CN104174252B - A device for eliminating alkali metal vapor in hyperpolarized gas - Google Patents

Abstract

The invention discloses a kind of device eliminating alkali metal vapour in hyperpolarized gas of the present invention, the welding of spiral glass tube two ends has vacuum glass valve, is arranged in ultra-low temperature constant temperature groove; PFA threeway connects PFA pipeline, vacuum glass valve, ultra-low temperature constant temperature groove, aluminium alloy fixed mount, spiral glass tube, pipeline, operated pneumatic valve, electromagnetic valve, pressure gauge, gas cylinder; Computer instruction electromagnetic valve conducting gases at high pressure drive the switch of operated pneumatic valve, control the glide path of hyperpolarized gas.Apparatus of the present invention structure is simple, easy to operate, purified pool is integrated, the highly purified hyperpolarized gas that circulation secondary condensation alkali metal vapour obtains, can meet the requirement of organism magnetic resonance imaging.

Description

A device for eliminating alkali metal vapor in hyperpolarized gas

technical field

The patent of the present invention relates to the field of spin exchange optical pump and hyperpolarized gas nuclear magnetic imaging, more specifically to a hyperpolarized gas collection and respiratory intervention system for imaging of small animals and human bodies, which is suitable for eliminating alkali metal vapor in hyperpolarized gas device system.

Background technique

Spin-exchange optical pumping technology can produce highly non-thermal equilibrium polarized inert gases, whose nuclear spin polarization is 4 to 5 orders of magnitude larger than that of thermal polarization under the same conditions, so it is called hyperpolarization gas. As a gas contrast agent, it can greatly improve the magnetic resonance signal, and make up for the regret that traditional magnetic resonance imaging cannot obtain information about the lungs of living organisms.

Hyperpolarized gas magnetic resonance imaging technology is based on the physical basis of spin-exchange optical pumping, which mainly includes two parts: generation and storage of hyperpolarized gas (for example, hyperpolarized noble gas xenon), and ultra-high sensitivity gas magnetic resonance imaging. The generation of hyperpolarized gas is obtained by the process of spin exchange collision between xenon in the working gas (usually a mixture of xenon + nitrogen + helium) and an alkali metal atom that is optically pumped to a high degree of polarization (polarization ~100%) The magnetic resonance imaging is mainly performed by introducing/inhaling the hyperpolarized gas into the body of the measured organism through the gas intervention system.

In the high-efficiency spin-exchange optical pumping process, it is required to use a working gas that is fully mixed with the alkali metal vapor. In biological hyperpolarized gas magnetic resonance imaging, it is necessary to use completely pure hyperpolarized gas without alkali metal vapor. In the hyperpolarized system, the method of glass tube + room temperature, or U-shaped tube + ice water Dewar is usually used, which greatly reduces the content of alkali metal vapor in the hyperpolarized gas, but there are still trace amounts of alkali metal vapor in the hyperpolarized gas. Residual alkali metal vapor, its technical details and causes of problems are:

Glass tube + room temperature technology, usually a long glass tube is connected to the outlet of the optical pump cell, and the glass tube is located in a room temperature environment far below the working temperature of the optical pump cell, so that the alkali metal vapor in the flowing working gas is cooled and adsorbed to the inner wall of the glass pipe. However, due to the limitation of the length of the glass pipe used in the hyperpolarized system, and the room temperature is usually not low enough, the alkali metal vapor contained in the hyperpolarized gas cannot be completely condensed on the inner wall of the glass;

U-shaped tube + ice water Dewar technology is an improvement of technology (1). Place a U-shaped glass tube in the ice water Dewar, and use the curved U-shaped glass tube and the temperature environment of ice water ~273K to make more alkali metal vapor detach from the working gas and condense on the inner wall of the U-shaped glass tube. However, the working gas with a higher flow rate still took a small amount of alkali metal vapor;

After that, a small amount of alkali metal vapor will flow into the collection and storage device together with the working gas. Although the collection and storage device of hyperpolarized gas usually works at the ultra-low temperature of liquid nitrogen, the stored solid hyperpolarized xenon is still in the sublimation process. There will be some alkali metal vapor mixed in the hyperpolarized gas.

