Estimation of scattered radiation dose

Abstract

To provide a method for estimation of a scattered radiation dose.SOLUTION: For estimating the scattered radiation dose, a scattered radiation model is provided, which indicates a spatial distribution of the scattered radiation to be expected in the vicinity of a radiation source (4) during predefined use of the radiation source (4). A mobile electronic device (6) is used to determine a position of the mobile electronic device (6) relative to the radiation source (4). The mobile electronic device (6) is used to determine at least one dose descriptor of the scattered radiation to be expected during the use of the radiation source (4) in dependence on the scattered radiation model and in dependence on the determined position.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for estimating scattered radiation dose, comprising a scattered radiation model, which describes the expected spatial distribution of scattered radiation around a radiation source during a predetermined use of the radiation source. The present invention further relates to a corresponding system and computer program product for estimating scattered radiation dose. [Background technology]

[0002] Radiation sources, such as X-ray sources, or other modalities using, for example, alpha, beta, gamma, ion, proton, or neutron radiation, or for imaging or radiation therapy, typically emit radiation not only in the area to be examined or treated, but also in the vicinity of the radiation source, particularly as scattered radiation. This can pose a health hazard to people in the vicinity of the radiation source, such as medical staff. Therefore, it is desirable to provide information about exposure to scattered radiation to people in the vicinity of the radiation source. This, for example, allows people to avoid areas of high exposure and improves dose awareness among medical staff.

[0003] It is known to provide so-called personal dosimeters, which can be carried by a person in the vicinity of a radiation source and which are capable of measuring the dose that actually reaches the location of the personal dosimeter. However, since these dosimeters are based on the direct measurement of scattered radiation, it is not easy to take into account the characteristics of the radiation source, the type of radiation used, the radiation's energy spectrum, and other operating parameters of the radiation source. This makes it difficult to immediately provide the user with relevant information. Furthermore, the measurements do not provide the possibility to estimate future dose values ​​or, in some cases, the total dose that can be expected over the entire period of use.

[0004] It is also known to create a scattered radiation model, also called a dose model, which provides the predicted spatial and / or temporal distribution of scattered radiation around a radiation source during a given use of the radiation source, in particular the corresponding dose rate of scattered radiation. Non-Patent Documents 1 and 2 propose an approach that combines data from wireless dosimeters with simulation of radiation propagation to provide a comprehensive radiation risk map for the periphery of an X-ray device. For this purpose, a multi-camera system is used to obtain a 3D point cloud reconstruction of the room. The positions of the patient table, X-ray device, and treating physician are then used to simulate radiation propagation in the actual periphery, and the resulting 3D risk map is overlaid on the scenario in an augmented reality manner. The simulation is calibrated or its accuracy is validated using wireless dosimeters.

[0005] The drawback of this method is that although it can visualize the risk distribution for a person, it cannot estimate the actual radiation exposure that can be expected at present or in the future. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] NLRodas et al: “3D global estimation and augmented realty visualization of intra-operative X-ray dose.”, Medical image computing and computer-assisted intervention, 17(Pt 1):415-22(2014) [Non-patent document 2] NLRodas et al: “Seeing is believing: increasing intraoperative awareness to scattered radiation in interventional procedures by combining augmented reality, Monte Carlo simulations and wireless dosimeters.”, International Journal of Computer Assisted Radiology and Surgery volume 10, 1181-1191 (2015) Summary of the Invention [Problem to be solved by the invention]

[0007] The object of the present invention is to disclose a possibility for estimating the scattered radiation dose from a radiation source without relying on specific measurements of the physical parameters of the scattered radiation, and to make it possible to present the user with predicted dose values ​​in relation to their position. [Means for solving the problem]

[0008] This problem is solved by the subject matter of the independent claims. Advantageous developments and embodiments are the subject matter of the dependent claims.

[0009] The present invention is based on the idea of ​​utilizing a user's mobile electronic device to self-identify the location of the mobile electronic device and determine at least one dose value of scattered radiation predicted by the mobile electronic device based on the location of the mobile electronic device determined thereby and a predetermined scattered radiation model.

[0010] According to one aspect of the present invention, a method for estimating a dose of scattered radiation is disclosed. The method comprises a scattered radiation model that indicates, or describes, a predicted spatial distribution of scattered radiation around a radiation source during a given use of the radiation source. A position of the mobile electronic device relative to the radiation source is determined by a user's mobile electronic device, in particular exclusively by the mobile electronic device. At least one dose value of scattered radiation predicted during use of the radiation source, in particular currently and / or in the future, is determined by the mobile electronic device, in particular exclusively by the mobile electronic device, depending on the scattered radiation model and the determined position of the mobile electronic device.

[0011] Since the mobile electronic device is an electronic device belonging to a user, it can be understood that the location of the mobile electronic device can at least approximately infer the location of the user. That is, the mobile electronic device is particularly carried by the user. This means that when the user's location changes, the location of the mobile electronic device generally also changes. The relationship between the location of the mobile electronic device and the location of the user can be derived, for example, from appropriate model assumptions. In particular, it is also possible to equate the location of the mobile electronic device with the location of the user, or to assume a fixed displacement between the location of the mobile electronic device and the location of the user.

