JPH0539552U - Constant pressure maintenance mechanism in oxygenator - Google Patents

Abstract

(57) [Summary] [Purpose] To maintain the pressure in the air piping within a certain range. [Structure] When air supplied from a compressor flows from a narrow inflow path 22 to a wide outflow path 12, the outflow path 12
If the inner pressure and the outer pressure are substantially equal, the air passes through the outflow passage 12 as it is. When the pressure in the outflow passage 12 rises and becomes higher than the atmospheric pressure, the air in the outflow passage 12 is discharged to the outside through the flow passage 30, so that the outflow passage 1
The pressure in 2 does not rise above the set pressure and is within a certain pressure range. The set pressure in the outflow passage 12 can be changed by adjusting the shape, direction, inclination and width of the flow passage 30.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a mechanism for maintaining the pressure in the air pipe of an oxygenator within a certain range.

[0002]

[Prior art and its problems]

 In an oxygenator that supplies compressed air from an air compressor to a patient's mask through an air pipe, it is essential to prevent overpressure in the mask from the viewpoint of patient protection. Therefore, conventionally, by providing an exhaust hole near the air pipe of the mask, air is exhausted from the exhaust hole so that the pressure inside the mask does not exceed a certain value when the patient uses the mask. In this case, the pressure in the mask changes periodically due to fluctuations in the air pressure supplied by the compressor and breathing by the patient. In FIG. 3, the solid line A is a graph of the pressure change in the mask at this time, and the amplitude is large vertically.

It is generally said that the pressure inside the mask is ideally constant at a water column of about 20 cm, but a mask provided with the exhaust holes cannot prevent pressure fluctuation inside the mask. To prevent pressure fluctuations in the mask, it is possible to increase the compressor capacity and supply a large amount of air. However, it is necessary to discharge a large amount of excess air outside the system at all times. become.

For this reason, it is known to attach a safety valve that operates at low pressure to the air pipe, but since the safety valve operates by a mechanical structure, there is a risk of failure and safety is reduced. There is no choice but to hesitate to adopt it in medical equipment, which is extremely important.

[0005]

[The purpose of the device]

 Therefore, the present invention provides a mechanism capable of preventing overpressure in the air pipe and maintaining the pressure in the air pipe within a certain range without constantly discharging excess air. To aim.

[0006]

[Device configuration]

 In order to achieve the above object, the constant pressure maintaining mechanism according to the present invention comprises, at one end of an air pipe, an inflow passage for air and an outflow passage having a larger cross-sectional area than this inflow passage in the axial direction. It is characterized in that a flow passage communicating with the outside air is provided between the inlet and the outlet and is inclined toward the inlet. Further, the flow passage is formed so as to be adjustable.

[0007]

[Action]

 When the air supplied from the compressor flows from a narrow inflow path to a wide outflow path, if the pressure in the outflow path and the outside air pressure are approximately equal, the air passes through the outflow path as it is. When the pressure in the outflow passage rises above the atmospheric pressure, the air in the outflow passage is discharged to the outside through the flow passage, so the pressure in the outflow passage does not rise above the set pressure. Moreover, it falls within a certain pressure range. The set pressure in the outflow passage can be changed by adjusting the shape, direction, inclination and width of the flow passage.

[0008]

【Example】

 Hereinafter, a preferred embodiment of the present invention provided in an air pipe of an oxygenator will be described with reference to the drawings. FIG. 1 is a vertical sectional front view of a constant pressure maintaining mechanism 8. The mechanism 8 includes an outer cylinder 10 having an outflow passage 12 in the axial direction and an inflow passage 22 having a flow passage cross-sectional area narrower than that of the outflow passage 12. It is composed of an inner cylinder 20 having a coaxial direction. The constant pressure maintaining mechanism 8 is connected as shown in FIG. 2, and in the following description, the pipe side connected to the compressor 7 side is referred to as the right part and the right end part, and the pipe side connected to the mask 9 side is referred to. Left side, left edge, etc.

The outflow passage 12 of the outer cylinder 10 has an inner diameter of the right portion larger than the inner diameter of the left portion through the inclined portion 13, and an internal thread 14 is formed on the inner peripheral surface of the right end portion thereof. A plurality of flow holes 15 are formed in the right end portion of the inclined portion 13 so as to penetrate the inner peripheral surface and the outer peripheral surface of the outer cylinder 10 and extend in the centrifuging direction. Reference numeral 16 is a connecting portion formed at the left end portion of the outer cylinder 10 for fitting the pipe on the mask 9 side.

