Non-invasive non-contact cerebral hemorrhage real-time detection device based on zero-current magnetic induction phase sensor

Abstract

A non-invasive non-contact cerebral hemorrhage real-time detection device based on a zero-flow magnetic induction phase sensor comprises a multi-channel signal generator, a signal separator, a radio frequency electronic feedback circuit module, a detection module, a multi-channel signal acquisition module, a signal processing module and a display module. The zero-current magnetic induction phase sensor can achieve a good experiment effect, on one hand, the exciting coil can generate a main magnetic field with high field intensity, meanwhile, the main magnetic field can be counteracted, the sensitivity is effectively improved, on the other hand, the main magnetic field is a uniform field, the defect that a dispersed field generated by a traditional coil is not beneficial to quantitative detection is overcome, and the detection accuracy is improved. And the influence of hematoma on the left and right hemispheres is avoided. The device well solves the problems that the detection result of an existing magnetic induction detection device is easily influenced by the positions of the left and right hemispheres of hematoma, and quantitative detection is difficult to realize, and the detection sensitivity is further improved.

Description

Technical Field

[0001] The invention relates to the technical field of biomedical medical equipment, and in particular to a non-invasive, non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor. Background Art

[0002] Cerebral hemorrhage usually refers to a type of brain injury caused by rupture of brain blood vessels under the influence of various risk factors without external trauma, and blood invading the brain substance. It is a type of stroke with high morbidity, high mortality, high disability rate and poor prognosis. According to research and investigation, the trend of population aging, low income, and underdeveloped medical conditions in areas have brought serious challenges to the diagnosis, treatment and prognosis of patients with cerebral hemorrhage.

[0003] Currently, computed tomography (CT) is the gold standard for diagnosing cerebral hemorrhage, with the advantages of precise positioning and quantification. However, CT is expensive, the equipment is bulky, the usage scenarios are limited, and it can cause ionizing radiation damage to the human body. It cannot detect patients in the pre-hospital stage, and it is not suitable for real-time detection of the course of patients receiving conservative treatment and ICU patients, which is not conducive to timely adjustment of treatment plans. In order to avoid the occurrence of adverse events caused by the lag of test results, help medical workers to adjust treatment plans in time, improve the level and efficiency of treatment, it is of great significance to develop a non-invasive, portable and real-time detection device that can reflect the physiological and pathological status of patients with cerebral hemorrhage.

[0004] The existing cerebral hemorrhage detection devices that have been put into clinical use have limited usage scenarios, and the sensitivity of magnetic induction-based detection devices or systems needs to be improved, making it difficult to achieve quantitative detection. Summary of the invention

[0005] The purpose of the present invention is to provide a non-invasive, non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, comprising a multi-channel signal generator, a signal separator, a radio frequency electronic feedback circuit module, a detection module, a multi-channel signal acquisition module, a signal processing module, and a display module.

[0006] The multi-channel signal generator is used to generate an excitation signal.

[0007] The signal separator is used to divide the excitation signal input by the multi-channel signal generator into two identical signals, one of which is input into the radio frequency electronic feedback circuit module, and the other is input into the multi-channel signal acquisition module as a reference signal.

[0008] The radio frequency electronic feedback circuit module is used to transmit the excitation signal input by the multi-channel signal generator and the signal input by the signal separator to the detection module.

[0009] The detection module is used to detect intracranial hemorrhage in patients.

[0010] The detection module is a zero-flow sensor, comprising an excitation coil and a detection coil.

[0011] The excitation coil is wrapped around the patient's head.

[0012] The excitation coil receives the signal transmitted by the radio frequency electronic feedback circuit module and generates a main magnetic field for magnetic induction phase detection.

[0013] The detection coil is placed on the top of the patient's skull and located in the center of the excitation coil.

[0014] The detection coil is used to eliminate the influence of the main magnetic field and transmit the detected signal to the multi-channel signal acquisition module.

[0015] The multi-channel signal acquisition module is used to collect the reference signal of the signal separator and the signal detected by the detection module, and transmit these two signals to the signal processing module.

[0016] The signal processing module is used to perform amplitude calculation, phase extraction and phase difference calculation on the two-way signals transmitted by the multi-channel signal acquisition module.

[0017] The display module is used to display the amplitude and phase difference calculated by the signal processing module.

[0018] Furthermore, the excitation signal generated by the multi-channel signal generator includes a sinusoidal wave excitation signal.

[0019] Furthermore, the phase of the excitation signal generated by the multi-channel signal generator is adjustable.