[0012] Mobile electronic devices may in particular be electronic terminals for wireless data communication, such as mobile phones, smartphones, tablet computers, so-called smart watches or other so-called wearable devices.

[0013] The scattered radiation model shows the distribution of scattered radiation around the radiation source in such a way as to show the physical quantities of the scattered radiation, in particular the dose rate or radiation energy or dose energy of the scattered radiation, and optionally also depending on time, as related to position or time according to a predefined use of the radiation source.

[0014] The term dose is used herein as an equivalent to the term radiation dose, as well as to derived terms such as dose rate. Depending on the embodiment or the specific setup of the scattered radiation model, dose may correspond to an equivalent dose in Gray or Sievert.

[0015] The term scattered radiation may be understood to mean components of radiation produced by a radiation source that are not emitted into or are not limited to the area of ​​the object being examined or treated, e.g., a patient.

[0016] As is known (see the documents cited at the beginning), the scattered radiation model can be created taking into account the type of radiation of the radiation source, the energy spectrum of the radiation produced by the radiation source, the change in the position of the radiation source in the room as a function of time, etc. When creating the scattered radiation model, the position and / or orientation of the object to be examined or treated relative to the radiation source, the spatial area and / or material properties of the object are also taken into account.

[0017] The scattered radiation model therefore presents, for each point within a predetermined region around the radiation source, which here and hereinafter shall be referred to as the periphery of the radiation source, or which shall be continuously presented or limited, the physical characteristics of the scattered radiation that are predicted when the radiation source is in use, possibly in relation to time.

[0018] The ability of the scattered radiation model to show the distribution of scattered radiation during use of a radiation source may mean that the radiation model takes into account one or more parameters of the use of the radiation source, such as, in particular, the energy spectrum of the radiation used, the movement trajectory of the radiation source, the period of its use or its individual sections, other details of the examination protocol, the X-ray acceleration voltage, the recording form, the set patient dose, etc.

[0019] The radiation source can be configured in various ways. Preferably, the radiation source is an X-ray source. However, it is also possible for the radiation source to be configured to emit other types of ionizing radiation, such as alpha radiation, beta radiation, gamma radiation, ionizing radiation, proton radiation or neutron radiation.

[0020] The radiation source is in particular a component of an imaging system for radiation-based imaging, such as medical imaging, in particular X-ray based imaging, and / or radiation therapy, in particular X-ray therapy.

[0021] The scattered radiation model is particularly provided in computer-readable form on a storage medium. The storage medium can be part of the mobile electronic device. Furthermore, the storage medium can be provided independently of the mobile electronic device, for example on a server computing unit or on another back-end facility. In the latter case, the mobile electronic terminal can load or read the scattered radiation model in whole or in part from the storage medium, particularly by wireless data communication.

[0022] The at least one dose value being a dose value predicted when using the radiation source can be interpreted in particular as the at least one dose value resulting from use of the radiation source, under the assumption that the scattered radiation model accurately reproduces the distribution of scattered radiation in the surroundings. Therefore, the evaluation of the at least one dose value is particularly problematic. The predicted at least one dose value can be determined taking into account the position of the mobile electronic device relative to the current time point, i.e. the time point at which the position of the mobile electronic device is determined, and / or taking into account future times.

[0023] The at least one dose value may include, for example, at least one dose rate and / or dose energy. In many embodiments, other information about the user, such as body dimensions or a typical holding position of the mobile electronic device, may also be taken into account to determine the at least one dose value, particularly in the form of a user model. It is advantageous to store the user model exclusively on the mobile device. In particular, personal information, such as body dimensions, gender, age, etc., may be stored exclusively on the mobile electronic device. This avoids centralized storage of personal user data. This achieves protection of the user's personal data.

[0024] The at least one dose value, in particular the dose rate and / or dose, can be determined for a single position, i.e. a fixed position of the mobile electronic device or a position derived therefrom, or can be determined for multiple positions, derived depending on the determined position of the mobile electronic device, for example to take into account multiple positions in or on the body of a user.

[0025] The position of the mobile electronic device is determined by the mobile electronic device itself, in particular by itself. For this purpose, known methods for self-location determination can be used, for example, by using visual markers or radio transmitters placed in the periphery, in particular known methods for self-location determination in an indoor area or indoor space. In other words, the mobile electronic device can of course also take into account information for determining the position that is external to the mobile electronic device itself, but the determination of the position, i.e., the implementation of all calculation steps required for this, is carried out exclusively by the mobile electronic device.

[0026] This in particular means that the fixed position of the mobile electronic device and, in a corresponding embodiment, all further positions resulting therefrom, for example with respect to the user, do not have to be stored or stored exclusively in advance in the mobile electronic device and transferred or transmitted from the mobile electronic device to another location, in particular to another external computing unit, such as a server or another central computing unit. The same applies analogously to the at least one predetermined dose value. Since this value is determined by the mobile electronic device, in particular exclusively by this device, it is possible to avoid or exclude the possibility of the corresponding information being used outside the mobile electronic device.

