JP4710015B2 - Nasal CPAP element - Google Patents

Description

  The present invention relates to nasal CPAP, and more particularly to a nasal CPAP element suitable for use in premature infants. In recent years, Nasal CPAP (Continuous Positive Airway Pressure) is being used for respiratory assistance or treatment of respiratory disorders in premature infants. CPAP maintains positive airway pressure at the end of the expiratory phase, prevents alveolar collapse in the expiratory phase, increases functional residual capacity, reduces intrapulmonary shunt, and improves hypoxemia To do. What applies positive pressure to the nostrils is called Nasal CPAP.

JP 2004-321549 A.

  The advantages of nasal CPAP are: (1) CPAP can be easily applied without the need for endotracheal intubation, (2) Airway infection associated with endotracheal intubation can be reduced because there is no airway resistance of the intubation tube The ability to avoid illness.

  However, on the other hand, (1) There is a possibility of developing nasal stenosis and nasal septal necrosis due to strong pressure on the nostril of the nostril attachment part. (2) It is difficult to fix and difficult to maintain sufficient CPAP due to leakage. (3) Since positive pressure is also applied to the esophagus, there is a point that should be improved such that the intestinal tract may be dilated and it may be difficult to enter nutrients.

  In order to cope with this, there is an application of hydrodynamic principles that responds sensitively to fine spontaneous breathing, provides stable airway pressure, and eliminates in-circuit resistance during expiration. . For example, there is what is called an infant flow system. In the infant flow system, since the instability of the impinging jet flow to the nostril is utilized, the basic shape of the element is a shape that opposes the nostril, and the air supply pipe and the exhalation discharge pipe are placed from the nose to the forehead. It must be hung and worn across the face vertically. Therefore, the method for fixing this becomes complicated, particularly when used for premature babies, which places a great burden on wearing, and may cause nasal stenosis or nasal septal necrosis of the patient when nasal CPAP is performed for a long time. There was still a point to be improved.

  The above-mentioned patent document 1 provides a small and horizontal nasal CPAP element that can reduce the burden of mounting an element on a newborn baby (for example, a premature baby) during nasal CPAP. One conventional example of this type is shown in FIG. The nasal CPAP element 1 shown in FIG. 5 has a jet channel 4 between the jet nozzle 3 for jetting air and the jet nozzle 3, and the tip is at a position facing the air jet of the jet nozzle 3. A jet branch plate 5 that extends in the direction in which the air jet flows and divides the air jet into first and second jets 5, a first branch passage 7 into which the first jet flows in, and a cavity 9 and a second jet that flow into the first branch passage 7 flow in. The second branch path 8 and the exhaust port 13 continuing to the second branch path 8 and the nasal prong ports 10 and 11 continuing to the cavity 9 and communicating with the nasal prongs (not shown) are provided.

  Air is supplied to the air supply pipe connection port 15 at a substantially constant pressure. This air enters the nozzle 3 from the air supply pipe connection port 15 through the jet port 2, and the air jet flowing out from the nozzle 3 moves along the jet flow path 4 at the knife edge at the tip of the jet branch plate 5, and the first jet flow. The second jet is divided into two, and the first jet enters the cavity 9 through the first branch 7 which is a cavity port, and turns clockwise along the wall surface. Thereby, a positive pressure (CPAP: Continuous Positive Airway Pressure) is applied to the cavity 9. The second jet flows through the exhaust port 13 through the second branch path 8 which is an excess air flow path, and flows out from the exhaust pipe connection port 18 to the outside. The nasal prong ports 10 and 11 that are coaxial and continuous with the connection ports 16 and 17 to which the nasal prongs (the bifurcated tube member coupled to the nostril; for example, 12 in FIG. 1) are attached, nozzles their axes. 3 is open to the cavity 9 in parallel to the y direction perpendicular to the axis 3 (x direction). That is, it communicates.

