Liver iron content magnetic detection device and method based on SERF atom magnetometer

Abstract

The invention discloses a liver iron content magnetic detection device and method based on an SERF atomic magnetometer, and the device comprises the SERF atomic magnetometer for measuring a liver ferromagnetic signal, a magnetic shielding device for shielding a geomagnetic field and environmental noise, a supporting and positioning mechanical platform, and a Helmholtz external polarization coil. A detected organism is fixedly arranged on a sample table, and after an iron compound in mouse liver tissue is polarized by a magnetic field generated by a Helmholtz external polarization coil, a magnetic field relaxation signal is detected by an SERF atomic magnetometer. The device has the advantages of being small, portable, low in cost and high in precision, targeted measurement can be conducted on the iron content in the liver, the iron content in the liver serves as an important marker of liver diseases, effective technical support is provided for early clinical diagnosis of iron overload diseases, an important monitoring means is provided for risk-free clinical practice, and the device is suitable for popularization and application. And the progress of the medical field is promoted.

Description

Technical Field

[0001] The present invention relates to the technical field of biomagnetic field detection, and in particular to a device and method for magnetically measuring liver iron content based on a SERF atomic magnetometer. Background Art

[0002] Iron is an essential trace mineral for the human body, performing vital physiological functions. The liver is the primary organ for iron storage and metabolism. Of the approximately 4 grams of total iron in an adult male, approximately 1 gram is stored in the liver. During normal iron metabolism, iron is stored in hepatocytes as ferrous iron bound to ferritin. The balance between iron absorption and loss determines the body's iron reserves. Normally, iron homeostasis is maintained by a finely regulated mechanism of iron absorption in the gastrointestinal tract, keeping iron concentrations within a steady-state range. However, due to the lack of a natural mechanism for excreting excess iron, excessive iron absorption can lead to iron overload. In cases of iron overload, free iron exceeding the storage capacity of ferritin accumulates within organ cells, forming hemosiderin, which can cause organ damage and even functional loss. The liver is a primary site of iron accumulation, and iron overload primarily affects the liver, potentially leading to serious conditions such as liver fibrosis, cirrhosis, and even liver cancer. Therefore, accurate measurement of liver iron concentration is crucial for the early diagnosis and treatment of these conditions.

[0003] Currently, the commonly used diagnostic method in clinical practice is liver biopsy, which assesses liver iron content through histological analysis. However, as an invasive method, liver biopsy carries certain risks, and as a semi-quantitative test, its accuracy is affected by sampling variability. Since the biopsy sample only represents a small part of the liver, the measurement results of iron content may differ from the overall liver condition. In addition, with the increase of iron load and the development of cirrhosis, the coefficient of variation (CV) of the test results may increase significantly, which further limits the reliability of liver biopsy. More importantly, the invasiveness and associated risks of liver puncture biopsy make it impossible to use for continuous monitoring and dynamic evaluation.

[0004] Among existing non-invasive methods, liver MRI is a typical method for analyzing liver iron content. Although it has a good correlation with liver biopsy and is widely used in clinical practice, it is subject to issues such as expensive equipment, complex scan scheduling, and long waiting times for results. Furthermore, MRI indirectly measures iron content, and its results are easily affected by the characteristics of tissues other than the liver, making it difficult to achieve highly specific detection of iron in the liver.

[0005] Another biomagnetic spectroscopy method provides a direct way to measure liver iron concentration in vivo. It does not rely on interactions between surrounding tissues and performs quantitative assessments by analyzing the magnetic perturbations of tissues with given magnetic susceptibility in an external magnetic field. This method has been calibrated and verified and is a reliable non-invasive detection technology. However, its main limitation is that it relies on a superconducting quantum interference device for precision measurement. This instrument needs to be cooled in liquid helium to maintain high performance. Its high cost and maintenance costs limit its widespread clinical application. In addition, the superconducting quantum interference device cannot be measured close to the liver, resulting in signal attenuation due to excessive distance, affecting the accuracy of the measurement. Summary of the Invention

[0006] In order to solve the problems in the prior art, the present invention proposes a magnetic measurement device and method for liver iron content based on a SERF atomic magnetometer.