[0027] This offers significant advantages in terms of data security and thus in terms of protecting the user's personal data. One possible alternative to the approach according to the invention would be to determine the user's position, for example, using a camera placed in the room, and then calculate at least one dose value based on the results, for example, by a central computing unit. However, this would have the significant drawback of having to monitor and possibly store the user's position by an external unit, possibly over a long period of time. It would also be conceivable to monitor or centrally monitor or store the at least one dose value. However, this would increase the risk of the user's personal data being misused. Ultimately, this would also be counter to efforts to gain user acceptance of the dose estimation method.

[0028] In contrast, according to the present invention, the distributed position determination and the calculation of the dose values ​​are achieved by using a mobile electronic device for these purposes. In particular, the method according to the present invention does not directly determine the user's position, but instead determines the position of the mobile electronic device and determines at least one dose value based thereon. As mentioned above, the position of the mobile electronic device can approximately reproduce the user's position, or one or more characteristic positions of the user can be calculated or estimated thereon.

[0029] By calculating at least one dose value using the scattered radiation model, the dose value and / or information derived therefrom can be provided directly to a user, allowing the user to estimate their particular risk from radiation exposure. Furthermore, it is possible to determine not only dose values ​​characterizing the scattered radiation at the current time of location determination, but also dose values ​​for the scattered radiation predicted for the future.

[0030] In particular, the mobile electronic device comprises at least one calculation unit, and all calculation steps necessary for the mobile electronic device to determine its position and for the mobile electronic device to determine at least one dose value for each case can be performed by the at least one calculation unit.

[0031] In some embodiments, and particularly depending on the self-location aspect used, various sensors of the mobile electronic device, such as one or more cameras, tilt sensors and / or acceleration sensors, may be used to provide corresponding sensor data to at least one computing unit so that the position of the mobile electronic device can be determined.

[0032] According to at least one embodiment of the method for dose estimation, information regarding the at least one predicted dose value can be displayed by a visual display unit of the mobile electronic device, such as one or more LEDs or a display. The displayed information can correspond, for example, to the at least one dose value predicted or derived therefrom. This information can additionally or alternatively include recommendations for the user that may lead to a reduction in personal exposure to scattered radiation.

[0033] According to at least one embodiment, the at least one dose value comprises an actual predicted dose rate when the radiation source is in use and / or a predicted dose rate at a predefined future time point.

[0034] In this case, the actual predicted dose rate is understood to be the dose rate at the time of determining the location of the mobile electronic device, whereas the predetermined future time is a time after the location of the mobile electronic device has been determined. The future time is defined absolute or relative to the determination of the location of the mobile electronic device. In other words, at least one dose rate predicted at a future time corresponds to at least one predicted dose rate.

[0035] The predicted at least one dose rate may also include suitable predicted dose rates for a plurality of predefined future time points.

[0036] Based on the actual predicted dose rate and the information generated and possibly published based on it, the user can estimate the degree of current risk from exposure to radiation and possibly reposition themselves to reduce this risk. The same applies to future or predicted dose rates. Based on this, the user can actively react to a later predicted increase in exposure to radiation, for example by repositioning themselves.

[0037] According to at least one embodiment, the at least one dose value is determined dependent on a predicted dose rate and / or a predicted dose rate at a predefined future time point.

[0038] According to at least one embodiment, the at least one dose value comprises a previous dose predicted when the radiation source is used and / or a future dose predicted when the radiation source is used, or the at least one dose value is determined depending on the previous dose and / or the future dose.

[0039] The dose here corresponds in particular to the dose rate integrated or summed over time.

[0040] By determining the dose to date, the user can assess whether a current or future location is associated with a particularly high exposure to radiation, as well as whether previous locations in the vicinity of the radiation source resulted in a high radiation exposure overall, i.e., in absolute terms. The future dose may correspond, for example, to the total predicted dose of the radiation source, which can be estimated based on the location history of the mobile electronic device, a prediction based on the current location of the mobile electronic device, and possibly predicted imaging steps during the workflow of an ongoing medical procedure.

[0041] According to at least one embodiment, the position of the mobile electronic device relative to the radiation source is determined by the mobile electronic device at multiple time points, i.e., multiple times at different time points. For each of the multiple time points, the mobile electronic device determines a dose rate that is expected when the radiation source is used at the corresponding time point depending on the position at that time and depending on a scattered radiation model. Past doses and / or future doses are determined depending on the dose rates determined for the multiple time points.

[0042] The multiple time points can include a current time point, one or more past time points, and / or one or more future time points. For the current or past time points, the location of the mobile electronic device can be determined by self-localization as described above. For future time points, the location of the mobile electronic device can be assumed to be maintained or estimated from the mobile electronic device's trajectory history, e.g., by extrapolation, from the mobile electronic device's past position history, and the location of the mobile electronic device at the future time point can be determined in relation thereto.

[0043] According to at least one embodiment, radio signals are received by a receiving unit of the mobile electronic device from a plurality of transmitting units distributed in the vicinity, and the location of the mobile electronic device is determined in dependence on the received radio signals, in particular by at least one computing unit.

[0044] The receiving unit is therefore in particular a radio receiver and includes, for example, one or more antennas for receiving radio signals. The receiving unit can be, for example, a WLAN receiving unit, a Bluetooth receiving unit or a receiving unit designed for another type of wireless network. The same applies to the transmitting unit.

