Apparatus and system for respiratory support

Abstract

The invention relates to a device (100) and system for positive pressure ventilation (PPV) and continuous positive airway pressure (CPAP) therapy, the device comprising: a fresh gas flow inlet (2) arranged to receive a fresh gas flow from a fresh gas flow tube (22) connectable thereto; a patient interface end (3) arranged to connect with a patient interface; an outlet (4) having an open end (5); a variable flow CPAP generator (6) comprising a first, second and third connection portion (10, 11, 12), wherein the first connection portion is connected with the fresh gas flow inlet, the second connection portion is connected with the patient interface end, and the third connection portion is connected with the outlet, wherein the generated CPAP level is adjusted by varying the fresh gas flow to the variable flow CPAP generator. The device further comprises an internal leak channel (9) arranged to extend between the fresh gas flow inlet and at least one of the patient interface end and the outlet, so as to create an internal fresh gas leak flow therebetween, bypassing the first connection portion of the variable flow CPAP generator, which internal fresh gas leak flow is added to the fresh gas flow provided by the variable flow CPAP generator in PPV mode. A simplified device and system, respectively, are provided which are easy to use and allow for quick switching between PPV and CPAP therapy without the need to change equipment.

Description

TECHNICAL FIELD

[0001] The present invention relates to devices and systems for positive pressure ventilation (PPV) and continuous positive airway pressure (CPAP) treatment, for example, for neonatal resuscitation and initial respiratory support. BACKGROUND

[0002] Positive pressure ventilation (PPV) and continuous positive airway pressure (CPAP) are two types of mechanical respiratory support commonly used for resuscitation and stabilisation of neonatal infants. Which of the two respiratory support systems is used depends on whether the infant is breathing or not. PPV is used for non-breathing infants, while CPAP is used for breathing infants. Infants who do not breathe after birth should be ventilated. This can be achieved by PPV using, for example, a face mask or an endotracheal tube. In most cases, a face mask is used. If the infant starts breathing or is breathing after birth, then for several conditions, CPAP is the recommended treatment to support ventilation. After regaining spontaneous breathing, if some infants do not breathe sufficiently or stop breathing, they will still need PPV intermittently. This is particularly common when treating premature infants. Thus, both types of support are common and the need often changes during resuscitation. During both PPV and CPAP, the distending pressure helps the lungs to maintain ventilation. When PPV is provided, this is referred to as positive end-expiratory pressure (PEEP), and for this type of device, it is functionally equivalent to CPAP.

[0003] Devices and systems that can provide both positive pressure ventilation and continuous positive airway pressure are disclosed in WO 2012 / 108826. The device comprises a first fresh gas flow tube arranged to provide a first fresh gas flow, a second fresh gas flow tube, a variable flow CPAP generator, a connector connectable to any infant interface, and a pressure release valve. The variable flow CPAP generator comprises a first connection portion connected with the first fresh gas flow tube, a second connection portion connected with the infant interface connector, and a third connection portion being an outlet of the variable flow CPAP generator having an open end. The second fresh gas flow tube bypasses the variable flow CPAP generator and is arranged to provide a second fresh gas flow that is added to the first fresh gas flow in a positive pressure ventilation mode when the open end of the outlet is plugged. Thus, in the PPV mode, the pressure is increased at a higher rate than using the first fresh gas flow only, which allows for a shortened inspiratory rise time. The system can be used for non-invasive ventilation and provides lower imposed work of breathing for breathing children receiving CPAP treatment and easy switching between PPV and CPAP respiratory support without the need to change equipment.

[0004] In order for the system to function optimally, it is necessary to adjust the fresh gas flow supplied during resuscitation by using a second fresh gas flow. The addition of a second fresh gas flow in PPV mode provides an adjustable inspiratory rise time, which for example can be shortened by increasing the second fresh gas flow to the second fresh gas flow conduit. This is desirable in order to provide stable and effective ventilation. However, the application of a second fresh gas flow is not possible in all medical facilities due to, for example, a lack of output at the gas source for connecting the second fresh gas flow conduit. Further, the second fresh gas flow adds complexity to the device and can increase the risk of user error with potentially serious consequences. Thus, the use of a second fresh gas flow conduit with a second fresh gas flow is not always possible, resulting in less efficient resuscitation therapy.