[0020] Furthermore, the radio frequency electronic feedback circuit module satisfies the impedance matching between ports at the working frequency of the detection module, thereby maximizing the energy transmission of the ports.

[0021] Furthermore, the excitation port S of the RF electronic feedback circuit module 11 <-15dB.

[0022] Furthermore, the excitation coil is made of copper.

[0023] Furthermore, the detection coil is made of copper.

[0024] Furthermore, each module of the detection device is connected by a radio frequency coaxial cable.

[0025] Furthermore, when the detection module is used to detect intracranial hemorrhage, it needs to be preheated.

[0026] Furthermore, the excitation coil includes a plurality of I-shaped copper foils.

[0027] A plurality of I-shaped copper foils are surrounded to form a circle, and two adjacent I-shaped copper foils are connected via a high-frequency capacitor.

[0028] The technical effect of the present invention is unquestionable. The non-invasive, non-contact, real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor provided by the present invention is mainly based on the principles of electromagnetic induction and the electrical characteristics of biological tissues. When the excitation coil is passed with current, the change of the induced magnetic field caused by cerebral hemorrhage can be detected by the principle of electromagnetic induction, and the pathological condition of cerebral hemorrhage can be reflected according to the phase difference information between the detection signal and the excitation signal. Since the higher the main magnetic field strength, the greater the induced current, the greater the detection sensitivity. However, due to the low conductivity of biological tissues, the induced field strength is often very small. The increase in the main magnetic field increases the magnetic flux in the detection coil, and the interference with the detection result increases. Therefore, in order to greatly improve the sensitivity, the main magnetic field is reduced while satisfying the increase in field strength. In addition, a uniform main magnetic field is also conducive to improving the detection linearity and more accurate quantitative hematoma. Using a zero-current magnetic induction phase sensor can achieve good experimental results. On the one hand, the excitation coil can generate a main magnetic field with a higher field strength, and can also achieve main magnetic field offset, effectively improving sensitivity. On the other hand, the main magnetic field is a uniform field, which overcomes the shortcomings of the dispersed field generated by the traditional coil that is not conducive to quantitative detection, and is not affected by the position of the hematoma in the left and right hemispheres. The device of the present invention solves the problem that the detection results of the existing magnetic induction detection device are easily affected by the positions of the left and right hemispheres of the hematoma and are difficult to achieve quantitative detection, and further increases the detection sensitivity.

[0029] Based on a large number of experimental studies, the present invention found that the non-invasive and non-contact real-time detection device for cerebral hemorrhage based on the zero-current magnetic induction phase sensor has high sensitivity, good stability and consistency, and the experiment is highly repeatable. This device can effectively distinguish different compensation stages of patients with cerebral hemorrhage. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of the structure of a non-invasive, non-contact, real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor provided by the present invention;

[0031] Figure 2 It is the test diagram of the RF electronic feedback circuit and the excitation port; Figure 2 (a) is the test result of excitation port S11 No. 1; Figure 2 (b) is the test result of excitation port S11 No. 2; Figure 2 (c) is the radio frequency electronic feedback circuit of excitation port No. 1; Figure 2 (d) is the RF electronic feedback circuit of excitation port No. 1;

[0032] Figure 3It is a schematic diagram of the zero-flow sensor structure and magnetic field simulation results; Figure 3 (a) is a schematic diagram of the zero flow sensor structure; Figure 3 (b) is a schematic diagram of magnetic field simulation results;

[0033] Figure 4 Schematic diagram of the relationship between the phase difference and solution volume of three solutions with different conductivity; Figure 4 (a) is a schematic diagram of the relationship curve of rabbit blood solution; Figure 4 (b) is a schematic diagram of the relationship curve of physiological saline solution; Figure 4 (c) is a schematic diagram of the relationship curve of 5% NaCl solution;

[0034] Figure 5 This is a diagram showing the relationship between the phase difference and the hemorrhage volume of one rabbit in the rabbit internal capsule cerebral hemorrhage experiment;

[0035] Figure 6 It is a schematic diagram of MRI imaging results; Figure 6 (a) is the rabbit brain imaging result before blood injection of rabbit I; Figure 6 (b) Rabbit brain imaging results before blood injection of rabbit II; Figure 6 (c) is the rabbit brain imaging result before blood injection of rabbit III; Figure 6 (d) Rabbit brain imaging result after 1.4 mL of blood was injected into rabbit I; Figure 6 (e) Rabbit brain imaging results after 1.4 mL of blood was injected into rabbit II; Figure 6 (f) is the rabbit brain imaging result after 1.4 mL of blood was injected into rabbit III. DETAILED DESCRIPTION

[0036] The present invention is further described below in conjunction with the embodiments, but it should not be understood that the above subject matter of the present invention is limited to the following embodiments. Without departing from the above technical ideas of the present invention, various substitutions and changes are made according to the common technical knowledge and customary means in the art, which should all be included in the protection scope of the present invention.

