JP2017148170A - Bubble generation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bubble generation device capable of adding oxygen in the vein of a patient without an extracorporeal circulation as a device taking place of an intravenous indwelling type artificial lung.SOLUTION: A bubble generation device 1 can generate microbubbles of oxygen gas G mainly composed of oxygen in the vein of a patient. The bubble generation device 1 includes a bubble generation chip 2 having a surface 2a where a large number of micropores Mp from which the oxygen gas G can flow out are opened, which can guide the supplied oxygen gas G to the large number of micropores Mp, and has a size that allows the insertion into the vein, and an oxygen supply tube 3 composed of a flexible material which can supply the oxygen gas G to the bubble generation chip 2 and has a size that allows the insertion into the vein.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bubble generation device capable of generating bubbles of oxygen gas in a patient's vein.

  As treatment methods for eliminating or avoiding a hypoxic state of a patient, there are methods using hyperbaric oxygen therapy and a ventilator, but these treatment methods put a burden on the living lung of the patient. PCPS (percutaneous cardiopulmonary support) and ECMO (extracorporeal membrane oxygenation) are known as examples of respiratory assistance that does not impose a burden on a living lung of a patient. Both PCPS and ECMO have a problem of blood compatibility because they involve extracorporeal circulation in which an artificial lung, a blood pump, or the like that comes into contact with blood to be gas exchanged is incorporated. In addition, antithrombotic therapy is indispensable for carrying out extracorporeal circulation, which may cause side effects in the patient. Under these circumstances, medical workers who think that extracorporeal circulation is highly invasive to patients are often reluctant to perform PCPS and ECMO.

  As a treatment method for exchanging gas in a patient's vein without extracorporeal circulation, there is a method of inserting an indwelling artificial lung (trade name: IVOX) into the vena cava. This is a kind of implantable oxygenator having a gas exchange hollow fiber bundle having the same principle and function as an oxygenator, and was published in 1987 and clinical trials were conducted (see Non-Patent Document 1).

Hiroshi Imai, 2 others, “Clinical trial of intravenous indwelling oxygenator”, Respiration and Circulation, Medical School, May 1992, Vol. 40, No. 5, p. 461

  However, the intravenous indwelling oxygenator of Non-Patent Document 1 has been discontinued in 1994 due to problems such as insufficient gas exchange capacity, thrombotic problems, difficulty in procedure, and influence on hemodynamics.

  Accordingly, an object of the present invention is to provide a bubble generating apparatus capable of adding oxygen in a patient's vein without extracorporeal circulation as an apparatus replacing an indwelling artificial lung.

  The bubble generation device of the present invention is a bubble generation device (1) capable of generating bubbles of oxygen gas (G) mainly composed of oxygen in a patient's vein, and a plurality of the oxygen gas can flow out. Each having a surface (2a, 21a, 22a, 23a) each having a size within a predetermined range and capable of guiding the supplied oxygen gas to the plurality of holes, And a bubble generating part (2, 21, 22, 23) having a size that can be inserted into the vein, and a flexible material, and can supply the oxygen gas to the bubble generating part, and into the vein And an oxygen supply tube (3) having a size that can be inserted.

  According to this bubble generation device, oxygen gas is supplied to the bubble generation unit via the oxygen supply tube in a state where the bubble generation unit and the oxygen supply tube are inserted into the patient's vein, thereby being supplied to the bubble generation unit. Oxygen gas is introduced into the plurality of holes. Since the plurality of holes are opened on the surface of the bubble generating portion, oxygen gas flows out from the openings of the plurality of holes, thereby generating oxygen gas bubbles in the vein of the patient. Thereby, oxygen addition can be performed in a patient's vein. Due to the partial pressure difference between the partial pressure of the bubbles and the partial pressure in the blood, gas exchange is realized in which the oxygen contained in the oxygen gas constituting the bubbles dissolves in the blood in the vein and the carbon dioxide in the blood moves to the bubbles.