[0007] The technical solution adopted in the present invention is as follows:

[0008] A magnetic measurement device for liver iron content based on a SERF atomic magnetometer, comprising a supporting and positioning mechanical platform, a Helmholtz external polarization coil, a SERF atomic magnetic sensor, and a host computer;

[0009] The SERF atomic magnetic sensor includes a SERF sensor probe, and the supporting and positioning mechanical platform includes a sample table for placing the measured organism and a probe bracket for fixing the SERF sensor probe, and the probe bracket is also used to realize the movement of the probe in the vertical direction and the horizontal direction;

[0010] The supporting and positioning mechanical platform and the SERF sensor probe are both located inside the Helmholtz external polarization coil. During the detection process, the Helmholtz external polarization coil is alternately turned on and off, generating a uniform magnetic field when turned on. The SERF sensor probe is suspended above the liver of the biological subject being tested and is used to detect the magnetic field signal strength when the coil is powered off. The host computer is used to control the switching on and off of the coil and the movement of the SERF sensor probe, and is also used to collect sensor detection data. The difference between the magnetic field signal detected immediately after the coil is powered off and the magnetic field signal strength when the coil is stable after the power is off is taken as the liver ferromagnetic signal at the current measurement position. The liver ferromagnetic signal is compared with a pre-established standardized data set to obtain the corresponding liver iron content.

[0011] A method for magnetic detection of liver iron content based on the above-mentioned liver iron content magnetic detection device, the method comprising:

[0012] 1) Place the subject on the sample table with the abdomen facing upward, and position the liver of the subject at the center of the Helmholtz external polarization coil. Adjust the probe holder and probe slot so that the SERF sensor probe is directly above the liver of the subject, with the probe less than 1 cm from the subject's body surface, but not in direct contact.

[0013] 2) Turn on the Helmholtz external polarization coil to polarize the iron-containing compounds in the liver of the measured organism for 1.5 to 3 seconds, then turn it off. Turn on the SERF atomic magnetic sensor to collect the magnetic field signal strength. The difference between the magnetic field signal strength 130 to 160 milliseconds after turning it off and the magnetic field signal strength when the magnetic field signal is stable is taken as the liver ferromagnetic signal at the current measurement location. Repeat this step and record the average value of the liver ferromagnetic signal at the current measurement location.

[0014] 3) Controlling the probe movement so that different locations of the liver of the organism to be tested are aligned with the SERF sensor probe, and repeating step 2) to obtain the spatial distribution of the liver ferromagnetic signal. By comparing the liver iron content corresponding to the liver ferromagnetic signal with a pre-established standardized data set, the liver iron content corresponding to the liver ferromagnetic signal is obtained, thereby obtaining the overall iron compound accumulation status of the liver.

[0015] The standardized data set includes multiple actual liver iron contents and corresponding liver ferromagnetic signals. The actual liver iron contents in the data set are obtained by liver puncture biopsy and liver nuclear magnetic resonance detection, and the liver ferromagnetic signal distribution in the data set is obtained by the liver iron content magnetic detection device.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The proposed device and method for detecting liver iron content using a SERF atomic magnetometer as a sensor can reduce the distance between the liver and the magnetometer to less than 1 cm, preventing significant attenuation of the magnetic field signal due to distance. This enhances the system's measurement accuracy and detection depth, and improves the signal-to-noise ratio. The SERF atomic magnetometer is compact, inexpensive, and easy to maintain, making it suitable for widespread application.

[0018] The detection device of the present invention can operate stably at room temperature, without requiring a low-temperature environment. Compared to devices such as superconducting quantum interference devices, it has higher stability and reliability, but the sensitivity of the SERF atomic magnetometer is comparable to that of the superconducting quantum interference device. In addition, because the SERF atomic magnetometer operates in a zero-magnetic field environment, it does not introduce additional magnetic field signal sources to interfere with the signal, thus achieving real-time and accurate detection of liver iron content, providing effective technical support for the early clinical diagnosis of iron overload diseases.

