gas entering the cavity 30 and to keep the pressure within the cavity 30 at a fairly constant level.

[0094] The controller 52 may, for example, be configured to open the valve 48′ if the pressure measured by the pressure sensor 50 falls below a predefined minimum threshold value, and to close the valve 48′ if the pressure measured by the pressure sensor 50 rises above a predefined maximum threshold value. The pressure sensor 50 and the valve 48′ are both connected to the controller 52 (see FIG. 8). These connections may be either realized as wireless connections or as hard-wired connections. The controller 52 may, for example, be realized as a microprocessor that is either arranged at or within one of the strap members 28a-28c, the sealing arrangement 16 or remote from the patient interface 10.

[0095] A further alternative for controlling the valve 48′ is a time-dependent control. The valve 48′ may, for example, be opened during certain predefined time intervals, e.g. every 30 minutes for one minute. The controller 52 may also be configured to open the valve 48′ only during certain times of the day, e.g. only during the night only between 1 a.m. and 5 a.m. when the patient 12 is asleep. This provides the advantage that the patient 12 does not even recognize the cooling and drying action performed by the presented headgear 26.

[0096] Instead of a time-dependent control of the valve 48′, the patient interface 10 may further comprise a vital sign sensor (not shown) that is configured to measure a vital sign of the patient, such as a blood pressure, a blood pulse or blood oxygenation. Such a vital sign sensor may, for example, comprise a photoplethysmographic (PPG) sensor. Connecting such a sensor to the controller 52 would allow the detection of a sleep state of the patient 12 based upon the measured vital sign(s). The controller 52 may in this case be configured to control the valve 48′ depending on a sleep state of the patient 12, i.e. open the valve 48′ only if the patient 12 is asleep.

[0097] Still further alternatives of controlling the valve 48′, i.e. of controlling the cooling and drying action of the herein presented headgear 26, are schematically shown in FIG. 5. According to the therein shown alternative, the strap member 28a may further comprise a humidity sensor 54 and/or a temperature sensor 56 arranged at the first side 40 of the strap member 28a. These sensors 54, 56 may be also connected to the controller 52 either by means of a wireless connection or by means of a hard-wired connection. The controller 52 may be configured to control the valve 48′ depending on the humidity/temperature measured by the humidity sensor 54/temperature sensor 56. Gas may thus be supplied to the areas underneath the headgear 26 only if a certain temperature or humidity threshold value underneath the headgear 26 is exceeded. The cooling and drying action is thus only provided if really needed. Otherwise, the valve 48′ is closed and the full amount of pressure is supplied to the airway of the patient 12.

[0098] It should be clear that the pressure sensor 50, the humidity sensor 54, the temperature sensor 56 and the vital sign sensor may also be used altogether such that the controller 52 controls the valve 48′ based upon the signals of all these sensors.

[0099] In the herein shown example, the pressurized flow of breathable gas is provided directly into the interior of the sealing arrangement 16 and only indirectly into the interior of the headgear 26. Alternatively, it is however also possible to connect the pressure generator 14 directly to the interior 30 of the headgear 26, such that the pressurized flow of breathable gas first enters the headgear 26 and is then guided into the interior of the sealing arrangement 16.

[0100] FIG. 6 shows a schematic cross-section of the strap member 28a according to a fourth embodiment of the present invention. The strap member 28a therein further comprises an actuator 58 for regulating an outflow of the pressurized flow of breathable gas through at least one of the plurality of openings 44 out of the cavity 30 by changing at least one of a size, a shape, a location, and a geometry of the at least one of the plurality of openings 44. This actuator 58 helps to regulate the amount of flow guided through the openings 44 in order to cool the skin of the patient 12 underneath the headgear 26. The flow rate of the gas flow for cooling the skin of the patient 12 is preferably controlled to be lower than the flow rate of the gas flow entering the interior of the sealing arrangement 16.

[0101] The actuator 58 is preferably realized as an electronically actuated actuator and may e.g. comprise an electromechanical valve. It shall be noted that in FIGS. 6 and 7 only one actuator 58 is shown. Alternatively, the strap member 28a may comprise a plurality of such actuators 58, one for each opening 44. According to a further alternative, only one common actuator 58 may be configured to change a size, a shape, a location, and a geometry of the plurality of openings 44.

[0102] According to the embodiment shown in FIG. 6 the strap member 28a also comprises a pressure sensor 50 for measuring the pressure within the cavity 30, and a controller 52 (see FIG. 9) for controlling the actuator 58. The controller 52 is configured to control the actuator 58 depending on the pressure measured by the pressure sensor 50. This arrangement may help to regulate the amount of gas leaving the cavity 30 through the openings 44.

[0103] The controller 52 may, for example, be configured to control the actuator 58 so as to enlarge the cross-section of the corresponding opening 44 if the pressure measured by the pressure sensor 50 falls below a predefined minimum threshold value, and to reduce the size of the cross-section of the corresponding opening 44 if the pressure measured by the pressure sensor 50 rises above a predefined maximum threshold value. The pressure sensor 50 and the actuator 58 are both connected to the controller 52 (see FIG. 9). These connections may be either realized as wireless connections or as hard-wired connections.

[0104] A further alternative for controlling the actuator 58 is a time-dependent control. The opening(s) 44 may, for example, be opened by the actuator 58 during certain predefined time intervals, e.g. every 30 minutes for one minute. The controller 52 may also be configured to control the actuator 58 to open the opening(s) 44 only during certain times of the day, e.g. only during the night only between 1 a.m. and 5 a.m. when the patient 12 is asleep. This provides the advantage that the patient 12 does not even recognize the cooling and drying action performed by the presented headgear 26.

[0105] The actuator 58 may, similar as explained above for the valve 48′, also be controlled based on signals of a vital sign of the patient, such as a blood pressure, a blood pulse or blood oxygenation. Connecting such a sensor to the controller 52 would allow the detection of a sleep state of the patient 12 based upon the measured vital sign(s). The controller 52 may in this case be configured to control the actuator 58 depending on a sleep state of the patient 12.

[0106] FIG. 7 shows a schematic cross-section of the strap member 28a according to a fourth embodiment of the present invention. According to the therein shown alternative, the strap member 28a may further comprise a humidity sensor 54 and/or a temperature sensor 56 arranged at the first side 40 of the strap member 28a. These sensors 54, 56 may be also connected to the controller 52 either by means of a wireless connection or by means of a hard-wired connection. The controller 52 may be configured to control the actuator 58 depending on the humidity/temperature measured by the humidity sensor 54/temperature sensor 56. Gas may thus be supplied to the areas underneath the headgear 26 only if a certain temperature or humidity threshold value underneath the headgear 26 is exceeded. The cooling and drying action is thus only provided if really needed.

[0107] It should be clear that the pressure sensor 50, the humidity sensor 54, the temperature sensor 56 and the vital sign sensor may also be used altogether such that the controller 52 controls the actuator 58 based upon the signals of all these sensors. It shall be also clear that the embodiments including the valve 48′ (see FIGS. 4 and 5) may be combined with the embodiments including the actuator 58 (see FIGS. 6 and 7).

[0108] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

[0109] In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single element or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0110] Any reference signs in the claims should not be construed as limiting the scope.