[0045] It is known to receive such radio signals from distributed transmitter units and use them to locate the receiving device. For this purpose, various information conveyed by the radio signals and / or other parameters of the radio signals, such as signal strength, can be evaluated, for example, to identify or locate individual transmitting units. In this manner, the at least one computing unit can determine the relative position of the mobile electronic device with respect to one or more transmitting units. The position of the radiation source with respect to the transmitting units is also known and, in some cases, specified as a function of time. Therefore, the at least one computing unit can also determine the position of the mobile electronic device with respect to the radiation source based on the relative position of the mobile electronic device with respect to the transmitting units and the relative position of the radiation source with respect to the transmitting units.

[0046] In particular, at least one of the transmitting units may be arranged at the radiation source such that the position of the mobile electronic device with respect to the transmitting unit corresponds to the relative position of the mobile electronic device with respect to the radiation source.

[0047] It is noted that various approaches for self-localization, including those described with respect to radio signals, can be combined with one another to more accurately determine the location of a mobile electronic device.

[0048] According to at least one embodiment, image data is used by the mobile electronic device, in particular by a camera of the mobile electronic device, of one or a number of reference objects and / or radiation sources in the vicinity, and the position of the mobile electronic device is determined in dependence on the image data, in particular by at least one computing unit.

[0049] Reference objects are in particular visually detectable objects or devices, the position of which is known in the vicinity of the radiation source. They can be, for example, the radiation source or other parts of the imaging diagnostic system, such as a patient table, a fixed or mobile robot stand, etc. They can also be parts of the architectural infrastructure or visual markers that are placed in the vicinity of the radiation source specifically for this purpose.

[0050] For example, at least one computing unit can use an image processing algorithm or a machine-reading algorithm to identify visual markers in image data including one or more camera images and determine their position and / or orientation relative to the mobile electronic device. For example, a specific two-dimensional pattern can be provided on each reference object, particularly a marker, to determine the position and / or orientation of each reference object, particularly a marker. An example of a visual marker is a so-called ArUco marker. Alternatively or additionally, information about their position and / or orientation in space can be displayed in text form or in other ways on the reference objects, particularly visual markers, so that it can be detected by a camera.

[0051] Thus, similar to the description of the transmitting unit for the wireless signal, the at least one computing unit can determine the current relative position of the reference object with respect to the mobile electronic device based on the image data, and furthermore, the relative position of the radiation source with respect to the reference object is also known, based on which the computing unit can finally determine the position of the mobile electronic device with respect to the radiation source.

[0052] One or more visual markers can be placed on the radiation source. Alternatively or additionally, the radiation source can be recognized and localized directly from the image data as a reference object.

[0053] According to at least one embodiment, sensor data is generated using at least one tilt sensor and / or acceleration sensor of the mobile electronic device, and the position of the mobile electronic device is determined by at least one computing unit depending on the sensor data.

[0054] Based on sensor data, e.g., related to, including, or derivable from tilt and / or acceleration of the mobile electronic device as a function of time, at least one computing unit can make inferences about the change in position of the mobile electronic device relative to its initial position or determine or estimate its relative movement. Various odometric methods are known, particularly in the field of robot navigation, that enable self-localization based on such sensor data. The initial position of the mobile electronic device can correspond to an initial position of the user or the mobile electronic device, which can be provided by the user or estimated from other circumstances. For example, the location of the entrance to a room where a radiation source is located can be known. The starting position can also be determined based on image data and / or radio signals, e.g., as described above.

[0055] According to at least one embodiment, a user position, which is related to the position of the mobile electronic device and in particular differs from the position of the mobile electronic device relative to the radiation source, is determined, in particular by the mobile electronic device, e.g., at least one computing unit, for which at least one predicted dose value is determined.

[0056] In other words, a specific relative position of the mobile electronic device with respect to the user's position is assumed to enable as accurate an estimation as possible of at least one dose value. The relative position of the mobile electronic device with respect to the user or with respect to the user's position can be determined in various ways. For example, the user may have corresponding information in advance, such as whether the mobile electronic device is on the left or right side of the user's body, in a trouser pocket, etc. Alternatively or additionally, a camera or another camera image of the mobile electronic device, i.e., image data or further image data from another camera, may be generated and used to determine the relative position of the mobile electronic device with respect to the user's position.

[0057] According to at least one embodiment, a three-dimensional spatial region is determined, in particular by the electronic device, for example by at least one calculation unit, depending on the position of the mobile electronic device. For each of a plurality of points in the three-dimensional spatial region, a local dose rate and / or a local dose is determined, in dependence on the use of a radiation source, by the mobile electronic device, in particular by the at least one calculation unit. The local dose rates and / or local doses, in particular for all points of the plurality of points, are added up to determine at least one predicted dose value.

[0058] In particular, the spatial region that can be defined relative to the radiation source can be determined as a continuous spatial region, whereby the plurality of points corresponds to a scan of the spatial region, but alternatively, the positions of each of the plurality of points can also be determined directly, and then the spatial region can be defined by the plurality of points.