Since alkali metal reacts violently with water to release heat, even a very small amount may cause some damage to the organism being tested. Therefore, from the crucial point of protecting the safety of organisms, it is necessary to reduce the content of alkali metal vapor in the hyperpolarized gas entering the measured organisms (generally less than 0.5ng) as much as possible, and more effective methods and technologies are needed.

The present invention proposes a device for eliminating alkali metal vapor in hyperpolarized gas, and its specific technology is:

Using a spiral glass tube increases the surface area of the glass inner wall, allowing the alkali metal vapor flowing with the hyperpolarized gas to more contact with the inner wall of the glass container;

Utilize the temperature of ultra-low temperature constant temperature bath (such as 243K) to condense alkali metal vapor more effectively;

The hyperpolarized gas is purified for the second time by circulating the secondary condensation of the alkali metal vapor.

In this way, the purpose of eliminating residual traces of alkali metal vapor in the flowing hyperpolarized gas is achieved.

Contents of the invention

In view of the above problems, the object of the present invention is to provide a device for eliminating alkali metal vapor in hyperpolarized gas, which has a simple structure and is easy to operate. It can provide high-purity hyperpolarized gas as a contrast agent for gas magnetic resonance imaging of living organisms.

To achieve the above object, the present invention adopts following technical measures:

Its technical concept is: when the mixed gas (such as hyperpolarized xenon + nitrogen + helium) containing a trace amount of alkali metal vapor flows through the device of the present invention, since the working point of the device of the present invention is at the set ultra-low temperature (243K), the alkali metal The vapor will condense on the inner wall of the spiral glass tube, but its temperature cannot condense any gas such as xenon, nitrogen and helium in the mixed gas, so as to achieve the purpose of separating the alkali metal vapor from the mixed gas. In the device of the present invention, the spiral glass tube has a large total contact area with the mixed gas, so the alkali metal vapor contained in the mixed gas can have more chances to condense on the inner wall of the spiral glass tube at ultra-low temperature. Then, the primary purified mixed gas flows out of the device of the present invention and enters the hyperpolarized xenon collection system. Under the condition of liquid nitrogen temperature, the hyperpolarized xenon gas is separated from nitrogen and helium in the mixed gas and solidified. After the collection is completed, it is necessary to sublimate the solid hyperpolarized xenon. After this process, the sublimated hyperpolarized gas passes through the device of the present invention to carry out the secondary condensation process of alkali metal vapor to further purify the hyperpolarized gas, and then The highly purified hyperpolarized gas that does not contain alkali metal vapor is output from the device of the present invention, enters a collection air bag, and is applied to biological magnetic resonance imaging.

A device for eliminating alkali metal vapor in hyperpolarized gas, comprising an ultra-low temperature constant temperature tank, a spiral glass tube is arranged in the ultra low temperature constant temperature tank, and one end of the spiral glass tube communicates with one end of a first vacuum glass valve arranged on the ultra low temperature constant temperature tank, The other end of the spiral glass tube communicates with one end of the second vacuum glass valve set on the ultra-low temperature constant temperature tank, and the other end of the first vacuum glass valve communicates with the second connection end of the first PFA tee through the first PFA pipe. The first connection end of the PFA tee is provided with a first pneumatic valve, the third connection end of the first PFA tee is provided with a third pneumatic valve, and the other end of the second vacuum glass valve is connected to the second PFA three-way through the second PFA pipe. The first connecting end of the second PFA tee is connected with the second connecting end of the second PFA tee, and the third connecting end of the second PFA tee is provided with the fourth pneumatic valve.

A device for eliminating alkali metal vapor in hyperpolarized gas, which also includes a gas cylinder, and a first electromagnetic valve, a second electromagnetic valve, a third electromagnetic valve and a fourth electromagnetic valve controlled by a computer, the first electromagnetic valve Control the connection between the cylinder and the first pneumatic valve, the second solenoid valve controls the connection between the cylinder and the third pneumatic valve, the third solenoid valve controls the connection between the cylinder and the fourth pneumatic valve, and the fourth solenoid valve controls the connection between the gas cylinder and the fourth pneumatic valve. The on-off of the bottle and the second pneumatic valve.