[0019] The present invention also uses a host computer to precisely control the on / off timing of the Helmholtz external polarization coil and the movement position of the SERF sensor probe. It also automatically collects sensor detection data and compares the data sets to determine the overall iron compound accumulation in the liver. The entire detection process is simple to operate and highly automated, reducing human error and improving detection efficiency and accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the device of the present invention;

[0021] Figure 2 This is a structural diagram of the liver magnetic field measurement platform of the present invention;

[0022] Figure 3 This is a schematic diagram of the attenuation of the measured liver ferromagnetic signal in one embodiment of the present invention;

[0023] Figure 4 is the measured signal attenuation value of liver cirrhosis tissue in one embodiment of the present invention;

[0024] Figure 5 is the signal attenuation value of normal liver tissue measured in one embodiment of the present invention.

[0025] Explanation of the accompanying symbols: 1. Base plate; 2. Probe base; 3. Sample table; 4. Probe bracket; 5. Probe slot; 6. Magnetic shielding device; 7. Helmholtz external polarization coil; 8. SERF sensor probe; 9. Cable; 10. SERF sensor controller. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and are therefore not to be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

[0028] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific contexts.

[0029] The basic theoretical support of the present invention is that the iron compounds such as ferritin and hemosiderin stored in the liver show paramagnetic characteristics, and the paramagnetic atomic arrangement has a permanent intrinsic magnetic moment, and there is no interaction between the magnetic moments. Under the action of an external magnetic field, the magnetic moment will tend to be consistent with the direction of the external magnetic field, thereby generating paramagnetic susceptibility. Current research shows that human tissue does not contain ferromagnetic substances, so the magnetic field responded by paramagnetic substances is proportional to the number of iron atoms stored. The magnetic susceptibility of the human body as a whole is jointly determined by the magnetic susceptibility of paramagnetic iron and antiferromagnetic tissue, wherein the magnetic susceptibility of normal human tissue is very close to the magnetic susceptibility of water. Considering that liver tissue exhibits a certain antimagnetic effect, the amount of iron stored in the liver can be inferred by measuring the response signal of the iron in the liver to the external magnetic field.

[0030] To this end, the present invention proposes a detection device based on spin exchange relaxation free atomic magnetometer (SERF) technology, which can directly measure the liver iron content by targeting the magnetic field signal of paramagnetic iron tissue inside the liver. In recent years, quantum magnetic measurement technology has developed rapidly, and the measurement accuracy of atomic magnetometers has been continuously improved, and it has become a powerful alternative to superconducting quantum interference devices (SQUIDs). As a highly sensitive, low-cost, and easily miniaturized magnetometer, the SERF atomic magnetometer performs well in weak magnetic field detection. Combining its advantages, the present invention realizes real-time and accurate detection of liver iron concentration, representing a new type of non-invasive detection technology.

[0031] Through experiments, the present invention has verified the feasibility of this new non-invasive detection technology. The experimental results show that, especially for the measurement of cirrhotic liver tissue, the detection device of the present invention can effectively reflect the discrimination, and the resulting magnetic field signal decay time is significantly faster than that of normal liver tissue.

[0032] The following describes the details in conjunction with specific embodiments.

[0033] Example 1

[0034] Reference Figure 1The liver iron content detection device based on SERF atomic magnetometer includes a liver ferromagnetic measurement platform module and a host computer.

[0035] The liver ferromagnetic measurement platform module includes a supporting and positioning mechanical platform, a magnetic shielding device 6, a Helmholtz external polarization coil 7 and a SERF atomic magnetic sensor; the supporting and positioning mechanical platform includes a base plate 1, a probe base 2, a sample table 3, a probe bracket 4 for probe lifting and lowering, and a probe slot 5 that can be dynamically adjusted and fixed on a slide rail; the magnetic shielding device 6 is used to shield the geomagnetic field and environmental noise; the Helmholtz external polarization coil 7 is used to provide uniform and stable magnetic field excitation within its internal space; the SERF atomic magnetic sensor is used to measure liver ferromagnetic signals, and the SERF atomic magnetic sensor includes a SERF sensor probe 8, a cable 9 and a SERF sensor controller 10.

