CN113768475A - Noninvasive cerebrovascular autonomous regulation function monitoring system based on magnetic induction technology - Google Patents
Noninvasive cerebrovascular autonomous regulation function monitoring system based on magnetic induction technology Download PDFInfo
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Abstract
The invention discloses a non-invasive cerebrovascular autonomous regulation function monitoring system based on a magnetic induction technology, which comprises a control module, an excitation source module (1), a head magnetic induction sensing device, a non-invasive blood pressure monitoring sensor, a blood pressure acquisition module (3), a magnetic induction signal acquisition module (2), a phase discriminator module, a signal preprocessing module, a characteristic quantity extraction module and a cerebrovascular autonomous regulation index calculation module (5); the invention has the main advantages that the invention can non-invasively measure the autonomous regulation function of the cerebral vessels, does not need to stick any electrode on the head of a human body, and monitors by spontaneous blood pressure slow wave excitation under the condition of no external blood pressure disturbance.
Description
Technical Field
The invention relates to the field of physiological parameter monitoring, in particular to a non-invasive cerebrovascular autonomous regulation function monitoring system based on a magnetic induction technology.
Background
For patients with brain diseases such as cerebral trauma and cerebral apoplexy, the device monitors the autonomous regulation function of cerebral vessels, and is very important for stabilizing the blood supply of the brain, preventing secondary injury caused by ischemia or edema and improving the cure rate. At present, the main cerebrovascular autonomic regulation continuous monitoring modes comprise two types of invasive and non-invasive. Invasive monitoring comprises intracranial pressure, brain tissue oxygen detection, laser Doppler blood flow meter, thermal diffusion blood flow detection and the like, and noninvasive monitoring comprises transcranial Doppler, near infrared spectroscopy, electrical impedance detection and the like. Among these monitoring techniques, invasive monitoring brings about problems such as infection when used for a long time. The non-invasive monitoring is mostly in the experimental stage, and has respective problems, such as a local brain area as a measurement area, limited measurement depth, contact measurement, easy loss of long-time signals and the like. The requirements of bedside, real-time and continuous monitoring cannot be completely met. The method and the system for monitoring the noninvasive cerebrovascular autonomous regulation function based on the magnetic induction technology are used as a method and a system for noninvasive and whole-brain detection of the noninvasive cerebrovascular autonomous regulation function monitoring system based on the magnetic induction technology, and are suitable for bedside, real-time and continuous monitoring of families and clinical environments.
At present, there are mainly monitoring systems based on electrical impedance, which are mainly based on the electrical impedance principle, and measuring electrodes need to be in contact with eyes for measurement and need to be externally injected with current.
Disclosure of Invention
The invention aims to provide a non-invasive cerebrovascular autonomous regulation function monitoring system based on a magnetic induction technology, which comprises a control module, an excitation source module, a head magnetic induction sensing device, a non-invasive blood pressure monitoring sensor, a blood pressure acquisition module, a magnetic induction signal acquisition module, a phase discriminator module, a signal preprocessing module, a characteristic quantity extraction module and a cerebrovascular autonomous regulation index calculation module.
The control module transmits an excitation magnetic field control signal to the excitation source.
And after receiving the excitation magnetic field control signal, the excitation source module transmits an excitation signal to the head magnetic induction sensing device and the magnetic induction signal acquisition module respectively.
After the head magnetic induction sensing device receives the excitation signal, an excitation alternating magnetic field is generated in the area where the head of the user is located. Under the action of the excitation alternating magnetic field, the user generates an induction magnetic field in the cranium.
The head magnetic induction sensing device monitors brain magnetic induction signals and transmits the brain magnetic induction signals to the magnetic induction signal acquisition module.
The magnetic induction signal acquisition module transmits the received brain magnetic induction signals and the excitation signals to the phase discriminator module.
The phase discriminator module processes the brain magnetic induction signals and the excitation signals to obtain brain magnetic induction phase shift data, and transmits the brain magnetic induction phase shift data to the signal preprocessing module.
The non-invasive blood pressure monitoring sensor monitors arterial pressure signals of a user and transmits the arterial pressure signals to the blood pressure acquisition module.
The blood pressure acquisition module transmits the received arterial pressure signal to the signal preprocessing module.
The characteristic quantity extraction module is used for carrying out characteristic extraction on the received arterial pressure signal and the brain magnetic induction phase shift data transmitted by the signal preprocessing module to obtain an electroencephalogram conductivity slow wave signal and a blood pressure pulsation slow wave signal, and transmitting the electroencephalogram conductivity slow wave signal and the blood pressure pulsation slow wave signal to the cerebrovascular autonomic adjustment index calculation module.
The cerebrovascular autonomic regulation index calculation module calculates the cerebrovascular autonomic regulation index according to the received brain conductivity slow wave signal and blood pressure pulsation slow wave signal. If the cerebrovascular autonomic regulation index is negative, the cerebrovascular autonomic regulation function is impaired.