[0005] Therefore, in the technical field of devices providing both PPV and CPAP, there is a need to overcome the problems that currently exist. SUMMARY

[0006] It is an object of the present invention to provide a device for PPV and CPAP therapy that alleviates the above-mentioned problems. This object is achieved by a device for PPV and CPAP therapy according to the present invention as disclosed herein.

[0007] Thus, according to an aspect of the present invention, there is provided a device for positive pressure ventilation and continuous positive airway pressure therapy, the device comprising:

[0008] - a fresh gas flow inlet arranged to receive a fresh gas flow through a fresh gas flow conduit connectable thereto;

[0009] - a patient interface end arranged to connect with a patient interface;

[0010] - an outlet having an open end;

[0011] - a variable flow CPAP generator comprising a first connection portion, a second connection portion and a third connection portion, wherein the first connection portion is connected with the fresh gas flow inlet, the second connection portion is connected with the patient interface end; and the third connection portion is connected with the outlet, wherein the generated CPAP level is adjusted by varying the fresh gas flow to the variable flow CPAP generator; and

[0012] - an internal leak channel arranged to extend between the fresh gas flow inlet and at least one of the patient interface end and the outlet, so as to create an internal fresh gas leak flow therebetween, thereby bypassing the first connection portion of the variable flow CPAP generator, the internal fresh gas leak flow being added to the fresh gas flow provided by the variable flow CPAP generator in PPV mode.

[0013] This provides a simplified device for CPAP and PPV therapy, in particular resuscitation and stabilisation intended for infants. The device is easy to use and allows for quick switching between PPV and CPAP without the need to change equipment. A safe and quick switching between these types of respiratory support will improve the care of unstable children and result in a higher resuscitation quality and a reduced mortality and morbidity. Due to the internal leak channel, the inspiratory gas flow in PPV mode is increased so that when the outlet is occluded, the internal fresh gas leak flow adds to the fresh gas flow provided by the variable flow CPAP generator, which quickly increases the pressure and generates an inspiration of the patient.

[0014] The provision of the internal leak channel simplifies the gas supply to the device, which is only required at the fresh gas flow inlet. Thus, the device requires only one single fresh gas drive flow, i.e. one single fresh gas flow inlet. This further allows to reduce the size of the device, compared to the case where two drive flows are required, which also facilitates its handling and use. A further advantage of providing only one drive flow for the device as disclosed herein is that it allows to integrate the device in both low- and high-technology ventilator equipment, requiring only one gas outlet channel for the fresh gas supply from the ventilator equipment. That is, the device can be installed in a system comprising only one gas outlet channel for the fresh gas supply. This allows to integrate the device with existing CPAP drives and ventilators without any modification of the hardware. Furthermore, another advantage is that it is simple to provide humidification of the flow to the fresh gas flow inlet, compared to a device comprising two drive flows.

[0015] The drive flow, i.e. the fresh gas flow supplied to the fresh gas flow inlet, can be set to an amount that allows for the desired CPAP to be generated by the variable flow CPAP generator. Due to the internal fresh gas leak, when the open end of the outlet of the device is occluded, the internal fresh gas leak flow is added to the fresh gas flow provided by the CPAP generator, resulting in an increase of the flow for the insufflation breath. Corresponding to the PPV mode, the flow increase resulting from the occlusion of the outlet enables a reduced pressure rise time, which is advantageous.

[0016] A range of devices can be provided, each of which is arranged to give a certain level of CPAP for a given range of supplied fresh gas flow. To achieve different levels of CPAP for a certain range of supplied fresh gas flow, the diameter of the internal leak channel can be modified between devices, thus adjusting the amount of leak generated by a particular device for a given range of supplied fresh gas flow. This allows a range of devices for CPAP and PPV therapy to be provided suitable for a range of patients from neonates to children of up to, for example, 10 kg body weight. Typically, the diameter of the internal leak channel can be between 0.5 mm and 2 mm. In an embodiment of the device, the diameter of the internal leak channel is 0.75 mm.

[0017] For the purposes of the present invention, the expressions "infant" and "child" are intended to cover patients requiring neonatal resuscitation and initial respiratory support, such as neonates and young children. These expressions are also intended to cover children up to about 10 kg body weight and toddlers. The fresh gas flow is adapted to the weight and size of the child so that a desired rise time is obtained. For the purposes of the present invention, the expression "fresh gas flow" is air, oxygen or a mixture of these gases flowing through the system and parts thereof, and the expression "fresh gas flow tube" is where the fresh gas flows.

