Device for detecting magnetic signal generated by beating heart

Abstract

The invention relates to a device (2) for detecting a magnetic signal generated by a beating heart (M), comprising: a first system (20) consisting of at least two nitrogen vacancy-center, NV, magnetometer units, the first system (20) having a first main extension plane; a second system (20) consisting of at least two NV-magnetometer units, the second system (20) having a second main plane of extension, the first main plane of extension being non-parallel to the second main plane of extension.

Description

[0001] The present invention relates to a device for detecting magnetic signals generated by a beating heart. Background Art

[0002] In order to measure the field strength of very small magnetism, quantum sensors that are optically pumped or based on NV centers in diamond are particularly suitable as sensors. DE 102022204526.2 describes a magnetometer that utilizes optically pumped and optically detected magnetic resonance (optically detected magnetic resonance, ODMR). What is utilized here is the energy level splitting of a specific spin state of unpaired electrons under the influence of an external magnetic field, the so-called Zeeman effect. Through the splitting of the energy levels, when relaxing from the excited state, a change transition is generated, which can then be measured, for example, by optical excitation and frequency-dependent detection of the generated fluorescent radiation or by observation of optical properties such as absorption of light. Then, the magnetic field strength can be inferred from the measured optical parameters. Summary of the invention

[0003] According to the invention, a device for detecting magnetic signals generated by a beating heart is provided having the features of claim 1. Advantageous embodiments are the subject matter of the dependent claims and the following description.

[0004] Magnetocardiography (MKG for short) is the recording and display of the magnetic field of the heart, which is generated by the electrophysiological activity of the myocardial cells. Within the scope of the present invention, a contactless, passive approach to long-term monitoring of the human heart with high resolution is presented. This is achieved by nitrogen-vacancy magnetometers (so-called NV magnetometers) in a geometric arrangement, in particular for vector gradient determination.

[0005] In detail, a device for detecting a magnetic signal generated by a beating heart is now introduced, the device having: a first system consisting of at least two NV-magnetometer units, the first system having a first main extension plane; a second system consisting of at least two NV-magnetometer units, the second system having a second main extension plane, wherein the first main extension plane is not parallel to the second main extension plane. Such a device can also be called a magnetocardiograph. As a result, the different directional components of the magnetic signal can be better distinguished. This has technical advantages, because the magnetic field lines of force are always distributed cyclically around the flowing current. As a result, the coverage of the sensors distributed in space is greatly improved. This expands the feasible scheme for signal processing, such as especially by integration. In addition, measurements can be performed well even when the user is moving.

[0006] In order to cover as wide a range as possible, in one embodiment, the first main extension plane and the second main extension plane enclose an angle of at least 25°, at least 30°, at least 45° or at least 60°. In one embodiment, the first main extension plane and the second main extension plane enclose an angle of 80°-90°. Thus, for example, magnetic signals can be detected for any rotational position of the heart around the axis of rotation when the user is standing or lying down.

[0007] The main extension plane of the system is generated in particular as the plane in which the projection of the system encompasses the largest surface.

[0008] In one embodiment, the device has a third system of at least two NV-magnetometer units, which has a third main extension plane, wherein the third main extension plane is not parallel to the first main extension plane and is not parallel to the second main extension plane. As a result, magnetic signals can be detected for any orientation of the heart in space. In one embodiment, there is an angle between each of the first, second and third main extension planes, which is selected from at least 25°, at least 30°, at least 45°, at least 60° or 80°-90°.

[0009] In one embodiment, the device has a further system consisting of at least one NV-magnetometer unit for detecting the background magnetic field. By directly measuring and taking into account the background magnetic field, the magnetic field of the heart can also be measured more accurately.

[0010] In one embodiment, the first and / or second and / or third and / or another system is embedded in a body selected from a building wall, a building ceiling, a building floor and a facility item. In order to detect the spatial magnetic field of the heart, in particular existing conditions, such as adjacent housing walls or roof slopes, can be used. On the other hand, for optimal noise suppression or background field detection, the system can be placed, for example, in the direction of a busy street or a high-current conductor, at the side of the house where the maximum level of magnetic noise can be detected.

[0011] A particular advantage of NV sensor systems is their size, in particular the size of the sensor medium. For the described application, the active measurement space should be small relative to the object to be measured (the heart), because otherwise the signal would be integrated over a large part of the surface coverage and the signal could disappear because the integral is zero. The smaller the active measurement space is compared to the heart, the better the signal detection. NV sensor systems have a very small active sensor space. In addition, this miniaturization and manufacturability allows the use of sensors in geometric arrangements. In particular, arrangements with very high resolution through a very small active sensor space are possible. This also allows easy integration into a body or an object.