[0037] Embodiment 1:

[0038] See also Figures 1 to 6 A non-invasive and non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor includes a multi-channel signal generator, a signal separator, a radio frequency electronic feedback circuit module, a detection module, a multi-channel signal acquisition module, a signal processing module, and a display module.

[0039] The multi-channel signal generator is used to generate an excitation signal.

[0040] The signal separator is used to divide the excitation signal input by the multi-channel signal generator into two identical signals, one of which is input into the radio frequency electronic feedback circuit module, and the other is input into the multi-channel signal acquisition module as a reference signal.

[0041] The radio frequency electronic feedback circuit module is used to transmit the excitation signal input by the multi-channel signal generator and the signal input by the signal separator to the detection module.

[0042] The detection module is used to detect intracranial hemorrhage in patients.

[0043] The detection module is a zero-flow sensor, comprising an excitation coil and a detection coil.

[0044] The excitation coil is wrapped around the patient's head.

[0045] The excitation coil receives the signal transmitted by the radio frequency electronic feedback circuit module and generates a main magnetic field for magnetic induction phase detection.

[0046] The detection coil is placed on the top of the patient's skull and located in the center of the excitation coil.

[0047] The detection coil is used to eliminate the influence of the main magnetic field and transmit the detected signal to the multi-channel signal acquisition module.

[0048] The multi-channel signal acquisition module is used to collect the reference signal of the signal separator and the signal detected by the detection module, and transmit these two signals to the signal processing module.

[0049] The signal processing module is used to perform amplitude calculation, phase extraction and phase difference calculation on the two-way signals transmitted by the multi-channel signal acquisition module.

[0050] The display module is used to display the amplitude and phase difference calculated by the signal processing module.

[0051] Embodiment 2:

[0052] A non-invasive, non-contact, real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, the main technical content of which is shown in Example 1. Furthermore, the excitation signal generated by the multi-channel signal generator includes a sinusoidal wave excitation signal.

[0053] Embodiment 3:

[0054] A non-invasive, non-contact, real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, the main technical content of which is shown in any one of Examples 1 to 2. Furthermore, the phase of the excitation signal generated by the multi-channel signal generator is adjustable.

[0055] Embodiment 4:

[0056] A non-invasive, non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, the main technical content of which can be found in any one of Examples 1 to 3. Furthermore, the radio frequency electronic feedback circuit module satisfies the impedance matching between ports at the operating frequency of the detection module, thereby maximizing the energy transmission of the ports.

[0057] Embodiment 5:

[0058] A non-invasive, non-contact, real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, the main technical content of which is shown in any one of Embodiments 1 to 4, and further, the excitation port S of the radio frequency electronic feedback circuit module 11 <-15dB.

[0059] Embodiment 6:

[0060] A non-invasive, non-contact, real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, the main technical content of which is shown in any one of Examples 1 to 5. Furthermore, the manufacturing material of the excitation coil includes copper.

[0061] Embodiment 7:

[0062] A non-invasive, non-contact, real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, the main technical content of which is shown in any one of Examples 1 to 6. Furthermore, the manufacturing material of the detection coil includes copper.

[0063] Embodiment 8:

[0064] A non-invasive, non-contact, real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, the main technical content of which is shown in any one of Examples 1 to 7. Furthermore, each module of the detection device is connected by a radio frequency coaxial cable.

[0065] Embodiment 9:

[0066] A non-invasive, non-contact, real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, the main technical content of which is shown in any one of Examples 1 to 8. Furthermore, when the detection module is used to detect intracranial hemorrhage, it is necessary to preheat it.

[0067] Embodiment 10:

[0068] A non-invasive, non-contact, real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, the main technical content of which can be found in any one of Examples 1 to 9. Furthermore, the excitation coil includes a plurality of I-shaped copper foils.

[0069] A plurality of I-shaped copper foils are surrounded to form a circle, and two adjacent I-shaped copper foils are connected via a high-frequency capacitor.