[0059] The shape of the spatial region is defined, for example, based on a user model. For this purpose, for example, the user's body dimensions can be defined in advance. As described above, the user model can be advantageously stored exclusively in the mobile electronic device. In particular, personal information, such as body dimensions, gender, and age, can be stored only in the mobile electronic device. This avoids centralized management of the user's personal data. This protects the user's personal data. As described above for the user's position, the position and / or orientation of the spatial region relative to the position of the mobile electronic device can also be defined in advance and can be determined and / or defined by a camera or an additional camera of the mobile electronic device. Thus, from the determined position of the mobile electronic device relative to the radiation source and the corresponding specified or determined relative position of the three-dimensional region relative to the position of the mobile electronic device, the at least one computing unit can determine the relative position and / or orientation of the spatial region relative to the radiation source, and then determine the current local dose rate or dose according to the scattered radiation model.

[0060] The summation of local dose rates and / or local doses may include weighting of the dose rates or doses determined for individual points of a three-dimensional region, which weighting may then be specified, for example, as part of a user model, to generate useful or more significant dose values, for example by taking into account material properties or biological hazards of tissue regions of the user's body.

[0061] According to at least one embodiment, the mobile electronic device, in particular at least one computing unit, determines further positions or areas around the radiation source depending on at least one dose value and depending on a scattered radiation model, in which the amount of scattered radiation absorbed by the user when the radiation source is used is reduced.

[0062] Here, the decrease in absorbed dose is the difference from the predicted absorbed dose under the assumption that the user moves from the current location to another location or region. In particular, the decrease in absorbed dose can be understood to mean what is expected by a scattered radiation model in which scattered radiation is likely to decrease.

[0063] The information that can be output by the visual display unit of the mobile electronic device in a corresponding embodiment can also include a recommendation that the user should move to a further location or surrounding area to reduce the amount of absorbed scattered radiation.

[0064] According to at least one embodiment, further image data are used that map or partially map the user by the mobile electronic device, in particular by a camera and / or a further camera of the mobile electronic device. A user model is created or adjusted by the mobile electronic device, in particular by the at least one computing unit, based on the further image data. The at least one predicted dose value is determined depending on the user model.

[0065] Based on the further image data it is possible to determine, for example, the relative position of the mobile electronic device with respect to the position of the user as described above, and also or alternatively to determine the spatial region in which the respective local dose rate and / or dose is determined as described above in the corresponding embodiment.Alternatively or additionally, it is also possible to ascertain based on the further image data whether the user was wearing protective clothing and to determine at least one predicted dose value taking the protective clothing into account, for example by taking into account a reduction in the dose rate and / or dose due to the protective clothing.

[0066] According to yet another aspect of the present invention, a system for estimating scattered radiation dose, in particular a system according to the inventive method for estimating scattered radiation dose, is disclosed. The system includes a mobile electronic device configured to determine its position relative to a radiation source, i.e., to determine the position of the mobile electronic device relative to the radiation source. The system, e.g., the mobile electronic device, has a storage medium storing a scattered radiation model. The scattered radiation model represents a predicted spatial distribution of scattered radiation around the radiation source during a predetermined use of the radiation source. The mobile electronic device is configured to determine at least one dose value of the scattered radiation predicted during use of the radiation source depending on the scattered radiation model and depending on the determined position of the mobile electronic device.

[0067] In particular, the mobile electronic device comprises at least one calculation unit configured to determine its position relative to the radiation source and to determine at least one predicted dose value.

[0068] A computation unit may in particular be a data processing device including processing circuits. A computation unit may therefore in particular process data to perform computational operations. This may also include operations for performing indexed access to data structures, for example look-up tables (LUTs).

[0069] The computing unit may in particular comprise one or more computers, one or more microcontrollers and / or one or more integrated circuits, such as one or more application-specific integrated circuits ASICs (English "application-specific integrated circuits"), one or more field programmable gate arrays FPGAs, and / or one or more systems on a chip SoCs (English "system on a chip"). The computing unit may also comprise one or more processors, such as one or more microprocessors, one or more central processing units CPUs (English "central processing units"), one or more graphic processing units GPUs (English "graphics processing units"), and / or one or more signal processors, in particular one or more digital signal processors DSPs. The computing unit may also comprise a computer or any other physical or virtual combination of said units.

[0070] In various embodiments, a computing unit includes one or more hardware and / or software interfaces and / or one or more memory units.

[0071] The memory unit may be embodied as a volatile memory, for example a dynamic random access memory DRAM (English "dynamic random access memory") or a static random access memory SRAM (English "static random access memory"), or for example a read-only memory ROM (English "read-only memory"), a programmable read-only memory PROM (English "programmable read-only memory"), an erasable programmable read-only memory EPROM (English "erasable programmable read-only memory"), an electrically erasable read-only memory EEPROM (English "electrically erasable programmable read-only memory"), a flash memory or flash EEPROM, a ferroelectric random access memory FRAM (English "ferroelectric random access memory"), a magnetic random access memory MRAM (English "magnetoresistive random access memory") or a phase-change random access memory PCRAM (English "phase-change random access memory").

[0072] According to at least one embodiment of the system, the electronic device comprises a receiving unit for receiving respective radio signals from a plurality of transmitting units distributed in a vicinity, the mobile electronic device, in particular the at least one computing unit, being configured to determine a position of the mobile electronic device depending on the received radio signals.

[0073] Therefore, the mobile electronic device, in particular the receiving unit, is adapted to receive radio signals.

[0074] In various embodiments, the system includes multiple transmitting units.