The step of calculating a cerebrovascular autonomic modulation index comprises:
1) and windowing to calculate the Pearson correlation coefficient of the brain conductivity slow wave signal and the blood pressure pulsation slow wave signal.
2) Windowing calculates the average of the pearson correlation coefficients. The average value of the Pearson correlation coefficients is the cerebrovascular autonomic regulation index.
Further, the induced magnetic field strength is proportional to the change in electrical conductivity caused by the change in intracranial volume.
Further, the excitation source module transmits an excitation signal to the head magnetic induction sensing device and the magnetic induction signal acquisition module as an alternating current signal.
Further, the head magnetic induction sensing device comprises an excitation coil and a detection coil.
The excitation coil is used for receiving an excitation signal and generating an excitation alternating magnetic field.
The detection coil is used for monitoring brain magnetic induction signals.
Further, the head magnetic induction sensing device is worn on the head of the user.
Further, the preprocessing includes down-sampling, wavelet de-baselining, normalization, 3dB low pass filter filtering.
Further, the magnetic induction signal acquisition module amplifies and filters the received brain magnetic induction signals and the excitation signals.
The blood pressure acquisition module amplifies and filters the received arterial pressure signal.
Furthermore, the system also comprises a statistical analysis module.
The statistical analysis module establishes a magnetic induction phase shift signal, an arterial pressure signal, a cerebrovascular autonomic regulatory index time domain graph and a cerebrovascular autonomic regulatory index frequency spectrogram, and calculates a mean value and a median of the cerebrovascular autonomic regulatory indexes.
Further, the display device also comprises a display module.
The display module displays the magnetic induction phase shift signal, the arterial pressure signal, the cerebrovascular autonomic regulatory index time domain graph, the cerebrovascular autonomic regulatory index frequency spectrum graph, the cerebrovascular autonomic regulatory index mean value and the median.
It is worth to be noted that the system for monitoring the noninvasive magnetic induction cerebrovascular autonomous regulation function of the invention measures the whole brain volume conductivity slow wave response change caused by intracranial vasodilation and contraction by using the magnetic induction sensor placed on the head, oscillates the acquired response and the peripheral blood pressure spontaneous slow wave which is acquired synchronously, and monitors the function of the whole brain cerebrovascular autonomous regulation by analyzing the change relationship between the whole brain volume conductivity slow wave response and the peripheral blood pressure spontaneous slow wave excitation, so as to evaluate the cerebrovascular regulation function state and assist the treatment to maintain the brain blood supply.
The technical effect of the invention is undoubted, and the invention has the main advantages that the invention can non-invasively measure the autonomous regulation function of the cerebral vessels, does not need to stick any electrode on the head of a human body, and monitors by spontaneous blood pressure slow wave excitation under the condition of no external blood pressure disturbance. The invention can display the physiological and pathological information of the corresponding nerve regulation function through system analysis, and carry out non-invasive, continuous and long-time monitoring on the object in clinical and family environments. The measuring sensor of the invention does not need to be in direct contact with a human body and does not need to carry out current injection. The invention checks the autonomous regulation function of the cerebral vessels by a system analysis method and through the relation between the blood pressure excitation and the conductivity response.
Drawings
FIG. 1 is a block diagram of a magnetic induction non-invasive cerebrovascular autonomic regulation function monitoring system;
FIG. 2 illustrates a coil arrangement of the sensing device of the present invention;
FIG. 3 is a schematic diagram of a magnetic induction cerebrovascular autonomic regulation function monitoring system;
FIG. 4 is a flow chart of a magnetic induction cerebrovascular autonomic adjustment monitoring index algorithm;
FIG. 5 is a graph showing the relationship between arterial pressure, intracranial pressure, and magnetic induction signals in animal experiments obtained by monitoring the non-invasive magnetic induction cardiopulmonary activity; FIG. 5(a) is a graph showing the relationship between animal experimental arterial pressure, intracranial pressure, and magnetic induction signal in normal rabbit; FIG. 5(b) is a graph showing the relationship between animal experimental arterial pressure, intracranial pressure, and magnetic induction signal in normal rabbit;
FIG. 6 shows the relationship between noninvasive and invasive cerebrovascular autonomic regulation indexes (PRx-intracranial pressure response index, MIPx-magnetic induction phase shift index) of ischemic rabbits;
in the figure, an excitation source module 1, a magnetic induction signal acquisition module 2, a blood pressure acquisition module 3, a display module 4 and a cerebrovascular autonomic adjustment index calculation module 5 are arranged.
Detailed Description
The present invention is further illustrated by the following examples, but it should not be construed that the scope of the above-described subject matter is limited to the following examples. Various substitutions and alterations can be made without departing from the technical idea of the invention and the scope of the invention is covered by the present invention according to the common technical knowledge and the conventional means in the field.
