JPS61115571A - Auxiliary lung apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an auxiliary lung device, particularly to a auxiliary lung device with a compact structure suitable for long-term use.

[Prior art 1] A model oxygenator constructed using a homogeneous membrane such as a silicone membrane or a porous membrane made of a hydrophobic material such as polypropylene or Teflon is already known, for example, from Japanese Patent Laid-Open No. 180098/1983. be. These model oxygenators bring gas and blood into contact through the membrane surface of a flat membrane or hollow fiber membrane, allowing gas exchange to take place between them. It is being put into practical use as a superior type of oxygenator because it is less likely to cause degeneration.

When an artificial lung device including such a model oxygenator is used as an auxiliary device for the human body, there are two methods: to remove blood from the femoral artery and return it to the femoral vein, or to remove blood from the femoral vein and return it to the axillary vein. Typical methods include draining blood from the femoral vein and returning fluid to the femoral artery.
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When used as an artificial lung, it is required that the artificial lung device has a simple structure and is compact enough to be installed and used at the bedside.

The amount of blood drawn from the human body when using the auxiliary tightening device with the blood circuit described above is mainly limited by the thickness of the blood vessels in the human body that connect the auxiliary pavement layer, and is generally about 1000 d/min. Blood flow is limited. On the other hand, the amount of carbon dioxide gas generated in the adult human body is generally 20
It is about 0 mA/min or more. Removal of this carbon dioxide gas is important for respiratory management and is specially designated as ECC02R. Therefore, in order to remove enough carbon dioxide from the body to prevent acid blood formation using the auxiliary tightening device, it takes 1000 d
It is necessary to use a membrane that has the ability to remove carbon dioxide (carbon dioxide gas transfer rate per unit membrane area) for 200 aj 7 minutes or more under a blood flow rate of approximately 200 aj/min. but,
With a compact oxygenator with a membrane area of about 1 ml, the above 200 tg under a blood flow rate of 1000 aj/min.
There is no known artificial lung that has a carbon dioxide removal capacity of about 1/min or more.

The carbon dioxide removal capacity of a particular oxygenator varies depending on the oxygen and blood supply flow rates to the oxygenator. FIG. 3 shows this relationship.

Therefore, as a method to increase carbon dioxide removal ability,
It is conceivable to increase the flow rate of oxygen supplied to the oxygenator, but as shown in FIG. 3, the carbon dioxide removal ability is saturated at a certain flow rate of oxygen and does not increase beyond that.

Regarding the blood supply flow rate, there is a limit to the blood flow rate extracted from the human body as mentioned above, so it is not possible to simply increase the blood supply flow rate to the artificial lung device. In order to make the performance sufficient, the membrane area within the oxygenator can be increased, but an increase in membrane area inevitably leads to 7 people, 1 lung device, and 0 large-sized lungs.
oEcMII- *It is possible to meet the requirements of *! ! do not have.

[Problems to be Solved by the Invention] As a result of intensive study on the development of an artificial lung device that is compact and suitable for long-term clinical use, the present inventors have found that blood extracted from the human body is temporarily stored in a reservoir, and this blood By adopting a system that supplies and circulates carbon dioxide to the gas exchange function unit at a flow rate higher than the blood flow rate supplied into the reservoir, this device has a carbon dioxide removal capacity of about 200 tg/min or more as described above. The present invention was completed by discovering that the function as an auxiliary tightening device can be achieved.

The purpose of the present invention is to be compact, suitable for long-term clinical use,
It is an object of the present invention to provide an artificial lung device suitable as a respiratory support device particularly for respiratory failure.

Means for Solving Problem c] That is, the auxiliary tightening device of the present invention includes a blood inlet, a blood outlet, a blood supply port to the gas exchange function section, and a blood reception port from the gas exchange function section. a reservoir having a blood inlet, a blood outlet, a gas exchange membrane having a blood inlet, a blood outlet, a gas outlet, and a gas outlet;
A liquid feeding port of the reservoir and a blood inlet of the gas exchange function section are connected to each other, and a liquid receiving port of the reservoir and a blood outlet of the gas exchange function section are connected to each other.

[PREFERRED EMBODIMENTS FOR CARRYING OUT THE INVENTION] The auxiliary tightening device of the present invention will be described in more detail below with reference to the drawings.

FIG. 1 is a schematic diagram showing the outline of the configuration of the auxiliary tightening device of the present invention.

As shown in Figure 1g1, the auxiliary tightening device of the present invention basically consists of a gas exchange function unit that receives and stores blood to be gas exchanged and performs gas exchange between the blood supplied from the reservoir 1 and the reservoir 1. 2, which are connected to each other.