[0070] Embodiment 11:

[0071] See also Figures 1 to 6A non-invasive and non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor includes a multi-channel signal generator, a signal separator, a radio frequency electronic feedback circuit module, a detection module, a multi-channel signal acquisition module, a signal processing module, and a display module.

[0072] The multi-channel signal generator is used to generate an excitation signal.

[0073] The multi-channel signal source uses the Tektronix vector signal source model AFG3252 as the signal generating device. The device can simultaneously transmit two excitation signals with adjustable amplitude and phase, and has the advantages of high precision and low phase noise, which can meet the requirements of this device.

[0074] One end of the multi-channel signal generator is connected to the signal separator, and the other end is connected to the radio frequency electronic feedback circuit module.

[0075] The signal separator is used to divide the excitation signal input by the multi-channel signal generator into two identical signals, one of which is input into the radio frequency electronic feedback circuit module, and the other is input into the multi-channel signal acquisition module as a reference signal.

[0076] The signal separator used is Mini-Circuits ZFSC-2-6-S+, which has an operating frequency range of 0.002-60MHz and stable performance, and can meet the requirements of this device.

[0077] The radio frequency electronic feedback circuit module is used to transmit the excitation signal input by the multi-channel signal generator and the signal input by the signal separator to the detection module.

[0078] The detection module is used to detect intracranial hemorrhage in patients.

[0079] The detection module is a zero-flow sensor, comprising an excitation coil and a detection coil.

[0080] The excitation coil is wrapped around the patient's head.

[0081] The excitation coil receives the signal transmitted by the radio frequency electronic feedback circuit module and generates a main magnetic field for magnetic induction phase detection.

[0082] The detection coil is placed on the top of the patient's skull and located in the center of the excitation coil.

[0083] The detection coil is used to eliminate the influence of the main magnetic field and transmit the detected signal to the multi-channel signal acquisition module.

[0084] The multi-channel signal acquisition module is used to collect the reference signal of the signal separator and the signal detected by the detection module, and transmit these two signals to the signal processing module.

[0085] The multi-channel signal acquisition module adopts a data acquisition device of model Agilent 34970A, which has the advantages of fast acquisition speed, multi-channel simultaneous acquisition, strong application expansibility, and meets the requirements of the device of the present invention.

[0086] The signal processing module is used to perform amplitude calculation, phase extraction and phase difference calculation on the two-way signals transmitted by the multi-channel signal acquisition module.

[0087] The signal processing unit uses a self-programmed phase difference calculation program based on LabVIEW. After the reference signal and the detection signal pass through the signal acquisition module, they undergo a series of transformations such as FFT to obtain the amplitude and phase of the signal, and finally obtain the phase difference through subtraction.

[0088] The display module is used to display the amplitude and phase difference calculated by the signal processing module.

[0089] The display module is used to display in real time the dynamic phase difference, detection signal amplitude and sampling rate setting information as the cerebral hemorrhage progresses.

[0090] Embodiment 12:

[0091] A non-invasive, non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, the main technical content of which is shown in Example 11. Furthermore, the excitation signal generated by the multi-channel signal generator includes a sinusoidal wave excitation signal.

[0092] Embodiment 13:

[0093] A non-invasive, non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, the main technical content of which is shown in any one of Examples 11 to 12. Furthermore, the phase of the excitation signal generated by the multi-channel signal generator is adjustable.

[0094] The multi-channel signal source outputs a continuously changing sinusoidal wave excitation signal with constant power, 60 MHz frequency, equal amplitude and adjustable phase.

[0095] Embodiment 14:

[0096] A non-invasive, non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, the main technical content of which can be found in any one of Examples 11 to 13. Furthermore, the radio frequency electronic feedback circuit module satisfies the impedance matching between ports at the operating frequency of the detection module, thereby maximizing the energy transmission of the ports.

[0097] Embodiment 15:

[0098] A non-invasive, non-contact, real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, the main technical content of which is shown in any one of Embodiments 11 to 14. Further, the excitation port S of the radio frequency electronic feedback circuit module 11 <-15dB.

[0099] Embodiment 16:

[0100] A non-invasive, non-contact, real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, the main technical content of which is shown in any one of Examples 11 to 15. Furthermore, the manufacturing material of the excitation coil includes copper.

[0101] Embodiment 17:

[0102] A non-invasive, non-contact, real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, the main technical content of which is shown in any one of Examples 11 to 16. Furthermore, the manufacturing material of the detection coil includes copper.