The above-mentioned first vacuum glass valve and the second vacuum glass valve are connected to the spiral glass tube by welding.

As mentioned above, one end of the first vacuum glass valve extends into the ultra-low temperature constant temperature tank and is fixed on the inner wall of the ultra low temperature constant temperature tank through the first aluminum alloy fixing frame, and one end of the second vacuum glass valve extends into the ultra low temperature constant temperature tank and passes through the second The aluminum alloy fixing frame is fixed on the inner wall of the ultra-low temperature constant temperature tank.

The device of the present invention adopts the following technical solutions and measures:

(1) Place the spiral glass tube in an ultra-low temperature constant temperature tank to make it work in an ultra-low temperature environment, which can effectively condense the alkali metal vapor flowing through the gas;

(2) The spiral glass tube is used to increase the contact area between the gas and the inner wall of the glass container in a small space, and improve the efficiency of the alkali metal vapor in the condensed gas;

(3) Through the computer command electromagnetic valve to conduct high-pressure gas to switch the pneumatic valve, control the flow channel of hyperpolarized gas, realize remote operation, and perform secondary condensation of alkali metal vapor in hyperpolarized gas to obtain hyperpolarization Secondary purification of gases.

The working process of the device is as follows: first, two vacuum glass valves are respectively welded to the spiral glass container according to the standard glass processing method; then the other ends of the two vacuum glass valves are respectively connected to the PFA tee through the PFA pipe; then, each Two vacant pipes on a PFA tee are connected to the pneumatic valve; the control interface of each pneumatic valve is connected to the electromagnetic valve through the pipeline, and the high-pressure gas is conducted through the electromagnetic valve to control the switch of the pneumatic valve. When the device of the present invention is working, the spiral glass tube is fixed in the ultra-low temperature constant temperature tank (243K) through the aluminum alloy fixing frame, and then the optical pump bubble outlet of the hyperpolarized gas generation system is connected with the pneumatic valve, and then the spiral glass container is opened. Two vacuum glass valves control the switch of the pneumatic valve by controlling the high-pressure gas through the electromagnetic valve, and then constitute the purified flow channel of the hyperpolarized gas. When the device of the present invention is in the process of collecting and purifying, a group of electromagnetic valves in the device of the present invention conduct high-pressure gas to control a corresponding group of pneumatic valves to open, and the mixed gas (for example, hyperpolarized xenon + nitrogen + helium) and alkali metal The steam flows together through the spiral glass tube in an ultra-low temperature environment, thereby realizing the primary condensation of the alkali metal vapor. Then, the mixed gas of primary purification flows out of the device of the present invention and enters the hyperpolarized gas collection system, where, due to the effect of liquid nitrogen temperature, nitrogen and helium are separated, and only the hyperpolarized gas is collected in solid state; when the present invention When used for sublimation purification, another set of electromagnetic valves conducts high-pressure gas to drive the corresponding pneumatic valve to open, and the hyperpolarized gas flows through the spiral glass tube again, and the residual traces of alkali metal vapor in the hyperpolarized gas are condensed by the second stage, making The hyperpolarized gas underwent secondary purification.

The present invention has the following advantages and effects:

It has the characteristics of simple structure, convenient operation, and integration of purification and collection. The device provided by the present invention for eliminating alkali metal vapor in hyperpolarized gas is of great significance for biological magnetic resonance imaging, especially for human lung and brain magnetic resonance imaging, which has very important application prospects and practical value . It can also meet the requirements of magnetic resonance spectroscopy and imaging studies such as porous materials, surfaces, etc. that require the use of hyperpolarized gases. Specifically reflected in the following points:

The device of the present invention has a simple structure and an integrated design, and utilizes a spiral glass tube working at ultra-low temperature to carry out circulating secondary condensation on the alkali metal vapor in the hyperpolarized gas, thereby realizing the secondary purification function of the hyperpolarized gas;

The device of the present invention realizes the automation and programming of collection and purification, sublimation and purification operations through computer-instructed electromagnetic valves to conduct high-pressure gas and drive and switch pneumatic valves;

When the device of the present invention works in conjunction with the hyperpolarized gas generation system, collection system, and sublimation system, it can provide high-purity hyperpolarized gas without alkali metal vapor, which provides a safe way for hyperpolarized gas to be used in biological magnetic resonance imaging. guarantee.

