System for safe production and injection of radioisotopes

Abstract

A system for the safe preparation and injection of the radioisotope H2 15 O for use in positron emission tomography (PET). The invention also relates to a safety valve for controlling the flow of H2 15 O for use in PET, the use of said safety valve, and a method for preparing and injecting H2 15 O.

Description

[0001] This application is a divisional application of the application filed on June 20, 2016, with application number 202111201632.0 and entitled "System for Safe Preparation and Injection of Radioisotopes". Technical Field

[0002] The invention relates in a first aspect to a conditioning device for a system used to prepare and inject H2 for use in positron emission tomography (PET). 15 O. In a second aspect, the invention also relates to a method for preparing and injecting H2. 15 The system of O, in a third aspect, relates to a method for controlling H2 used in PET. 15 The fourth aspect relates to the use of the safety valve for the flow of O, and the fifth aspect relates to a method for preparing and injecting H2. 15 O's method. Background Technology

[0003] Radioisotopes (also known as radionuclides) have several applications in medical treatment, imaging, and research. By emitting positrons from radioisotopes, PET allows for the imaging and measurement of physiological processes within the human body.

[0004] for example 18 F, 11 C 15 O、 14 O、 82 Rb, and 13 Radioactive isotopes such as nitrogen are typically used to label radiopharmaceuticals used in PET. The half-lives associated with these radioisotopes are very short, typically on the order of minutes (except for...). 18 F has a half-life of almost two hours. (Oxygen-15) 15 O has a half-life of 122.24 seconds and is one of the most suitable radioisotopes for quantifying regional cerebral blood flow (rCBF) and regional myocardial blood flow (rMBF) in PET.

[0005] Most systems for producing radioactive water include a cyclotron that generates a target gas. The target gas from the cyclotron is then transferred to a HotCell located in a qualified laboratory environment, where it is either heated to approximately 800°C using a catalytic process or combined with an H2 injection to transfer the target gas from... 15 O-O2 is converted into H2 15 O. Then the H2 obtained from the conversion. 15 O is typically bubbled into the salt solution in the reservoir, thereby capturing H2 in the solution. 15 O. Then H2 15The O solution is manually transferred from the reservoir into a syringe chamber or similar, then typically a dose desired for the patient is manually drawn into the syringe, which is then manually carried into the PET scan room.

[0006] As 15 O has a short half-life, it can only be used in systems that produce the radioisotope and inject it directly into the patient 15 O. Therefore, due to safety aspects regarding the patient directly connected to the system, O is only used to a limited extent, for example for research purposes or under special exemption conditions. 15 O.

[0007] A key aspect of safety considerations in systems that produce radioisotopes and inject them into patients is the circulation of compressed gas. The cyclotron is connected at one end of such a system and delivers compressed radioactive gas, which is pressurized to 10 atm or higher. The patient is typically connected at the other end of the system through a peripheral intravenous catheter, establishing a direct connection between the patient and the compressed radioactive gas.

[0008] Standard safety features typically consist of gas passing one side of a semi-permeable membrane, and saline passing the other side. A sterile filter made of a similar material as the first semi-permeable membrane will be positioned in close front of the patient. This sterile filter will gas lock in the event of any gas passing the first membrane, but if the gas waste tube that directs gas away is blocked, the pressure can rise to a higher pressure than the membrane can cope with, which can allow gas to pass through the filter and into the patient. The result can be infusion of radioactive gas into the patient from hundreds of ml / min up to 1-21 / min, which can lead to fatal venous air embolism.

[0009] In known valves for such systems, the valve can be configured to have a drain opening, where to release excess fluid from the system, the valve has to be turned to a configuration where a flow path is established through the valve between the inflow fluid and the drain opening. This requires the valve to be turned manually or automatically to said configuration, and thus if a malfunction occurs in the system, the valve will not act as a safety valve.

[0010] Further, the system that runs on compressed gas faces the fundamental problem that a failsafe feature is needed to ensure that compressed gas cannot enter other parts of the system to thereby possibly affect or damage them.

[0011] To minimize the risk level to the patient, the manual transfer of the radioisotope from the reservoir through the syringe to the patient is performed by medical personnel. In this way, the patient is not directly or indirectly connected to the cyclotron, thereby reducing the risk of accidental infusion of radioactive gas.

[0012] Manual handling of radioisotopes is safe for the patient, but due to the repeated radioactive exposure of the medical personnel, this is not feasible for routine patient examinations, as the medical personnel are subjected to unwanted and dangerous radiation each time an uptake and injection is performed.

[0013] Typically, under this manual approach, a double amount of the desired radioactivity is measured in a dose calibrator and taken up. A timer is started and when the radioactivity has decreased to the desired level due to the decay of the associated radioisotope, the taken up amount is transferred to the patient. Due to the short half-life of the radioisotope, the timing of the uptake and injection has to be very precise to determine the actual amount of radioactivity transferred to the patient.

[0014] Therefore, there is a need for a system that is able to produce and inject a specific amount of H2 15 O with high precision and with negligible risk for both the patient and the medical personnel. SUMMARY

[0015] In this context, it is an object of the present invention to provide a regulating device, a system, a safety valve, and a method with enhanced safety features for producing H2 15 O and injecting it into a salt solution.

[0016] For the third aspect of the invention, this object is achieved by providing a method for controlling H2 15A relief valve for the flow of O, the valve comprising: a valve element having a flow passage extending through the valve element; a valve housing having at least three valve openings, each valve opening allowing fluid to flow into or out of the valve; and at least two spillway recesses, each spillway recess having at least one outlet opening, wherein the valve element and valve housing are connectable to form an assembled valve, the valve element and the valve housing being in contact with each other in a contact area, wherein the assembled valve can be arranged in at least two different open configurations, one of the open configurations defining a flow path through the flow passage and a set of the valve openings, and another of the open configurations defining a flow path through the flow passage and another, different set of the valve openings, and wherein in each of the at least two open configurations: each spillway recess is arranged between the valve element and the valve housing; at least two of the valve openings are connected by the flow passage; at least one of the valve openings is not connected to the flow passage; the contact area forms a fluid barrier for preventing fluid from flowing into the at least one valve opening not connected to the flow passage; the spillway recesses are not in fluid communication with the flow passage; each spillway recess is positioned to establish an interruption of the contact area, such that the spillway recesses establish a safe release port for spill flow fluid that passes the fluid barrier through the respective outlet opening in case of overpressure, such that in the at least two open configurations the spill flow fluid is prevented from entering the at least one valve opening not connected to the flow passage.

[0017] By providing a valve comprising the at least two spillway recesses, when the assembled valve is arranged in the at least two different open configurations, the spillway recesses ensure that no fluid will travel from the at least two valve openings connected by the flow passage to the at least one valve opening not connected to the flow passage, as the fluid will pass through the spillway recesses and be discharged away from the valve.

[0018] The assembled valve can be arranged in a closed configuration in which the flow passage is not connected to any of the valve openings, such that no flow path is established through the flow passage and valve openings. In this closed configuration, fluid present in the valve openings can also experience overpressure. The spillway recesses cause spill flow fluid to be discharged through the respective outlet opening if the fluid passes the fluid barrier.

[0019] As the pressure in the spillway recesses is less than the pressure integrity of the adjacent valve opening, a pressure differential ensures that spill flow fluid will be discharged from the valve.

[0020] The valve thus acts as a safety valve preventing the ingress of undesired pressurized fluid into one or more valve openings when such ingress is not expected.

[0021] In the context of the present application, it is understood that the pressurized fluid can also be a fluid at atmospheric pressure (approximately 1.01325 bar). Preferably, the fluid is at approximately 1 to 3 bar, preferably 1.5 to 2.5 bar, more preferably approximately 2 bar, when the system is functioning under normal conditions.

[0022] It is also understood that "undesired" fluid means, but is not limited to, a fluid that is not expected to flow from one opening of the valve to the other opening of the valve, regardless of the pressure of the fluid, when the valve is in the closed configuration, and a fluid that is pressurized to a higher than expected undesired pressure due to, for example, a malfunction in the system before the valve. Vice versa, the term "desired" fluid means a fluid that is expected to pass through the valve in the open configuration under normal functioning conditions.

[0023] Under such normal functioning conditions of the system, and when the valve is arranged in the open configuration with the flow passage connected to the valve openings, the amount of fluid passing through the valve is in the range of approximately 500 ml / min to 1000 ml / min.

[0024] When the desired fluid passes through the flow passage and the valve openings, the fluid can be near atmospheric pressure. When the fluid is passing normally through the flow passage and the valve openings, there is no significant pressure drop.

[0025] When the valve is arranged in a system for producing H2 15 O and injecting it into a salt solution, the valve will act as a safety valve and thus will prevent undesired pressurized fluid from reaching a patient fluidly connected to the system and causing harm to the patient.

[0026] The safety valve will ensure that in case of a malfunction in the functioning of the system before the valve, for example a malfunction resulting in undesired high pressure fluid reaching the openings of the valve and the flow passage of the valve not being connected to either valve opening, the fluid will be discharged from the valve through the spill recesses and will not enter the other valve openings.

[0027] This is equally true for the case where the valve is in the open position and a patient is connected to the connecting element of the valve, wherein the valve opening of said connecting element is not in fluid connection with the flow path. Here, the fluid will flow between the valve openings and the flow path, and if a malfunction occurs and undesired pressurized fluid enters the valve openings and the flow path, the spill fluid that enters the contact area between the valve element and the valve housing will be discharged through the recesses positioned between the valve openings of the connecting element connected to the patient and the valve opening connected to the flow path.