[0103] Embodiment 18:

[0104] A non-invasive, non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, the main technical content of which is shown in any one of Examples 11 to 17. Furthermore, each module of the detection device is connected by a radio frequency coaxial cable.

[0105] The connection between each module is made by shielded RF coaxial cable.

[0106] Embodiment 19:

[0107] A non-invasive, non-contact, real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, the main technical content of which is shown in any one of Examples 11 to 18. Furthermore, when using the detection module to detect intracranial hemorrhage, preheating is required.

[0108] Embodiment 20:

[0109] A non-invasive, non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, the main technical content of which can be found in any one of Examples 11 to 19. Furthermore, the excitation coil includes a plurality of I-shaped copper foils.

[0110] A plurality of I-shaped copper foils are surrounded to form a circle, and two adjacent I-shaped copper foils are connected via a high-frequency capacitor.

[0111] Embodiment 21:

[0112] See also Figures 1 to 6 The non-invasive and non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor includes a multi-channel signal generator, a signal separation module, a radio frequency electronic feedback circuit module, a detection module, a multi-channel signal acquisition module, a signal processing module and a display module. Among them:

[0113] The multi-channel signal generator is used to generate multiple sinusoidal wave excitation signals, and the amplitude, frequency and phase can be adjusted. One port of the signal source is connected to the signal separator, and the other port is connected to the RF electronic feedback circuit module.

[0114] The signal separator, which is composed of a one-to-two power divider, divides the excitation signal generated by the signal source into two identical signals, one of which is used as the input signal of the sensor and the other is input into the signal acquisition module as a reference signal.

[0115] The RF electronic feedback module connects the detection module and the signal source and the signal separator to achieve impedance matching, thereby maximizing the energy transmission between the ports.

[0116] The detection module mainly includes a zero-current magnetic induction phase sensor, which is used to detect the signal generated by the change of tissue conductivity caused by intracranial hemorrhage. The head to be measured is placed in the center of the sensor.

[0117] The multi-channel signal acquisition module collects the reference signal from the signal separator and the detection signal from the detection module, and outputs the two signals to the signal processing module.

[0118] The signal processing module receives and processes the reference signal and the detection signal from the signal acquisition module, completes the phase extraction and the phase difference calculation, and forwards them to the display for real-time display.

[0119] The display module displays the phase difference processed by the above module in real time.

[0120] The connections between the above modules are all made using shielded RF coaxial cables.

[0121] The multi-channel signal source outputs a continuously changing sinusoidal wave excitation signal with constant power, 60 MHz frequency, equal amplitude and adjustable phase.

[0122] The RF electronic feedback circuit module must meet the impedance matching between the ports at the working frequency of the detection module. 11 <-15dB.

[0123] The zero-flow sensor of the detection module consists of an excitation coil and a detection coil. The excitation coil is composed of 8 I-shaped copper foils with a width of 5mm and a thickness of 0.1mm wrapped around a cylinder, and a high-frequency capacitor is welded between two adjacent I-shaped copper foils. The radius and height of the excitation coil are equal, both of which are 8-12cm. The excitation coil can be wrapped around the head to be measured. The detection coil has a diameter of 6-8cm and is made of 10 turns of 1mm diameter copper wire. It is placed on the top of the head to be measured and in the center of the excitation coil. The zero-flow sensor is used to detect overall intracranial hemorrhage.

[0124] The signal processing module is used to calculate the amplitude of the detection signal and the phase difference between the detection signal and the reference signal.

[0125] The display module is used to display in real time the dynamic phase difference, detection signal amplitude and sampling rate setting information as the cerebral hemorrhage progresses.

[0126] Embodiment 22:

[0127] See also Figures 1 to 6 A non-invasive and non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor includes a multi-channel signal generator, a signal separator, a radio frequency electronic feedback module, a detection module, a multi-channel signal acquisition module, a signal processing module and a display module.

[0128] The multi-channel signal generator has a certain output power and generates a sinusoidal excitation signal with adjustable amplitude and phase at a certain operating frequency. One output port is connected to the signal separation module, and the other output port is connected to the radio frequency electronic feedback module.

[0129] The signal separation module divides the signal from the signal source into two equal signals, one of which is output as an excitation signal to the RF electronic feedback circuit, and the other is output as a reference signal to the signal acquisition module.

[0130] The RF electronic feedback circuit module is a circuit composed of high-frequency capacitors and resistors designed according to the operating frequency of the sensor. It is used for impedance matching between ports to maximize energy transmission. It connects the signal source and the signal separator.

