Respiration auxiliary device

Abstract

To assist respiration with a simple configuration.SOLUTION: A respiration auxiliary device 100 includes: a bubble generator 13 that generates liquid containing ultrafine bubbles of oxygen; and an introduction pipe 21 that introduces the liquid to a peritoneal cavity PC. An average diameter of the ultra fine bubbles is 1 μm or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a technique for assisting a patient's breathing.

Background Art

[0002] For patients with reduced lung function who have fallen into dyspnea, generally, treatment with a ventilator or ECMO (extracorporeal membrane oxygenation) is performed. However, for example, regarding COVID-19 patients in Japan, the mortality rate of patients treated with a ventilator was 21.5%, and the mortality rate of patients treated with ECMO was 36.0% (as of February 28, 2023), and the treatment results were not very good. In addition, in the treatment with a ventilator, it is necessary to insert a tube into the trachea, and in the treatment with ECMO, it is necessary to insert a cannula into the great vessels. In both cases, the difficulty of accessing the living body is high and it is highly invasive. Therefore, the facilities where the equipment can be introduced are limited, and in the pandemic due to COVID-19, triage of patients due to medical congestion was carried out.

[0003] On the other hand, a breathing assistance method for supplying oxygen through the peritoneum has been proposed. For example, in Non-Patent Document 1, it has been reported that oxygenated perfluorocarbon (artificial blood) was introduced into the peritoneal cavity of pigs, and oxygen could be supplied to the whole body. In addition, in Non-Patent Document 2, it has been reported that a liquid containing oxygen microbubbles was introduced into the peritoneal cavity of rats with acute lung injury, and the rats could be extended their lives by 2 hours. The technique of introducing a liquid into the peritoneal cavity has a relatively low difficulty and is less invasive than a ventilator or ECMO.

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Since the oxygen concentration of the liquid introduced into the peritoneal cavity decreases as gas exchange progresses, it is necessary to continuously circulate new liquid into the peritoneal cavity. However, since the oxygen-dissolved perfluorocarbon in Non-Patent Document 1 is expensive, the cost for continuously circulating it into the peritoneal cavity becomes high. In Non-Patent Document 2, since the bubbles contained in the liquid are relatively large (average diameter 3.4 ± 1.9 μm), the bubbles are stabilized by coating with phospholipids. However, since phospholipid-coated bubbles are time-consuming to manufacture, the cost for continuously circulating them into the peritoneal cavity also becomes high.

[0006] The present invention has been made in view of the above problems, and an object thereof is to assist breathing with a simple configuration.

Means for Solving the Problems

[0007] In order to solve the above problems, the present invention includes the following aspects. Item 1. A bubble generator that generates a liquid containing ultra-fine bubbles of oxygen, An introduction tube for introducing the liquid into the peritoneal cavity, A breathing assistance device comprising: A respiratory assist device, wherein the average diameter of the ultra-fine bubbles is 1 μm or less. Item 2. The respiratory assist device according to Item 1, wherein the average diameter of the ultra-fine bubbles is 50 nm to 500 nm. Item 3. A suction tube for sucking the liquid introduced into the peritoneal cavity to the outside of the body, Circulation means for circulating the sucked liquid to the bubble generator, The respiratory assist device according to Item 1 or 2, further comprising:

Advantages of the Invention

[0008] According to the present invention, respiration can be assisted with a simple configuration.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that the present invention is not limited to the following embodiments, and various modifications are possible without departing from the spirit thereof.

[0011] FIG. 1 is a schematic diagram showing the configuration of a respiratory assist device 100 according to an embodiment of the present invention. The respiratory assist device 100 mainly includes an oxygen ultra-fine bubble (OUFBs) console 1 and a double-lumen catheter 2.

[0012] The OUFBs console 1 mainly includes an input tube 11, a circulation pump (circulation means) 12, a bubble generator 13, and an output tube 14.

[0013] The input pipe 11 is provided with a circulating water injection part 111. The liquid injected from the circulating water injection part 111 passes through the filter 3 and is then sent by the circulation pump 12 to the bubble generator 13. The liquid is, for example, physiological saline.

[0014] The bubble generator 13 is a device that generates a liquid containing oxygen ultra-fine bubbles (OUFBs) (hereinafter referred to as "OUFBs solution"), and includes a bubble generation engine 131 and an oxygen inlet 132. The average diameter of the ultra-fine bubbles is 1 μm or less, and in this embodiment, it is 50 nm to 500 nm. Note that the oxygen concentration in the OUFBs does not necessarily have to be 100%, and it is not particularly limited as long as it can supply a sufficient amount of oxygen to the patient.