[0036] The host computer includes a system control and data processing unit and a system operation unit;

[0037] refer to Figure 2 In this embodiment, the supporting and positioning mechanical platform is arranged in the magnetic shielding device 6, including: a bottom plate 1, a probe base 2, a sample table 3, a probe bracket 4 for raising and lowering the probe, and a probe slot 5 that can be dynamically adjusted and fixed on the slide rail. The specific structure is as follows: the bottom plate 1 is provided with two parallel long slots, and the Helmholtz external polarization coil 7 is fixed in the bottom plate 1 through the long slots; the probe base 2 is fixed on the bottom plate 1 and is located in the central position of the bottom plate 1, the sample table 3 is fixed in the central position above the probe base 2, the mouse is fixed above the sample table 3, and the mouse liver is located in the central position inside the Helmholtz external polarization coil 7 and below the SERF sensor probe 8; the probe bracket 4 is a door-shaped structure, including support arms on both sides and a crossbeam between the support arms. The probe bracket 4 is fixed to the notches at both ends of the probe base 2 through the support arms on both sides and is stabilized by screws; the support arms of the probe bracket 4 are retractable structures, used to support the probe to move in the vertical direction; a slide rail is installed on the crossbeam, and the probe slot 5 is embedded through the slide rail above the probe bracket 4 and can be dynamically adjusted to support the probe to move in the horizontal direction.

[0038] In this embodiment, the magnetic shielding device 6 for shielding the earth's magnetic field and environmental noise is made of a high magnetic permeability material to ensure measurement accuracy, and has an internal space for accommodating the supporting positioning mechanical platform and the Helmholtz external polarization coil 7.

[0039] Human biomagnetic signals are extremely weak. If left uncontrolled, the Earth's magnetic field and ambient electromagnetic waves can severely impact measurements. Magnetic shielding devices shield external magnetic fields and electromagnetic noise, protecting internal devices from external interference. Certain atomic magnetic technologies, such as SERF, require sensor probes to operate in a near-zero magnetic field environment.

[0040] To shield against external interference, the magnetic shielding device 6 is constructed from a high-permeability alloy. Commonly used high-permeability materials include Permalloy and silicon steel. The magnetic shielding device 6 utilizes a high-permeability alloy plate of a certain thickness, forming a closed or semi-enclosed cavity. The cavity must be large enough to accommodate the sensor probe, its accessories, and the biological subject being measured. The magnetic field strength within the cavity, in its entirety or in a localized area, must be less than a specified value, such as 50 nT (the Earth's magnetic field ranges from 45,000 nT to 60,000 nT). This area must be large enough to at least cover all measurement points.

[0041] The thickness of high-magnetic-permeability alloy plates typically ranges from 0.1 mm to 10 mm. Using multiple layers of alloy plates to construct a magnetic shielding device can achieve better shielding effectiveness and meet the required shielding performance. In this embodiment, 3 to 5 layers of permalloy are used to construct the magnetic shielding device; in other embodiments, 8 to 10 layers of silicon steel alloy can be used. The magnetic shielding device utilizes a fully enclosed structure, equipped with a door or lid for the entry and exit of the detected organism.

[0042] In this embodiment, a closed cylindrical magnetic shielding device 6 is preferred. The main body of the magnetic shielding device is made of five layers of permalloy, with an inner diameter of 300 mm, an outer diameter of 320 mm, and a length of 400 mm. A 10 mm thick aluminum alloy cylindrical shell is placed over the main body of the magnetic shielding device to support and protect it. At one end of the magnetic shielding device, five permalloy caps are placed sequentially over the five-layer permalloy cylinder, and an aluminum alloy cap is placed over the aluminum alloy shell, forming a passage for the detected organism to enter and exit.

[0043] In this embodiment, the Helmholtz external polarization coil 7 is fixed to the base plate 1 through two long slots of the base plate 1 and is connected to a magnetic field switch. The magnetic field switch controls the external excitation magnetic field to polarize the mouse liver placed on the sample table 3, generating a detectable spatial magnetic field. The direction of the polarization magnetic field is perpendicular to the direction of the magnetic field detected by the SERF sensor probe 8.

[0044] A Helmholtz coil is a device consisting of two identical current loops, primarily used to generate a uniform magnetic field. It works based on the principle that current flowing through a wire generates a magnetic field, and uses the principle of magnetic field superposition to achieve a uniform magnetic field within a local area.