[0131] The detection module mainly includes a zero-current magnetic induction phase sensor, which is used to detect the signal generated by the change of tissue conductivity caused by intracranial hemorrhage. The head to be measured is placed in the center of the sensor. Two aspects are mainly considered when designing the excitation coil: first, to increase the main magnetic field strength and the main magnetic field offset to improve the signal sensitivity; second, to maximize the uniformity of the main magnetic field distribution to achieve the purpose of quantitative detection. The output signal of the detection module is connected to the signal acquisition module.

[0132] The signal acquisition module acquires the detection signal and the reference signal and outputs them to the signal processing module.

[0133] The signal processing module extracts the amplitude and phase of the detection signal and the reference signal, calculates the phase difference between the two and inputs the information to the display module.

[0134] The display module displays in real time the dynamic information of the phase difference and the signal amplitude which change with the bleeding volume.

[0135] After the RF feedback electronic circuit module is installed, its port S 11 <-15dB.

[0136] The sensor's excitation coil is cylindrical, and the radius and height of the coil are equal to satisfy the Helmholtz law so that the uniformity of the magnetic field inside the coil is improved. The coil diameter is 18-20cm, slightly larger than the head, and can wrap around the head. The detection coil is in the form of a solenoid, with a coil diameter of 6-8cm, made of 10-14 turns of 1mm diameter copper wire, and placed on the top of the head to be measured and in the center of the excitation coil.

[0137] Embodiment 23:

[0138] See also Figures 1 to 6 , a non-invasive and non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, including a multi-channel signal source, a signal separator, a radio frequency electronic feedback module, a detection module, a multi-channel signal acquisition module, and a signal processing and display module. For specific device structure and details, please refer to the following models: The multi-channel signal source uses the Tektronix vector signal source model AFG3252 as the signal generating device. The device can simultaneously transmit two excitation signals with adjustable amplitude and phase, with the advantages of high precision and low phase noise, which can meet the requirements of this device. The signal separator uses the Mini-Circuits ZFSC-2-6-S+ model. The operating frequency range of this signal separator is 0.002-60MHz, with stable performance, which can meet the requirements of this device. The radio frequency electronic feedback circuit is an independent design, consisting of a number of capacitors and resistors, which are used to achieve direct impedance matching between the detection module and the signal source and signal separator. According to the transmission line theory, when port S 11 <﹣10dB can achieve the maximum power transmission between ports. The test results of RF electronic feedback circuit and excitation port are as follows: Figure 2 As shown, the S 11 The detection module mainly includes a self-designed zero-current sensor, which has the characteristics of generating a uniform main magnetic field and achieving the main magnetic field offset. It has the advantages of high sensitivity and linearity, which is conducive to quantitative detection. The main magnetic field generated by the traditional sensor based on magnetic induction phase detection is a dispersed field. Its structure and simulation results are shown in Figure 1. Figure 3 As shown, Figure 3 (a) shows that the main magnetic field generated by the sensor is parallel to the plane where the detection coil is located, which means that the net magnetic flux of the detection coil is 0, which can eliminate the influence of the main magnetic field and increase the detection sensitivity. Figure 3(b) The main magnetic field strength is concentrated between 4-5A / m, and the magnetic field is evenly distributed inside the detection coil. Both can improve the linearity of the detection and are conducive to quantitative detection. The multi-channel signal acquisition module uses a data acquisition device of model Agilent 34970A. The acquisition device has a fast acquisition speed, can perform multi-channel simultaneous acquisition, has strong application scalability, and meets the needs of the device of the present invention. Signal processing and display module signal processing unit and display unit. The signal processing unit uses a self-programmed phase difference calculation program based on LabVIEW. After the reference signal and the detection signal pass through the signal acquisition module, they are transformed by a series of transformations such as FFT to obtain the amplitude and phase of the signal respectively, and finally the phase difference is obtained by subtraction. The display unit displays the phase difference information and signal amplitude information in real time.

[0139] The non-invasive and non-contact real-time detection device for cerebral hemorrhage based on zero-current magnetic induction phase sensor is used as follows:

[0140] Turn on the detection device and preheat for 30 minutes. Place the head under test in the center of the zero-flow sensor. Channel 1 of the vector signal source is connected to the power divider in the signal separation module, and channel 2 of the vector signal source is connected to the RF electronic feedback module. The power divider is then connected to channel 1 of the signal acquisition module and the RF electronic feedback module respectively. The RF electronic feedback module is connected to the two input ports of the zero-flow sensor, and the output port of the sensor is connected to channel 2 of the signal acquisition module. All connections are made of high-frequency coaxial cables.