[0018] For the purposes of the present invention, the internal fresh gas leak flow can be considered a bypass fresh gas flow in the sense that the fresh gas leak flow does not drive the variable flow CPAP generator like the fresh gas flow. That is, in a certain sense, the fresh gas leak flow bypasses the variable flow CPAP generator, at least the first connection part thereof. Thus, when used in CPAP mode, the internal fresh gas leak flow does not contribute to the generation of the CPAP level of the device, which is generated by the variable flow CPAP generator and the fresh gas flow therethrough only.

[0019] For the purposes of the present invention, the expression "variable flow CPAP generator" is intended to cover a device which is any continuous positive airway pressure device, where the CPAP level is adjusted by varying the fresh gas flow.

[0020] For the purposes of the present invention, the expression "driving flow" will be used as a synonym for the fresh gas flow provided to the fresh gas flow inlet of the device.

[0021] For the purposes of the present invention, the expression "work of breathing imposed" is the additional work required to breathe through the device and is an established way of measuring the pressure stability of the system. The work of breathing imposed can be obtained by calculating the area within the pressure-volume loop of a breath.

[0022] For the purposes of the present invention, the expression "patient interface" is intended to encompass any interface suitable for connection to a patient (e.g., an infant or a child), such as a pair of nasal prongs, a face mask, an endotracheal tube, or any other suitable device.

[0023] There are different ways to arrange the internal fresh gas leak passage in order to achieve the advantages set out above.

[0024] According to an embodiment of the device, the internal leak passage comprises a hole through the inner wall portion of the device. The inventors have surprisingly found that providing a hole through the inner wall portion such that the internal leak passage extends between the fresh gas flow inlet and one of the patient interface end and the outlet of the device for CPAP and PPV therapy, bypassing the first connection portion of the variable flow rate CPAP generator, creates an internal leak fresh gas flow which does not alter the efficiency of the variable flow rate CPAP generator, but achieves the advantages described herein.

[0025] According to an embodiment of the device, the internal leak passage extends partially through a portion of the second connection portion of the variable flow rate CPAP generator to the patient interface end of the device. In this embodiment, a hole is provided through the inner wall portion extending between the fresh gas flow inlet and the second connection portion of the variable flow rate CPAP generator. In other words, the inner wall portion separates the fresh gas flow inlet from the second connection portion. Thereby, the internal leak passage extends through at least a portion of the second connection portion and between the fresh gas flow inlet and the patient interface end.

[0026] According to an embodiment of the device, the internal leak passage extends partially through a portion of the third connection portion of the variable flow rate CPAP generator to the outlet of the device. In this embodiment, a hole is provided through the inner wall portion extending between the fresh gas flow inlet and the third connection portion of the variable flow rate CPAP generator, such that the internal leak passage, constituted by the hole and at least a portion of the third connection portion of the variable flow rate CPAP generator, extends between the fresh gas flow inlet and the outlet of the device.

[0027] According to an embodiment of the device, the device further comprises a pressure relief connection portion arranged partly in parallel with the second connection portion of the variable flow CPAP generator and having a first end connected with the patient interface end of the device and a second end connectable with the pressure relief tube, wherein the internal leak passage extends partly through the pressure relief connection portion to the patient interface end of the device. The pressure relief connection portion is substantially tubular and extends through the portion of the device between the patient interface end and the sidewall of the device, thereby forming an internal passage therethrough. The pressure relief tube is connectable with the hole through the sidewall provided by the pressure relief connection portion. In this embodiment, a hole is further provided through the inner wall portion extending between the fresh gas flow inlet and the pressure relief connection portion, thereby separating the two, so that the internal leak passage extends between the fresh gas flow inlet and the patient interface end of the device, thereby bypassing the first connection portion of the variable flow CPAP generator.

[0028] According to an embodiment of the device, the fresh gas flow supplied to the fresh gas flow inlet in the device is in the range of 5-15 litres / minute. Typically, the fresh gas flow provided is between 10-12 litres / minute. However, a fresh gas flow above 15 litres / minute can also provide therapy for larger children. The device is further configured so that this supplied fresh gas flow generates a CPAP level of 3-10 cm H2O. In a preferred embodiment, the generated CPAP level is 5-6 cm H2O.