[0028] Thus, regardless of the configuration of the valve, these recesses will act as a safety measure and do not require switching between configurations, thereby increasing the safety of the patient connected to the system.

[0029] Thus, in embodiments, the assembled valve can be arranged in a third, different closed configuration, in which the flow channel is not connected to any of the valve openings, so that no flow path is established through the flow channel and valve openings.

[0030] The contact area between the valve element and the valve housing is to be understood as the area where the surface of the valve element is directly adjacent to the surface of the valve housing. The fluid stop in the contact area ensures the functional tightness between the valve housing and the valve element.

[0031] In the context of the present application, the term "connected" can also be understood as fluidically connected and / or in fluid communication.

[0032] In the context of the present application, the term "fluid" includes both gases and liquids.

[0033] The at least three valve openings can have any shape that permits fluid to flow from one side of the opening to the other. The valve openings are preferably circular.

[0034] The valve housing and / or the valve element can be of any desirable shape, such as cylindrical, circular, rectangular, or spherical.

[0035] The dimensions of the valve element can vary depending on the dimensions of the valve housing.

[0036] The safety valve can be formed of a material selected from the group consisting of: inert materials, polymeric materials, metals and metal alloys, and ceramics; or made of a combination of these materials. In principle, any material that is compatible with the fluid, has sufficient strength and material properties to provide a tight fluid barrier, and is able to withstand sterilization can be used.

[0037] Depending on the material of the safety valve, the valve can be produced by a variety of methods, such as injection molding, lathe machining, milling, casting, and / or 3D printing.

[0038] The valve element and the valve housing can be made of different material compositions. By configuring the valve element and the valve housing with different material compositions, a tighter fit can be obtained. The valve element can be formed of a material that is less strong than the material of the valve housing, to enable selective rupture of the valve element rather than the valve housing during an accidental pressure increase.

[0039] In an embodiment, the valve housing further comprises a connection element having a first end and a second end and an inner fluid space, the connection element being connected to the valve housing at the second end such that said fluid space is in fluid contact with one of said at least three valve openings.

[0040] By providing a connection element, it is easy to connect the safety valve directly to different medical systems in which valves are used to prevent pressurized fluid from entering e.g. a vein or an artery of a patient and where it is therefore desirable to enhance the safety of the system to ensure that no overflow fluid will travel to an undesired valve opening. Such medical systems can be systems for preparation and injection of H2 15 O, where the safety valve will ensure that overflow fluid will not be transferred to the patient line and that an accidental infusion of fluid into the circulatory system of a patient is avoided, which can lead to a potentially life-threatening situation.

[0041] In an embodiment, the connection element is cylindrical. The at least three connection elements can extend radially from the housing. The at least three connection elements can have substantially equal lengths.

[0042] In an embodiment, the valve housing comprises three connection elements.

[0043] In an embodiment, the at least two overflow recesses are arranged in the valve housing.

[0044] In an embodiment, the at least two overflow recesses are arranged in the valve element.

[0045] The overflow recesses can have any shape, such as a curved or a twisted shape. The overflow recesses are preferably linear.

[0046] By providing the at least two overflow recesses in the valve housing and / or the valve element, an easy-to-assemble valve with a minimum number of components is provided, which makes the valve cost-effective and easy to produce and assemble.

[0047] In embodiments, the valve element further comprises a first end and a second end defining a first longitudinal axis, and the valve housing further comprises: a housing comprising a first end and a second end and a second longitudinal axis extending between the first end and the second end, the second longitudinal axis being coaxial with the first longitudinal axis; an inner spacing for receiving the valve element, said inner spacing being enclosed by the housing; and the at least three valve openings arranged in the housing, each opening allowing fluid to flow into or out of the inner spacing, wherein the at least two spillway recesses extend axially between said first end and said second end of the housing, wherein the valve element is axially movable along the second longitudinal axis such that a portion of the valve element can be inserted into the inner spacing of the valve housing to form an assembled configuration, and the valve element is rotatable within the inner spacing about the second longitudinal axis such that the valve element and the valve housing can be changed between said at least two different open configurations, wherein each spillway recess is arranged between the valve element and the housing when the valve element is arranged inside the inner spacing in said two different open configurations.

[0048] By providing the safety valve with a valve element that can be inserted into the valve housing, the valve element can be fixed inside the valve housing, preventing the valve element from moving in a radial direction relative to the first longitudinal direction, thereby establishing a very high functional tightness in the contact area and thus a better fluid barrier to prevent any excess fluid from passing through the contact area.

[0049] The valve housing can be rotatable about the valve element, around the first longitudinal axis 124 of the valve element, when a portion of the valve element is inserted into the inner spacing.

[0050] The rotation of the valve element and / or valve housing can be automatic and / or manual.

[0051] In embodiments, the valve housing comprises three valve openings.

[0052] In embodiments, the safety valve comprises three spillway recesses.

[0053] In embodiments, the valve element comprises one flow channel.

[0054] In embodiments, the number of valve openings is equal to the number of spillway recesses.

[0055] In some embodiments, the valve housing comprises six valve openings and / or six spillway recesses. The six valve openings and / or the six spillway recesses are preferably evenly distributed along the circumference of the valve housing and / or the valve element.

[0056] In embodiments, the at least three valve openings are equally distributed in the housing. Each of the valve openings is preferably 120 degrees relative to the angle between adjacent valve openings.

[0057] In embodiments, the flow channel comprises a first flow channel and a second flow channel, wherein the first flow channel and the second flow channel extend at an angle relative to each other. The angle is preferably 120 degrees.

[0058] By providing the valve openings at approximately equal angles to the first and second flow channels, when the valve element is arranged inside the inner spacing, the first and second flow channels through the valve element will coincide with two of the at least three valve openings of the valve housing, such that the two of the at least three valve openings can be connected by the flow channel.

[0059] In embodiments, the at least two spillway recesses are arranged in the housing.

[0060] In embodiments, the at least two spillway recesses extend between and open into the first and second ends of the housing.

[0061] In embodiments, the at least two spillway recesses extend between and open into the first and / or second ends of the housing.

[0062] The spillway recesses can extend radially in the housing, the spillway recesses having a depth up to the thickness of the housing.

[0063] In embodiments, the at least two spillway recesses are arranged in the valve element.

[0064] In embodiments, the at least two spillway recesses extend between and open into the first and / or second ends of the valve element.

[0065] By providing spillway recesses extending the entire length of the housing or the valve element, the spillway recesses ensure that any fluid travelling along the fluid barrier between the valve element and the valve housing will be expelled from the valve through the spillway recesses.

[0066] In embodiments, the connection element extends into the inner spacing.

[0067] In some embodiments, the spillway recesses can comprise a material having different material properties than the housing material. This is advantageous when using the valve in systems coping with high pressure and / or being constructed of high-strength materials such as metals or metal alloys or ceramics.

[0068] In embodiments, the housing is cylindrical.

[0069] In embodiments, the valve element is cylindrical.

[0070] By providing a cylindrical housing and / or valve element, a good balance between the amount of material used and the strength and rigidity of the entire valve is ensured.

[0071] In embodiments, the flow channel and the at least three valve openings are arranged in and extend along the same plane in at least two configurations of the assembled valve.

[0072] Thus, the safety valve can be arranged without requiring too much space, as both the inlet and the outlet are arranged in the same plane, rather than having the inlet perpendicular to the flow channel / valve openings.

[0073] In embodiments, said plane is substantially perpendicular to the first axis and the second axis when the valve is in the assembled configuration.

[0074] It is to be understood that a plane is a flat, two-dimensional surface that extends infinitely far, and that the flow channel and the valve openings are positioned on the same plane and extend in different directions on the same plane.

[0075] In embodiments, the overflow fluid is at substantially 1 to 10 bar, preferably substantially 1 to 5 bar, and more preferably substantially 1 to 3 bar.

[0076] In embodiments, the valve openings are equally distributed around the circumference of the housing, the valve openings preferably being distributed at substantially 120 degrees.

[0077] The inner circumference of the housing can be substantially equal to the outer circumference of the valve element.

[0078] The valve element comprises a first end and a second end defining a first longitudinal axis. The valve housing comprises a first end, a second end, and a second longitudinal axis extending between the first end and the second end. When the valve is in the assembled configuration, the second longitudinal axis is coaxial with the first longitudinal axis of the valve element.

[0079] In embodiments, the valve element comprises a handle for rotating the valve element inside the valve housing.

[0080] When assembling the safety valve, the valve element can be rotated inside the valve housing, the rotation being around the second longitudinal axis.

[0081] The handle can protrude from the valve element outside the housing when a part of the valve element is inserted in the inner spacing. The handle preferably extends radially from the valve element.

[0082] In embodiments, the handle comprises a first protrusion, a second protrusion, and a third protrusion extending radially from the valve element. The first protrusion and the second protrusion are preferably arranged in the circumference of the valve element at an angle of 90 degrees relative to each other. The second protrusion and the third protrusion are preferably arranged in the circumference of the valve element at an angle of 90 degrees relative to each other.

[0083] The handle can be a recess in the valve element. Said recess can be configured to have a shape such as a square, a triangle, a circle, an ellipse, a rectangle, a star, or any combination thereof.

[0084] In embodiments, the valve housing further comprises a sterile filter element, the filter being arranged such that any overflow fluid discharged from the overflow recesses passes through the filter element. The filter element can be arranged at the first end and / or the second end of the housing.

[0085] In further embodiments, the filter covers the entire at least one outlet opening of each of the at least two overflow recesses.