  The size of bubbles generated in the vein varies depending on the size of the plurality of holes. In the bubble generating device of the present invention, since the plurality of holes are opened within the predetermined range, the size of the plurality of holes is made uniform within the predetermined range. Therefore, the size and number of bubbles can be optimized by appropriately setting the predetermined range. A small opening hole has a higher resistance when oxygen gas flows out than a large opening hole, and is difficult to pass through the hole. Therefore, if there are holes with large openings out of the predetermined range in the plurality of holes, oxygen gas concentrates on the large holes even if there are other holes that fall within the predetermined range. As a result, the number of generated bubbles is reduced and the size of the bubbles is increased as compared with a case where the bubbles are uniformized within a predetermined range. As a result, the contact area per unit time between the generated bubbles and blood is reduced, and the gas exchange efficiency is lowered. Therefore, according to the bubble generating device of the present invention, since the size of the openings of the plurality of holes is made uniform within a predetermined range, the number of bubbles having an unexpected size can be suppressed, so that the gas exchange efficiency is lowered. Can be suppressed. However, even if bubbles of an unexpected size are generated, such bubbles are absorbed by the patient's living lung, so there is no risk of being sent to the patient's artery.

  In one aspect of the bubble generation device of the present invention, the oxygen supply tube may further include a control unit (5) capable of controlling a flow rate and pressure of the oxygen gas supplied to the bubble generation unit. The size and number of air bubbles generated in the vein change not only with the size of the opening of the hole, but also with the flow rate and pressure of oxygen gas supplied to the bubble generating unit, and also with the patient's venous blood pressure and blood flow, etc. to be influenced. According to this aspect, since the flow rate and pressure of the oxygen gas supplied to the bubble generation unit can be controlled by the control unit, it is possible to perform oxygen addition in accordance with the patient's blood pressure, blood flow, and the like.

  As one aspect of the bubble generation device of the present invention, the surface of the bubble generation unit may include a curved surface in which the plurality of holes are formed. Since the bubble generating part can be inserted into a patient's vein, there is a limit to the size of the bubble generating part, and a margin that does not impair hemodynamics is required. Therefore, if the maximum width of the bubble generating part that affects hemodynamics is the same, a larger surface area can form more holes with the same density. Increases efficiency. According to this aspect, since the curved surface in which a plurality of holes are formed is included on the surface of the bubble generating portion, the surface area is larger than when the surface of the bubble generating portion having the same maximum width is configured by only a plane. Thereby, efficient oxygenation is realizable as long as hemodynamics are not impaired.

  As described above, the predetermined range that defines the size of the opening of the plurality of holes may be set as appropriate. For example, in the case where the plurality of holes are formed in a circular shape, and an inner diameter of an opening portion at which the plurality of holes opens on the surface is defined as a size at which the plurality of holes open on the surface, As the predetermined range, a range of 1 μm to 300 μm may be set. Forming a hole having an inner diameter smaller than 1 μm involves technical difficulties, and thus the processing cost becomes severe. On the other hand, if the inner diameter is larger than 300 μm, the generation rate of bubbles having an unexpected size increases, and the gas exchange efficiency decreases. Accordingly, the inner diameter of the plurality of holes is preferably in the range of 1 μm to 300 μm.

  In one aspect of the bubble generation device of the present invention, the surface of the bubble generation unit may be covered with a coating layer capable of suppressing adhesion of blood components. According to this aspect, since the surface of the bubble generating part is covered with the coating layer, the blood component is suppressed from adhering to the surface, so that the blood component adheres to the surface and the hole is blocked. It can prevent that the bubble generation capability of a bubble generation part deteriorates.

  In addition, in the above description, in order to make an understanding of this invention easy, the reference sign of the accompanying drawing was attached in parenthesis, but this invention is not limited to the form of illustration by it.

  As described above, according to the bubble generation device of the present invention, by supplying oxygen gas to the bubble generation unit via the oxygen supply tube in a state where the bubble generation unit and the oxygen supply tube are inserted into the vein of the patient. The oxygen gas can flow out from the openings of the plurality of holes to generate oxygen gas bubbles in the patient's vein.

The figure which showed typically the whole structure of the bubble generator which concerns on one form of this invention. The elements on larger scale of the site | part II of FIG. Sectional drawing regarding the III-III line of FIG. The figure which showed the 1st other form of the bubble generation part. The figure which showed the 2nd other form of the bubble generation part. The figure which showed the 3rd other form of the bubble generation part.