[0029] The different embodiments of the device can be summarized as a device comprising: a fresh gas flow inlet connected to a variable flow CPAP generator which in turn is connected to a patient interface end and an outlet of the device; and an internal leak passage extending between the fresh gas flow inlet and one of the patient interface end and the outlet.

[0030] According to another aspect of the present invention, there is provided a system for PPV and CPAP therapy comprising: a device as disclosed herein; a fresh gas flow tube; a fresh gas source connected with the fresh gas flow inlet through the fresh gas flow tube; and a pressure relief valve arranged to prevent excessive positive pressure in the PPV mode. Thus, the system contains a fresh gas source and a pressure relief valve which is set to accommodate a specific opening pressure suitable for the patient to be treated.

[0031] According to embodiments of the system, the system is arranged such that when the open end of the outlet of the device is blocked, the pressure from the variable flow CPAP generator will increase until the opening pressure of the pressure relief valve is reached, the pressure increase causes an inhalation flow, and thus the pressure in the system will remain at the set PPV pressure until the blockage is removed from the outlet, and when the blocked outlet is opened, the pressure will return to the set CPAP level, whereby the pressure decrease causes an exhalation flow.

[0032] According to embodiments of the system, the system is arranged such that during spontaneous breathing, the patient flow and the fresh gas flow leave the system through the variable flow CPAP generator which keeps the positive pressure in the airway stable by changing the flow generating the CPAP, and thus the CPAP in the airway can be adjusted as needed.

[0033] According to embodiments of the system, the pressure relief valve is connected with one of the patient interface end and the outlet of the device. These are two alternative ways of arranging the pressure relief valve in the system, where the main purpose is to arrange the pressure relief valve in a position where the pressure involved can be measured in a reliable manner. Arranging the pressure relief valve in connection with the outlet of the device allows the removal of the pressure relief tube and the pressure relief connection part, thus providing a compact device and system. However, providing the pressure relief connection part and the pressure relief tube, where the pressure relief valve is arranged, is equally effective for resuscitation treatment, and can be a more familiar way of arranging the pressure relief valve for the user.

[0034] According to embodiments of the system, the system further comprises a pressure measuring device. Thereby, the operation of the system can be easily monitored and desired adjustments of the fresh gas flow can be made. Preferably, the pressure measuring device is connected in the vicinity of the patient interface end of the device. According to embodiments of the system with a device comprising a pressure relief connection part, the pressure measuring device is connected to the patient interface end through the pressure relief connection part. Naturally, the main purpose is to arrange the pressure measuring device in a position where the pressure involved can be measured in a reliable and accurate manner.

[0035] Different embodiments of the system can be summarized as a system comprising a device having a fresh gas flow inlet connected to a variable flow CPAP generator which in turn is connected to a patient interface end and an outlet of the device, and an internal leak channel extending between the fresh gas flow inlet and one of the patient interface end and the outlet. The system further comprises a fresh gas flow tube connected at one end to the fresh gas flow inlet and at the other end to a fresh gas source for supplying a fresh gas flow to the device. The system further comprises a pressure release valve connected to one of the outlet and the patient interface end of the device. Optionally, the system comprises a pressure measuring device arranged in the vicinity of the patient interface end of the device for accurately and reliably measuring the pressure there.

[0036] The device as disclosed herein can be used for PPV and CPAP treatment of neonatal resuscitation.

[0037] The system as disclosed herein can be used for PPV and CPAP treatment of neonatal resuscitation.

[0038] These and other aspects and advantages of the present invention will become apparent from the embodiments described herein after and will be elucidated with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0039] The present invention will now be described in more detail and with reference to the drawings. The drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification. Other embodiments of the present invention and many of the intended advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.

[0040] Figure 1a is a schematic cross-sectional view of an embodiment of a device according to the present invention;

[0041] Figure 1b is a schematic cross-sectional view of another embodiment of a device according to the present invention;

[0042] Figure 1c is a schematic cross-sectional view of yet another embodiment of a device according to the present invention;

[0043] Figures 2a to 2c schematically illustrates an embodiment of a system according to the present invention;

[0044] Figure 3a and Figure 3b schematically illustrates the flow of the system shown during positive pressure ventilation; Figure 2a the flow of the system shown; and Figure 4is schematically illustrated during spontaneous ventilation Figure 2a The flow in the system shown. DETAILED DESCRIPTION