[0086] In further embodiments, the at least two overflow recesses are arranged in the housing and extend between the first end and the second end of the housing. The at least one outlet opening is arranged in the second end of the housing such that the overflow recesses open into the second end of the housing, wherein the filter element is arranged inside the inner spacing at the second end of the housing. Fluid thus discharged exits the safety valve only at the second end of the housing and thereby all discharged fluid passes through the sterile filter before being discharged from the safety valve.

[0087] The filter further prevents any contaminated air from the valve surroundings from entering the safety valve.

[0088] The filter element can have any suitable shape. The filter element can have the same shape as the inner spacing and is preferably circular.

[0089] The filter element can be formed of a material selected from the group consisting of a porous polymer membrane, sintered particles or fibers made of a polymer, a metal or a ceramic; or made of a composition of such materials.

[0090] The filter element can have a pore size of 0.10 um to 100 um, preferably 0.2 um to 0.45 um.

[0091] The filter element can be a HEPA filter.

[0092] In a fourth aspect, the present invention relates to a safety valve according to the third aspect as described above for use in a process for the production of H2 15- use of the system for injecting it into a saline solution.

[0093] The system can be a system according to the second aspect as described below.

[0094] By providing a safety valve in such a system, the safety valve will protect the patient from being harmed by an unwanted fluid in the tubing connected to the patient, if the system malfunctions, i.e. a malfunction that can result in the fluid in the tubing connected to the patient being at an unwanted high level.

[0095] In a second aspect, the present invention relates to a system for preparing and injecting H2 15 O for use in Positron Emission Tomography (PET), the system comprising: a production device for producing a H2 15 O saline solution; a bolus device for establishing a first bolus for injection, the first bolus comprising the H2 15 O saline solution and having a pre-defined volume and a radioactivity concentration (mBq / ml), the bolus device comprising a valve; and an adjustment device for adjusting an injection profile of the first bolus.

[0096] As used herein, the term "oxygen-15 labeled water" is denoted to encompass H2 15 O with similar notation, such as 015-H2O, O15-H2O, H2[ 15 O], H2O[ 15 O], and 15 OH2O.

[0097] By providing a system for preparing and injecting H2 15 O according to the present invention, which can be arranged in close proximity to a PET-scanner, the need for manual handling of radioisotopes is eliminated, thus improving the safety of patients and medical personnel.

[0098] Further, since the system is continuously running, dose injection can be performed accurately at the moment of interest. This enables time-critical studies, such as brain activation studies and heart stress studies. The system supports various different study protocols by providing different infusion boluses.

[0099] According to the second aspect of the present invention, the amount of radioactivity prepared (since the H2 15 O is prepared in a pre-defined bolus) can be accurately determined, and the injection profile, i.e. the injection rate in relation to time, which defines the amount of radioactivity injected during the injection phase, is defined and adjusted. In some embodiments, the injection rate is constant throughout the injection phase. In this way, the radioactivity and the bolus volume are well defined.

[0100] In some embodiments, the injection speed varies throughout the injection phase.

[0101] As used herein, the term "bolus" refers to a specific volume amount.

[0102] As used herein, the term "injection curve" refers to a graph on an XY plot, where the Y-axis represents the radioactivity concentration [Bq / s] as a function of time [s], and the X-axis represents time [s].

[0103] In embodiments, the system according to the second aspect comprises a processing unit.

[0104] Herein and in the following, the term 'processing unit' is intended to comprise any circuit and / or device adapted to be fitted to perform the functions described herein. In particular, the above-mentioned term comprises a general or special purpose programmable microprocessor, a Digital Signal Processor (DSP), an Application-Specific Integrated Circuit (ASIC), a Programmable Logic Array (PLA), a Field- Programmable Gate Array (FPGA), a special purpose electronic circuit, etc., or a combination thereof.

[0105] The processing unit can be connected to the production device and / or the bolus device and / or the adjustment device and / or the whole system according to the second aspect and / or specific parts thereof.

[0106] In embodiments, the valve is a safety valve according to the third aspect of the application.

[0107] The system can be connected to a patient, so that a bolus can be injected directly from the system into the patient. The bolus can be administered as an intravenous injection, an intramuscular injection, an intrathecal injection, or a subcutaneous injection.

[0108] Parts of the system can be arranged in or behind a radiation shield.

[0109] In embodiments, the application relates to a production device for a system according to the second aspect, the production device comprising: a conversion element for converting a gas mixture comprising 15 O and H2 into H2 15 O at an elevated temperature; a valve control element for adjusting the flow of the gas mixture; a merging device for merging H2 15 O with brine from a first brine feeder to produce a H2 15 O brine solution; a first radiation detector for measuring the radioactivity in the H2 15 O brine solution, wherein the valve control element is adjusted by the first radiation detector.

[0110] According to this embodiment, a gas mixture comprising 15The gas mixture of O and H2 is fed to the production device at a constant flow rate and pressure. The valve control element provided can regulate the amount of gas mixture of O that is converted into H2 15 O, and thereby the amount of H2 15 O in the salt solution. 15 O.

[0111] The gas mixture can comprise a compressed or pressurized gas mixture.

[0112] The gas mixture is preferably converted into H2 15 O in vapour form.

[0113] The radiation detector can comprise a control element for comparing the measured amount of radiation with a predefined radiation interval, which interval depends on the amount of H2 15 O desired in the salt solution. The interval can be manually and / or automatically inputted depending on the amount of H2 15 O desired, which can vary depending on the patient. The control element can be controlled by a processing unit.

[0114] In embodiments, the conversion element comprises an oven for converting the gas mixture into H2 15 O at an elevated temperature.

[0115] The elevated temperature can be 200 °C to 1000 °C, preferably approximately 800 °C for a non-catalytic reaction, and approximately 300 °C for a Pd catalytic reaction.

[0116] In embodiments, the valve control element comprises at least one valve for directing the gas mixture flow through the conversion element (whereby the gas mixture is converted into H2 15 O), or bypassing the conversion element (whereby the gas mixture will not be converted into H2 15 O) when no production of any more H2 15 O is desired.

[0117] In further embodiments, the at least one valve is a double pass valve.

[0118] In further embodiments, the at least one valve is a safety valve according to the third aspect of the invention.

[0119] In further embodiments, the valve control element further comprises a third gas waste device. The at least one valve directs the gas mixture to the oven, or bypasses the oven and the gas is directed into the third gas waste device.

[0120] The third gas waste device can be a slow-leaking gas waste device. Alternatively, the third gas waste device can be an external venting pipe dedicated to venting the gas mixture.

[0121] In embodiments, the merging device comprises: a reservoir for receiving H2 15 O and the first salt solution; a second gas waste device for venting any excess gas from said reservoir; a third pump connected at one end to the reservoir and at the other end to a decay line connected to a liquid waste device, wherein the third pump pumps excess liquid waste from the reservoir through the decay line and into the liquid waste device.

[0122] By providing a merging device that operates without pressurization / under normal pressure, an additional safety feature is provided to ensure that no gas is dissolved in the radioactive water.

[0123] It is noted that in the context of the present description, the term "reservoir" is not limited to a specific reservoir, but can also be other containers with a predefined volume, such as tanks, basins, storage / storage elements, vessels, or receptacles.

[0124] It is noted that in the context of the present description, the term "slow-leaking gas waste device" refers to a system that allows excess gas containing small amounts of radioisotopes, such as H2 15 O, to be delayed for an appropriate number of half-lives, preferably at least five half-lives, before the excess gas is vented to open space, so that the residual radioactivity is reduced to an acceptable level. The slow-leaking gas waste device will typically be positioned behind a radiation shield.

[0125] The second gas waste device can be a slow-leaking gas waste device. Alternatively, the second gas waste device can be an external venting pipe dedicated to venting excess radioactive gas. Since 15 O has a short half-life and the gas volume involved is small, the radioactivity is almost zero when the gas is vented.

[0126] The gas mixture comprising H2 15 O and H2 fed to the conversion element can contain small amounts of nitrogen oxides (NOx) that are reduced to ammonia (NH3) by reaction with hydrogen. Therefore if ammonia accumulates, the pH of the H2 15 O salt solution in the reservoir will increase.

[0127] In embodiments, the merging device further comprises: a first pump connected to the first salt water feeder to provide the reservoir with the salt solution; and a pH measuring device connected to the decay line, wherein the first pump is regulated by the pH measuring device.

[0128] The amount of the first salt solution from the first brine feeder can be an adjustable amount. The amount of the first salt solution can be adjusted manually and / or automatically by a processing unit.

[0129] The first salt solution can be continuously pumped into the reservoir.

[0130] By providing a pH measuring device, the measuring device can detect changes in the pH value of the H2 15 O salt solution. These changes can occur if there is a substantial amount of ammonia present in the H2 15 O salt solution.

[0131] To ensure that no ammonia accumulation occurs in the reservoir, the inflow amount of the salt solution and the outflow amount of the H2 15 O salt solution can be adjusted so that ammonia is flushed out of the reservoir.

[0132] The content of ammonia in the reservoir should be below 15 ppm, preferably below 10 ppm. The pH level in the reservoir should be from 4 to 10, preferably from 5 to 9, more preferably from 5.5 to 8.5.

[0133] Providing a relatively long decay line allows radioactive H2 15 O to reach the waste bottle after decaying. The radioactive H2 15 O will preferably be delayed by at least five half-lives before reaching the waste bottle.

[0134] The waste bottle can be placed outside of a radiation shield arranged to surround the system. A radiation detector can also be arranged adjacent to the decay line or the waste bottle.

[0135] The pumping speed of P3 is greater than or equal to the pumping speed of PI to ensure that the reservoir of H2 15 O salt solution does not overflow.

[0136] Any excess gas present in the reservoir is expelled through a second gas waste device. The second gas waste device can be a slow leak gas waste device.