[0015] The bubble generation engine 131 generates OUFBs by mixing the liquid sent from the circulation pump 12 and the oxygen taken in from the oxygen inlet 132, and outputs the OUFBs solution from the output pipe 14. As the bubble generation engine 131, for example, a Shibata engine manufactured by Shibata Corporation can be used.

[0016] The output pipe 14 is connected to an introduction pipe 21 that introduces the liquid into the peritoneal cavity PC via a connection part C1. The input pipe 11 is connected to a suction pipe 22 that sucks the liquid outside the body via a connection part C2. The introduction pipe 21 and the suction pipe 22 constitute a double-lumen catheter 2, which is inserted into the peritoneal cavity PC of a patient who requires respiratory assistance. The insertion method of the double-lumen catheter 2 is the same as that in peritoneal dialysis.

[0017] After the double-lumen catheter 2 is inserted, the bubble generation engine 131 is operated, and the OUFBs solution is output from the output pipe 14. The liquid is introduced into the peritoneal cavity PC from the inlet 211 of the introduction pipe 21. The amount of the liquid in the peritoneal cavity PC may be such that the abdomen bulges to the extent that the burden on the patient does not increase. Thereby, oxygen is taken into the capillaries from the OUFBs in the peritoneum P.

[0018] Figure 2 is an image diagram showing gas movement in the peritoneum. When the OUFBSs contained in the liquid come into contact with the peritoneum, oxygen molecules pass through the mesothelial cells and are taken into the capillaries. The taken-in oxygen molecules bind to red blood cells and are delivered to the cells in the body.

[0019] As gas movement progresses, the oxygen concentration in the liquid decreases, so it is necessary to continuously circulate the liquid. In this embodiment, when the liquid in the peritoneal cavity PC reaches a sufficient amount, the injection of the liquid from the circulating water injection unit 111 is stopped, and the liquid is suctioned out of the body from the suction port 221 of the suction tube 22. The suctioned liquid is circulated by the circulation pump 12 to the bubble generator 13 and mixed again with the oxygen taken in from the oxygen suction port 132. Thereby, while circulating the liquid, the introduction of the OUFBS solution and the suction of the liquid out of the body are performed.

[0020] Note that the liquid suctioned out of the body may be discarded without being reused. In this case, the injection of the liquid from the circulating water injection unit 111 is not stopped.

[0021] As described above, in the respiratory assist device 100 according to this embodiment, the OUFBS solution is introduced into the peritoneal cavity, and gas exchange is performed through the peritoneum, thereby assisting the patient's breathing. Since the ultra-fine bubbles contained in the OUFBS solution have an average diameter of 1 μm or less, they can stably exist in the liquid for a long time without being coated with phospholipids or the like. Also, the price of the bubble generator 13 for generating the OUFBS solution is, for example, several thousand yen to several tens of thousand yen in the case of a Shibata engine, and is much cheaper compared to the devices for generating oxygen-dissolved perfluorocarbon in Non-Patent Document 1 and phospholipid-coated bubbles in Non-Patent Document 2. Therefore, new OUFBSs can be continuously supplied at low cost, and breathing can be assisted with a simple configuration.

[0022] As described above, the embodiments of the present invention have been described, but the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit thereof.

Example

[0023] Hereinafter, examples of the present invention will be described, but the present invention is not limited to the following examples.

[0024] In this example, an experiment was conducted to demonstrate that an adequate amount of oxygen for respiratory assistance can be supplied into the blood by the OUFBS solution.

[0025] First, as a model M for reproducing the peritoneal cavity, a hollow fiber dialyzer (model name: FB-50) manufactured by Nipro Corporation was prepared. The model M has a configuration in which a large number of hollow fibers F are stretched in the internal space of a cylindrical main body case, and the materials of the hollow fibers F are as follows. Material: Cellulose triacetate Total area: 0.5 m 2 Diameter: 200 μm Pore diameter: 5 - 7 nm Priming liquid volume: 35 mL Effective length: 25 cm

[0026] 400 mL of blood collected from a healthy subject was diluted with 400 mL of physiological saline at pH 7.4 and subjected to deoxygenation treatment to produce deoxygenated blood B1. The partial pressure of oxygen PO 2 of the deoxygenated blood B1 was 58.3 mmHg.