[0045] Examples of different embodiments of the present invention are provided. Embodiments of the device for PPV and CPAP treatment described herein have in common that they comprise a fresh gas flow inlet 2, a patient interface end 3, an outlet 4 with an open end 5, a variable CPAP generator 6, and an internal leak passage 9. Furthermore, the variable flow CPAP generator 6 comprises a first connection portion 10, a second connection portion 11 and a third connection portion 12. In all embodiments, the fresh gas flow inlet 2 is connected with the first connection portion 10 of the variable flow CPAP generator 6; the patient interface end 3 is connected with the second connection portion 11; and the third connection portion 12 is connected with the outlet 4 of the device. The outlet 4 is typically tubular and arranged as a protruding tube end with a free open end 5. The patient interface end 3 of the device can be connected with any patient interface, such as a mask, a nasal prong or an endotracheal tube.

[0046] The first connection portion 10, the second connection portion 11 and the third connection portion 12 of the variable flow CPAP generator 6 are generally tubular. In the embodiments shown herein, the second connection portion 11 and the third connection portion 12 of the variable flow CPAP generator 6 are arranged at an angle to each other. Further, the first connection portion 10 is connected at an angle with the third connection portion 12 and arranged substantially coaxially with the second connection portion 11. This geometry of the variable flow CPAP generator 6 is advantageous because it provides a stable CPAP generated by the variable flow CPAP generator 6 and provides a lower imposed work of breathing for the patient when in use. However, it is also conceivable within the concept of the present invention that the first connection portion 10, the second connection portion 11 and the third connection portion 12 of the variable flow CPAP generator 6 are arranged with a different geometry.

[0047] The internal leak passage 9 can also be referred to as an internal bypass flow passage because in embodiments and operational modes, the internal fresh gas leak flow will bypass the first connection portion 10 of the variable CPAP generator 6 and thus not flow through there. The internal leak passage 9 can be arranged in several different positions, see Figures 1a to 1c .

[0048] Reference is made to Figure 1aAccording to the first embodiment of the device 100, the internal leak channel 9 extends between the fresh gas flow inlet 2 and the patient interface end 3 of the device 100 through an inner wall portion 13 which extends between the fresh gas flow inlet 2 and the pressure relief connection portion 14 of the device 100. The pressure relief connection portion 14 is generally tubular, forming a passage through a portion of the device 100. More particularly, the pressure relief connection portion 14 extends partially in parallel with the second connection portion 11 of the variable flow CPAP generator 6, and comprises a first end 16 and a second end 17. The first end 16 is connected with the patient interface end 3 of the device 100, and the second end 17 is connectable to the pressure relief tube 15, see Figure 2a Thus, the internal leak channel 9 extends through the inner wall portion 13 present between the fresh gas flow inlet 2 and the pressure relief connection portion 14, and further through the pressure relief connection portion 14 to the patient interface end 3 of the device 100.

[0049] As disclosed in Figure 1b , according to the second embodiment of the device 200, the internal leak channel 9 extends between the fresh gas flow inlet 2 and the outlet 4 of the device 200. In this illustrated embodiment, the internal leak channel 9 extends through an inner wall portion 18 present between the fresh gas flow inlet 2 and the third connection portion 12 of the variable flow CPAP generator 6, and further through the third connection portion 12 to the outlet 4 of the device 200. Thus, the internal leak channel 9 extends partially through the third connection portion 12 of the variable flow CPAP generator, while bypassing the first connection portion 10. This provides a compact device 200.

[0050] According to yet another embodiment of the device 250 as shown in Figure 1c , the internal leak channel 9 extends between the fresh gas flow inlet 2 and the patient interface end 3 of the device 250, partially through the second connection portion 11 of the variable flow CPAP generator 6. To this end, a portion of the internal leak channel 9 is provided as a hole through an inner wall portion 24 of the device 250 which extends between the fresh gas flow inlet 2 and the second connection portion 11 of the variable flow CPAP generator 6. Thus, another portion of the internal leak channel 9 extends through the second connection portion 11 to the patient interface end 3.

[0051] In the illustrated embodiment, the bore is substantially straight and can be, for example, an internal bore. As described in the background section of the present invention, this allows adaptation of a device previously used for CPAP and PPV therapy by providing an internal bore between the fresh gas flow inlet 2 and one of the patient interface end 3 and the outlet 4, bypassing the first connection portion 10 of the variable flow CPAP generator 6 and removing any second fresh gas flow tube. However, the skilled person will understand from the teaching of the present disclosure that it is possible within the concept of the present invention to provide an internal leak passage 9 of any other shape or extent than that described herein with reference to the illustrated embodiment, provided that it extends between the fresh gas flow inlet 2 and one of the patient interface end 3 and the outlet 4 and bypasses the first connection portion 10 of the variable flow CPAP generator 6.