  When inspiratory pressure is applied to the nasal prong ports 10 and 11 by spontaneous breathing of a newborn baby (for example, a premature baby), the air in the cavity 9 is drawn to the ports 10 and 11. The air flow rate of the first jet flow into the cavity 9 increases. This helps the newborn's inspiration. When the expiratory pressure is applied to the ports 10 and 11, the pressure of the cavity 9 increases, thereby increasing the air flow rate of the second jet from the nozzle 3 to the exhaust port 13, and the air flow rate of the first jet from the nozzle 3 to the cavity 9. Decreases. This facilitates exhalation of the newborn. In this way, a breathing assistance operation, that is, an amplification operation is performed on the spontaneous breathing.

  In addition, the air supply pipe connected to the intake pipe connection port 15 and the exhaust pipe connected to the exhaust pipe connection port 18 are arranged in the same direction x, and the nasal prongs coupled to the connection ports 16 and 17 are included in these. On the other hand, since these tubes are arranged in the vertical direction y, as shown in FIG. 4, for example, these tubes can be worn across the face of the patient, thereby reducing the burden of wearing.

  By the way, in order to stabilize the positive pressure (CPAP) of the cavity 9 and to stabilize the respiration assisting operation that responds to the spontaneous breathing, that is, the amplification of the spontaneous breathing pressure by the fluid control element, and to increase the reliability, the jet of the nozzle is changed. The power is preferably set to a certain level or more, and the stagnation pressure (positive pressure) of the cavity 9 is preferably about 500 Pa (pascal). However, if it does so, the pulmonary pressure fluctuation by respiration assistance may become 300-400 Pa, and it is thought that it may become excessive for premature infants.

  An object of the present invention is to maintain a breathing assistance operation that responds to spontaneous breathing in a stable and highly reliable manner, and to reduce lung pressure fluctuation due to breathing assistance to an appropriate range.

(1) A jet nozzle (3) for jetting air; a jet channel (4) is provided between the nozzle and the jet nozzle (3), and the tip is at a position facing the air jet of the jet nozzle (3). A jet branch plate (5a, 5b) extending in the flow direction of the air jet and dividing the air jet into first and second jets; a first branch path (7) into which the first jet flows and a cavity ( 9); a second branch (8) into which the second jet flows and an exhaust port (13) continuous therewith; and a nasal prong port (10) connected to the cavity (9) and connected to the nasal prong (12) , 11); in a nasal CPAP element (1) comprising:
A bypass (6) allowing air flow between the cavity (9) and the second branch (8) is provided at the rear of the tip of the jet branch plate (5a, 5b). A nasal CPAP element (FIG. 1).

(2) Jet nozzle (3) that ejects air;
A jet channel (4) is provided between the jet nozzle (3) and a tip is located at a position facing the air jet of the jet nozzle (3), and the air jet is divided into first and second jets. Wedge to do (5a);
A separation part (5b) that is downstream of the wedge (5a) with respect to the flow direction of the air jet and extends in the flow direction of the air jet;
A first branch (7) into which the first jet flows and a cavity (9) continuous therewith;
A second branch (8) into which the second jet flows and an exhaust port (13) continuous therewith;
A nasal prong port (10, 11) continuous with the cavity (9) to which a nasal prong (12) is coupled; and
A bypass (6) between the wedge (5a) and the separator (5b);
The cavity (9) and the second branch path (8) are separated by the separation part (5b), and the bypass (6) is provided between the cavity (9) and the second branch path (8). Allow air flow;
Nasal CPAP element (FIG. 1).

  In addition, in order to make an understanding easy, the code | symbol of the corresponding element or the corresponding matter of the Example which is shown in drawing and mentions later in a parenthesis was added as an example for reference. The same applies to the following.

  According to the nasal CPAP elements (1) and (2) above (FIG. 1), when inspiratory pressure is applied to the nasal prong port (10, 11) by spontaneous breathing of a newborn (for example, premature infant), the cavity (9 ) Is drawn to the nasal prong port (10, 11), the pressure of the cavity (9) is lowered, and the air flow rate from the jet nozzle (3) to the cavity (9) is increased. This assists (assums) the inspiration of the newborn. When expiratory air pressure is applied to the nasal prong ports (10, 11), the pressure in the cavity (9) increases, thereby increasing the air flow rate from the jet nozzle (3) to the exhaust port (13), and from the jet nozzle (3). The air flow rate to the cavity (9) decreases. This facilitates exhalation of the newborn. In this way, a breathing assistance operation is performed for spontaneous breathing.