[0137] In embodiments, the present invention relates to a bolus device for a system according to the second aspect, wherein the bolus device comprises: a reservoir containing a H2 15 O salt solution; a delivery tube for circulating the H2 15 O salt solution from the reservoir through a loop element and an adjustment device and back into said reservoir; a second pump for adjusting said flow, wherein the adjustment device comprises a valve, the adjustment device having a first configuration and a second configuration, wherein the second configuration of the adjustment device establishes a first bolus of the H2 15 O salt solution, the first bolus having a predefined volume and a radioactive concentration.

[0138] by providing a continuously circulating, readily available H2 15 O salt solution, the system is ready to establish a first bolus volume for injection into a patient at any point in time, thereby avoiding unnecessary waiting time.

[0139] The reservoir can comprise H2 15 O salt solution produced according to embodiments of the present application.

[0140] Further, since H2 15 O salt solution is continuously circulated and cycled from the reservoir to the reservoir at high speed in the delivery tube by the second pump, newly formed H2 15 O is continuously mixed with saline in the loop element, the H2 15 O salt solution will maintain a substantially constant radioactivity concentration.

[0141] The speed of the second pump is preferably from 0.1 ml / min to 100 ml / min.

[0142] In embodiments, the bolus device comprises a processing unit.

[0143] The regulating means can be manually controlled and / or automatically controlled by the processing unit.

[0144] In embodiments, the regulating means comprises at least two valves.

[0145] In embodiments, the regulating means comprises a safety valve according to the third aspect of the present application.

[0146] In embodiments, the at least two valves are arranged on either side of the loop element. One of the two valves can be connected to the patient line.

[0147] By using a safety valve according to the third aspect of the present application, there will be no spillage of liquid into the patient line, thereby ensuring a safer system.

[0148] In embodiments, the loop element has an adjustable volume. The volume of the loop element can be manually and / or automatically adjusted by the processing unit. The volume of the loop element can also be adjusted by changing one or more parts of the loop element, thereby giving one or more different parts of the loop element a volume such that the loop element has another volume.

[0149] Thus, different bolus volumes and radioactivity concentrations can easily be provided for different patients and / or measurements, thereby eliminating the need for medical personnel to manually draw a bolus.

[0150] In embodiments, a first radiation detector is arranged adjacent to the loop element, the first radiation detector comprising a first detector unit and a second detector unit, wherein said first detector unit and said second detector unit measure said H2 15 a first and a second radioactivity value of the O salt solution.

[0151] The first and the second detector unit are preferably arranged at different positions adjacent to the loop element, so that these detectors measure said H2 15 O salt solution at different positions in the loop element. The first radiation detector can be shielded individually to produce accurate radiation measurements.

[0152] In a first aspect, the present invention relates to an adjustment device for a system according to the second aspect, the adjustment device comprising: a second saline feeder; a loop element comprising a first bolus of said H2 15 O salt solution; an injection device for collecting a predefined second bolus of saline from said second saline feeder and injecting said second bolus into the loop element at a predefined speed, so that the second bolus pushes the first bolus into the patient line; a second radiation detector adjacent to the patient line, said radiation detector measuring an injection profile of the first bolus, wherein the injection speed and volume of the second bolus adjust the injection profile of the first bolus.

[0153] By providing the injection device, the injection profile of the first bolus for injection into the patient line can be adjusted depending on individual requirements for different measurements.

[0154] In embodiments, the adjustment device according to the first aspect comprises a processing unit.

[0155] The predefined injection speed can vary during the injection. The speed is preferably decreasing during the injection. The variation in said speed can be controlled manually or by the processing unit.

[0156] The predefined second bolus of saline can have a variable volume depending on different patients and measurements. The predefined second bolus can be collected manually and / or automatically by the injection device. The automatic collection can be controlled by the processing unit.

[0157] In embodiments, the injection device comprises a fourth valve. The fourth valve can be a safety valve according to the third aspect of the present invention.

[0158] The second saline feeder can be connected to the fourth valve.

[0159] In an embodiment, the injection device comprises a collection element. The collection element can be connected to the fourth valve. The collection element can be a medical syringe.

[0160] The second detector measures the radioactivity value of a specific portion of the patient line. This portion has a known length, size, and volume. Since the volume of this portion of the patient line is constant, the radioactivity is measured at short time intervals (1 to 10 measurements per second), and the injection speed is known, a curve (referred to herein as an injection curve) can be obtained in the XY coordinate system that shows the amount of injected activity as a function of time.

[0161] The second radiation detector measures the injection curve of the first bolus immediately before the first bolus is injected into the patient.

[0162] In a fifth aspect, the present invention relates to a method for preparing H2 15 O for use in positron emission tomography, the method comprising the steps of: converting a gas mixture comprising 15 O and H2 into H2 15 O at an elevated temperature; providing a valve control element to regulate the flow of the gas mixture; combining H2 15 O with saline from a first saline feeder to produce a H2 15 O saline solution; providing a first radiation detector to measure radioactivity in the H2 15 O saline solution; regulating the flow of the gas mixture by the first radiation detector; providing a reservoir to receive the H2 15 O saline solution; providing a second gas waste device for expelling any excess gas from the reservoir; providing a third pump connected at one end to the reservoir and at the other end to a decay line connected to a liquid waste device; pumping any excess liquid waste from the reservoir through the decay line and into the liquid waste device with the third pump; providing a delivery tube and a second pump to circulate the H2 15 O saline solution from the reservoir through a loop element and back into the reservoir; providing a regulating means; establishing a first bolus of the H2 15 O saline solution in the loop element, the first bolus having a pre-defined volume and radioactivity concentration; providing a second saline feeder; collecting a pre-defined second bolus of saline from the second saline feeder; injecting the second bolus into the loop element at a pre-defined speed such that the second bolus pushes the first bolus into a patient line; measuring the injection curve values of the first bolus with a second radiation detector adjacent to the patient line, thereby regulating the injection curve of the first bolus by the injection speed and volume of the second bolus.

[0163] In embodiments of the fifth aspect, the regulating means comprises a safety valve according to the third aspect of the application.

[0164] Systems for the production and injection of radioisotopes to patients have a number of challenges. The safety requirements for such systems that can be connected to a patient are extremely high to ensure the safety of the patient and medical personnel. By providing a system according to the second aspect, different parts of the system help to ensure a higher safety standard than previously possible.

[0165] The safety valve according to the third aspect is particularly useful in a system according to the second aspect, as it will stop the overflow fluid from moving forward in the system and eventually into the patient. In particular excess gas is a very high risk factor, which can easily be eliminated by implementing a safety valve according to the third aspect.

[0166] The different aspects of the application can be implemented in different ways, each of which gives rise to one or more of the benefits and advantages described in connection with at least one of the aspects described above, and each of which has one or more preferred embodiments, including embodiments described in connection with at least one of the aspects disclosed above and / or in the dependent claims. BRIEF DESCRIPTION OF DRAWINGS

[0167] The above and / or additional objects, features, and advantages of the present application will be further understood through the following illustrative and non-limiting detailed description of embodiments of the present application, with reference to the appended drawings, where:

[0168] Figure 1 A schematic illustration of a system for the production and injection of H2 15 O for use in positron emission tomography according to the second aspect of the application is shown.

[0169] Figure 2 A flow chart illustrating the interaction between the bolus amount device and the injection device is shown.

[0170] Figure 3A and Figure 3B An embodiment and a first aspect according to the present application is shown.

[0171] Figure 4A and Figure 4B Different injection profiles of a first bolus amount are shown.

[0172] Figure 5 A perspective view of an embodiment of a safety valve according to the second aspect of the application is shown.

[0173] Figure 6 A perspective view of the safety valve shown in an assembled configuration is shown. Figure 5 ​

[0174] Figure 7A , Figure 7B ,and Figure 7C Cross-sectional views are shown of the assembled safety valve in the first, second, and third assembly configurations.

[0175] Figure 8 A perspective view of an embodiment of a valve according to a third aspect of the present invention is shown.

[0176] Figure 9 It shows Figure 8 The safety valve shown is a cross-sectional view when it is in the assembled position. Detailed Implementation

[0177] The following description is illustrated with reference to the accompanying drawings, which show by way of illustration how the invention can be practiced. It should be noted that, for illustrative purposes, the dimensions of the distances between the various different elements shown are not actual.

[0178] It should be understood that the terms "safety valve" and "valve" are used in the context of this invention to describe a safety valve according to the third aspect of the invention.

[0179] Figure 1 This invention illustrates the preparation of sterile, injectable H2 in a form suitable for performing PET scans. 15 A schematic diagram of system 1 of O.

[0180] System 1 includes a processing unit for controlling the various parts of the system. This processing unit can be manually rewritten if desired.

[0181] Herein and hereinafter, the term 'processing unit' is intended to include any circuitry and / or device adapted to perform the functions described herein. Specifically, the above term includes general-purpose or special-purpose programmable microprocessors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), programmable logic arrays (PLAs), field-programmable gate arrays (FPGAs), special-purpose electronic circuits, and combinations thereof.

[0182] Radioactivity is typically generated in the cyclotron within the Crypt 500 cyclotron by irradiating a flowing gas target with nitrogen and oxygen. 15 O gas. Released from target chamber 501 of the cyclotron. 15 The amount of O gas is controlled by a mass flow controller (MFC) (not shown) connected and positioned to the target chamber 501. The MFC is preset to control the gas within a specific flow rate range.

[0183] The MFC is equipped with a closed loop control system that is given an input signal by a system operator or processing unit, compares this input signal with the value from the mass flow sensor and adjusts the proportional valve accordingly to achieve the desired flow.