  As shown in FIGS. 1 to 3, the bubble generation device 1 includes a bubble generation chip 2 as a bubble generation unit and an oxygen supply tube 3 communicating with the bubble generation chip 2. The bubble generating chip 2 is fixed to a hollow connecting portion 4, and the connecting portion 4 is connected to the oxygen supply tube 3 in an airtight state. A gas supply source GS is connected to the other side of the oxygen supply tube 2. The gas supply source GS is provided with a gas blender (not shown). The gas supply source GS uses the gas blender to prepare an oxygen gas G mainly composed of oxygen as necessary, and the oxygen gas G after preparation. Is reduced to a predetermined pressure and supplied to the bubble generating device 1. The bubble generator 1 is provided with a mass flow controller (MFC) 5 as a control unit for controlling the flow rate and pressure of the oxygen gas G flowing through the oxygen supply tube 3. The oxygen gas G whose flow rate and pressure are adjusted by the MFC 5 is supplied to the bubble generating chip 2 through the oxygen supply tube 3.

  The bubble generating chip 2 is a cylindrical metal part whose tip is closed. As will be described later, since the bubble generating chip 2 is inserted into a patient's vein, a less invasive material (for example, a metal such as stainless steel or titanium) is selected as the material. As the material for the bubble generating chip 2, a non-metallic and minimally invasive material such as ceramic, carbon, or resin can be selected. The connecting portion 4 fixed to the bubble generating chip 2 is made of a material capable of preventing leakage and removal between different materials of the oxygen supply tube 3 and the bubble generating portion 2, for example, a sealant such as a photo-curing adhesive or a silicone-based adhesive. Selected. The bubble generating chip 2 and the connecting portion 4 are joined to each other by an appropriate joining means corresponding to these materials. The oxygen supply tube 3 has substantially the same outer diameter as the bubble generating chip 2, and is made of a flexible material such as soft PVC or elastomer. Since a part of the bubble generating chip 2, the connecting portion 4 and the oxygen supply tube 3 are inserted into the veins of the patient, their outer diameters are enough to prevent operability during insertion and hemodynamics after insertion. It is set so that it can be secured.

  The outer diameter and length of the bubble generating chip 2 depend on the physique of the patient and the inner diameter of the femoral vein to be incised, but the outer diameter of the bubble generating chip 2 is about 3 mm to 8 mm, and the length of the bubble generating chip 2 is It is set to about 5 mm to 40 mm. The same applies to the outer diameters of the connecting portion 4 and the oxygen supply tube 3. Further, in consideration of insertion of the bubble generating chip 2, the connecting portion 4, and a part of the oxygen supply tube 3 into the vein of the patient, an appropriate coating may be applied to these surfaces. In particular, the surface 2a of the bubble generation chip 2 has a coating layer C (see FIG. 2) that can suppress the adhesion of blood components so that the micropores Mp described later are not blocked by the adhesion of blood components and the bubble generation capability does not deteriorate. 3).

  A plurality of micropores Mp are formed on the surface 2 a of the bubble generating chip 2. The plurality of minute holes Mp correspond to the plurality of holes according to the present invention. As shown in FIGS. 2 and 3, each micro hole Mp penetrates the cylindrical portion of the bubble generating chip 2 with substantially the same inner diameter, and is opened on each of the surface 2 a and the inner surface 2 b of the bubble generating chip 2. The size at which the microhole Mp opens at the surface 2a, that is, the inner diameter d of the opening of the microhole Mp is made uniform within a range of 1 μm to 300 μm. In order to control the inner diameter of the opening of the minute hole Mp within such a range, the minute hole Mp is processed by a method having a relatively low processing cost and high formation accuracy, for example, a precision electroforming method. In addition, various processing methods such as cutting, laser processing, and electrical discharge processing may be employed as long as the minute hole Mp having an opening with an inner diameter d within the above range can be formed. The number of micropores Mp is adjusted to a large number in consideration of the amount of oxygen supplied to the patient per unit time.

  When the bubble generating device 1 is used for treatment of a patient, it is treated in the same manner as insertion of a femoral vein catheter. The bubble generating chip 2 is inserted into the femoral vein through the puncture site of the patient, and the bubble generating chip 2 is inserted into the ascending vena cava along the guide wire previously inserted into the vein as necessary. As a result, in the bubble generating device 1, the bubble generating chip 2 is placed in the ascending vena cava, a part of the oxygen supply tube 3 connected to the bubble generating tip 2 is placed in the vein, and the rest of the oxygen supply tube 3 is left in the patient. It is exposed outside the body. Needless to say, the oxygen supply tube 3 has a length sufficient to be connectable to the MFC 5 disposed outside the body.