  Since a bypass (6) allowing air flow between the cavity (9) and the second branch (8) is provided at the rear of the tip of the jet branch plate (5a, 5b), the bypass (6 ) Always flows from the cavity (9) to the second branch (8). This bypass (6) relieves pressure fluctuations in the cavity (9) accompanying breathing. That is, during the intake period, when the pressure of the cavity (9) decreases due to the intake air, the flow rate of air flowing from the cavity (9) to the second branch (8) through the bypass (6) decreases, and the pressure of the cavity (9) is reduced. When the pressure of the cavity (9) increases due to exhalation during the exhalation period, the flow rate of air flowing from the cavity (9) to the second branch (8) through the bypass (6) increases and the cavity (9 ) Pressure increase is small. That is, the fluctuation in lung pressure due to respiratory assistance is reduced. For example, when the stagnation pressure (positive pressure) of the cavity 9 is set to about 500 Pa (pascal), the lung pressure fluctuation due to respiratory assistance can be set to 100 to 150 Pa, and optimal respiratory assistance can be performed for premature infants.

  (3) An air supply port (2, 15) communicating with the jet nozzle (3) is provided upstream of the jet nozzle (3) with respect to the air jet, and the exhaust port (13) is provided downstream. The nasal CPAP element according to claim 1 or 2, wherein the central axis of the nasal prong port (10, 11) extends in a direction (y) perpendicular to the nozzle axis (x) of the jet nozzle (3); ).

  According to this, the air supply pipe (21) connected to the air supply pipe connection port (15) and the exhaust pipe (24) connected to the exhaust pipe connection port (18) are arranged in the same direction x, and The nasal prongs (12) to which the nasal prong ports (10, 11) are coupled are arranged in a direction y perpendicular to the air supply pipe (21) and the exhaust pipe (24), so that these pipes are shown in FIG. As shown in FIG. 4, it becomes possible to wear the patient's face across the side, thereby reducing the wearing burden.

  Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

  In FIG. 1, the longitudinal cross-section of the nasal CPAP element 1 of one Example of this invention is shown. This drawing shows an element cross section in an enlarged manner than the actual one. Nasal CPAP element 1 is made of synthetic resin. The nasal prong 12 made of flexible resin has two flexible tubes that are inserted into the nostrils of the newborn and project outward in the y direction. FIG. 4 shows the appearance of the element 1 attached to a newborn.

  Similar to the conventional example (FIG. 5), the nasal CPAP element 1 has a jet flow path 4 between the jet nozzle 3 for jetting air and the jet nozzle 3, and the tip is the air jet of the jet nozzle 3. The jet branch plates 5a and 5b that divide the air jet into the first and second jets, the first branch passage 7 into which the first jet flows, and the continuation thereof, extend in the direction in which the air jet flows in the opposing positions. There are a cavity 9, a second branch passage 8 into which the second jet flows and an exhaust port 13 continuous therewith, and a nasal prong port 10, 11 connected to the cavity 9 and communicating with the nasal prong 12. In addition to these, a bypass 6 that divides the knife edge portion 5a at the tip of the jet branch plates 5a and 5b is opened in the jet branch plate.

  In other words, the jet flow path 4 is provided between the nozzle 3 and the wedge 5a that divides the air jet into the first and second jets at the position where the tip is opposed to the air jet of the nozzle 3, the air jet And a bypass 6 between the wedge 5a and the separation portion 5b. The separation portion 5b is downstream of the wedge 5a and extends in the direction of the air jet flow. The cavity 9 and the second branch path 8 are separated by the separation portion 5 b, and the bypass 6 allows air to flow between the cavity 9 and the second branch path 8.