[0184] Then 15 The O-gas is passed through a NOx-trap 502 in which most of the nitrogen oxides, such as NO, N2O and / or NO2, formed in the target chamber 501 due to the reaction between nitrogen and oxygen are trapped. At this point it is desirable to remove the nitrogen oxides because they can subsequently be converted into unwanted ammonia (NH3) by reaction with hydrogen.

[0185] The gas is subsequently mixed with hydrogen (H2) from a hydrogen reservoir 503 to form a gas mixture 221 of H2and 15 O-gas. The amount of H2-gas mixed with the O-gas is controlled by another MFC (not shown) located behind the hydrogen reservoir 503. 15

[0186] The gas mixture 221 is then directed through a tube 504 extending from the cyclotron vault 500 and into a PET scan chamber 505 in which a PET scanner (not shown), a patient 521 and the application according to the second aspect are arranged. To avoid high pressures that can lead to unstable flow rates, the tube 504 is equipped with a pressure release valve (not shown).

[0187] The gas mixture 221 is then passed through a first sterile filter 506 to remove any unwanted particulate and microbial impurities, thereby ensuring that the system remains sterile.

[0188] Behind the first sterile filter 506, a pressure sensor 507 and a pressure release valve 508 are connected to the gas transport tube 504. The pressure sensor 507 continuously measures the pressure in the tube 504. If the pressure exceeds a predetermined safety level, the valve 508 directs the gas mixture 221 to a first gas waste 509.

[0189] The gas mixture 221 is then directed to a tube node 510. A valve control element 250 controls the way in which the gas mixture 221 is directed from the tube node 510. The valve control element 250 comprises a second valve 251 and a third valve 252.

[0190] When the second valve 251 is open, the gas 221 is directed through a conversion element 220. The conversion element 220 is a furnace 220 in which the gas mixture 221 is converted into H2 15 O. If the second valve 251 is closed and the third valve 252 is open, the gas mixture 221 will bypass the furnace 220 and the gas mixture 221 will not be converted into H2​15 O. This is achieved without desiring to produce any more H2 15 O.

[0191] The gas mixture 221 from the third valve 252 and / or the H2 15 O is then guided into a reservoir 281. A first pump 292 connected to a first saline feeder 290 continuously pumps a first saline stream 291 into the reservoir 281. Thus, H2 15 O and saline combine in the reservoir 281 into a H2 15 O salt solution.

[0192] A first radiation detector 240 is positioned elsewhere in the system. The first radiation detector 240 measures the radioactivity in the H2 15 O salt solution. The signal from the first radiation detector 240 is used as an input in a closed loop regulation algorithm, such as a PID or fuzzy logic executed on a processing unit. The output from the processing unit regulates the valve control element 250 and thus determines how much H2 15 O is produced.

[0193] A second gas waste 282 is connected to the reservoir 281. The second gas waste 282 vents gas from the reservoir 281, thus ensuring that no gas is dissolved in the H2 15 O salt solution.

[0194] A third pump 283 is connected to the reservoir 281 at one end and to a decay line 284 at the other end. The decay line 284 is further connected to a liquid waste 285. The third pump 283 continuously pumps excess liquid waste from the reservoir 281 through the decay line 284 and into the liquid waste 285.

[0195] The reservoir 281 is also connected to a delivery tube 301 to circulate the H2 15 O salt solution from the reservoir 281 and back into the reservoir 281. The H2 15 O salt solution is pumped from the reservoir 281 into the delivery tube 301 by a second pump 302 and into the regulating means 340 and the loop element 320.

[0196] The regulating means 320 comprises a fifth valve 422 and a sixth valve 423, which valves 422, 423 are as Figure 5 the valves shown in figure 7. The valves 422, 423 are arranged on either side of the loop element 320. The fifth valve 424 is further connected to an injection device 420 and the sixth valve 425 is further connected to a patient line 520.

[0197] The fifth valve 424 is arranged in a first configuration of at least two different configurations such that H2O salt solution flows through the fifth valve 424 and is directed into the loop, and the infusion device 420 is isolated from the rest of the system. 15 If the fifth valve 424 is arranged in a second configuration, then H2O salt solution will not be able to pass through the fifth valve 424, which disconnects the connection between the loop 320 and the infusion device 420. 15 If the fifth valve 424 is arranged in a second configuration, then H2O salt solution will not be able to pass through the fifth valve 424, which disconnects the connection between the loop 320 and the infusion device 420.

[0198] The sixth valve 425 is arranged in a first configuration of at least two different configurations such that H2O salt solution flows through the sixth valve 425 and is further directed into the delivery tube 301 and back into the reservoir 281. 15 If the sixth valve 425 is arranged in a second configuration, then H2O salt solution will be directed into the patient line 520, and the part of the delivery tube 301 that carries H2O salt solution back into the reservoir 281 is isolated from the sixth valve 425. 15 If the sixth valve 425 is arranged in a second configuration, then H2O salt solution will be directed into the patient line 520, and the part of the delivery tube 301 that carries H2O salt solution back into the reservoir 281 is isolated from the sixth valve 425. 15 If the sixth valve 425 is arranged in a second configuration, then H2O salt solution will be directed into the patient line 520, and the part of the delivery tube 301 that carries H2O salt solution back into the reservoir 281 is isolated from the sixth valve 425.

[0199] The first radiation detector 240 is arranged adjacent to the loop element 320. The first radiation detector 240 comprises a first detector unit and a second detector unit (not shown), wherein the first detector unit and the second detector unit measure a first radioactivity value and a second radioactivity value of the H2O salt solution present in the loop element 320. 15 The first radiation detector 240 is arranged adjacent to the loop element 320. The first radiation detector 240 comprises a first detector unit and a second detector unit (not shown), wherein the first detector unit and the second detector unit measure a first radioactivity value and a second radioactivity value of the H2O salt solution present in the loop element 320.

[0200] If the first radioactivity value and the second radioactivity value differ more than 20%, preferably 15%, more preferably 10% from a user preset threshold level, the processing unit will prevent the infusion from taking place.

[0201] When the fifth valve 422 and the sixth valve 423 are arranged in the second configuration, the fifth valve 424, the sixth valve 425, and the loop element 320 establish a first bolus amount of the H2O salt solution. The first bolus amount has a pre-defined volume and a radioactivity concentration. 15 When the fifth valve 422 and the sixth valve 423 are arranged in the second configuration, the fifth valve 424, the sixth valve 425, and the loop element 320 establish a first bolus amount of the H2O salt solution. The first bolus amount has a pre-defined volume and a radioactivity concentration.

[0202] The infusion device 420 comprises a fourth valve 422 and a collection element 423. The collection element 420 is a medical syringe 420. The fourth valve 422 is a valve as shown in Figures 5 to 8 The medical syringe 420 can be manually controlled, and / or automatically controlled by the processing unit. The second saline feeder 401 is connected to the fourth valve 423.

[0203] The fourth valve 423 is arranged in a first configuration of at least two different configurations such that the connection between the medical injector 422 and the fifth valve 424 is disconnected. If the fourth valve 423 is arranged in a second configuration, the connection between the medical injector 422 and the second saline feeder 401 will be disconnected.

[0204] When the fourth valve 423 is in the second configuration, the medical injector 422 can collect a predefined second bolus of saline from the second saline feeder 401.

[0205] The patient line 520, which is connected to the sixth valve 425, is also connected to a bubble detector 522, a check valve 523, a second sterile filter 524, and a patient 521.

[0206] The bubble detector 522 detects whether any undesired bubbles are present in the first bolus and / or the second bolus. In the event of an undesired event of detecting bubbles, a processing unit connected to the bubble detector 522 stops the injection into the patient.

[0207] The check valve 523 is a one-way valve. The valve 523 ensures that the first bolus and / or the second bolus that has passed through the valve 523 cannot pass back into the system. Likewise, any fluid from the patient 521 cannot cross the check valve 523 and pass back into the system.

[0208] The second sterile filter 524 removes any unwanted particulate and microbial impurities that can be present, thus ensuring that the first bolus and / or the second bolus is sterile before entering the patient 521.

[0209] A second radiation detector 440, which is arranged adjacent to the patient line, measures the injection profile of the first bolus.

[0210] The patient 521 can be placed in a scanner, such as a positron emission tomography (PET) scanner (not shown), where the distribution of the radioisotope in the patient 521 can be monitored before, during, and after the injection of the first bolus.

[0211] Figure 2 is a flow chart illustrating the interaction of the bolus device with the injection device to provide an injectable H2 15 O salt solution with a predefined volume and radioactivity concentration.

[0212] In part A, a second pump 302, which is connected to the delivery tube 301, regulates the flow of the H2 15 O salt solution such that the H2 15 O salt solution is continuously pumped from the reservoir 281 through the delivery tube 301, the loop element 320, and the regulating means 340, thereby providing readily available H215 O salt solution.

[0213] The adjustment means 340 comprises a fifth valve 424 and a sixth valve 425 arranged on each side of the loop element 320 in the first configuration.

[0214] The first radiation detector 240 is arranged adjacent to the loop element 320. The first radiation detector 240 comprises a first detector unit and a second detector unit that measure the H2 15 O salt solution first and second radioactivity values.

[0215] When the radioactivity in the loop element 320 reaches a desired level, which can vary between different measurements and between different patients, part B is started automatically or manually.

[0216] In part B, the fifth valve 424 and the sixth valve 425 are changed from the first configuration to a second configuration so that the loop element 320 is not connected to the delivery tube 301 and the H2 15 O salt solution part of the system. In addition, the patient 521 is also isolated from the rest of the system.