Description of drawings

Fig. 1 is a schematic diagram of a device for eliminating alkali metal vapor in hyperpolarized gas.

Among them: 1-the first pneumatic valve, 2-the first PFA tee, 3-the first PFA pipe, 4-the first vacuum glass valve, 5-the first aluminum alloy fixing frame, 6-ultra-low temperature constant temperature bath, 7-helix Glass tube, 8-the second aluminum alloy fixing frame, 9-the second vacuum glass valve, 10-the second PFA pipe, 11-the second PFA tee, 12-the second pneumatic valve, 13-the third pneumatic valve, 14 -The fourth pneumatic valve, 15-the first electromagnetic valve, 16-the second electromagnetic valve, 17-cable wire, 18-computer, 19-the third electromagnetic valve, 20-the fourth electromagnetic valve, 21-pipeline, 22-pressure Gauge, 23-gas cylinders.

Fig. 2 is a diagram illustrating the implementation of the device of the present invention.

G1- mixed gas from hyperpolarized gas generation system (hyperpolarized gas + nitrogen + helium), G2- primary purified mixed gas (hyperpolarized gas + nitrogen + helium), G3- through the collection system And hyperpolarized gas after sublimation system, G4- hyperpolarized gas after secondary purification.

detailed description

Example 1:

Below in conjunction with Fig. 1 and Fig. 2 the present invention is described in further detail:

First, the materials, shape and construction of the components of a device for eliminating residual alkali metal vapors in hyperpolarized gases are described:

The present invention is a device for eliminating residual alkali metal vapor in hyperpolarized gas, comprising a first pneumatic valve 1, a first PFA tee 2, a first PFA pipeline 3, a first vacuum glass valve 4, and a first aluminum alloy Fixing frame 5, ultra-low temperature constant temperature tank 6, spiral glass tube 7, second aluminum alloy fixing frame 8, second vacuum glass valve 9, second PFA pipeline 10, second PFA tee 11, second pneumatic valve 12, third Pneumatic valve 13, fourth pneumatic valve 14, first electromagnetic valve 15, second electromagnetic valve 16, cable 17, computer 18, third electromagnetic valve 19, fourth electromagnetic valve 20, pipeline 21, pressure gauge 22, gas cylinder twenty three.

The first pneumatic valve 1 is sequentially connected to the first PFA tee 2, the first PFA pipe 3, the first vacuum glass valve 4, the ultra-low temperature constant temperature tank 6, the first aluminum alloy fixing frame 5, the spiral glass tube 7, and the second aluminum alloy fixing frame 8, the second vacuum glass valve 9, the second PFA pipe 10, the second PFA tee 11, and the second pneumatic valve 12; wherein the other end of the first PFA tee 2 is connected with the third pneumatic valve 13, and the second PFA The other end of the tee 11 is connected to the fourth pneumatic valve 14; the first vacuum glass valve 4 and the second vacuum glass valve 9 are welded together with the spiral glass tube 7; the first aluminum alloy fixing frame 5 and the second aluminum alloy are fixed Frame 8 fixes the first vacuum glass valve 4, the second vacuum glass valve 9 and the connected spiral glass tube 7 in the ultra-low temperature constant temperature tank 6; the first pneumatic valve 1, the second pneumatic valve 12, the third pneumatic valve 13, the The four pneumatic valves 14 are respectively connected to the first electromagnetic valve 15, the fourth electromagnetic valve 20, the second electromagnetic valve 16, and the third electromagnetic valve 19 through the pipeline 21, and are connected with the pressure gauge 22 and the gas cylinder 23;

The spiral glass tube 7 is installed in the ultra-low temperature constant temperature bath 6. When the hyperpolarized gas containing a trace amount of alkali metal vapor flows through the spiral glass tube 7, the alkali metal vapor will condense on the glass inner wall of the spiral glass tube 7, thereby eliminating residual The purpose of alkali metal vapor.

