JPH04108430A - Catheter - Google Patents

Abstract

PURPOSE:To draw gases in the specific section in blood vessel by providing a flexible outside tube which is closed at the front end, is constituted of a flexible permeable membrane in the position slightly retreated from the closed end and is provided with a gas taking out port in the base end part and a flexible gas supply tube extending to the front end of the outside tube into this outside tube. CONSTITUTION:This catheter is inserted into the blood vessel and the side wall 4 at the front end is positioned to the position where the gases are to be drawn. An inert gas, for example, gaseous helium, is supplied through the gas supply tube 8 from the outside. The gaseous helium emerges from the front end of the gas supply tube 8, passes the spacing between the outside tube 2 and the gas supply tube 8 and is taken out of a gas take-out port 6. Since the side wall 4 is a flexible permeable material, the gaseous components dissolved in the blood existing on the outside, for example, acetone, krypton, etc., pass the membrane of the side wall 4 and enters the inside of the outside tube. These gases ride in the flow of the gaseous helium and are taken out of the gas take-out port 6. An analyzer is kept connected to the gas take-out port 6, by which the kinds and concns. of the taken out gases are detected.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a catheter for diagnosis and treatment used in the medical field.

(Conventional technology) The catheter is used to collect blood, measure blood pressure, and measure temperature.

It is inserted into a blood vessel in order to inject liquid medicine into a specific area within the blood vessel.

On the other hand, low molecular gases such as acetone and krypton dissolved in blood are particularly related to the depth of anesthesia during surgery, and it is important to accurately measure these low molecular gases. However, with conventional catheters, it is not possible to directly measure the gas concentration within blood vessels, and the gas concentration is measured by drawing blood.

(Problems to be Solved by the Invention) An object of the present invention is to enable gas collection at a specific site in a blood vessel using a catheter.

Another object of the present invention is to enable external supply of a gaseous component to a specific site in a blood vessel using a catheter.

(Means for Solving the Problems) In order to collect gas at a specific site in a blood vessel, the catheter of the present invention has a closed tip and a gas permeable membrane at a position slightly retracted from the tip, It includes a flexible outer tube having a gas outlet at its base end, and a flexible gas supply tube provided inside the outer tube and extending to the distal end of the outer tube.

In a preferred embodiment, the distal end of the gas supply pipe is disposed closer to the distal end than the distal end of the gas permeable membrane of the outer tube.

In order to supply a gaseous component from the outside to a specific site in a blood vessel, the catheter of the present invention has a distal end made of a gas-permeable membrane, and gas is supplied from the proximal end.

(Function) Since the side wall of the distal end of the catheter is a gas-permeable membrane, when this catheter is inserted into a blood vessel, gas dissolved in the blood permeates into the interior of the catheter. When an inert gas such as helium is supplied from the gas supply pipe, the gas that has entered the catheter from the blood is sent out by the inert gas and guided to an analyzer or the like through the gas outlet.

In contrast to collecting gaseous components from blood, if gaseous components such as anesthetic gas are supplied from the outside through the gas supply tube, the gaseous components will dissolve into the blood through the gas-permeable membrane at the tip. To go. When supplying gaseous components, a catheter with a double tube structure for gas collection can be used, but even if it is not a double tube, a catheter with a gas permeable membrane at the tip can be used to collect gaseous components from the outside. The supply of components can also dissolve gaseous components in the blood.

(Example) FIG. 1 represents one embodiment.

Reference numeral 2 denotes a flexible outer tube 1 made of, for example, a silicone rubber material. The distal end of the outer tube 2 is closed, and a side wall 4 at a position slightly set back from the distal end surface is made of a gas permeable material.

As the gas permeable material, for example, a thin film of polytetrafluoroethylene having a thickness of about 0.1 to 0.2 mm can be used. The side wall 4 made of gas-permeable material serves as an inlet for gas dissolved in the blood.

A gas outlet 6 is provided at the base end of the outer tube 2 to take out the gas taken in from the side wall 4 together with the inert gas.

A gas supply tube 8 made of a flexible material is inserted into the outer tube 2, and the outer tube 2 and the gas supply tube 8 have a double tube structure. The space between the outer tube 2 and the gas supply tube 8 is hermetically sealed by a ring 1o at the proximal end of the gas outlet 6.

The tip opening 12 of the gas supply pipe 8 is positioned closer to the tip than the tip of the side wall 4 of the gas permeable membrane.

In one embodiment, the outer diameter of the outer tube 2 is about 3 mm, and the length of the side wall 4 is about 5 cm. The length from the tip of the outer tube 2 to the gas outlet 6 is about 1 to 2 m.

Next, the operation of this embodiment will be explained.

This catheter is inserted into a blood vessel, and the side wall 4 of the distal end is positioned at the position where gas sampling is to be performed. An inert gas, such as helium gas, is supplied from the outside through the gas supply pipe 8. The flow rate of helium gas is, for example, 2 to 5 mQ.
/minute. Helium gas comes out from the tip of the gas supply pipe 8, passes between the outer tube 2 and the gas supply pipe 8, and is taken out from the gas outlet 6. Since the side wall 4 is made of a gas-permeable material, gas components dissolved in the blood on the outside can be absorbed.

For example, acetone, krypton, etc. pass through the membrane of the side wall 4 and enter the outer tube 2. These gases are taken out from the gas outlet 6 along with the flow of helium gas.

By connecting an analyzer such as a gas chromatograph-mass spectrometer to the gas outlet 6, the type and concentration of the extracted gas can be detected.

If the tip of the gas supply tube 8 is placed closer to the tip than the tip of the side wall 4 as shown in FIG. , is quickly removed along with the flow of inert gas.

The embodiment shown in FIG. 1 is not only used to collect dissolved gases in blood, but also can be used to externally supply a gaseous component such as anesthetic gas to a specific site in a blood vessel. At this time, if the side wall 4 is located at a specific location in the blood vessel and a gaseous component is supplied from the gas supply tube 8, the gaseous component will be dissolved into the blood through the membrane of the side wall 4.

As shown in FIG. 2, a catheter for supplying gaseous components into blood includes a distal end 16 of an outer tube 14 made of a flexible material.
It may have a structure in which the membrane is made of a gas permeable membrane. In this case, the gaseous component is supplied from the proximal end of the outer tube 14.

(Effects of the Invention) In the catheter of the present invention, a gas permeable membrane portion is provided at the distal end of the flexible outer tube, so that dissolved gas in blood can be collected through the gas permeable membrane.

Further, gaseous components can be supplied into the blood through the gas permeable membrane at the tip of the outer tube.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are sectional views each showing an embodiment. 2.14-... Outer tube, 4... Side wall of gas permeable membrane, 6... Gas extraction 0.8... Gas supply pipe, 12-...・Tip opening of gas supply pipe, 16・
...Dus permeable membrane part at the tip of the outer tube. Patent applicant: Shimadzu Corporation

Claims (3)

[Claims] (1) A flexible outer tube with a closed tip and a gas permeable membrane at a position slightly set back from the tip, and a gas outlet at the proximal end, and an outer tube provided within this outer tube. a flexible gas supply tube extending to the distal end of the catheter; (2) The catheter according to claim 1, wherein the distal end of the gas supply tube is disposed closer to the distal end than the distal end of the gas permeable membrane of the outer tube. (3) A flexible tube catheter whose distal end is composed of a gas-permeable membrane and to which gas is supplied from the proximal end.