The reservoir 1 in the auxiliary tightening device of the present invention includes a blood inlet 3, a blood outlet 4, and a blood supply port 5 to the gas exchange function section.
and a blood receiving port 6 from the gas exchange function section, and may have deaeration means if desired. Blood (venous blood) taken from the human body.

Blood is supplied into the reservoir 1 from the blood introduction port 3.

The reservoir 1 has a structure such that the blood supplied into the reservoir 1 does not flow directly to the blood outlet 4, but almost the entire amount is sent to the gas exchange function section 2 through the blood supply port 5. This is desirable.

Of course, during priming or when the blood flow rate received from the blood inlet port 2 is lower than the blood flow rate received from the blood receiving port from the gas exchange function section, the above conditions do not need to be met; the blood outlet port of the reservoir 1 4, the arterial blood is discharged through the gas exchange function section 2 and returned to the body.

On the other hand, the gas exchange function section 2 has a blood introduction lower, a blood outlet 8, a gas inlet 9, and a gas outlet 10, and a gas exchange membrane such as a flat membrane or a hollow fiber membrane is disposed inside thereof. These membranes and predetermined partitions separate the chamber into a contact chamber through which blood flows and a gas channel through which gas containing oxygen flows.

The specific internal structure of the gas exchange function part l can take various forms, and various conventionally known so-called oxygenator modules can be used as they are, but it has a compact structure, oxygen uptake ability, It is desirable to have an excellent ability to remove carbon dioxide gas and to have a small pressure drop in the contact chamber through which blood flows from the blood introduction lower to the blood outlet 8.

An example of a preferable gas exchange function section 1 that satisfies the above required performance is one having an internal structure as shown in FIG. 2, for example. That is, in this example, the gas exchange function section 2 is formed in the shape of a shallow box, and a porous hollow fiber W1413 is used as the gas exchange membrane in the contact chamber 12, and the hollow fiber membrane 13 is arranged in the blood flow direction. It is arranged so that it runs almost perpendicular to. The direction of blood flow here is
The interior of the contact chamber 12 refers to the direction from the inlet to the outlet of the blood within the contact chamber 12, rather than the flow direction of the blood flow actually formed when blood flows into the contact chamber 12. , installed in a direction transverse to the blood flow direction and having a width in a direction perpendicular to the installation direction of the hollow fiber membrane + ti I
y 6 J: 3 configurations 6hf = blood flow path section 14. ! −、、
1m-.

It is divided into a plurality of small chambers 15 which are separated through a blood flow path section 14 and each have a hollow fiber membrane 13 built therein.

The blood flow path portion 14 may be provided with struts extending in the thickness direction of the contact chamber.The reason why such a blood flow path portion 13 is provided inside the contact chamber 12 is because the blood flow path portion 14 is provided with a strut extending in the thickness direction of the contact chamber. This is to prevent blood channeling by causing turbulence in the blood flow in the thickness direction as well. The filling rate of the hollow fiber membrane 13 in the contact chamber 12 is preferably 10 to 55%.
If the filling rate is less than 10%, blood channeling tends to occur, and if it is more than 55%, the blood flow resistance becomes excessive, increasing the pressure drop in the contact chamber and at the same time inducing hemolysis.

As the waste exchange membrane built into the gas exchange function section z of the auxiliary imager of the present invention, a flat membrane or a hollow fiber membrane can be used.
Porous hollow fiber membranes with excellent gas permeability are preferred, and for example, microporous hollow fiber membranes made of polyolefin resins such as polyethylene and polypropylene can be suitably used.

In the auxiliary imaging device of the present invention, the reservoir 1 and the gas exchange function section 2 are composed of the liquid feeding port 5 of the reservoir and the blood introduction lower of the waste exchange function section, and the liquid receiving port 6 of the reservoir and the gas exchange function section. Normally, tubes made of polyvinyl chloride or the like, preferably treated with anti-thrombotic treatment, are used for these connections; A pump for blood perfusion is installed on the side of the body.

Further, the auxiliary imaging device of the present invention may be provided with a heat exchange means in order to maintain the blood undergoing gas exchange at an appropriate temperature.
For example, a jacket type heat exchange means can be attached to the outside of the contact chamber 12 of the gas exchange function section 2.