[0141] Set the vector signal source output power to -20dBm, frequency to 60MHz, and two equal-amplitude sinusoidal wave excitation signals with a phase difference of 90°. The magnetic field generated by the excitation signal in the sensor excitation coil passes through the entire head under test, generates an induced current in the equivalent loop of the brain tissue in the head under test, and the induced current generates a secondary induced magnetic field. The original excitation main magnetic field and the secondary induced magnetic field signal are superimposed on the magnetic field signal. The phase of the superimposed magnetic field signal relative to the original excitation magnetic field changes. The change in phase shift is related to the change in the overall conductivity of the brain caused by cerebral hemorrhage. As the severity of the hemorrhage increases, the overall conductivity of the brain increases, so the measured magnetic induction phase difference changes.

[0142] The sensor detection coil detects the superimposed field signal, and the signal acquisition module converts the detection signal and the reference signal into a digital signal through A / D. The signal processing unit calculates the phase difference between the two signals and the display unit displays the calculation result in real time.

[0143] The following physical experiments and animal experiments are used to further verify and illustrate the effect of the non-invasive and non-contact real-time detection device for cerebral hemorrhage based on the zero-current magnetic induction phase sensor of the present invention.

[0144] The present invention selects three different conductivity solutions (0.9%, 5% NaCl solution, rabbit arterial blood) to simulate the overall brain conductivity of patients with cerebral hemorrhage at different stages of the disease. The solution volume is 10mL, which is injected into a beaker located in the center of the sensor at a rate of 2mL / min and the change of phase difference is detected in real time. The whole experimental process takes 15min.

[0145] The animal experiments were described as follows:

[0146] 1. Select 15 New Zealand white rabbits (purchased from the Animal Experiment Center of Army Medical University) with a body weight of 2.0-2.5 kg and a cranial circumference of 17.0-18.0 cm.

[0147] 2. Establish a rabbit internal capsule cerebral hemorrhage model. Use 25% urethane at a dose of 5ml / kg to inject anesthesia into the rabbit through the ear vein. Draw 5mL of blood from the rabbit ear artery with a vacuum blood collection tube, and draw 5mL of blood with a disposable syringe and fix it on the injection pump. One end of the syringe is connected to a plastic tube for standby use. Depilate the rabbit's skull, and after disinfection, cut the scalp along the midline to expose the cross suture. Use a dental drill to drill holes 1mm behind the sagittal suture and 6mm to the right of the coronal suture. Be careful not to damage the dura mater here. Fix the rabbit on the experimental table, and after the state stabilizes, insert the plastic tube 13mm along the skull hole, turn on the injection pump, set the liquid volume to 3mL, the time to 600sec, start injecting blood and observe the phase shift difference in real time. The experimental observation time is 15 minutes.

[0148] 3. Figure 4 , Figure 5 Schematic diagrams of the relationship between the phase difference and hemorrhage volume of a rabbit in the physical simulation experiment and the rabbit cerebral hemorrhage experiment. Figure 4 The blue curve in the middle is the original data of the phase difference, and the red curve is the result of the first-order linear fitting. The results show that as the volume of the solution increases, the phase difference gradually increases, and the adjusted R between the two using the first-order linear fitting is 2 The fitting effect is good, indicating that there is an excellent linear function relationship between the two, which is conducive to quantitative detection. When 10mL of 0.9% and 5% NaCl solution and rabbit arterial blood were injected, the average phase difference was 2.37°, 2.76°, and 3.34°, respectively, and the sensitivity was 1.84, 1.39, and 1.22 times higher than that of the traditional magnetic induction phase sensor. Figure 5The blue curve in the middle is the original data of the phase difference, the green curve is the first-order linear fitting result when the bleeding volume is 1-1.4mL, and the orange curve is the first-order linear fitting result when the bleeding volume is 1.4-3mL. The results show that as the amount of bleeding increases, the phase difference gradually increases. The phase difference is not a simple linear function relationship with the amount of bleeding, but presents three stages of changes, which is due to the complex physiological regulation mechanism existing in rabbit cerebral hemorrhage. When cerebral hemorrhage occurs, first of all, in order to maintain the constant intracranial pressure and normal brain function, the intracranial cerebrospinal fluid compensatory mechanism plays a role. As the amount of bleeding continues to increase, the cerebrospinal fluid is continuously discharged from the skull. At this stage, the overall conductivity of the brain changes very little, so the phase difference shows the first stage of slow changes. After the amount of bleeding reaches 1mL, the intracranial cerebrospinal fluid content is already at a very low level (the previous research group has verified it through MRI imaging), and the cerebrospinal fluid compensatory mechanism begins to fail, that is, the decompensation stage. At this time, the overall conductivity of the brain changes more, and the phase difference changes more. At this time, the phase difference shows the second stage of change. When the amount of bleeding reaches 1.4 mL, the cerebrospinal fluid compensation mechanism completely fails, which means that the intracranial cerebrospinal fluid has been completely emptied. As the amount of bleeding increases, the phase difference increases sharply, showing the third stage of change. The adjusted R of the first-order linear fit between the phase difference and the bleeding volume in each stage is 2 The phase difference of 3mL bleeding was 3.15°, which was 6.3 times that of the traditional coaxial coil sensor and 1.67 times that of the hemispherical elimination coil.