The passage of the hyperpolarized gas flow is through the computer 18 instructing the first, fourth, second, and third electromagnetic valves (15, 20, 16, 19) to conduct high-pressure gas to drive the first, second, third, and third electromagnetic valves respectively. The switch of four pneumatic valves (1, 12, 13, 14) is realized. The pneumatic valve without ferromagnetic material will not cause the attenuation of the non-equilibrium nuclear spin polarization of hyperpolarized gas, and realizes a non-destructive polarization. A degree of automation for the removal of alkali metal vapors.

The computer 18 is connected with the first, second, third and fourth electromagnetic valves (15, 16, 19, 20) through the cable 17. During work, the first, fourth, second and third electromagnetic valves are controlled The valves (15, 20, 16, 19) conduct high-pressure gas and respectively switch the first, second, third, and fourth pneumatic valves (1, 12, 13, 14) to guide the hyperpolarized gas to flow into the ultra-low temperature constant temperature tank 6 In the spiral glass tube 7, when the hyperpolarized gas flows through the spiral glass tube 7, the residual alkali metal vapor contained in it condenses on the glass inner wall of the spiral glass tube 7, so as to achieve the purpose of elimination.

The detailed description of each component is as follows:

The model of the first pneumatic valve 1 is PMDP-2K-1/4UG, non-magnetic, and the material is PEEK, as the mixed gas G1 of the hyperpolarized gas generation system flows into the inlet port of the device of the present invention;

The first PFA tee 2, the model is SwagelokPFA-420-3, made of polytetrafluoroethylene plastic, used to connect the first and third pneumatic valves (1, 13), and the first PFA pipe 3, also used as gas flow Two-way channel.

The first PFA pipeline 3, the model is SwagelokPFA-T4-047, the material is polytetrafluoroethylene plastic, its port is grooved, and the two ends can be connected with the first PFA tee 2 and the first vacuum glass valve 4 respectively;

The material of the first vacuum glass valve 4 is Pyrex glass, the model is Kimble/kontesHI-VAC826651, and its function is to precisely control the airflow flowing into the spiral glass tube 7;

The function of the first aluminum alloy fixing frame 5 is to fix the spiral glass tube 7 so that it is in the environment of the ultra-low temperature constant temperature tank 6, and ensure the stability of the gas pipeline in this area, which is self-made;

The function of the ultra-low temperature constant temperature bath 6 is to provide an ultra-low temperature working environment for the spiral glass tube 7, usually the ultra-low temperature working range is 200-265K. In the implementation of the present invention, the model of the ultra-low temperature constant temperature bath used is XC-100B (the working temperature range is 243-373K), and the lowest temperature of 243K is used;

The spiral glass tube 7 is used as a condensation pipe for eliminating residual traces of alkali metal vapor in the laser prepolarized gas. The material is Pyrex glass. The diameter, diameter, length, and number of turns of the glass tube used depend on the capacity of the ultra-low temperature constant temperature bath 6 used . In the embodiment of the present invention, the spiral glass tube 7 is made of a Pyrex glass tube with a diameter of 10 mm. The outer diameter of the spiral glass tube 7 is 100 mm, the length is 200 mm, and the number of spiral turns is 8. ;

The second aluminum alloy fixing frame 8 has the same effect as the first aluminum alloy fixing frame 5, and the two are used in pairs;

The second vacuum glass valve 9 is identical with the material and model of the first vacuum glass valve 4, and is used to control the flow of gas flowing out of the spiral glass tube 7;

The second PFA pipeline 10 has the same function, material and model as the first PFA pipeline 3, and is sealed and connected with the second vacuum glass valve 9 and the second PFA tee 11 respectively;

The second PFA tee 11 is the same model as the first PFA tee 2, and is used to connect the second and fourth pneumatic valves 12, 14, and the second PFA pipeline 10,

The second, third, and fourth pneumatic valves (12, 13, 14) are the same type and function as the first pneumatic valve 1, and are respectively connected by the fourth, second, and third electromagnetic valves (20, 16, 19). The high-pressure gas is correspondingly controlled to open or close to guide the flow route of the hyperpolarized gas;

The first, second, third and fourth electromagnetic valves (15, 16, 19, 20) are all precision electromagnetic valves, the model is Airtec4V210-08, which are used to conduct high-pressure gas to control the opening and closing of pneumatic valves.