[0052] As Figure 2a , Figure 3a and Figure 3b as well as Figure 4 disclosed, the first embodiment of the system 300 comprises an embodiment of the device 100 described with reference to Figure 1a . The system 300 further comprises a fresh gas source 20 providing a fresh gas flow to the fresh gas flow inlet 2 through a fresh gas flow tube 22 of the system 300. The level of CPAP is adjusted at the fresh gas source 20. The system further comprises a pressure release valve 7 and a pressure measuring device 8. See Figures 2a to 2c . The pressure release valve 7 and the pressure measuring device 8 can be arranged in several different positions. However, the pressure measuring device 8 can be omitted in any embodiment if the measured pressure is of no interest. In the illustrated embodiment Figure 2a and Figure 2b , the system further comprises a pressure release tube 15 connected to the pressure release connection portion 14. The pressure release valve 7 and the pressure measuring device 8 are here connected to the pressure release connection portion 14 through the pressure release tube 15.

[0053] As Figure 2b disclosed, the second embodiment of the system 400 comprises an embodiment of the device comprising a pressure release connection portion 14 and wherein the internal leak passage 9 extends between the fresh gas flow inlet 2 and the outlet 4 of the device. The system 400 comprises a pressure release tube 15 connected to the pressure release connection portion 14. The pressure release valve 7 is arranged at an end of the pressure release tube 15 distal to the pressure release connection portion 14. The pressure measuring device 8 is arranged at the pressure release tube 15 between the pressure release valve 7 and the pressure release connection portion 14.

[0054] As Figure 2c disclosed, the third embodiment of the system 500 comprises an embodiment of the device comprising a pressure release connection portion 14 and wherein the internal leak passage 9 extends between the fresh gas flow inlet 2 and the outlet 4 of the device. The system 500 comprises a pressure release tube 15 connected to the pressure release connection portion 14. The pressure release valve 7 is arranged at an end of the pressure release tube 15 distal to the pressure release connection portion 14. The pressure measuring device 8 is arranged at the pressure release tube 15 between the pressure release valve 7 and the pressure release connection portion 14. Figure 1bAn embodiment of the described apparatus 200 is illustrated. In this exemplary embodiment, the pressure relief valve 7 is arranged in connection with the outlet 4 of the apparatus 200. More particularly, the system 500 comprises an outlet tube 19 connected to the outlet 4 of the apparatus 200 through its open end 5. The pressure relief valve 7 is arranged along the outlet tube 19. The outlet tube 19 comprises an open end 23. Further, in this illustrated embodiment, the pressure measuring device 8 is arranged in the vicinity of the patient interface end 3 of the apparatus 200.

[0055] The system operates as follows. Reference will be made to the first embodiment of the system 300, but the second and third embodiments have corresponding operations. The oxygen concentration and fresh gas flow are adjusted by standard blenders and flow meters. The fresh gas flow can vary and is typically set to 5 to 15 litres per minute. More preferably, the fresh gas flow is set to between 10 to 12 litres per minute. The fresh gas flow in this range should prevent rebreathing, provide a gas flow to achieve sufficient inspiratory flow, volume and time, and provide some margin for leaks in the patient interface, in addition to the internal leak provided by the internal leak passage 9.

[0056] The fresh gas flow is used to drive the variable flow CPAP generator 6. However, within the apparatus, a portion of the fresh gas flow passes through the internal leak passage 9, while at least bypassing the first connection portion 10 of the variable flow CPAP generator 6. The internal bypass flow, i.e. the internal fresh gas leak flow, is used to provide sufficient flow for the positive pressure ventilation by bypassing the variable flow CPAP generator 6. The internal bypass flow is connected in such a way that when the apparatus 1 is occluded during positive pressure ventilation, the internal bypass flow is added to the inspiratory patient flow. The fresh gas flow to the variable flow CPAP generator 6 is adjustable. Typical values for the fresh gas flow provided to the fresh gas flow inlet 2 are 5-15 litres per minute. In order to provide higher levels of CPAP, the flow driving the variable flow CPAP generator 6 can be further increased. For the same size of internal leak passage 9, i.e. for the same apparatus 100, 200, the further increased driving flow generates higher than normal use CPAP levels. However, the apparatus can be provided with an internal leak passage 9 generating a larger leak, e.g. by providing an increased diameter of the internal leak passage 9, for which an increased driving flow is required to provide a certain level of CPAP. In the PPV mode, when the open end 5 of the occluded apparatus 100, 200, the larger leak and the higher driving flow cause an increased flow to be added to the fresh gas flow generated by the variable flow CPAP generator 6 and thus a faster increase in pressure.