[0217] The fifth valve 424 and the sixth valve 425 can be changed in configuration simultaneously or separately. The second configuration of the fifth valve 424 and the sixth valve 425 establishes a first bolus of the H2 15 O salt solution, which is the amount of the H2 15 O salt solution present in the loop element 320. The first bolus thus has a pre-defined volume and a radioactivity concentration, which is measured by the first detector unit and the second detector unit.

[0218] The loop element 320 has an adjustable volume, which can vary between different patients and between different measurements.

[0219] In the second configuration, the sixth valve 425 is connected to the patient line 520 and the fifth valve 424 is connected to the fourth valve 422.

[0220] In part C, the fourth valve 422 is connected to the second saline feeder 401 and the collection element 423. When the fourth valve 422 is in the first configuration, the connection between the collection element 423 and the fifth valve 424 is broken.

[0221] The fourth valve 422 is switched to the second configuration, then the connection between the collection element 423 and the second saline feeder 401 is broken.

[0222] In part D, the collection element 423 draws the desired amount of saline from the second saline feeder 401, thus establishing a second bolus of saline. This second bolus of saline is preferably 5 ml to 150 ml, more preferably 10 ml to 100 ml.

[0223] In part E, the fourth valve 422 is switched to the first configuration, thus establishing a connection between the collection element 423 comprising the second bolus of saline and the fifth valve 424.

[0224] In part F, the fourth valve 422, the fifth valve 424, and the sixth valve 425 are arranged in the first configuration. The collection element 423 injects the second bolus of saline into the loop element 320.

[0225] In part G, the second bolus of saline pushes the first bolus of H2 15 O salt solution present in the loop element 320 at a speed. The second bolus of saline itself, together with the O salt solution, pushes into the patient line 520 and eventually into the patient 521. The injection speed and amount of saline adjust the injection profile of the second bolus into the patient 521.

[0226] The second radiation detector 440 adjacent to the patient line 520 measures the injection profile of the first bolus.

[0227] All parts from A to G in the above Figure 2 explanation can be started and executed manually and / or automatically by a processing unit. The start of a certain part also depends on the termination of another part.

[0228] Figure 2 An arrangement is shown as an example for each different part. Parts C and D, in which a second bolus of saline is established, can also be executed before part B, in which a first bolus of H2 15 O salt solution is established.

[0229] Figure 3A and Figure 3B Another embodiment according to the first aspect of the invention is shown.

[0230] The reservoir 281 comprises H2 15 O salt solution. The second pump 302 continuously pumps H2 15 O salt solution from the reservoir 281 into the delivery tube 301, through the regulating means 340 and the loop element 320, and back into the reservoir 281.

[0231] The regulating means 340 comprise a plurality of safety valves according to the third aspect of the invention. In Figure 3A and Figure 3B the plurality of valves is represented as 7 valves.

[0232] In Figure 3A which the regulating means 340 is in a first configuration in which H2 15 The salt solution is pumped through the loop element 320. The injection device 420 is also in a first configuration in which a second bolus of saline is established.

[0233] In Figure 3B which the regulating means 340 is in a second configuration in which a second bolus is established and the connection from the loop element 320 to the patient line 520 is disconnected. The injection device 420 is also in a second configuration in which a second bolus of saline can be injected into the loop element 320 and the first and second bolus can enter the patient line 520.

[0234] Figure 4A and B illustrate different injection profiles of the first bolus.

[0235] When regulating the injection profile of the first bolus, also referred to as bolus modulation, there are two external parameters that can be used to influence this injection profile, namely the injection speed and the bolus volume.

[0236] According to the present invention, the volume of the first bolus is determined by the volume of the loop element 320. The volume of the loop element 320 can be varied depending on the specific patient or the desired bolus volume of the measurement.

[0237] According to the present invention, the injection speed is determined by the injection device 420. The injection speed can be varied depending on the specific patient or the desired speed of the measurement.

[0238] These parameters can be varied manually and automatically.

[0239] Further, the radioactivity is measured by a second radiation detector (not shown). An accurate measurement can only be made in a specific measurement window in which the radioactivity level is in a certain range. This range, and thus the measurement window, can vary with the different types of measurements performed.

[0240] Most commonly, the injection is performed with a uniform injection speed, thereby resulting in an injection profile as shown in Figure 4A .

[0241] The uniform injection speed results in an injection profile with a steep peak. The steep peak limits the time period in which the radioactivity level is within the measurement window, and thus the time period in which the second radiation detector can measure the radioactivity from the first injection profile.

[0242] Conversely, if the injection is started with a slightly higher injection speed, which is then decreased during the injection, then as shown in Figure 4BThe illustrated injection profile is more evenly distributed in the region of interest, providing an injection profile where the radioactivity level lasts for a longer period of time within the measurement window compared to an injection profile injected at a uniform rate as illustrated in Figure 4a.

[0243] With the radioactivity level lasting for a longer period of time in the desired measurement window, for example, it is possible to have a longer period of time for the PET scanner to accumulate data.

[0244] Further, the ability to modulate the injection profile is very useful during examinations related to cardiac studies, where the injection bolus cannot be either too steep or too wide with respect to the patient's pulse. A too steep curve will result in too few data points available in the usable window. A too wide curve will result in an inability to determine parameters necessary for cardiac studies, such as different centroid times.

[0245] In Figure 5 The valve 100 is shown prior to assembly into an assembled valve 100. The valve includes a valve element 120, a valve housing 150, and three spillway recesses 180A, B, C.

[0246] The valve element 120 includes a first end 122 and a second end 123. The first end 122 and the second end 123 define a first longitudinal axis 124. The valve element 120 is cylindrical. A flow passage 121 extends through the valve element 120 generally perpendicular to the first longitudinal axis 124.

[0247] The valve housing 150 is cylindrical and includes a cylindrical outer shell 156. The outer shell 156 includes a first end 157, a second end 158, and a second longitudinal axis 159 extending between the first end and the second end. When the valve is in an assembled configuration, the second longitudinal axis 159 is coaxial with the first longitudinal axis 124 of the valve element 120.

[0248] The valve housing 150 also includes an interior spacing 165 enclosed by the outer shell 156, and includes first, second, and third valve openings 151 A, B, C. Each valve opening 151 A, B, C allows fluid to flow into or out of the outer shell 156. The valve openings 151 A, B, C are equally spaced at approximately 120 degree angles from each other along a circumferential direction 160 of the outer shell.

[0249] The valve element 120 is axially movable along the second longitudinal axis 159 such that the second end and a portion of the valve element 120 can be inserted into the interior spacing 165 of the valve housing 150 to form the assembled valve 100.

[0250] The valve element 120 comprises at a first end a handle for rotating the valve element 120 inside the valve housing 150. The handle comprises a first, a second, and a third protrusion 125A, B, C arranged in the outer circumference 126 of the valve element 120, which protrude radially from the valve element 120. The first and the second protrusion 125A, B are arranged at a 90 degree angle relative to each other. The second and the third protrusion 125B, C are arranged at a 90 degree angle relative to each other. The first and the third protrusion 125A, C are arranged at a 180 degree angle relative to each other. The protrusions 125A, B, C have a rectangular shape.

[0251] The valve housing 150 comprises a first, a second, and a third hollow connection element 152A, B, C. The connection elements 152A, B, C each have a first end 153A, B, C, a second end 154A, B, C, and an inner fluid space 155A, B, C. The connection elements 152A, B, C are connected to the valve housing 150 at the second ends 154A, B, C such that the fluid spaces 155A, B, C are in fluid contact with the three valve openings 151A, B, C.

[0252] Three linear spillway recesses 180A, B, C are arranged in the valve housing 150, more precisely in the outer shell 156. Each spillway recess 180A, B, C extends axially between the first end 157 and the second end 158 of the outer shell 156. Each spillway recess 180A, B, C has a first and a second outlet opening 181A, B. The spillway recesses 180A, B, C are equally distributed at a roughly 120 degree angle relative to each other in the circumferential direction 160 of the outer shell.

[0253] Figure 6 A perspective view of the assembled valve 100 is shown.

[0254] The valve element 120 is arranged inside the inner spacing 165. The valve element 120 is rotatable within the inner spacing 165 around the second longitudinal axis 159 such that the valve element 120 and the valve housing 150 can be changed between at least three different open configurations 100A, B, C, i.e. Figure 7A 、 Figure 7B , and Figure 7C the first, the second, and the third open configuration shown.

[0255] The valve housing 150 comprises a circular bottom plate 162. The bottom plate 162 is connected to the second end 158 of the outer shell 156, extending across the entire second end 158 such that the bottom plate 162 closes the inner spacing 165 at the second end 158.

[0256] The three outlet openings 181 B of the overflow recesses 180A, B, C are arranged in the base plate 162 such that excess fluid can be drained through the overflow recesses 180A, B, C across the base plate 162.

[0257] Figure 7A Figure 7B and Figure 7C Cross-sectional views of the assembled valve in the first assembled configuration, the second assembled configuration, and the third assembled configuration are shown.

[0258] In Figure 7A -C, the first, second, and third connecting elements 152A, B, C are connected to the first, second, and third valve openings 151 A, B, C.

[0259] The valve element 120 and the valve housing are in contact with each other in three contact areas 101 A, B, C. More precisely, the outer circumference 126 of the valve element 120 is adjacent to the inner circumference 161 of the outer shell 156 of the valve housing 156 in these three contact areas 101 A, B, C. Each of these contact areas 101 A, B, C forms a fluid block 103.

[0260] Each overflow recess 180A, B, C is arranged between the valve element 120 and the valve housing 150. These overflow recesses 180A, B, C are not in fluid communication with the flow channel 121.