[0075] According to at least one embodiment, the mobile electronic device has a camera configured to generate image data mapping one or more reference objects, in particular visual markers, in its surroundings, and the mobile electronic device, in particular the at least one computing unit, is configured to determine a position of the mobile electronic device depending on the image data.

[0076] In various embodiments, reference objects, particularly visual markers, are also part of the system.

[0077] According to at least one embodiment, the mobile electronic device has at least one tilt sensor and / or acceleration sensor configured to generate sensor data, and the mobile electronic device, in particular the at least one computing unit, is configured to determine a position of the mobile electronic device depending on the sensor data.

[0078] Further embodiments of the system according to the invention follow directly from the various embodiments of the method according to the invention, and vice versa. In particular, the individual features and corresponding descriptions and advantages of the various embodiments of the method according to the invention can be transferred analogously to the corresponding embodiments of the system according to the invention. In particular, the system according to the invention is embodied or programmed to carry out the method according to the invention. In particular, the system according to the invention implements the method according to the invention.

[0079] According to another aspect of the present invention, a computer program is disclosed having instructions which, when executed by a system according to the present invention, in particular by at least one computing unit of a mobile electronic device, cause the system to perform a method according to the present invention for estimating scattered radiation dose.

[0080] According to yet another aspect of the present invention, a computer readable storage medium storing a computer program according to the present invention is disclosed.

[0081] The computer program according to the invention or the computer-readable storage medium according to the invention may be referred to as a respective computer program product comprising instructions. [Brief explanation of the drawings]

[0082] The present invention will now be described in more detail with reference to specific embodiments and associated schematic drawings, in which identical or functionally identical elements are given the same reference numerals, and descriptions of identical or functionally identical elements may not necessarily be repeated for different figures.

[0083] [Figure 1] 1 is a schematic diagram of an exemplary embodiment of a system according to the present invention for estimating scattered radiation dose; [Figure 2] 3 is a flow chart of an exemplary embodiment of a method according to the present invention for estimating scattered radiation dose; [Figure 3] 3 is a schematic diagram of another exemplary embodiment of a system for estimating scattered radiation dose according to the present invention; [Figure 4] 3 is a schematic diagram of another exemplary embodiment of a system for estimating scattered radiation dose according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0084] 1 is a schematic diagram of an exemplary embodiment of a system 13 according to the present invention for estimating scattered radiation dose. The system 13 includes a storage medium 8 and a mobile electronic device 6, such as a smartphone, where the storage medium 8 can be part of the mobile electronic device 6 in various embodiments. In other embodiments, the storage medium 8 can be external to the mobile electronic device 6, and the mobile electronic device 6 can read the storage medium 8, for example, based on wireless data communication.

[0085] FIG. 1 further illustrates a modality 1 for radiation-based imaging and / or radiation therapy. The modality 1 includes a radiation source 4 configured to generate and emit ionizing radiation. For example, this may be x-ray radiation, although other modalities are possible. Purely by way of example, FIG. 1 illustrates modality 1 as a C-arm x-ray system with a stand 3 and a patient bed 2, where the radiation source 4 and x-ray detector 5 are located at opposite ends of the C-arm. However, this is not intended to be a limitation of the inventive concept, but rather is applicable to any ionizing radiation and corresponding radiation source 4.

[0086] The storage medium 8 stores a scattered radiation model that indicates the expected spatial distribution of scattered radiation around the radiation source 4 during a given use of the radiation source 4. The mobile electronic device 6 is configured to have its position relative to the radiation source 4 determined.

[0087] The mobile electronic device 6 is further configured to determine at least one dose value of scattered radiation that is predicted when the radiation source 4 is in use, depending on the scattered radiation model and depending on the determined position of the mobile electronic device 6.

[0088] The self-positioning of the mobile electronic device 6 can be performed in various ways depending on the embodiment of the system 13. In particular, the mobile electronic device 6 comprises a positioning means 9, which in particular comprises one or more sensors, e.g. a tilt sensor and / or an acceleration sensor, one or more receiving units for receiving radio signals and / or one or more cameras. Furthermore, the electronic device 6 comprises a calculation unit 7, which can substitute for one or more calculation units of the mobile electronic device 6. The calculation unit 7 can determine the position of the mobile electronic device 6 relative to the radiation source 4 based on signals detected by the positioning means 9 or the like or on sensor measurements.

[0089] The mobile electronic device 6 may be, for example, a device carried by the user 12. The location of the mobile electronic device 6 may therefore directly or indirectly infer the location of the user 12 relative to the radiation source 4.

[0090] Figure 2 shows a schematic flow chart of an exemplary embodiment of a method according to the invention for estimating scattered radiation dose, as can be performed, for example, by the system 13 described in Figure 1. In step S1 of this chart, a scattered radiation model is provided and in step S2 the mobile electronic device determines a position of the mobile electronic device 6 relative to the radiation source 4. In step S3 the mobile electronic device 6 determines at least one predicted dose value depending on the scattered radiation model and depending on the determined position.

[0091] Steps S2 and S3 may optionally be repeated, for example periodically, so that the position of the mobile electronic device 6 or at least one dose value to be predicted is determined repeatedly, in particular periodically, and changes in the position of the mobile electronic device can be taken into account.