[0057] The outlet 4 of the variable flow CPAP generator 6 has an open end 5. See Figure 2a and Figure 3aIf the open end 5 is blocked, then the pressure delivered to the infant will increase from the set pressure of the variable CPAP generator 6 until the opening pressure of the pressure relief valve 7 is reached. The typical value for the opening of the pressure relief valve 7 is about 20-30 cm H20. The pressure increase causes an inspiratory flow. The pressure in the system 300 will remain at the set positive pressure ventilation pressure until the outlet blockage is removed. See Figure 3b When the blocked open end 5 is opened, the pressure delivered to the patient will return to the set CPAP level and this pressure decrease will cause an expiratory flow.

[0058] During spontaneous breathing, the infant flow and the fresh gas flow leave the system 300 through the variable flow CPAP generator 6, see Figure 4 This keeps the positive pressure in the airway stable. By varying the flow that generates the CPAP pressure, i.e. the fresh gas flow, the CPAP pressure in the airway can be adjusted as needed.

[0059] The patient interface end 3 can be designed in any suitable form to suit connection to a patient interface. Further, the patient interface can take a variety of designs suitable to establish a connection with the patient's nasal airways (not shown). Thus, the patient interface can comprise a pair of opposing nasal prongs, a mask, an endotracheal tube, or any other suitable device.

[0060] The systems 300, 400, 500 can have a back-up system for failure of the pressure relief valve 7. This can be an alarm, a second relief valve, or a system to shut off the fresh gas flow.

[0061] The pressure measuring device 8 should be positioned as close to the patient as possible to provide an accurate record of the pressure of the gas delivered to the patient. The accuracy will depend on the flow resistance of the patient interface, and for infants, if possible, a low resistance interface should be used. Reference is made to Figure 1b Embodiments of the described device can be considered advantageous in that fewer tubes are required in the system 500.

[0062] It should be noted that the device according to the principles of the present invention can be used with a wide variety of patient interface configurations, which can or can not incorporate some or all of the features described above in connection with the patient interface. Thus, the patient interface is in no way limiting.

[0063] It should be noted that the device according to the principles of the present invention can be used with a wide variety of variable flow CPAP generators, which can or can not incorporate some or all of the features described above in connection with the variable flow CPAP generator 6. Thus, the model of the variable flow CPAP generator 6 is in no way limiting.

[0064] It should be noted that according to the principles of the present invention, the device can be used for a wide variety of pressure relief valves 7 or similar devices that serve the purpose of releasing air depending on the pressure in the system. Thus, the model or type of pressure relief valve is by no means limiting.

[0065] It should be noted that according to the principles of the present invention, the device can be used for a wide variety of pressure measuring devices 8 or similar devices that serve the purpose of measuring the pressure in the system. Thus, the model or type of pressure measuring device is by no means limiting.

[0066] Typical CPAP levels for resuscitating or stabilizing an infant are in the range of 3-10 cm H2O. Typical peak pressures for PPV are 20-30 cm H2O. This is achieved by plugging these systems and having a properly adjusted pressure relief valve.

[0067] The above embodiments of the device and system according to the present invention as defined in the appended claims have been described. These embodiments should only be seen as non-limiting examples. As will be understood by a person skilled in the art, many modifications and alternative embodiments are possible within the scope of the present invention as defined by the appended claims. For example, according to an embodiment, the device comprises several variable flow CPAP generators, each connected to the fresh gas flow inlet, the patient interface end and the outlet of the device. Together with the internal leak channel extending between the fresh gas flow inlet and at least one of the patient interface end and the outlet of the device, this allows operating the device at high fresh gas flow while maintaining a stable CPAP level in CPAP mode. Further, in PPV mode, the rise time, i.e. the time required to reach a predetermined airway pressure of the patient when the open end of the outlet is plugged, is reduced.