  When oxygen gas G is supplied from the gas supply source GS to the bubble generating device 1 in a state where the patient is treated in this manner, the oxygen gas G supplied to the bubble generating chip 2 via the oxygen supply tube 3. Is guided to the micropores Mp that open to the surface 2a of the bubble generating chip 2, and flows out from each micropore Mp. Thereby, microbubbles of oxygen gas G are generated in the ascending vena cava of the patient. Microbubbles (hereinafter referred to as MB) correspond to bubbles according to the present invention. Since the inner diameter d of the opening of the micropore Mp is uniform within the range of 1 μm to 300 μm, the expected size of the generated MB is about 1 μm to 1000 μm. The reason why the uniform range of MB is set to a numerical value range of 1 μm to 300 μm is that forming a hole with an inner diameter smaller than 1 μm is accompanied by technical difficulties, and the processing cost becomes severe, whereas the inner diameter is smaller than 300 μm. This is because if it increases, the occurrence rate of MBs with unexpected sizes increases and the gas exchange efficiency decreases.

  When MB occurs in a vein, the carbon dioxide in the blood moves to the MB while the oxygen contained in the oxygen gas G in the MB dissolves in the blood due to the partial pressure difference between the partial pressure in the MB and the partial pressure in the blood. Gas exchange is realized. This gas exchange is performed in the process in which MB generated in the ascending vena cava passes through the vena cava through the bloodstream and flows to the living lung through the right atrium of the heart. Even if an MB of an unexpected size occurs for some reason, if such MB reaches the living lung, it is absorbed by the living lung, so there is no risk of being sent to the patient's artery. In addition, since MB that has passed without being absorbed by the living lung has a size that passes through alveolar blood vessels, it passes through a large blood vessel that becomes a problem due to occlusion, so that problems such as vascular occlusion that cause serious symptoms occur. Absent.

  According to the bubble generating device 1 of the present embodiment, since the inner diameter d of the opening of the minute hole Mp is made uniform within the above range, the number of MBs having an unexpected size can be suppressed, so that the gas exchange efficiency is lowered. Can be suppressed. If the inner diameter d of the opening of the microhole Mp is not uniform as in the present embodiment, the oxygen gas G concentrates in the microhole Mp having a large inner diameter d, and the number of generated MBs decreases and the size of the MB. This is because the contact area per unit time between the generated MB and blood is reduced and the gas exchange efficiency is lowered.

  Moreover, since the bubble generator 1 can control the flow rate and pressure of the oxygen gas G flowing through the oxygen supply tube 3 by the MFC 5, it can perform blood oxygenation in accordance with the patient's blood pressure, blood flow, and the like. The size and number of MBs generated in the patient's veins vary depending not only on the inner diameter d of the opening of the micropore Mp but also on the flow rate and pressure of the oxygen gas G supplied to the bubble generating chip 2, and the patient's veins. This is because blood pressure and blood flow are also affected. However, by controlling the flow rate and pressure of the oxygen gas G with the MFC 5, it is possible to control the oxygen addition capability and the carbon dioxide removal capability to some extent. It becomes the upper limit. For this reason, the treatment with only the bubble generating device 1 may lack the ability to remove carbon dioxide. In such a case, dialysis is used together, and a countermeasure for discharging carbon dioxide in the blood as bicarbonate or heavy carbon ions by dialysis is effective. Although dialysis is a kind of extracorporeal circulation, medical staff understand from experience that dialysis is a much simpler procedure than PCPS and ECMO, and is less invasive and highly safe. Therefore, the combined use of the bubble generator 1 and dialysis is effective.

  The use of the bubble generating device 1 during emergency lifesaving is also suitable for an emergency request because access to the patient is at one place of the puncture unit. Further, since it is minimally invasive without extracorporeal circulation, it seems that there is little resistance or hesitation of medical staff regarding the use of the bubble generator 1 for emergency lifesaving. In general, the most urgent response in emergency lifesaving is the improvement of hypoxia in patients. For the subsequent removal of carbon dioxide, dialysis may be performed in consideration of the pH value, the PCO2 value, and the like after measures of low oxygen with higher priority.