[0012] Diamond NV magnetometers are based on the readout of the magnetic resonance of specific vacancy centers in diamond, in particular nitrogen vacancies (NV), which occur as impurities in the carbon lattice of diamond and can also be introduced in a targeted manner. If the NV center in the ground state is optically excited, for example by irradiating a pump laser beam with a suitable wavelength (in this case in the green wavelength range, for example at 532 nm for off-resonance excitation), the electrons are raised from the triple ground state to the excited triple state and relax at 650-800 nm (637 nm = zero phonon line) while emitting fluorescence in the red wavelength range. Since the NV center with m s = ±1 spin quantum number, the possibility of non-spin-maintaining transition is relatively high, so continuous excitation pumping makes the NV-center mostly in spin state m s =0 is hyperpolarized.

[0013] In the basic state m s =0 and m s = ±1, there is an energy difference between the spin states, which in this case is approximately 2.87 GHz. Therefore, if microwave radiation is radiated into the diamond in addition to the optical excitation, then in this case a red fluorescence interference occurs at this resonance frequency of 2.87 GHz, because the spin-polarized electrons are driven from the m by the microwave field. s =0 basic status increased to m s = ±1 basis state, and from there it is pumped to m s = ±1 excited state. However, from there, firstly non-radiative transitions and weak infrared fluorescence transitions occur via the singlet state, while the fluorescence in the red range is cancelled.

[0014] If an external magnetic field is present, the so-called Zeeman effect occurs: the energy m s= ±1 triplet-levels are split into Zeeman levels that are equidistant in energy. Then, when the fluorescence close to the spectrum of microwave excitation is marked, two dips are shown in the fluorescence spectrum, the frequency spacing of which is proportional to the magnetic field strength of the external magnetic field. The magnetic field sensitivity is first defined by the minimum resolvable frequency shift and can reach 1pT / √Hz or less. Since the NV-centers in single-crystal diamond have four possible arrangements in the lattice, the following situation occurs when there is an oriented magnetic field, namely: the NV-centers present in the crystal react to the external magnetic field to different degrees depending on their position in the crystal. As a result, in an ideal case, four pairs of fluorescence minima may appear in the spectrum, and from the shape and relative position of the four pairs of fluorescence minima, it is possible to clearly determine not only the magnetic field strength of the external magnetic field as a numerical value but also the direction of the external magnetic field.

[0015] In order to be able to perform vectorial magnetic field measurements, the device has, in one design, a mechanism for generating a substantially uniform bias magnetic field in the region of the magnetometer unit or its sensor medium, wherein the bias magnetic fields of different NV-magnetometer units are preferably different. The mechanism can also be integrated in the body. Here, it can involve a Helmholtz coil device, wherein at least the sensor medium is arranged inside the Helmholtz coil device. It can also involve other mechanisms, such as simple coils, elongated coils, permanent magnet solutions such as in a Halbach array, etc.

[0016] The heart signal has a magnetic signature with an amplitude of (still only) 1 to 2 digits of picoTesla (pT) at a distance of a few centimeters, compared to the geomagnetic field in Central Europe, for example, which is about 50 μT (microTesla), thus 10 times stronger. 6 However, even such low field strengths can be resolved with great precision over a long period of time using the proposed technology. For example, magnetic shielding or gradiometer wiring can be used for this purpose.

[0017] By means of high-resolution detection of precise cardiac signals, a large number of diseases can be detected, such as, for example, persistent atrial fibrillation and paroxysmal ("burst") atrial fibrillation. As a result, myocardial infarctions and therefore strokes (especially after unrecognized myocardial infarctions) can be prevented. In addition, the present invention is suitable for the early identification of ST-elevation myocardial infarctions, other types of elevation myocardial infarctions, pulmonary embolism, AV-node-reentry-tachycardia, ventricular extrasystoles, but also very rare etiological diseases such as, for example, right ventricular tachyarrhythmias, which otherwise can only be identified by gene sequencing, can be identified at an early stage.