[0068] According to another embodiment, the device comprises several internal leak channels, each extending between the fresh gas flow inlet and one of the patient interface end and the outlet of the device. For example, the device can comprise a first internal leak channel and a second internal leak channel, wherein the first internal leak channel extends between the fresh gas flow inlet and the patient interface end and the second internal leak channel extends between the fresh gas flow inlet and the outlet of the device. Providing several internal leak channels also allows providing the device with a higher fresh gas flow while maintaining a stable CPAP level in CPAP mode and reducing the rise time in PPV mode.

[0069] It should be noted that for the purposes of this application, especially with regard to the appended claims, the word "comprising" does not exclude other elements or steps, and the word "a" or "an" does not exclude a plurality, especially with regard to the appended claims.

Claims

1. A device (100, 200, 250) for positive pressure ventilation (PPV) and continuous positive airway pressure (CPAP) therapy, the device comprising: - Fresh gas inlet (2), which is arranged to receive a fresh gas flow from a fresh gas flow pipe to which it can be connected; A patient interface terminal (3) is arranged to connect to a patient interface; -Exit (4), which has an open end (5); - A variable flow CPAP generator (6) includes a first connection portion, a second connection portion, and a third connection portion (10, 11, 12), wherein the first connection portion is connected to the fresh gas inlet, the second connection portion is connected to the patient interface end, and the third connection portion is connected to the outlet, wherein the generated CPAP level is adjusted by changing the fresh gas flow to the variable flow CPAP generator; and - An internal leakage channel (9) is arranged to extend between the fresh gas inlet and at least one of the patient interface and the outlet, so as to generate an internal fresh gas leakage flow therebetween, thereby bypassing the first connection portion of the variable flow CPAP generator, the internal fresh gas leakage flow being added to the fresh gas flow provided by the variable flow CPAP generator in PPV mode. The internal leakage channel includes a hole extending through the inner wall portion, which extends between the fresh gas inlet and one of the second connection portion, the third connection portion, and a pressure relief connection portion (14) arranged partially parallel to the second connection portion and having a first end (16) connected to the patient interface end and a second end (17) connectable to the pressure relief tube (15).

2. The apparatus (250) according to claim 1, wherein, The internal leakage channel (9) extends partially through the second connection portion (11) of the variable flow CPAP generator (6) to the patient interface end (3) of the device.

3. The apparatus (200) according to claim 1, wherein, The internal leakage channel (9) extends partially through the third connection section (12) of the variable flow CPAP generator (6) to the outlet (4) of the device.

4. The apparatus (100) according to claim 1, wherein, The internal leakage channel (9) extends partially through the pressure relief connection (14) to the patient interface end of the device.

5. The apparatus (100, 200, 250) according to any one of the preceding claims, wherein, The fresh gas flow supplied to the variable flow CPAP generator (6) is 5-15 liters / minute.

6. A system (300, 400, 500) for PPV and CPAP therapy, the system comprising: The apparatus (100, 200, 250) according to any one of claims 1 to 5; fresh gas flow tube (22); A fresh gas source (20) is connected to the fresh gas inlet (2) via the fresh gas flow pipe; and a pressure relief valve (7) is arranged to prevent excessive positive pressure in PPV mode.

7. The system (300, 400, 500) according to claim 6, wherein the system is arranged such that when the open end (5) of the outlet (4) of the device (100, 200, 250) is blocked, the pressure from the variable flow CPAP generator (6) will increase until it reaches the opening pressure of the pressure relief valve (7), the pressure increase causing an inhalation flow, thereby maintaining the pressure in the system at the set PPV pressure until the blockage is removed from the outlet, and when the blocked outlet is opened, the pressure will return to the set CPAP level, thereby reducing the pressure and causing an exhalation flow.

8. The system (300, 400, 500) according to claim 6, wherein the system is arranged such that during spontaneous breathing, the variable flow CPAP generator (6) that maintains a stable positive pressure in the airway can be exited from the system by changing the flow of CPAP generated, the infant flow and the fresh gas flow, thereby enabling the CPAP in the airway to be adjusted as needed.

9. The system (300, 400, 500) according to any one of claims 6 to 8, wherein, The pressure relief valve (7) is connected to one of the patient interface (3) and outlet (4) of the device (100, 200, 250).

10. The system (300, 400, 500) according to any one of claims 6 to 8, further comprising a pressure measuring device (8).

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