  A jet port 2 is continuous with the nozzle 3, and an air supply pipe connection port 15 (FIG. 2) is continuous with the jet port 2. An air supply base 22 is attached to the air supply pipe connection port 15, and an air supply tube 21 is connected to the air supply base 22. Constant pressure air is supplied to the air supply tube 21 from an air supply device (not shown). A throttle 14 is inserted into the exhaust port 13, an exhaust base 23 is attached to an exhaust pipe connection port 18 (FIG. 2) continuous with the exhaust port 13, and an exhaust tube 24 is connected to the exhaust base 23. In order to stabilize the positive pressure of the cavity 9 to a desired constant pressure (for example, an average pressure of 500 Pa), the throttle 14 has a delivery pressure specification of an air supply device (not shown) that sends constant pressure air to the jet port 2 through the air supply tube 21. In addition, the flow resistance of the exhaust port 13 is adjusted (set). When only an air supply device having a required delivery pressure specification is used, or when adjustment (setting) with high reliability is possible in the air supply device, the throttle 14 is omitted and the exhaust port 13 is connected to the required flow rate. Design and place in road resistance.

  Nasal prong connection ports 16 and 17 (FIG. 2) are connected to the nasal prong ports 10 and 11, and the nasal prong 12 is attached to these connection ports 16 and 17. Two flexible tubes inserted in the nostril of the newborn of the nasal prong 12 and projecting outward in the y direction communicate with the cavity 9.

  When the nasal CPAP element 1 shown in FIG. 1 is used and the two flexible tubes of the nasal prong 12 projecting outward in the y direction are inserted into the nostrils of a newborn (premature infant), as shown in FIG. In addition, the air supply tube 21 and the exhaust tube 24 cross the face of the newborn. In this state, the element 1 is fixed to the head with a fixing holder with a band, string, etc. (not shown).

  In such a use state, air is supplied to the supply pipe connection port 15 at a substantially constant pressure. This air enters the nozzle 3 from the air supply pipe connection port 15 through the jet port 2, and the air jet flowing out from the nozzle 3 moves along the jet flow path 4 and has a knife of a wedge 5 a corresponding to the tip of the jet branch plate. At the edge, the jet is divided into a first jet and a second jet, and the first jet enters the cavity 9 through the first branch 7 which is a cavity port, and turns clockwise along the wall surface. As a result, a positive pressure is applied to the cavity 9. The second jet flows through the exhaust port 13 through the second branch path 8 which is an excess air flow path, and flows out from the exhaust pipe connection port 18 to the outside.

  In FIG. 2, an outline of the air flow in the nasal CPAP element 1 in the inspiratory phase in which the inspiratory pressure is applied to the nasal prong ports 10 and 11 by spontaneous breathing of the newborn is shown by a solid line arrow. The outline of the air flow in the nasal CPAP element 1 in the expiratory phase in which expiratory pressure is applied to the nasal prong ports 10 and 11 by spontaneous breathing of the newborn is indicated by solid arrows. The amount of air supplied to the element 1 by the jet flow from the nozzle 3 is about 7 liters per minute, but most of this is for maintaining the CPAP, that is, the mean airway pressure (MAP) in the airway. Then, it circulates three-dimensionally in the cavity 9 and flows out from the vicinity of the lower and upper wall surfaces of the bypass 6, which is the gap between the wedge 5 a and the separating portion 5 b, to the second branch path 8. To do.

The inspiratory and expiratory flow rates of newborn breathing are about 20 milliliters per breath, and the number of breaths is about 30 per minute, so the amount of inspiration and expiration per minute is about 0.6 liters. It is about 10% of the amount of air supplied. Therefore, the main air flow is
Nozzle 3-cavity 9-bypass 6-throttle 14-exhaust pipe connection port 18
Then, a part passes through the nasal prong 12 and becomes inhalation (FIG. 2) and expiration (FIG. 3). Further, the flow separated by the wedge 5a is mostly the flow in the direction of the cavity 9, that is, the first jet flow, and the second jet flow rate in the direction of the second branch path 8 is small. However, the ratio between the first jet flow rate and the second jet flow rate is slightly different between the inspiratory phase and the expiratory phase, and the first jet flow rate slightly increases in the inspiratory phase, but the first jet flow rate slightly decreases in the expiratory phase. .