[0018] Only an accurate resolution of the cardiac signal makes this detection of symptoms possible. That is, if the signal is heavily contaminated by noise or poorly resolved, the offsets of the different PQRST complexes of the heart relative to each other or over time, fluctuations in their amplitude, deformations or small disturbances cannot be detected. However, this resolution of the standards is an important factor, because the above-mentioned problems can lead to confusion of the complexes (e.g., elevated and offset T waves are interpreted as R waves, which often occur in "healthy" hearts) and to false alarms.

[0019] If the gradiometer wiring of the at least two NV-magnetometer units of the system is used, one magnetometer unit always has a larger spacing relative to the heart (as a relatively weak magnetic field source) than the other magnetometer unit. Through the gradiometer wiring, that is, the basic (vectorial) subtraction of the measured parameters, the magnetic field gradient almost corresponds to the field emitted by the weak source, while the much stronger background field (which is basically the same in the two magnetometer units) is eliminated. Thus, the necessity of magnetic shielding is cancelled, making it possible to measure the magnetic field in the daily environment. The present invention is accordingly particularly suitable for measuring weak magnetic fields without shielding. The technical details of the gradiometer solution that can also be used within the scope of the present invention are disclosed in DE 102022201690.4 and should be included here together.

[0020] In one embodiment, the device is configured to detect the magnetic field strength and field direction with the aid of each NV magnetometer unit of the first and / or second and / or third and / or further system. Another advantage of the NV sensor system is the direction or vector information. Compared to other technologies, this technology is inherently generated for the NV sensor system. Therefore, it is not necessary to introduce interferences by modulation technology or to use more unfavorable projections, nor is it necessary to use multiple individual sensors. As a result, one has vector and gradient measurement information (diamond size, i.e. single-digit mm) at exactly the same position. ∧3 and below) and not separated by a few centimeters to more centimeters as in other technologies. With NV magnetometer units that can determine not only the field strength of the magnetic field but also the direction of the magnetic field, an improved suppression of the background field can be achieved and thus a better detection of signals that are strongly superimposed by interference signals can be achieved. This is based on two mechanisms of action: Firstly, the signal is not so easily influenced by the tilt of the sensors relative to each other (in standard gradiometer applications, the tilt of the 1D magnetometer leads to different projections of the measurement field or the interference field) and can be compensated for, which is important for non-rigid supports, especially in combination with positioning, for example in the relevant mattress. Secondly, the interference field can have a different spatial direction than the field to be measured. This makes it easier to separate the signal and the background.

[0021] In one embodiment, the device has a signal processing unit, to which the NV-magnetometer unit of the first and / or second and / or third and / or further system is connected, wherein the device is configured to determine an effective magnetic field strength and / or an effective magnetic field direction by means of the signal processing unit as a difference in magnetic field strengths or field directions detected by means of the at least two NV-magnetometer units. Both a wireless connection and a wired connection are provided between the sensor device and the signal processing unit.

[0022] For the application described, a sampling rate higher than the heart signal, in particular greater than 50 Hz, is required in order to resolve the heart signal. Here, a range of 200 Hz to 400 Hz is considered to be particularly advantageous. A higher range is always better for resolution, but increases the requirements on sensitivity.

[0023] Further advantages and embodiments of the invention are apparent from the description and the drawings.

[0024] The invention is schematically illustrated in the drawings on the basis of exemplary embodiments and is described below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The main components of an NV center magnetometer as can be used within the scope of the present invention are shown in a schematic block diagram.

[0026] Figure 2 In the various illustrations a) to c), a possible arrangement of an NV magnetometer unit of a device for detecting magnetic signals according to one embodiment is shown in each case in the form of a schematic block diagram.

[0027] Figure 3 A user and a device according to one embodiment of the invention are shown schematically in a side view.

[0028] Figure 4 A number of systems according to an embodiment of the invention are schematically shown in a perspective view in a living room, said systems being embedded in different bodies. DETAILED DESCRIPTION

[0029] Figure 1 The main components of the NV center magnetometer are schematically shown. Here, as the sensor medium, there is first a diamond 110 with nitrogen vacancies (NV). The optical excitation of the NV center can be achieved by a suitable light source 120, such as an LED or a pump laser. Here, for example, a frequency-doubled Nd:YAG laser or a semiconductor laser in the green range of, for example, 510-532 nm, such as 532 nm, is suitable for off-resonance excitation. As an alternative, an LED in a suitable wavelength range can also be used. Depending on the layout, the light of the light source 120 can be radiated into the diamond 110 through suitable optical elements 122, such as, for example, reflectors, beam splitters, focusing mirrors, such as lenses, and if necessary, through fiber-optic elements. In addition, the excitation light can be radiated continuously or pulsed by a laser, so as to, for example, retain a time window for interference-free fluorescence measurement.