  This invention is not limited to the said form, It can implement with a various form within the range of the summary of this invention. In the above embodiment, the inner diameter d of the openings of the micro holes Mp that are a plurality of holes is uniformized within a range of 1 μm to 300 μm, but the range of the inner diameter d is not limited to this, and other numerical values It may be limited within the range. The narrower the range, the higher the uniformity of the micropores Mp and the higher the MB uniformity, so that the gas exchange efficiency is increased. Therefore, the present invention can be implemented by setting the above range according to the purpose of use and the object. Further, although the minute hole Mp is a circular hole, the shape of the hole is not necessarily circular. The present invention can also be implemented in a form in which a non-circular elliptical shape or a rectangular hole is formed. In such a case, when the size of the hole opened on the surface of the bubble generating part is made uniform within a predetermined range, the maximum width of the inner circumference of the non-circular hole is used as an adjustment parameter, and the maximum width May be adjusted so as to fall within a predetermined range.

  The bubble generating chip 2 having the above-described form is formed in a cylindrical shape with a closed tip, but the shape of the bubble generating part is not limited. For example, the present invention can be implemented in a form provided with a quadrangular prism-shaped bubble generating section. However, since the surface 2a of the bubble generating chip 2 is a cylindrical surface and a curved surface, the surface on which the plurality of holes are formed is all flat and has a larger surface area than that having the same maximum width. Thereby, efficient oxygenation can be achieved as long as hemodynamics is not impaired. Also, the present invention is carried out by replacing the bubble generating chip 2 of the above form with any of the other forms of bubble generating chips 21, 22, 23 having curved surfaces on the surfaces shown in FIGS. 4A to 4C. You can also. Each bubble generating chip 21, 22, 23 corresponds to a bubble generating portion according to the present invention.

  The bubble generating chip 21 in FIG. 4A has a dome-shaped surface 21a. The surface 21a includes a spherical surface and other curved surfaces in which a plurality of minute holes Mp are opened in the same manner as the bubble generating chip 2 and forms a dome shape. The bubble generating chip 22 of FIG. 4B has a conical surface 22a. The surface 22a includes a conical surface that is a curved surface in which a plurality of micropores Mp are opened in the same manner as the bubble generating chip 2 and constitutes a conical shape. The bubble generating chip 23 shown in FIG. 4C has a frustoconical surface 23a. The surface 23a includes a conical surface that is a curved surface that has a plurality of minute holes Mp that are open in the same manner as the bubble generating chip 2 and that forms a truncated cone shape. 4A to 4C all have a curved surface on the surface on which the micropores Mp are formed, so that the surface area can be increased as long as the hemodynamics are not impaired as with the bubble generating chip 2. it can.

  In the above description, the bubble generating part or the like is inserted into the patient's vein and then the bubble is generated in the vein. However, blood taken out of the patient's body using the bubble generating device of the present invention or predetermined The bubble generating device of the present invention can also be used to realize a method of generating bubbles in a liquid and thereby injecting blood or liquid mixed with bubbles into a patient's vein.

1 Bubble generator 2, 21, 22, 23 Bubble generation chip (bubble generation unit)
2a, 21a, 22a, 22c Surface 3 Oxygen supply tube 5 MFC (control unit)
G Oxygen gas Mp Micropore C Coating layer

Claims (5)

A bubble generator capable of generating oxygen gas bubbles mainly composed of oxygen in a patient's veins,
The plurality of holes through which the oxygen gas can flow out have a surface that opens in a predetermined size, respectively, and the supplied oxygen gas can be guided to the plurality of holes, and into the vein A bubble generator having a size that can be inserted;
An oxygen supply tube made of a flexible material, capable of supplying the oxygen gas to the bubble generating unit, and having a size that can be inserted into the vein;
A bubble generator comprising:   The bubble generating apparatus according to claim 1, further comprising a control unit capable of controlling a flow rate and pressure of the oxygen gas supplied to the bubble generating unit by the oxygen supply tube.   The bubble generating device according to claim 1, wherein the surface of the bubble generating unit includes a curved surface in which the plurality of holes are formed.   The predetermined range when the plurality of holes are formed in a circular shape, and an inner diameter of an opening portion at which the plurality of holes opens on the surface is defined as a size at which the plurality of holes open on the surface. The bubble generating device according to claim 1, wherein a range of 1 μm to 300 μm is set.   The bubble generating device according to any one of claims 1 to 4, wherein the surface of the bubble generating unit is covered with a coating layer capable of suppressing adhesion of blood components.