[0027] The OUFBS solution was produced by supplying physiological saline at pH 7.4 and 100% oxygen to a Shibata engine (model name: U10N) manufactured by Shibata Corporation. The supply rate of oxygen was 0.2 L / min. The dissolved oxygen in the OUFBS was 17.55 mg / L, and the partial pressure of oxygen was 330.6 mmHg.

[0028] As shown in Figure 3, the OUFBS solution was introduced into the main body case of the model M from the introduction tube 21 and discharged to the outside from the suction tube 22. The discharged liquid was supplied to the Shibata engine again, mixed with oxygen, and then introduced into the inside of the model M. The circulation rate of the liquid was 50 mL / min.

[0029] In parallel with this, deoxygenated blood B1 was introduced from an introduction tube 23 connected to one end of the model M into the hollow fiber F. When the deoxygenated blood B1 passes through the hollow fiber F, it exchanges gas with the OUFBs solution and is discharged from a discharge tube 24 connected to the other end of the model M. A part of the discharged blood B2 was collected from a sampling section 25, and the partial pressure of oxygen and the like were analyzed.

[0030]

Table 1

[0031] Table 1 shows the partial pressure of carbon dioxide (PCO 2 ), partial pressure of oxygen (PO 2 ), dissolved oxygen (DO), oxygen saturation (SO 2 ), hematocrit value (Ht), and hemoglobin value (Hgb) of the deoxygenated blood B1 and the blood B2 in the 1st to 5th circulation cycles (1st to 5th). In any cycle, the blood B2 has an increased partial pressure of oxygen, dissolved oxygen, and oxygen saturation, and a decreased partial pressure of carbon dioxide, compared with the deoxygenated blood B1 before gas exchange. On the other hand, since the hematocrit value and the hemoglobin value hardly change, it is considered that the dissolved oxygen solution in the OUFBs solution does not move into the capillary and only oxygen molecules move.

[0032]

Table 2

[0033] Table 2 shows the gas exchange function of the model M and the lungs of a healthy person. CaO 2 is the oxygen content of the blood B2 (1st to 5th) or the arterial blood oxygen content (lungs), and CvO 2 is the oxygen content of the deoxygenated blood B1 (1st to 5th) or the venous blood oxygen content (lungs). The exchange amount means the oxygen exchange amount per minute. The exchange rate means the exchange amount per unit area of the membrane where oxygen exchange occurs. The total area of the membrane (hollow fiber) of the model M is 0.5 m 2, calculated assuming that the total area of the lungs (alveoli) is 7.0 m 2 The gas exchange function of the lungs is calculated assuming that the hematocrit value (Ht) is 45%, the hemoglobin value (Hgb) is 15 g / dL, and the inhaled oxygen concentration is 21%.

[0034] Assuming that the oxygen exchange ratio in the hollow fiber F of model M is equivalent to that of peritoneal capillary endothelial cells, the total area of the human peritoneum is 1.7 - 2.0 m 2 Therefore, the amount of oxygen exchange in the peritoneum is comparable to that in the lungs. Thus, it was found that oxygen supply via the peritoneum using the OUFBs solution can sufficiently replace the oxygen supply function of the lungs.

Explanation of Symbols

[0035] 1 Oxygen ultra-fine bubble console 2 Double-lumen catheter 3 Filter 11 Inlet pipe 12 Circulation pump (circulation means) 13 Bubble generator 14 Outlet pipe 21 Introduction pipe 22 Suction pipe 23 Introduction pipe 24 Discharge pipe 25 Sampling section 100 Respiratory assist device 111 Circulating water injection section 131 Bubble generation engine 132 Oxygen inlet 211 Inlet 221 Suction port B1 Deoxygenated blood B2 Blood C1 Connection part C2 Connection part F Hollow fiber M Model P Peritoneum PC Peritoneal cavity

Claims

1. A bubble generator that generates a liquid containing ultra-fine oxygen bubbles; an introduction tube for introducing the liquid into the peritoneal cavity; A respiratory assistance apparatus comprising: A respiratory assistance device, wherein the ultra-fine bubbles have an average diameter of 1 μm or less.

2. The respiratory assistance device of claim 1, wherein the ultra-fine bubbles have an average diameter of 50 nm to 500 nm.

3. a suction tube for suctioning the liquid introduced into the peritoneal cavity to the outside of the body; a circulation means for circulating the sucked liquid to the bubble generating device; 3. A respiratory assistance apparatus as claimed in claim 1 or 2, further comprising:

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