The cable 17 is connected to the electromagnetic valve and the computer 18, so that the computer 18 can drive the electromagnetic valve to work, conduct high-pressure gas to drive the pneumatic valve switch;

The function of the computer 18 is dual control of programming and hardware, realizing the operation of four solenoid valves, conducting high-pressure gas to switch corresponding pneumatic valves;

The pipeline 21 is used as a high-pressure gas flow channel, and the material is stainless steel, and copper tubes or Teflon tubes can also be used instead;

Manometer 22 monitors the high-pressure gas pressure, using a commonly used nitrogen manometer;

The gas cylinder 23 provides the high-pressure gas needed for the pneumatic valve switch. It can be disassembled after use and replaced with a new gas cylinder. A nitrogen cylinder or high-pressure air can also be used here;

The alkali metal may be potassium, sodium, rubidium, or cesium.

The connection of the device of the present invention: firstly weld the first vacuum glass valve 4 and the second vacuum glass valve 9 to the spiral glass tube 7 respectively; then pass the spiral glass tube 7 through the first and second aluminum alloy fixing frames (5, 8) Fix in the ultra-low temperature constant temperature tank 6 (working temperature is 243K); connect the other ends of the first vacuum glass valve 4 and the second vacuum glass valve 9 to the first PFA pipeline 3 and the second PFA pipeline 10 respectively; the first PFA three The three ports of the pass 2 are respectively connected to the first pneumatic valve 1, the third pneumatic valve 13 and the first PFA pipeline 3; the three ports of the second PFA tee 11 are respectively connected to the second PFA pipeline 10, the fourth pneumatic valve 14, The second pneumatic valve 12; the control interfaces of the first, second, third and fourth pneumatic valves (1, 2, 13, 14) are respectively connected with the first, fourth, second and third electromagnetic valves ( 15, 20, 16, 19), and connected to the pressure gauge 22, gas cylinder 23. When the device of the present invention is working, the first vacuum glass valve 4 and the second vacuum glass valve 9 of the spiral glass tube 7 are opened first, and then the corresponding pneumatic valve is controlled to open or close by switching the electromagnetic valve through the command switch electromagnetic valve of the computer 18 to conduct high-pressure gas. , and then realize the flow route of the hyperpolarized gas.

The present invention is a device for eliminating alkali metal vapor in hyperpolarized gas, and its working process is described as follows:

When the device of the present invention is in the working state of collection and purification, the mixed gas G1 (hyperpolarized gas + nitrogen + helium) from the hyperpolarized gas generation system is connected to the first pneumatic valve 1 at the inlet end of the device of the present invention. When the first electromagnetic valve 15 controls the conduction of high-pressure gas to open the first pneumatic valve 1, G1 can enter the device of the present invention, and at the same time, the second pneumatic valve 12 is opened, and the third and fourth pneumatic valves 13 and 14 are in the closed state . G1 flows into the spiral glass tube 7 in the ultra-low temperature constant temperature tank 6 through the first PFA tee 2, the first PFA pipe 3, and the first vacuum glass valve 4. The alkali metal vapor in G1 is condensed by the first stage, and G1 is condensed by the first stage. Purification; the mixed gas G2 after the primary purification flows out of the device of the present invention through the second vacuum glass valve 9, the second PFA pipeline 10, the second PFA tee 11, and the second pneumatic valve 12, and enters the subsequent super Polarized gas collection system and sublimation system. In this embodiment, the spiral glass tube 7 is made of a Pyrex glass tube with a diameter of 10 mm. The outer diameter of the spiral glass tube 7 is 100 mm, the length is 200 mm, and the number of spiral turns is 8. When it is in the working mode of sublimation gas purification, the first and second pneumatic valves (1, 12) are closed, the third and fourth pneumatic valves (13, 14) are opened, and the sublimated hyperpolarized gas G3 passes through the first Three pneumatic valves 13 enter the device of the present invention again, and flow through the first PFA tee 2, the first PFA pipeline 3, and the first vacuum glass valve 4 in the spiral glass tube 7 in the ultra-low temperature constant temperature tank 6 successively, and the alkali in G3 The metal vapor is condensed, and G3 is purified to obtain highly purified hyperpolarized gas G4; the highly purified hyperpolarized gas G4 passes through the second vacuum glass valve 9, the second PFA pipeline 10, the second PFA tee 11, the fourth The pneumatic valve 14 flows out of the device of the present invention, enters the subsequent air bag for collection, and is then directly used in biological magnetic resonance imaging research.