[0030] In addition, the magnetometer can include a microwave source 150, which can generate an electromagnetic field in the sensor medium, that is, in the region of the NV center of the diamond 110, within the bandwidth covering the desired resonance frequency. A microwave resonator structure can be used to uniformly distribute the generated microwaves in the space of the measurement range in the diamond. The resonator structure or microwave source 150 is preferably matched to the frequency of the electron spin resonance. In order to achieve vector magnetometry, an additional static bias magnetic field 140 is generated. As a result, the measurement becomes intrinsic vector. For this purpose, different spatial directions in the crystal structure are used. For example, Helmholtz coils are suitable for generating such a magnetic field 140, for which a substantially uniform magnetic field in a restricted range can be generated by means of a coil pair.

[0031] The generated fluorescence 112 from the diamond 110 can be guided to the first photodetector 130 by suitable optical elements 134, such as optical filters, beam splitters, lenses and / or fiber optic elements, which are sensitive at least in the range of the fluorescence wavelength. The first photodetector 130 can also be arranged directly on the diamond 110. The second photodetector 132 is arranged so that it can detect at least a part of the excitation light of the light source 120, which can be coupled out by beam splitters, filters or partially transparent elements. This detector signal 132 of the excitation light can be used as a reference signal, so as to eliminate background signals and highlight the resonance signal of interest, for example, by means of a phase-locked amplifier through modulation of the excitation light. As a supplement or alternative, this reference signal can be used to take into account the fluctuations of the excitation light. Corresponding circuits 160, such as preamplifiers, logarithmic amplifiers, phase-locked amplifiers, signal filters or other circuits are thus provided for obtaining the signals of the first and second photodetectors and preprocessing the signals in a suitable manner for further evaluation. Finally, the preprocessed fluorescence signal can be evaluated by a signal processing unit 170 , for example using a suitable microcontroller or processor, in order to derive from the signal desired parameters of the detected magnetic field, in particular the magnetic field strength and direction of the magnetic field.

[0032] It goes without saying that such a device can also have further units (not shown), such as a communication unit or an interface for outputting measurement results. Such a device can also be advantageously integrated into an ASIC or FPGA.

[0033] In order to be able to use in everyday environments, magnetic fields that do not originate from the expected weak sources, especially those at 10 -5 The Earth's magnetic field in the range of a few microteslas is eliminated as much as possible from the measurement. In contrast, the heart's magnetic field is in the range of 10 to 100 times 10 -12 Fluctuates within the range of Tesla (picotesla).

[0034] The elimination of the background magnetic field can be achieved during the measurement of the magnetic field according to exemplary embodiments by shielding or by a gradiometer system. In principle, a gradiometer is a sensor unit that can detect both the field strength and the gradient of the field.

[0035] For this purpose, at least two individual magnetometer units can be used, which are arranged at different locations in space. Figure 2 A sensor unit is described which uses two or more NV-center-magnetometers in a gradiometer system.

[0036] Figure 2 In different illustrations a) to c), possible geometric arrangements of NV-magnetometer units of a device for detecting magnetic signals according to a design are shown. Figure a) shows in a side view the arrangement of at least two NV-magnetometer units S1, ..., Sn in an arbitrary arrangement relative to each other in one plane (the plane is perpendicular to the illustrated plane, that is, only the first row can be seen). The main extension plane is therefore perpendicular to the illustrated plane. Figure b) shows in a side view two NV-magnetometer units S1 and S2, whose sensor media are segments of the same diamond crystal 110. Figure c) shows in a side view a certain number (n times m) of NV-magnetometer units S11, S21, ..., Sn1, S12, S22, ..., Sn2, S1m, ..., Snm in an arrangement parallel to the illustrated plane. The main extension plane is therefore in the illustrated plane.

[0037] Furthermore, M denotes a signal source, here the heart, and O denotes an optional surface, in particular the body skin, which limits the accessibility or reachability of the magnetic field source M.

[0038] In a design of the invention, more than two (but at least two) NV magnetometer units can be combined to form a gradiometer. With each additional NV magnetometer unit, the background field can be better determined and the position and intensity of the actuator can be better separated from the background.

[0039] In other embodiments of the invention, two NV-magnetometer units can also form a gradiometer, wherein a plurality of gradiometers can then form and detect the signal of interest in total according to the number of NV-magnetometer units. A valid measurement signal can then be formed therefrom, in particular by a signal processing unit, for example by averaging, summing, etc.