A male screw 24 that is screwed into the female screw 14 is formed on the right portion of the outer peripheral surface of the inner cylinder 20 so that the inner cylinder 20 can move left and right inside the outer cylinder 10. The left end of the inner cylinder 20 has a conical shape matching the inclined portion 13 of the outer cylinder 10, and a conical surface-shaped flow passage 30 is formed between the conical surface 23 and the inclined portion 13. The left end portion of the flow passage 30 communicates with the outflow passage 12 of the outer cylinder 10, and the right end portion of the flow passage 30 communicates with the flow hole 15 formed in the outer cylinder 10. The width (radial length) of the flow passage 30 can be adjusted by the relative positional relationship between the inside of the outer cylinder 10 and the inner cylinder 20, and if the two are completely screwed together, the flow passage 30 is closed. It Reference numeral 26 is a female screw formed on the inner peripheral surface of the right end portion of the inner cylinder 20 for connecting to a pipe on the compressor 7 side.

Reference numeral 32 denotes a rocking ring that is screwed into the male screw 24 of the inner cylinder 20 at the right end of the outer cylinder 10 to prevent the outer cylinder 10 from unintentionally moving to the right and blocking the flow passage 30. To do.

Next, the operation of the above embodiment will be described. When the patient wearing the mask 9 is in the inhalation state, when the air supplied from the compressor 7 flows from the narrow inflow path 22 to the wide outflow path 12, the pressure in the outflow path 12 and the outside air pressure are almost equal, so the air is left as it is. It passes through the outflow passage 12 and flows toward the mask 9.

Further, in the exhalation state, the outflow passage 12 is blocked by the exhalation of the patient, so that the pressure in the pipe tends to rise above the atmospheric pressure. At this time, the air is discharged to the outside through the flow passage 30 formed between the inflow passage 22 and the outflow passage 12, so that the pressure in the mask 9 does not rise above the set pressure.

The set pressure in the mask 9 can be changed by adjusting the width of the flow passage 30. A constant pressure maintaining mechanism 8 in which the width of the flow passage 30 is adjusted so that the pressure in the mask 9 becomes a water column of 20 cm is provided in the middle of the air pipe, and the pressure change in the mask 9 due to the breathing of the patient is measured. Show. In the figure, the almost horizontal solid line B shows the change with time at this time, and it can be seen that it is extremely close to the ideal line shown by the broken line.

By sufficiently narrowing the diameter of the left end portion of the inflow passage 22 with respect to the diameter of the outflow passage 12, the velocity of the air immediately after being introduced from the left end portion of the inflow passage 22 to the outflow passage 12 is increased. By doing so, the outside air can be introduced into the outflow passage 12 from the flow passage 30 by the ejector effect.

In the above embodiment, the constant pressure maintaining mechanism 8 is composed of two members, the outer cylinder 10 and the inner cylinder 20, and the width of the flow passage 30 can be adjusted. However, the set pressure is set to a predetermined value, and the value is set to a predetermined value. When it is not necessary to change the present invention, the present invention is not limited to the above-mentioned embodiment, and the constant pressure maintaining mechanism 8 can be integrally formed to reduce the weight of the mechanism 8. In this case, the lock ring 32 becomes unnecessary.

The shape of the flow passage 30 is not limited to a straight line, but the air introduced into the connection portion between the inflow passage 22 and the outflow passage 12 via the inflow passage 22 is directly flowed from the connection portion to the flow passage 30 and the circulation. It is necessary to form it in a shape, a direction or an inclination so that it does not easily flow out through the hole 15 and easily flows toward the outflow passage 22.

[0018]

[Effect of the device]

 According to the constant pressure maintaining mechanism of the present invention, it is possible to prevent overpressure in the air pipe and maintain the pressure in the air pipe within a certain range without constantly discharging excess air. .. Further, since the number of parts is small and the structure is simple, no failure occurs, and it can be applied to an air pipe in a field requiring extremely high safety such as medical equipment. That is, if it is used in the air pipe of the artificial lung device, the pressure in the mask can be kept constant, so that there is an effect that the breathing action of the patient becomes comfortable.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a constant pressure maintaining mechanism.

FIG. 2 is a schematic view showing a usage state of the oxygenator.

FIG. 3 is a graph showing a pressure fluctuation curve in a mask,
A solid line A shows a conventional example, and a solid line B shows a case where the constant pressure maintaining mechanism of the present invention is used.

[Explanation of symbols]

 10 Outer Cylinder 12 Outflow Channel 15 Circulation Hole 20 Inner Cylinder 22 Inflow Channel 30 Flow Channel

Claims (2)

[Scope of utility model registration request] 1. A flow passage having an air inflow passage and an outflow passage having a larger cross-sectional area than the inflow passage in an axial direction at one end of an air pipe, and a flow passage communicating with outside air between the inflow passage and the outflow passage. A constant pressure maintaining mechanism in an artificial lung device in which the valve is inclined toward the inflow path side. 2. The constant pressure maintaining mechanism in the artificial lung device according to claim 1, wherein the flow passage is formed so as to be adjustable.