[0045] In this embodiment, a Helmholtz external polarization coil 7 is preferred, with a winding wire diameter φ of 1.4 mm, an inner coil diameter φ of 150 mm, an outer coil diameter φ of 170 mm, 168 turns per winding group N, a total of 336 turns N, and a total coil resistance (20°C) of 1.215 Ω. Testing has shown that, at an input voltage of 15 V and an input current of 1 A, the magnetic field B generated in the central region is 0.994 mT, with a uniformity of 99% within a central uniform region measuring 63 mm * 63 mm * 63 mm.

[0046] In this embodiment, the SERF atomic magnetic sensor is used to receive and collect liver ferromagnetic signals;

[0047] The SERF atomic magnetic sensor, based on the interaction between light and atoms, detects changes in atomic energy levels under the influence of a magnetic field, thereby achieving precise magnetic field measurement. It consists of a laser light source, optical prisms and lenses, an atomic gas chamber, and a photoelectric conversion module.

[0048] The atomic magnetic sensor consists of an atomic magnetic sensor probe, an atomic magnetic sensor controller, and a sensor cable. The atomic gas cell is installed in the atomic magnetic sensor probe to detect the magnetic field at its location. The sensor probe also houses a laser generator, a magnetic field generator, a temperature control device, and a laser detection device. The sensor controller provides control signals required by these operating devices of the sensor probe and receives and processes the output signals of the laser detection device. These input and output signals are transmitted to the sensor controller via the sensor cable.

[0049] In this embodiment, the SERF sensor probe 8 is installed in the probe slot 5 and positioned above the liver of the mouse to be tested. The SERF sensor probe 8 installed in the probe slot 5 is connected to the SERF sensor controller 10 installed outside the magnetic shielding device 6 via a sensor cable 9. In this way, the SERF sensor probe 8 is close to the liver sample to more closely receive the liver ferromagnetic signal, and the SERF sensor controller 10 is kept at an appropriate distance from the SERF sensor probe 8 to reduce magnetic field interference from the tested sample.

[0050] In this embodiment, the system control and data processing unit includes several modules for sensor control, magnetic field switch control, data acquisition, and data processing, as well as auxiliary equipment such as a power supply, and is located outside the magnetic shielding device 6. The sensor control, magnetic field switch control, data acquisition, and data processing modules include programs to implement their respective functions.

[0051] In this embodiment, the system operation unit, comprised of an intelligent electronic device such as a computer or tablet computer and a program, is connected to the system control and data processing unit via a high-speed data channel. It is responsible for integrated processing and control of the sensor control, magnetic field switch control, data acquisition, and data processing modules. The system supports simultaneous operation of multiple system operation units.

[0052] In this embodiment, the functions of sensor control, magnetic field switch control, data acquisition, and data processing are realized by the host computer. The on and off of the Helmholtz external polarization coil 7 is controlled by the magnetic field switch, and each on and off cycle is 10 seconds, wherein the polarization magnetic field lasts for 2 seconds and is off for 8 seconds. When the magnetic field is off, the SERF sensor probe 8 works normally and detects changes in the external magnetic field. After the Helmholtz external polarization coil 7 is turned on, the iron compounds in the liver are polarized. At this time, the SERF sensor probe has no output. After the Helmholtz external polarization coil 7 is turned off, the SERF sensor probe 8 works normally. The polarized iron-containing compounds exhibit an exponential decay model in the macroscopic magnetic field due to the Nie Er relaxation and Brownian relaxation phenomena. The relaxation phenomenon refers to the spontaneous evolution process of the magnetic moment of the paramagnetic material from the non-equilibrium state excited by the external magnetic field to the equilibrium state. By introducing the relaxation time constant τ, which describes the rate at which the system recovers the equilibrium state, into the mathematical model, the time behavior during the relaxation process can be quantitatively described and predicted. The SERF sensor probe 8 can be used to measure the liver ferromagnetic signal. The difference in magnetic field signal intensity between 130-160ms after the polarization magnetic field is turned off and at the end of relaxation is related to the iron content in the liver, and can be used to quantitatively analyze the iron content in the liver.