In such an auxiliary imaging device of the present invention, blood taken out from a human body is first supplied into the reservoir 1 through the blood introduction port 3 at a predetermined blood flow rate. The blood stored in the reservoir 1 is supplied from the liquid feeding port 5 to the blood introduction lower of the gas exchange function section 2 at a flow rate higher than the blood flow rate supplied into the reservoir 1, and gas exchange is performed in the gas exchange function section 2. Blood that has been converted into arterial blood is discharged from the blood outlet 8 and circulated to the reservoir 1 via the liquid receiving port 6. Of the blood that has undergone gas exchange and is circulated to reservoir 1, blood inlet 3
A flow rate equal to the flow rate flowing into the reservoir 1 is discharged from the blood outlet 4 of the reservoir 1 and returned to the human body, while the remaining flow rate of blood is circulated again from the liquid supply port 5 to the gas exchange function section 2.

In this way, in the auxiliary imaging device of the present invention, the flow rate of blood sent from the reservoir 1 to the gas exchange function section 2 can be selected regardless of the flow rate of blood taken out from the human body. Therefore, if the flow rate of blood supplied to the gas exchange function section 2 is selected according to the inherent carbon dioxide removal ability of the gas exchange function section 2, it is possible to achieve carbon dioxide removal for 2Qlaj 7 minutes or more. The object of the present invention is achieved, which is to perform blood gas exchange while preventing stiffening without increasing the size of the exchange function section.

[Effects of the Invention] The auxiliary imaging device of the present invention is compact enough to be installed and used at the bedside, yet has sufficient carbon dioxide removal ability to prevent stiffening. It is suitable for long-term clinical use, especially as a respiratory support device for respiratory failure.

[Example] Hereinafter, the auxiliary image device of the present invention will be described in more detail according to an example.

EXAMPLE A gas exchanger cylinder having an internal structure as shown in FIG. 2 and a reservoir with an internal volume of 70 tj are connected as shown in FIG. 1 via an antithrombotic polyvinyl chloride tube. The imaging device was configured.

A blood perfusion pump was disposed between the liquid feeding port 5 and the blood introduction lower portion of the gas exchange function section. The hollow fiber membrane filled in the gas exchange function part is a microporous hollow fiber membrane made of polypropylene, and its inner diameter is approximately 200 μm and outer diameter is approximately 244 μm.
-, the outer surface area of the hollow fiber membrane in the contact chamber in the gas exchange function section was about lrn', and the filling rate was about 25%.

Venous blood was supplied to the reservoir of this auxiliary drawing device at a flow rate of 1000 sd for 7 minutes, and blood was circulated from the reservoir to the gas exchange function section at a flow rate of 3000 ml/min.

Pure oxygen was flowed through the gas exchange function section at a flow rate of 9,000 aj/7 min to add oxygen and remove carbon dioxide gas.

At this time, the oxygenation and carbon dioxide removal capacities calculated by analyzing the blood discharged from the blood outlet 4 of the reservoir of the auxiliary imaging device are as follows: blood flow rate 1000aj/layer ITI
/ m″ each about 85cc/win, about 20
It was 5cc/win.

For comparison, when venous blood was directly supplied to the above gas exchange function unit at a flow rate of 100011jZ without providing a reservoir, and the oxygenation and carbon dioxide removal t@ were kept constant at δ, each of approximately fiOcc/+a 'in, about 1
It was 20cc/in.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the configuration of the auxiliary image device of the present invention, and FIG. 2 is a vertical sectional view (&) and a partially cutaway plane view showing an example of the -i aspect of the gas exchanger part. FIG. 3 is a graph showing the relationship between the carbon dioxide removal capacity and the oxygen supply flow rate and blood supply flow rate in an artificial pavement. l: Reservoir 2 = Gas exchange function part 3 2 Blood inlet 4: Blood outlet 5: Liquid feeding port 6: Liquid receiving port A: Blood inlet 8: Blood outlet 9: Gas inlet 10: Gas outlet ll: Blood pump 12: Blood inlet 13: Blood outlet 14
:Blood flow path section 15: Small chamber 1 Figure 2a

Claims (1)

[Scope of Claims] 1) A reservoir having a blood inlet, a blood outlet, a blood supply port to the gas exchange function section, and a blood reception port from the gas exchange function section; a gas exchange function section incorporating a gas exchange membrane having an outlet, a gas inlet port, and a gas outlet port, a liquid feeding port of the reservoir, a blood inlet port of the gas exchange function section, and a liquid receiving port of the reservoir; and a blood outlet of the gas exchange function section are connected to each other. 2) When the flow rate of blood received from the blood inlet of the reservoir by the reservoir is lower than the flow rate of blood received from the blood receiving port from the gas exchange function section, substantially the entire amount of blood received from the blood inlet of the reservoir; The auxiliary lung device according to claim 1, wherein the auxiliary lung device has a structure for discharging the liquid from the liquid feeding port.