[0092] In an optional step S4 of the method, at least one dose value to be predicted determined one or more times in step S3 is further processed, for example if a current dose rate is determined in step S3, the total dose accumulated so far can be calculated in step S4.

[0093] Similarly, optional step S5, which may occur immediately after step S3 or after periodic performance of S2 and S3 or after step S4 if performed, may display user information to the user on the mobile electronic device 6, for example on the display 14, depending on the results of steps S3 and / or S4.

[0094] Figure 3 is a schematic diagram of a further exemplary embodiment of a system 13 according to the invention. The embodiment of the system 13 of Figure 3 is based on the one of Figure 1. Here, the mobile electronic device 6 has in particular a camera 9a as positioning means 9, and a number of visual markers 10a, 10b, 10c, e.g. ArUco markers, arranged around the radiation source 4, whose positions and, e.g., orientations relative to the radiation source 4 are known.

[0095] The camera 9a can be used to generate image data mapping the markers 10a, 10b, 10c, and the calculation unit 7 can rely on the image data to determine the position of the mobile electronic device 6. To this end, the calculation unit 7 can determine, based on the image data, in particular the relative position and / or orientation of the mobile electronic device 6 with respect to one or more of the markers 10a, 10b, 10c, and can calculate the relative position of the mobile electronic device 6 with respect to the radiation source 4 based on the specified relative position of the radiation source 4 with respect to the markers 10a, 10b, 10c.

[0096] Figure 4 is a schematic diagram of a further exemplary embodiment of a system 13 according to the invention, also based on the embodiment of Figure 1. Instead of the visual markers 10a, 10b, 10c of the embodiment of Figure 3, the embodiment of Figure 4 is provided with a plurality of transmitting units 11a, 11b, 11c, which are arranged at known positions of the radiation source 4 and are able to emit radio signals. Thus, the mobile electronic device 6, and in particular the positioning means 9, comprises a receiving unit 9b that is able to receive the radio signals emitted by the transmitting units 11a, 11b, 11c. Based on the radio signals, the calculation unit 7 can determine the position of the mobile electronic device 6 relative to one or more of the transmitting units 11a, 11b, 11c and ultimately relative to the radiation source 4.

[0097] In another embodiment (not shown), the markers 10a, 10b, 10c and the transmitting units 11a, 11b, 11c as well as the camera 9a and the receiving unit 9b can be used to determine the position of the mobile electronic device 6 relative to the radiation source 4. Alternatively or additionally, the aforementioned tilt sensor and / or acceleration sensor (not shown) of the mobile electronic device 6 can be used to track the movement of the mobile electronic device 6 around the radiation source 4, and the position of the mobile electronic device 6 relative to the radiation source 4 can be determined based on the sensor data from the tilt sensor and / or acceleration sensor.

[0098] In particular, as shown by the figures, the present invention provides the possibility to estimate the amount of scattered radiation from a radiation source without relying on specific measurements of the physical parameters of the scattered radiation, making it possible to provide the user with predicted dose values ​​that are location-dependent.

[0099] Scattered radiation can pose a health hazard to medical staff or visitors in, for example, X-ray examination, angiography, or computed tomography examination rooms, or hybrid operating rooms. Therefore, it is desirable to increase dose awareness among medical staff. Accessible and simple information about the expected exposure to scattered radiation at various locations around a corresponding radiation source, such as can be provided by the present invention, can identify areas with high exposure to radiation and facilitate their avoidance. This is particularly beneficial for untrained staff and visitors.

[0100] According to a corresponding embodiment of the present invention, based on at least one dose value, information regarding currently predicted exposure to scattered radiation, for example during a scheduled or ongoing radiation-based examination or treatment of a patient, or another type of examination object, can be displayed on the user's mobile electronic device.

[0101] The scatter radiation model used can be generated and provided by known methods, optionally using a model of the examined object, also called a patient model, which can be generated, for example, based on a previous image data set of the examined object or can be a statistical patient model.

[0102] Optionally, known data about the user of the mobile electronic device, such as height, weight and / or typical positions for wearing the mobile electronic device, whether the device is held in the user's right or left hand or carried on the left or right hand of the body, at what height, etc., can be used to generate or adjust the user model, which allows the intensity of scattered radiation or at least one dose value for the user's whole body to be calculated. For this purpose, it is possible to assume, in particular, a constant position of the user's body relative to the mobile electronic device and / or for example, to assume that the user is standing upright on the floor.

[0103] It is also possible to optionally use sensors of the mobile electronic device, such as a camera, also called a selfie camera, e.g., a front camera, to create a user model, in which case any radiation protection clothing can be identified, the user's body dimensions can be estimated, and / or the relative position of the mobile electronic device with respect to the user can be identified.

[0104] Known parameters relating to continuous or current imaging geometry and / or dose settings can optionally be obtained from the mobile electronic device, for example via an interface to a system including the radiation source. The scatter radiation model can be statistically predicted based on these parameters, among others, and / or parameterized or simulated based on actual data.

[0105] In various embodiments, the mobile electronic device can display recommendations regarding where the user should move to reduce the predicted scattered radiation.

[0106] In various embodiments, the calculated scattered radiation, particularly the dose rate, is summed or integrated over the period of use of the radiation source so that a total future or previous dose can be calculated and displayed to the user.