[0053] Example 2

[0054] Based on the above-mentioned liver iron content magnetic measurement device based on SERF atomic magnetometer, a liver iron content magnetic measurement method has the following specific steps:

[0055] Step 1: Place the subject's abdomen upward with its back against the sample table 3, with the liver positioned at the center of the Helmholtz external polarization coil 7. Adjust the probe holder 4 and probe slot 5 so that the SERF sensor probe 8 is directly above the liver.

[0056] Step 2: The Helmholtz external polarization coil 7 is controlled by the magnetic field switch to polarize the iron-containing compounds stored in the liver of the tested organism to generate a detectable spatial magnetic field. The system control and data processing unit controls the SERF atomic magnetic sensor to collect the real-time magnetic field signal intensity and perform filtering processing. It can be observed that the magnetic field signal in the time domain shows an exponential decay form, as shown in FIG. Figure 3As shown, the filtering process is used to filter the electrical signal interference introduced by the coil; the magnetic field signal strength 130-160ms after the polarization magnetic field is turned off is obtained, and the magnetic field signal strength data of a section when the signal is stable (i.e., the end of relaxation) is numerically averaged, and the average value is used as the magnetic field signal strength when the signal is stable. The difference between the magnetic field signal strength 130-160ms after the polarization magnetic field is turned off and the magnetic field signal strength at the end of relaxation is taken to obtain the liver ferromagnetic signal of the current measurement point;

[0057] Step 3: Repeat step 2 multiple times to measure and record the average value of the liver ferromagnetic signal at the same measurement point, fine-tune the position of the measured organism, align different positions of the liver of the measured organism with the SERF sensor probe 8, detect the magnetic field signals at different spatial positions of the liver, obtain the spatial distribution of the liver ferromagnetic signal, and consult the standardized data set established by comparing with liver puncture biopsy and liver nuclear magnetic resonance detection to infer the overall iron compound content of the liver.

[0058] The standardized data set includes multiple actual liver iron contents and corresponding liver ferromagnetic signals. The actual liver iron contents in the data set are obtained by liver puncture biopsy and liver nuclear magnetic resonance detection, and the liver ferromagnetic signal distribution in the data set is obtained by the liver iron content magnetic detection device.

[0059] Example 3

[0060] The liver iron content in humans can be detected by the magnetic measurement device and method based on SERF atomic magnetometer in Examples 1 and 2. To verify the detection effect, mice were used instead of humans for the experiment. Figure 3 is the change in magnetic field signal at a certain measurement point in step 2, Figure 4 、 Figure 5 The horizontal axis represents the liver ferromagnetic signal obtained by testing cirrhotic mice and normal mice. Figure 3-5 Experimental data show that, especially for the measurement of cirrhotic liver tissue with more serious iron overload, the detection device of the present invention can effectively demonstrate the discrimination, and the resulting magnetic field signal decay time is significantly faster than that of normal liver tissue, which is numerically reflected in the magnetic signal intensity difference significantly lower than that of normal liver.

[0061] The contents described in the embodiments of this specification are merely an enumeration of the implementation forms of the inventive concept. The scope of protection of the present invention should not be regarded as limited to the specific forms described in the embodiments. The scope of protection of the present invention also extends to equivalent technical means that can be conceived by those skilled in the art based on the inventive concept.

Claims

1. A magnetic detection device for liver iron content based on SERF atomic magnetometer, characterized in that: Including supporting and positioning mechanical platform, Helmholtz external polarization coil, SERF atomic magnetic sensor and host computer; The SERF atomic magnetic sensor includes a SERF sensor probe, and the supporting and positioning mechanical platform includes a sample table for placing the measured organism and a probe bracket for fixing the SERF sensor probe, and the probe bracket is also used to realize the movement of the probe in the vertical direction and the horizontal direction; The supporting and positioning mechanical platform and the SERF sensor probe are both located inside the Helmholtz external polarization coil. During the detection process, the Helmholtz external polarization coil is alternately turned on and off, generating a uniform magnetic field when turned on. The SERF sensor probe is suspended above the liver of the biological subject being tested and is used to detect the magnetic field signal strength when the coil is powered off. The host computer is used to control the switching on and off of the coil and the movement of the SERF sensor probe, and is also used to collect sensor detection data. The difference between the magnetic field signal detected immediately after the coil is powered off and the magnetic field signal strength when the coil is stable after the power is off is taken as the liver ferromagnetic signal at the current measurement position. The liver ferromagnetic signal is used to obtain the corresponding liver iron content by comparing it with a pre-established standardized data set.