[0040] The distance d between two NV magnetometer units S1, S2, ... or more precisely their sensor media corresponds to the distance between the following positions at which the magnetic field measurement is carried out simultaneously. If the distance between the measurement positions is relatively small, it can be assumed that the additional background magnetic field B env The strength of the magnetic field B is approximately the same at both locations. In contrast, the weak magnetic field B of interest decreases significantly with increasing distance from the magnetic field source M. In addition, the different orientations of the magnetic field of an exciter (e.g., the heart) allow a clear separation from the background field even at small distances.

[0041] Therefore, by arranging two NV-magnetometer units at different spacings and angles from the source or heart, the background field can be eliminated or determined by vector arithmetic, and the small magnetic field of interest can be determined thereby, and its source can be characterized (position and orientation). This can be further improved by a distant magnetometer unit or another system, which is so far away that the weak magnetic field of interest falls below the detection threshold. With such a configuration, local changes in the background field can be compensated by the at least two nearby magnetometer units. For this purpose, two NV-magnetometer units can be arranged up and down, for example, in an axial gradiometer configuration, so that an NV-magnetometer unit of the first layer forms a gradiometer with an NV-magnetometer unit of the second layer below it, respectively.

[0042] exist Figure 3 and 4 A possible embodiment of the invention is schematically shown in FIG. 1 and is generally described below. Identical elements are provided with the same reference numerals and are not described multiple times.

[0043] Here, a device for detecting magnetic signals is shown, which has at least two systems 20 composed of at least two NV-magnetometer units, each of which has a main extension plane. The device is used to detect magnetic signals generated by a beating heart (M), but in principle it can detect all magnetic signals, especially biological signals, that is, biological signals emitted by a living being, such as signals from the brain (M). For illustration, the drawings have a coordinate system in the upper left part, in which the illustrated level represents the xz plane and the y axis extends into the inside of the illustrated level. The device also has a signal processing unit (not shown), and the NV-magnetometer unit of the system 20 is connected to the signal processing unit to determine the effective magnetic field strength and / or field direction. In addition, a communication unit (not shown) can be provided to connect the device to other devices, such as a PC, a tablet PC, a smartphone, for input and output and operation. The communication unit can have, for example, a wired and / or wireless interface. The signal processing unit and the communication unit can also be integrated in the body or arranged outside the body, for example as a stand-up device. Arranged in switch cabinet, etc.

[0044] exist Figure 3 The mattress 1 and the wall 2 are shown as the main body. Figure 4 2 shows a mattress 1 on a bed, a wall 2 and a roof slope 3, in which each system 20 is embedded. In addition to the examples mentioned, embedding in any furniture items, such as furniture, pictures, lamps, table carpets, etc. is conceivable.

[0045] A mattress 1 , a mattress topper, a bed or a slatted mat for integration into a system is suitable for testing in the frontal plane of the user.

[0046] The headboard part of a bed, a wall 2 , a room ceiling or a roof slope 3 are suitable for detecting the vertical component.

[0047] Many sources of ambient magnetic noise (background fields) are outside private living areas and cannot be reduced. External and internal walls are particularly suitable for detecting and calculating the sources of ambient magnetic noise when broadband magnetic noise fields flow through them. By means of synchronized recording, the signals of different systems can be calculated and the signals close to the heart of the ambient noise can be reduced.

Claims

1. A device for detecting magnetic signals generated by a beating heart (M), having A first system (20) consisting of at least two nitrogen-vacancy-centers, NV, magnetometer units (S1, S2, ..., Sn; S11, S21, ..., Sn1, S12, S22, ..., Sn2, S1m, ..., Snm), wherein the first system (20) has a first main extension plane, A second system (20) consisting of at least two NV magnetometer units (S1, S2, ..., Sn; S11, S21, ..., Sn1, S12, S22, ..., Sn2, S1m, ..., Snm), wherein the second system (20) has a second main extension plane, The first main extension plane is not parallel to the second main extension plane. 2 . The device according to claim 1 , wherein the first main extension plane and the second main extension plane enclose an angle of at least 25°, at least 30°, at least 45° or at least 60°. 3 . The device according to claim 2 , wherein the first main extension plane and the second main extension plane enclose an angle of 80°-90°.