In conjunction with Figure 1 and Figure 2 below, the hyperpolarization system uses an optically pumped alkali metal rubidium vapor, and the working gas is a mixed gas (5 atm) of xenon (1%), helium (90%), and nitrogen (9%). For example, a kind of device of eliminating the alkali metal vapor in the hyperpolarized gas of the present invention, implementation process are described in further detail:

First, the first pneumatic valve 1 of the device of the present invention is connected with the hyperpolarized gas generation system, the second pneumatic valve 12 is connected with the subsequent hyperpolarized gas collection system, and the first vacuum glass valve 4 and the second vacuum glass valve 4 are opened. Glass valve9. When the hyperpolarized gas xenon generating device works continuously, a mixed gas G1 (hyperpolarized xenon + nitrogen + helium) is generated, and at the same time, the flowing gas G1 contains alkali metal rubidium vapor. The computer 18 controls the first electromagnetic valve 15 and the fourth electromagnetic valve 20 to conduct high-pressure gas to respectively drive the first pneumatic valve 1 and the second pneumatic valve 12 to open. Make the first pneumatic valve 1, the first PFA tee 2, the first PFA pipe 3, the first vacuum glass valve 4, the spiral glass tube 7 under the ultra-low temperature (243K) working environment, the second vacuum glass valve 9, and the second PFA The pipeline 10, the second PFA tee 11 and the second pneumatic valve 12 form a gas flow channel.

During the collection and purification process, the mixed gas G1 flows into the device of the present invention through the first pneumatic valve 1 and flows through this channel. Since the spiral glass tube 7 is at an ultra-low temperature of 243K, and the solidification temperature of alkali metal rubidium is much higher than this temperature, the alkali metal rubidium vapor in the mixed gas G1 can be condensed, and the hyperpolarized xenon, nitrogen, and It is impossible for helium to be solidified, so the purification of the mixed gas G1 is realized. The gas after primary purification is marked as mixed gas G2 (hyperpolarized xenon + nitrogen + helium), and finally flows out of the device of the present invention through the second pneumatic valve 12 controlled by the fourth electromagnetic valve 20, and enters the subsequent hyperpolarized gas gas collection system. In the collection system, the nitrogen and helium in the gas mixture G2 are separated, leaving only solid hyperpolarized xenon.

During the sublimation and purification process, the hyperpolarized gas sublimation system is directly connected to the third pneumatic valve 13 through a pipeline, and the hyperpolarized gas collection bag is connected to the fourth pneumatic valve 14 through a pipeline. The computer 18 controls the first electromagnetic valve 15 and the fourth electromagnetic valve 20 to close the first pneumatic valve 1 and the second pneumatic valve 12. At the same time, the computer 18 controls the second electromagnetic valve 16 and the third electromagnetic valve 19 to conduct high-pressure gas respectively The third pneumatic valve 13 and the fourth pneumatic valve 14 are opened. The sublimated hyperpolarized xenon gas G3 flows into the device of the present invention from the third pneumatic valve 13, and then flows through the first PFA tee 2, the first PFA pipeline 3, the first vacuum glass valve 4, and the ultra-low temperature (243K) working environment The spiral glass tube 7 below, in the spiral glass tube 7, the residual trace alkali metal rubidium vapor in the hyperpolarized xenon gas G3 is condensed, and the hyperpolarized xenon gas after the purification of G3 is marked as G4, which flows through the second vacuum glass valve 9 , the second PFA pipeline 10, the second PFA tee 11, and finally flow out of the device of the present invention through the fourth pneumatic valve 14 and enter the hyperpolarized xenon gas collection bag, and the hyperpolarized gas G4 of the secondary purification will be directly used in biological Magnetic resonance imaging of the body (small animals, human lungs and brain, etc.). In the technical solution of the present application, the gas after secondary purification at a temperature of 243K basically eliminates alkali metal vapor, and can directly act on organisms.