[0149] 4. Figure 6 The rabbit brain images before MRI scanning and when the bleeding volume was 1.4 mL, where the highlighted part in the red circle represents the intracranial cerebrospinal fluid. The results showed that the intracranial cerebrospinal fluid was completely emptied at 1.4 mL, further verifying the inference of the third stage of phase difference change in animal experiments, and proving that the device can accurately detect the amount of bleeding when the cerebrospinal fluid compensation completely fails.

Claims

1. A non-invasive and non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor, characterized in that: It includes a multi-channel signal generator, a signal separator, a radio frequency electronic feedback circuit module, a detection module, a multi-channel signal acquisition module, a signal processing module, and a display module; The multi-channel signal generator is used to generate an excitation signal; The signal separator is used to divide the excitation signal input by the multi-channel signal generator into two identical signals, one of which is input into the radio frequency electronic feedback circuit module, and the other is input into the multi-channel signal acquisition module as a reference signal; The radio frequency electronic feedback circuit module is used to transmit the excitation signal input by the multi-channel signal generator and the signal input by the signal separator to the detection module; The detection module is used to detect intracranial hemorrhage in patients; The detection module is a zero-flow sensor, comprising an excitation coil and a detection coil; The excitation coil is wrapped around the patient's head; The excitation coil receives the signal transmitted by the radio frequency electronic feedback circuit module to generate a main magnetic field for magnetic induction phase detection; The detection coil is placed on the top of the patient's skull and located in the center of the excitation coil. The detection coil is used to eliminate the influence of the main magnetic field and transmit the detected signal to the multi-channel signal acquisition module; The multi-channel signal acquisition module is used to collect the reference signal of the signal separator and the signal detected by the detection module, and transmit these two signals to the signal processing module. The signal processing module is used to calculate the amplitude, extract the phase and calculate the phase difference of the two signals transmitted by the multi-channel signal acquisition module; The display module is used to display the amplitude and phase difference calculated by the signal processing module.

2. The non-invasive and non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor according to claim 1 is characterized in that: The excitation signal generated by the multi-channel signal generator includes a sinusoidal wave excitation signal.

3. The non-invasive and non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor according to claim 1 is characterized in that: The phase of the excitation signal generated by the multi-channel signal generator is adjustable.

4. The non-invasive and non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor according to claim 1 is characterized in that: The radio frequency electronic feedback circuit module satisfies the impedance matching between ports at the working frequency of the detection module, thereby maximizing the energy transmission of the ports.

5. The non-invasive and non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor according to claim 1 is characterized in that: The excitation port S of the radio frequency electronic feedback circuit module 11 <-15dB.

6. The non-invasive and non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor according to claim 1 is characterized in that: The exciting coil is made of copper.

7. The non-invasive and non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor according to claim 1 is characterized in that: The detection coil is made of copper.

8. The non-invasive and non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor according to claim 1 is characterized in that: The modules of the detection device are connected by radio frequency coaxial cables.

9. The non-invasive and non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor according to claim 1, characterized in that: When the detection module is used to detect intracranial hemorrhage, it needs to be preheated.

10. The non-invasive and non-contact real-time detection device for cerebral hemorrhage based on a zero-current magnetic induction phase sensor according to claim 1, characterized in that: The excitation coil includes a plurality of I-shaped copper foils; A plurality of I-shaped copper foils are surrounded to form a circle, and two adjacent I-shaped copper foils are connected via a high-frequency capacitor.

Images