[0261] The first overflow recess 180A is positioned to establish an interruption of the first contact area 101 A. The second overflow recess 180B is positioned to establish an interruption of the second contact area 101 B. The third overflow recess 180C is positioned to establish an interruption of the third contact area 101 C.

[0262] Each overflow recess 180A, B, C establishes an interruption of the contact area 101 A, B, C such that each overflow recess 180A, B, C establishes a safe release for draining overflow fluid that, in case of an overpressure, passes the fluid block 103 through the respective outlet opening 181 A, B (not shown).

[0263] In Figure 7A , the assembled valve 100 in the first assembled open configuration is shown. The first and second valve openings 151 A, B are connected by the flow channel 121. The third valve opening 151 C is not connected to the flow channel 121.

[0264] The first assembled open configuration 100A has a flow path 102 through the first and second connecting elements 152A, B, the flow channel 121, and the first and second valve openings 151 A, B. ​

[0265] The second and third contact areas 101B, C each form a fluid stop 103 that prevents fluid flow into the third valve opening 151C that is not connected to the flow channel 121. If any fluid passes through the fluid stop 103 in the second contact area 101B, the fluid will be drained through the second spill recess 180B. If any fluid passes through the fluid stop 103 in the third contact area 101C, the fluid will be drained through the third spill recess 180C.

[0266] In Figure 7B the assembled valve 100 is shown in a second assembled open configuration. The second and third valve openings 151B, C are connected by the flow channel 121. The first valve opening 151A is not connected to the flow channel 121.

[0267] The second assembled open configuration 100B has a flow path 102 through the second and third connection elements 152B, C, the flow channel 121, and the second and third valve openings 151B, C.

[0268] The first and third contact areas 101A, B each form a fluid stop 103 that prevents fluid flow into the first valve opening 151A that is not connected to the flow channel 121. If any fluid passes through the first stop 103 in the first contact area 101C, the fluid will be drained through the first spill recess 180C. If any fluid passes through the fluid stop 103 in the second contact area 101B, the fluid will be drained through the second spill recess 180B.

[0269] In Figure 7C the assembled valve 100 is shown in a third assembled open configuration. The first and third valve openings 151A, C are connected by the flow channel 121. The second valve opening 151B is not connected to the flow channel 121.

[0270] The third assembled open configuration 100C has a flow path 102 through the first and third connection elements 152A, C, the flow channel 121, and the first and third valve openings 151A, C.

[0271] The first and second contact areas 101A, B each form a fluid stop 103 that prevents fluid flow into the first valve opening 151A that is not connected to the flow channel 121. If any fluid passes through the first stop 103 in the first contact area 101C, the fluid will be drained through the first spill recess 180C. If any fluid passes through the fluid stop 103 in the second contact area 101B, the fluid will be drained through the second spill recess 180B.

[0272] In Figure 7A and Figure 7C a plane P is shown. The valve openings 151A, B, C and the flow paths 121 are arranged in and extend along said plane P.

[0273] When the valve is in the assembled configuration, said plane P is substantially perpendicular to the first axis 124 and the second axis 159 Figure 5 as shown.

[0274] In Figure 8 and Figure 9 embodiments of a safety valve according to the third aspect of the application are shown in an unassembled position and in an assembled position, respectively. This embodiment is configured corresponding to the embodiment shown in Figure 5 to Fig. 7, with the difference that:

[0275] The valve element 120 has three flow passages 121A, B, C, each extending through the valve element 120.

[0276] The valve housing 150 has six valve openings 151A, B, C, D, E, F. Each valve opening 151A, B, C, D, E, F allows fluid to flow into or out of the housing 156. The valve openings 151A, B, C, D, E, F are distributed equidistantly at an angle of substantially 60 degrees to each other in the circumferential direction 160 of the housing. The valve housing 150 has six hollow connection elements 152A, B, C, D, E, F.

[0277] The valve comprises six overflow recesses 180A, B, C, D, E, F. The overflow recesses are distributed equidistantly at an angle of substantially 60 degrees to each other in the circumferential direction 160 of the housing.

[0278] The assembled valve 100 can be changed between six different open configurations 100A, B, C, wherein: in one open configuration three flow paths 102A, B, C are defined through three flow passages 121A, B, C and three groups of said valve openings; and in another of said open configurations three different flow paths 102D, E, F are defined through three flow passages 121A, B, C and a different three groups of said valve openings; and in a third of said open configurations three different flow paths 102G, H, I are defined through flow passages 121A, B, C and a yet different three groups of said valve openings.

[0279] The following items are embodiments of the application:

[0280] 1. A valve 100 for controlling the flow of H2 15 O used in positron emission tomography, the valve 100 comprising:

[0281] a valve element 120 having a flow channel 121 extending through the valve element 120,

[0282] a valve housing 150 having at least three valve openings 151A, B, C, each valve opening 151A, B, C allowing fluid to flow into or out of the valve 100, and

[0283] at least two spillway recesses, each spillway recess having at least one outlet opening,

[0284] wherein the valve element 120 and the valve housing 150 are connectable to form an assembled valve 100, the valve element 120 and the valve housing 150 being in contact with each other in a contact area,

[0285] wherein the assembled valve 100 is capable of being arranged in at least two different configurations, one of said configurations defining a flow path through the flow channel 121 and a set of said valve openings, and another of said configurations defining a flow path through the flow channel 121 and another, different set of said valve openings, and

[0286] wherein in each of said at least two configurations:

[0287] - each spillway recess is arranged between the valve element 120 and the valve housing 150,

[0288] - at least two of the valve openings are connected by the flow channel 121,

[0289] - at least one of the valve openings is not connected to the flow channel 121,

[0290] - said contact area forms a fluid barrier for preventing fluid from flowing into said at least one valve opening not connected to the flow channel 121,

[0291] - the spillway recesses are not in fluid communication with the flow channel 121,

[0292] - each spillway recess is positioned to establish an interruption of said contact area, such that the spillway recesses establish a safe release port for spillway fluid passing said fluid barrier through a respective said outlet opening in case of overpressure, such that in said at least two configurations said spillway fluid is prevented from entering said at least one valve opening not connected to the flow channel 121.

[0293] 2. The valve 100 according to item 1, wherein the valve housing 150 further comprises a connection element having a first end and a second end and an inner fluid space, the connection element being connected to the valve housing 150 at the second end such that the fluid space is in fluid contact with one of the at least three valve openings 151A,B,C.

[0294] 3. The valve 100 according to item 1 or 2, wherein the at least two overflow recesses are arranged in the valve housing 150 and / or in the valve element 120.

[0295] 4. The valve 100 according to any of the preceding items, wherein

[0296] the valve element 120 further comprises a first end and a second end defining a first longitudinal axis, and

[0297] the valve housing 150 further comprises:

[0298] - a housing comprising a first end and a second end and a second longitudinal axis extending between the first end and the second end, the second longitudinal axis being coaxial with the first longitudinal axis,

[0299] - an inner spacing for receiving the valve element 120, said inner spacing being enclosed by the housing, and

[0300] - the at least three valve openings 151A,B,C arranged in the housing, each opening allowing fluid to flow into or out of the inner spacing,

[0301] wherein the at least two overflow recesses extend axially between said first end and said second end of the housing,

[0302] wherein the valve element 120 is axially movable along the second longitudinal axis such that a portion of the valve element 120 is insertable into the inner spacing of the valve housing 150 to form an assembled configuration, and the valve element 120 is rotatable within the inner spacing about the second longitudinal axis such that the valve element 120 and the valve housing 150 are changeable between said at least two different configurations,

[0303] wherein each overflow recess is arranged between the valve element 120 and the housing when the valve element 120 is arranged inside the inner spacing in said two different configurations.

[0304] 5. The valve 100 according to any of the preceding items, wherein the valve housing 150 comprises three valve openings 151A,B,C, and / or the valve comprises 3 overflow recesses, and / or the valve element 120 comprises one flow passage 121.

[0305] 6. The valve 100 according to any of the preceding items, wherein the at least two overflow recesses are arranged in the housing, and / or the at least two overflow recesses extend between the first end and the second end of the housing and open into the first end and / or the second end, and / or the at least two overflow recesses extend between the first end and the second end of the valve element 120 and open into the first end and / or the second end.

[0306] 7. The valve 100 according to any of the preceding items, wherein the housing is cylindrical, and / or the valve element 120 is cylindrical, and / or the valve openings are distributed equidistantly around the circumference of the housing, the valve openings preferably being distributed at an angle of substantially 120 degrees to each other in circumferential direction.

[0307] 8. A system for producing and injecting H2 15 O for use in positron emission tomography, the system comprising:

[0308] - a production device for producing a H2 15 O salt solution,

[0309] - a bolus device for establishing a first bolus for injection, the first bolus comprising the H2 15 O salt solution and having a pre-defined volume and a radioactivity concentration, the bolus device comprising a valve 100, and

[0310] - an adjustment device for adjusting an injection profile of the first bolus.

[0311] 9. A production device for use in a system according to item 8, the production device comprising:

[0312] - a conversion element for converting a gas mixture 221 comprising 15 O and H2 at an elevated temperature into H2 15 O,

[0313] - a valve control element 250 for adjusting a flow of the gas mixture 221,

[0314] - a merging device for merging H2 15 O with a salt water from a first salt water feeder to produce a H2 15 O salt solution,

[0315] - a first radiation detector 240 for measuring a radioactivity in the H2 15 O salt solution,

[0316] wherein the valve control element 250 is adjusted by the first radiation detector 240.