  The largest change in flow due to inspiration and expiration is in the first jet entering the cavity 9. The first jet branched by the wedge 5a swirls clockwise in the cavity 9 along the wedge 5a and along the separation part 5b, and exits to the second branch 8 through the bypass 6. This swirl flow in the cavity 9 is biased toward the nasal prong ports 10 and 11 as shown in FIG. 2 during inhalation, and away from the nasal prong ports 10 and 11 as shown in FIG. 3 during exhalation. This flow change is caused by slight pressure fluctuations applied to the cavity 9 during inhalation and exhalation from the nasal prong ports 10 and 11, interfering with the jet flow from the nozzle 3, and changing the jet split ratio at the tip of the wedge 5 a, As a result, the state of the flow in the cavity changes to assist inspiration and expiration.

  In the case where the cavity positive pressure is maintained at an average value of about 500 Pa by buffering the pressure fluctuation in the cavity due to the presence of the bypass 6 described above, the fluctuation in the lung pressure is suitable for comfortable breathing assistance for premature infants. It can be in the range of 100 to 150 Pa.

  Similarly to the prior art (FIG. 5), the air supply tube 21 and the exhaust tube 24 are arranged in the same direction x, and in contrast to these, two flexible tubes inserted into the nostrils of the nasal prong 12 Since these are arranged in the vertical direction y, these supply and exhaust tubes can be mounted across the face of the newborn, for example, as shown in FIG. 4, thereby reducing the mounting burden.

It is a longitudinal cross-sectional view of the nasal CPAP element 1 of one Example of this invention. It is an enlarged view which shows the outline | summary of the air flow in an element when the inspiratory pressure is added to the nasal cavity long connection ports 16 and 17 of the nasal CPAP element 1 shown in FIG. It is an enlarged view which shows the outline | summary of the air flow in an element when the expiratory pressure is added to the nasal cavity long connection ports 16 and 17 of the nasal CPAP element 1 shown in FIG. FIG. 2 is a front view of a newborn wearing the nasal CPAP element 1 shown in FIG. 1. It is a longitudinal cross-sectional view of a conventional example nasal CPAP element.

Explanation of symbols

1: Nasal CPAP element 2: Jet port 3: Jet nozzle 4: Jet channel 5: Jet branch plate 6: Bypass 7: First branch 8: Second branch 9: Cavity 10, 11: Nasal prong port 12: Nasal cavity Prong 13: Exhaust port 14: Throttle 15: Supply pipe connection port 16, 17: Nasal prong connection port 18: Exhaust pipe connection port 21: Supply tube 22: Supply base 23: Exhaust base 24: Exhaust tube

Claims (3)

A jet nozzle for jetting air; a jet flow path is provided between the nozzle and the nozzle, and a tip is located at a position facing the air jet of the jet nozzle and extends in a direction in which the air jet flows; And a jet branch plate divided into a second jet; a first branch path into which the first jet flows and a cavity continuous therewith; a second branch path into which the second jet flows into and an exhaust port continuous therewith; and continuous to the cavity A nasal prong port to which a nasal prong is coupled;
A nasal CPAP element, wherein a bypass allowing air flow between the cavity and the second branch path is provided at a rear portion of the tip of the jet branch plate. A jet nozzle that ejects air;
A wedge that divides the air jet into first and second jets, with a jet flow path between the jet nozzle and a tip at a position facing the air jet of the jet nozzle;
A separation portion that is downstream of the wedge with respect to the flow direction of the air jet and extends in the flow direction of the air jet;
A first branch into which the first jet flows and a cavity continuous therewith;
A second branch passage into which the second jet flows and an exhaust port continuous therewith;
A nasal prong port continuous with the cavity and coupled with a nasal prong; and
A bypass between the wedge and the separation part;
The cavity and the second branch are separated by the separation part, and the bypass allows air to flow between the cavity and the second branch;
Nasal CPAP element. An air supply port communicating with the jet nozzle on the upstream side of the jet nozzle with respect to the air jet, and the exhaust port on the downstream side; provided in the direction perpendicular to the nozzle axis of the jet nozzle, A nasal CPAP element according to claim 1 or 2, wherein the central axis extends.

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