4. The device according to any of the preceding claims, having a third system (20) composed of at least two NV-magnetometer units (S1, S2, ..., Sn; S11, S21, ..., Sn1, S12, S22, ..., Sn2, S1m, ..., Snm), wherein the third system (20) has a third main extension plane, wherein the third main extension plane is not parallel to the first main extension plane and is not parallel to the second main extension plane.

5. The device according to claim 4, wherein the third main extension plane and the first and / or second main extension plane enclose an angle selected from at least 25°, at least 30°, at least 45°, at least 60° or 80°-90°.

6. The device according to any of the preceding claims has another system (20) composed of at least one NV-magnetometer unit (S1, S2, ..., Sn; S11, S21, ..., Sn1, S12, S22, ..., Sn2, S1m, ..., Snm), which is used to detect the background magnetic field.

7. The device according to any of the preceding claims, wherein the first and / or second and / or third and / or another system (20) is embedded in a body selected from a building wall, a building ceiling, a building floor and an item of facility.

8. A device according to any of the preceding claims, wherein the device is configured to detect the magnetic field strength and field direction with the aid of each NV-magnetometer unit (S1, S2, ..., Sn; S11, S21, ..., Sn1, S12, S22, ..., Sn2, S1m, ..., Snm) of the first and / or second and / or third and / or another system (20).

9. The device according to claim 8, comprising a signal processing unit (170), to which the NV magnetometer units (S1, S2, ..., Sn; S11, S21, ..., Sn1, S12, S22, ..., Sn2, S1m, ..., Snm) of the first and / or second and / or third and / or further system (20) are connected, The device is configured to determine, with the aid of the signal processing unit (170), an effective magnetic field strength and / or field direction as a difference between the magnetic field strength or field direction detected with the aid of the NV magnetometer units (S1, S2, ..., Sn; S11, S21, ..., Sn1, S12, S22, ..., Sn2, S1m, ..., Snm).

10. An apparatus according to any one of the preceding claims, wherein the system (20) is a two-dimensional system (20), wherein the NV-magnetometer units (S1, S2, ..., Sn; S11, S21, ..., Sn1, S12, S22, ..., Sn2, S1m, ..., Snm) of the first and / or second and / or third and / or another system (20) are arranged in corresponding main extension planes.

11. An apparatus according to any one of the preceding claims, wherein the NV-magnetometer units (S1, S2, ..., Sn; S11, S21, ..., Sn1, S12, S22, ..., Sn2, S1m, ..., Snm) of the first and / or second and / or third system include at least four NV-magnetometer units, and wherein the system (20) is a three-dimensional system (20), wherein at least one of the at least four NV-magnetometer units is not arranged in a corresponding main extension plane, and at least three other NV-magnetometer units of the at least four NV-magnetometer units are arranged in the main extension plane.

12. A device according to any of the preceding claims, wherein each NV magnetometer unit (S1, S2, ..., Sn; S11, S21, ..., Sn1, S12, S22, ..., Sn2, S1m, ..., Snm) of the first and / or second and / or third and / or another system (20) has a diamond crystal or a segment of a diamond crystal with nitrogen-vacancy centers as a sensor medium (110), wherein the device is configured to detect the magnetic field strength and / or field direction by reading out a spin resonance in the sensor medium (110) that depends on the magnetic field strength.

13. The device according to claim 12 also has at least one excitation light source (120) for radiating light (124) into the sensor medium (110), at least one microwave source (150) for generating a resonance field in the sensor medium, and at least one photodetector (130) for detecting resonance-dependent fluorescence (112) from the sensor medium (110).

14. The device according to claim 13, wherein the NV-magnetometer units (S1, S2, ..., Sn; S11, S21, ..., Sn1, S12, S22, ..., Sn2, S1m, ..., Snm) of the system (20) are assigned the same excitation light source (120) and / or the same microwave source (140).

15. A device according to any one of claims 12 to 14, wherein the sensor medium of at least two NV-magnetometer units (S1, S2, ..., Sn; S11, S21, ..., Sn1, S12, S22, ..., Sn2, S1m, ..., Snm) of the system (20) respectively has a segment of the same diamond crystal (110).

16. An apparatus according to any one of claims 12 to 15, wherein the spacing (d) between the sensor media (110) of the at least two NV-magnetometer units (S1, S2, ..., Sn; S11, S21, ..., Sn1, S12, S22, ..., Sn2, S1m, ..., Snm) of the system (20) is between 1 and 30 mm, preferably between 5 and 20 mm.

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