[0107] In various embodiments, the position of radiation protection aprons, plates or barriers on the system or radiation source may also be detected and taken into account.

[0108] Compared to camera-based approaches using indoor surveillance cameras to track a user's location, the present invention can offer advantages in terms of data protection and acceptance, as the user's movements are not tracked outside the mobile electronic device and no corresponding data is recorded or stored. [Explanation of symbols]

[0109] 1. Modality 2 patient beds 3 Mounting stand 4 Radiation source 5 X-ray detector 6. Mobile electronic devices 7 Computational Units 8 Storage medium 9 Positioning means 10 Visual Markers 11 Transmitting unit 12 users 13 System

Claims

1. 1. A method for estimating scattered radiation dose, comprising: - providing a scattered radiation model that describes the expected spatial distribution of scattered radiation around the radiation source (4) during a predefined use of said radiation source (4); - determining the position of the mobile electronic device (6) of the user (12) relative to the radiation source (4); determining by the mobile electronic device (6) at least one dose value of the scattered radiation predicted by using the radiation source (4) depending on the scattered radiation model and depending on the determined position, information about the user stored exclusively on the mobile electronic device is also taken into account for determining the at least one dose value; A method characterized by:

2. The at least one dose value - containing the actual expected dose rate when using said radiation source (4) and / or the expected dose rate at a predefined future time, or determined depending on currently predicted dose rates and / or predicted dose rates at a predefined future time point, The method of claim 1.

3. The at least one dose value - containing the previous doses predicted when using said radiation source (4) and / or the future doses predicted when using said radiation source (4), or determined depending on said previous dose and / or said future dose, The method of claim 1.

4. - determining the position of said mobile electronic device (6) relative to said radiation source (4) at multiple points in time using said mobile electronic device (6); - determining, for each of said plurality of time points, by said mobile electronic device (6), a dose rate that is predicted depending on the position defined in each case and depending on said scattered radiation model (4) and depending on the use of said radiation source at the corresponding time point; - the previous dose and / or the future dose is determined depending on the dose rates determined for the plurality of time points; The method of claim 3.

5. receiving, by a receiving unit (9b) of said mobile electronic device (6), the radio signals of each of said plurality of transmitting units (11a, 11b, 11c) distributed in said vicinity; - determining the location of said mobile electronic device (6) in dependence on said received radio signals; The method of claim 1.

6. - using said mobile electronic device (6) to generate image data mapping one or more reference objects (10a, 10b, 10c) in its vicinity; - determining the location of said mobile electronic device (6) in dependence on said image data, The method of claim 1.

7. generating sensor data by at least one tilt sensor and / or acceleration sensor of said mobile electronic device (6); determining the location of said mobile electronic device (6) in dependence on said sensor data, The method of claim 1.

8. determining a location of the user (12) that is different from the location of the mobile electronic device (6) depending on the location of the mobile electronic device (6); determining at least one predicted dose value for the position of said user (12); The method of claim 1.

9. - determining a three-dimensional spatial region depending on the position of said mobile electronic device (6), - determining a local dose rate and / or a local dose for each of a plurality of points of the three-dimensional spatial region using said mobile electronic device (6); - adding up the local dose rate and / or the local dose using the mobile electronic device (6) to determine the at least one predicted dose value; The method of claim 1.

10. 2. The method of claim 1, further comprising using the mobile electronic device to determine, depending on the at least one dose value and depending on the scattered radiation model, further positions or areas around the radiation source where the amount of scattered radiation absorbed by the user when using the radiation source is reduced.

11. - using said mobile electronic device (6) to generate further image data mapping said user (12); - using said mobile electronic device (6) to create or adjust a user model based on said further image data, determining at least one predicted dose value in dependence on said user model, The method of claim 1.

12. A scattered radiation dose estimation system having a storage medium (8) storing a scattered radiation model showing a predicted spatial distribution of scattered radiation around a radiation source (4) during a given use of the radiation source, comprising: - the system comprises a mobile electronic device (6), the mobile electronic device (6) being configured to define its position relative to the radiation source (4); the mobile electronic device (6) is configured to determine at least one dose value of scattered radiation to be expected when using the radiation source (4) depending on the scattered radiation model and depending on the defined position of the mobile electronic device (6), the mobile electronic device (6) is configured to determine the at least one dose value depending on information about the user stored exclusively on the mobile electronic device; A scattered radiation dose estimation system comprising:

13. The mobile electronic device (6) - comprising a receiving unit (9b) for receiving current radio signals from a plurality of transmitting units (11a, 11b, 11c) distributed in said vicinity, and adapted to determine the location of said mobile electronic device (6) depending on the received radio signals; and / or - a camera (9a) configured to generate image data mapping one or more reference objects (10a, 10b, 10c) in said vicinity, and configured to determine the position of said mobile electronic device (6) depending on said image data; The system of claim 12.

14. - said mobile electronic device (6) comprises at least one tilt sensor and / or acceleration sensor configured to generate sensor data; the mobile electronic device (6) is configured to determine its location depending on the sensor data; The system of claim 12.

15. A computer program product comprising instructions for performing the method of claim 1 when executed on a system according to claim 12.

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