[0317] 10. The production device according to item 9, wherein the merging device comprises:

[0318] - a reservoir 281 for receiving H2 15 O and the first salt solution,

[0319] - a second gas waste device for expelling any excess gas from said reservoir 281,

[0320] - a third pump connected at one end to the reservoir 281 and at the other end to a decay line connected to a liquid waste device,

[0321] wherein the third pump pumps excess liquid waste from the reservoir 281 through the decay line and into the liquid waste device,

[0322] and / or the merging device further comprises:

[0323] - a first pump connected to the first salt water feeder to provide the reservoir 281 with the salt solution, and

[0324] - a pH measuring device connected to the decay line,

[0325] wherein the first pump is regulated by the pH measuring device.

[0326] 11. A bolus device for use in the system according to item 8, wherein the bolus device comprises:

[0327] - a reservoir 281 containing a H2 15 O salt solution,

[0328] - a delivery tube 301 for circulating the H2 15 O salt solution from the reservoir 281 through a loop element 320 and a regulating device 340 and back into said reservoir 281,

[0329] - a second pump 302 for regulating said flow,

[0330] wherein the regulating device 340 comprises a valve, the regulating device 340 having a first configuration and a second configuration, wherein the second configuration of the regulating device 340 establishes a first bolus of said H2 15 O salt solution, the first bolus having a pre-defined volume and a radioactivity concentration.

[0331] 12. The bolus device according to item 11, wherein the valve is the valve according to any one of items 1 to 5, and / or

[0332] the loop element 320 has an adjustable volume, and / or

[0333] A first radiation detector 240 is arranged adjacent to the loop element 320, the first radiation detector 240 comprising a first detector unit and a second detector unit, wherein the first detector unit and the second detector unit measure the H2 15 A first radioactivity value and a second radioactivity value of the H2

[0334] 13. An adjustment device for the system according to item 8, the adjustment device comprising:

[0335] - a second saline feeder 401,

[0336] - a loop element 320 comprising a first bolus of the H2 15 O saline solution,

[0337] - an injection device 420 for collecting a predefined second bolus of saline from the second saline feeder 401 and injecting the second bolus into the loop element 320 at a predefined speed, such that the second bolus pushes the first bolus into the patient line 520,

[0338] - a second radiation detector 440 adjacent to the patient line 520, the radiation detector measuring an injection profile of the first bolus,

[0339] wherein the injection speed and volume of the second bolus adjust the injection profile of the first bolus.

[0340] 14. A method for preparing H2 15 O for use in positron emission tomography, the method comprising the steps of:

[0341] - converting a gas mixture 221 comprising 15 O and H2 at an elevated temperature into H2 15 O,

[0342] - providing a valve control element 250 to adjust the flow of the gas mixture 221,

[0343] - combining the H2 15 O with saline from a first saline feeder to produce a H2 15 O saline solution,

[0344] - providing a first radiation detector 240 to measure the radioactivity in the H2 15 O saline solution,

[0345] - adjusting the flow of the gas mixture 221 by the first radiation detector 240,

[0346] - providing a reservoir 281 to receive the H2 15 O salt solution,

[0347] - providing a second gas waste device for expelling any excess gas from said reservoir 281,

[0348] - providing a third pump connected at one end to the reservoir 281 and at the other end to a decay line connected to a liquid waste device,

[0349] - pumping any excess liquid waste from the reservoir 281 through the decay line and into the liquid waste device with the third pump,

[0350] - providing a delivery tube 301 and a second pump 302 to circulate the H2 15 O salt solution from the reservoir 281 through a loop element 320 and back into said reservoir 281,

[0351] - providing a regulating device 340,

[0352] - establishing a first bolus of said H2 15 O salt solution in the loop element 320, the first bolus having a pre-defined volume and radioactivity concentration,

[0353] - providing a second saline feeder 401,

[0354] - collecting a pre-defined second bolus of saline from said second saline feeder 401,

[0355] - injecting said second bolus into the loop element 320 at a pre-defined speed, such that the second bolus pushes the first bolus into a patient line 520,

[0356] - measuring an injection profile of said first bolus with a second radiation detector 440 adjacent the patient line 520,

[0357] - adjusting the injection profile of the first bolus with the injection speed and volume of said second bolus.

[0358] 15. The system according to item 8, wherein

[0359] the valve is according to any one of items 1 to 7, and / or

[0360] the production device is according to item 9 or 10, and / or

[0361] the bolus device is according to item 11 or 12, and / or

[0362] the regulating device is according to item 13, and / or

[0363] The valve is according to any one of items 1 to 7 and the production device is according to item 9 or 10, and / or

[0364] The valve is according to any one of items 1 to 7 and the bolus device is according to item 11 or 12, and / or

[0365] The valve is according to any one of items 1 to 7 and the regulating device is according to item 13, and / or

[0366] The production device is according to item 9 or 10 and the bolus device is according to item 11 or 12, and / or

[0367] The production device is according to item 9 or 10 and the regulating device is according to item 13, and / or

[0368] The bolus device is according to item 11 or 12 and the regulating device is according to item 13, and / or

[0369] The valve is according to any one of items 1 to 7 and the production device is according to item 9 or 10 and the bolus device is according to item 11 or 12, and / or

[0370] The valve is according to any one of items 1 to 7 and the production device is according to item 9 or 10 and the regulating device is according to item 13, and / or

[0371] The valve is according to any one of items 1 to 7 and the bolus device is according to item 11 or 12 and the regulating device is according to item 13, and / or

[0372] The production device is according to item 9 or 10 and the bolus device is according to item 11 or 12 and the regulating device is according to item 13, and / or

[0373] The valve is according to any one of items 1 to 7 and the production device is according to item 9 or 10 and the bolus device is according to item 11 or 12 and the regulating device is according to item 13.

Claims

1. A safety valve for controlling the flow of H2 15 O used in positron emission tomography, the valve comprising: a valve element having a flow passage extending through the valve element, a valve housing extending between a first end and a second end and having at least three valve openings, each valve opening allowing fluid to flow into or out of the valve, and at least two spillway recesses, each extending to the first end and the second end of the valve housing, each spillway recess comprising an outlet opening at both the first end and the second end of the valve housing, wherein the valve element and the valve housing are connectable to form an assembled valve, the valve element and the valve housing being in contact with each other in a contact area, wherein the assembled valve is arrangeable in at least two different open configurations, one of said open configurations defining a first flow path through the flow passage and a set of valve openings, and another of said open configurations defining a second flow path through the flow passage and another, different, set of valve openings, and wherein in each of said at least two open configurations: - each spillway recess is arranged between the valve element and the valve housing, - at least two of the valve openings are connected by the flow passage, - at least one of the valve openings is not connected to the flow passage, - the contact area forms a fluid barrier for preventing fluid from flowing into said at least one valve opening that is not connected to the flow passage, - the spillway recesses are not in fluid communication with the flow passage, - each spillway recess is positioned to establish an interruption of the contact area, such that the spillway recesses establish a safe release port for spill flow fluid that, in case of overpressure, passes said fluid barrier through the respective said outlet opening, such that in said at least two open configurations, said spill flow fluid is prevented from entering said at least one valve opening that is not connected to the flow passage.

2. The safety valve according to claim 1, wherein the assembled valve is arrangeable in a third, different, closed configuration in which the flow passage is not connected to any of the valve openings, such that no flow path through the flow passage and valve openings is established.

3. The safety valve according to claim 1, wherein the valve housing further comprises a connection element having a first end and a second end and an inner fluid space, the connection element being connected to the valve housing at the second end such that said fluid space is in fluid contact with one of said at least three valve openings.

4. The safety valve according to claim 1, wherein the at least two spillway recesses are arranged in the valve housing.

5. The safety valve according to claim 1, wherein the valve element further comprises a first end and a second end defining a first longitudinal axis, and the valve housing further comprises: - a housing comprising a first end and a second end and a second longitudinal axis extending between the first end and the second end, the second longitudinal axis being coaxial with the first longitudinal axis, - an inner spacing for receiving the valve element, said inner spacing being enclosed by the housing, and - the at least three valve openings arranged in the housing, each opening allowing fluid to flow into or out of the inner spacing, wherein the at least two overflow recesses extend axially between the first end and the second end of the housing, wherein the valve element is axially movable along the second longitudinal axis such that a portion of the valve element is insertable into an inner spacing of the valve housing to form an assembled configuration, and the valve element is rotatable within the inner spacing about the second longitudinal axis such that the valve element and the valve housing are changeable between the at least two different configurations, wherein each overflow recess is arranged between the valve element and the housing when the valve element is arranged inside the inner spacing in the two different configurations.

6. The safety valve according to claim 5, wherein the at least two overflow recesses are arranged in the housing and / or the at least two overflow recesses extend between the first end and the second end of the housing and open into the first end and / or the second end.

7. The safety valve according to claim 5, wherein in the at least two configurations of the assembled valve, the flow passage and the at least three valve openings are arranged in and extend in a same plane.

8. The safety valve according to claim 7, wherein said same plane is approximately perpendicular to the first longitudinal axis and the second longitudinal axis when the valve is in the assembled configuration.

9. The safety valve according to claim 1, wherein the overflow fluid is at 1 to 10 bar.

10. The safety valve according to claim 5, wherein the housing is cylindrical.

11. The safety valve according to claim 1, wherein the valve element is cylindrical.

12. The safety valve according to claim 5, wherein the valve openings are equally distributed around a circumference of the housing, the valve openings being angularly distributed to each other in a circumferential direction by approximately 120 degrees.

13. The safety valve according to claim 1, wherein the valve housing comprises three valve openings.

14. The safety valve according to claim 1, wherein the valve housing comprises 3 overflow recesses.

15. The safety valve according to claim 1, wherein the valve element comprises one flow passage.

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