2. The liver iron content magnetic detection device based on SERF atomic magnetometer according to claim 1, characterized in that: When the Helmholtz external polarization coil is turned on, the magnetic field strength inside the coil is less than 1 mT; the direction of the polarization magnetic field is perpendicular to the direction of the magnetic field detected by the SERF sensor probe.

3. The liver iron content magnetic detection device based on SERF atomic magnetometer according to claim 1, characterized in that: The liver iron content magnetic measurement device also includes a magnetic shielding device for shielding the earth's magnetic field and environmental noise. The magnetic shielding device adopts a fully enclosed structure and is provided with a door for the measured organism to enter and exit. The supporting positioning mechanical platform, Helmholtz external polarization coil and SERF sensor probe are all located inside the magnetic shielding device.

4. The liver iron content magnetic detection device based on SERF atomic magnetometer according to claim 3, characterized in that: The magnetic shielding device is composed of 3 to 5 layers of permalloy plates or 8 to 10 layers of silicon steel alloy plates.

5. The liver iron content magnetic detection device based on SERF atomic magnetometer according to claim 1, characterized in that: The probe bracket adopts a door-type frame structure, including two support arms and a crossbeam between the support arms. The support arms are retractable, and a probe slot is provided on the crossbeam. The probe slot is dynamically fixed on the crossbeam through a slide rail, and the SERF sensor probe is fixed in the probe slot.

6. The liver iron content magnetic detection device based on SERF atomic magnetometer according to claim 1, characterized in that: The supporting and positioning mechanical platform also includes a bottom plate with two long slots. The Helmholtz external polarization coil is fixed to the bottom plate through the two long slots of the bottom plate. A probe base is also fixed to the bottom plate, and a probe bracket and a sample table are fixed on the probe base.

7. The liver iron content magnetic detection device based on SERF atomic magnetometer according to claim 1, characterized in that: The SERF atomic magnetic sensor also includes an atomic magnetic sensor controller. The controller and the probe are connected by a cable. The host computer is connected to the atomic magnetic sensor controller and sends control signals to the probe through the controller and receives detection data collected by the probe.

8. A method for magnetic detection of liver iron content based on the liver iron content magnetic detection device according to claim 1, characterized in that: The method comprises: 1) Place the subject on the sample table with the abdomen facing upward, and position the liver of the subject at the center of the Helmholtz external polarization coil. Adjust the probe holder and probe slot so that the SERF sensor probe is directly above the liver of the subject, with the probe less than 1 cm from the subject's body surface, but not in direct contact. 2) Turn on the Helmholtz external polarization coil to polarize the iron-containing compounds in the liver of the measured organism for 1.5 to 3 seconds, then turn it off. Turn on the SERF atomic magnetic sensor to collect the magnetic field signal strength. The difference between the magnetic field signal strength 130 to 160 milliseconds after turning it off and the magnetic field signal strength when the magnetic field signal is stable is taken as the liver ferromagnetic signal at the current measurement location. Repeat this step and record the average value of the liver ferromagnetic signal at the current measurement location. 3) Controlling the probe movement so that different locations of the liver of the organism to be tested are aligned with the SERF sensor probe, and repeating step 2) to obtain the spatial distribution of the liver ferromagnetic signal. By comparing the liver iron content corresponding to the liver ferromagnetic signal with a pre-established standardized data set, the liver iron content corresponding to the liver ferromagnetic signal is obtained, thereby obtaining the overall iron compound accumulation status of the liver.

9. The method for magnetic detection of liver iron content according to claim 8, characterized in that: The standardized data set includes multiple actual liver iron contents and corresponding liver ferromagnetic signals. The actual liver iron contents in the data set are obtained by liver puncture biopsy and liver nuclear magnetic resonance detection, and the liver ferromagnetic signal distribution in the data set is obtained by the liver iron content magnetic detection device.

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