The device of the present invention is a part of the overall hyperpolarization system, and a plurality of different component channels are connected front and back, which can realize connection or disconnection in the purification process and the sublimation process, and the same ultra-low temperature constant temperature bath can be used in the two processes.

The device of the present invention is used in conjunction with a hyperpolarized gas generation system, a collection system, and a sublimation system, which can meet the requirements of high purification of hyperpolarized gas for biological magnetic resonance imaging (for example, imaging research on human lungs and brains) (here, especially Aiming at the requirement of not containing alkali metal), therefore, it has very important practical value and potential application prospect.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which the present invention belongs can make various modifications or supplements to the described specific embodiments or adopt similar methods to replace them, but they will not deviate from the spirit of the present invention or go beyond the definition of the appended claims range.

Claims (4)

1. eliminate the device of alkali metal vapour in hyperpolarized gas for one kind, comprise ultra-low temperature constant temperature groove (6), it is characterized in that: in ultra-low temperature constant temperature groove (6), be provided with spiral glass tube (7), spiral glass tube (7) one end is communicated with the one end of the first vacuum glass valve (4) be arranged on ultra-low temperature constant temperature groove (6), spiral glass tube (7) other end is communicated with the one end of the second vacuum glass valve (9) be arranged on ultra-low temperature constant temperature groove (6), the other end of the first vacuum glass valve (4) is communicated with the second link of a PFA threeway (2) by a PFA pipeline (3), first link of the one PFA threeway (2) is provided with the first operated pneumatic valve (1), 3rd link of the one PFA threeway (2) is provided with the 3rd operated pneumatic valve (13), the other end of the second vacuum glass valve (9) is communicated with the first link of the 2nd PFA threeway (11) by the 2nd PFA pipeline (10), second link of the 2nd PFA threeway (11) is provided with the second operated pneumatic valve (12), 3rd link of the 2nd PFA threeway (11) is provided with the 4th operated pneumatic valve (14), the operating temperature range of ultra-low temperature constant temperature groove (6) is 200-265K.

2. a kind of device eliminating alkali metal vapour in hyperpolarized gas according to claim 1, it is characterized in that, also comprise gas cylinder (23), also comprise by first electromagnetic valve (15) of computer (18) gauge tap, second electromagnetic valve (16), 3rd electromagnetic valve (19) and the 4th electromagnetic valve (20), first electromagnetic valve (15) controls the break-make of gas cylinder (23) and the first operated pneumatic valve (1), second electromagnetic valve (16) controls the break-make of gas cylinder (23) and the 3rd operated pneumatic valve (13), 3rd electromagnetic valve (19) controls the break-make of gas cylinder (23) and the 4th operated pneumatic valve (14), 4th electromagnetic valve (20) controls the break-make of gas cylinder (23) and the second operated pneumatic valve (12).

3. a kind of device eliminating alkali metal vapour in hyperpolarized gas according to claim 1, it is characterized in that, the first described vacuum glass valve (4) and the second vacuum glass valve (9) are welding with spiral glass tube (7) connected mode.

4. a kind of device eliminating alkali metal vapour in hyperpolarized gas according to claim 1, it is characterized in that, first described vacuum glass valve (4) one end extend into the inwall being also fixed on ultra-low temperature constant temperature groove (6) in ultra-low temperature constant temperature groove (6) by the first aluminium alloy fixed mount (5), and second vacuum glass valve (9) one end extend into the inwall being also fixed on ultra-low temperature constant temperature groove (6) in ultra-low temperature constant temperature groove (6) by the second aluminium alloy fixed mount (8).