Example 1:
referring to fig. 1 to 6, a system for monitoring noninvasive cerebrovascular autonomic adjustment based on magnetic induction technology comprises a control module, an excitation module 1, a head magnetic induction sensing device, a noninvasive blood pressure monitoring sensor, a blood pressure acquisition module 3, a magnetic induction signal acquisition module 2, a phase discriminator module, a signal preprocessing module, a characteristic quantity extraction module, a cerebrovascular autonomic adjustment index calculation module 5, a statistical analysis module and a display module 4.
The control module transmits an excitation magnetic field control signal to the excitation source.
And after receiving the excitation magnetic field control signal, the excitation source module 1 transmits an excitation signal to the head magnetic induction sensing device and the magnetic induction signal acquisition module 2 respectively. The amplitude and the frequency of the excitation signal are adjustable. The excitation source module 1 adopts PXIe-5451.
The excitation source module 1 transmits an excitation signal to the head magnetic induction sensing device and the magnetic induction signal acquisition module 2 to be an alternating sinusoidal current signal.
After the head magnetic induction sensing device receives the excitation signal, an excitation alternating magnetic field is generated in the area where the head of the user is located. Under the action of the excitation alternating magnetic field, the user generates an induction magnetic field in the cranium.
The induced magnetic field strength is proportional to the change in electrical conductivity caused by the change in intracranial volume.
The head magnetic induction sensing device monitors brain magnetic induction signals and transmits the brain magnetic induction signals to the magnetic induction signal acquisition module.
The head magnetic induction sensing device comprises an excitation coil and a detection coil.
The excitation coil is used for receiving an excitation signal and generating an excitation alternating magnetic field.
The detection coil is used for monitoring brain magnetic induction signals.
The head magnetic induction sensing device is worn on the head of a user, and the head is not in contact with the head magnetic induction sensing device.
The magnetic induction signal acquisition module transmits the received brain magnetic induction signals and the excitation signals to the phase discriminator module.
The magnetic induction signal acquisition module amplifies and filters the received brain magnetic induction signals and the excitation signals. The magnetic induction signal acquisition module and the blood pressure acquisition module 3 adopt a PXIe-5124 acquisition card.
The phase discriminator module processes the brain magnetic induction signals and the excitation signals to obtain brain magnetic induction phase shift data, and transmits the brain magnetic induction phase shift data to the signal preprocessing module. The phase discriminator module adopts a Lab VIEW phase discriminator.
The non-invasive blood pressure monitoring sensor monitors arterial pressure signals of a user and transmits the arterial pressure signals to the blood pressure acquisition module 3.
The blood pressure acquisition module 3 transmits the received arterial pressure signal to the signal preprocessing module.
The blood pressure acquisition module 3 amplifies and filters the received arterial pressure signal.
The signal preprocessing module preprocesses the arterial pressure signal and the brain magnetic induction phase shift data and transmits the signals to the characteristic quantity extraction module.
The preprocessing includes down-sampling, wavelet de-baselining, normalization, 3dB low pass filter filtering. The data preprocessing and the feature extraction are realized by MATLAB and Lab VIEW mixed programming.
The characteristic quantity extraction module performs characteristic extraction on the received arterial pressure signal and the brain magnetic induction phase shift data to obtain an electroencephalogram conductivity slow wave signal and a blood pressure pulsation slow wave signal, and transmits the signals to the cerebrovascular autonomic adjustment index calculation module 5.
The cerebrovascular autonomic regulation index calculation module 5 calculates the cerebrovascular autonomic regulation index according to the received brain conductivity slow wave signal and blood pressure pulsation slow wave signal. If the cerebrovascular autonomic regulation index is negative, the cerebrovascular autonomic regulation function is impaired. The cerebrovascular autonomic regulation index calculation module 5 adopts Lab VIEW.
The step of calculating a cerebrovascular autonomic modulation index comprises:
1) and windowing to calculate the Pearson correlation coefficient of the brain conductivity slow wave signal and the blood pressure pulsation slow wave signal.
2) Windowing calculates the average of the pearson correlation coefficients. The average value of the Pearson correlation coefficients is the cerebrovascular autonomic regulation index.
The statistical analysis module establishes a magnetic induction phase shift signal, an arterial pressure signal, a cerebrovascular autonomic regulatory index time domain graph and a cerebrovascular autonomic regulatory index frequency spectrogram, and calculates a mean value and a median of the cerebrovascular autonomic regulatory indexes.
The display module 4 displays the magnetic induction phase shift signal, the arterial pressure signal, the cerebrovascular autonomic regulatory index time domain graph, the cerebrovascular autonomic regulatory index frequency spectrum graph, the cerebrovascular autonomic regulatory index mean value and the median. The display module 4 and the control module adopt PXIe 8133.
Example 2:
a non-invasive cerebrovascular autonomous regulation function monitoring system based on magnetic induction technology is disclosed in an embodiment 1, wherein the system has the following principle: based on the pathophysiological mechanism of conductivity change caused by the change of the whole brain volume of a human body and the characteristics of slow wave generation after cerebrovascular autonomous regulation injury, the intracranial integral conductivity response under the excitation of blood pressure slow wave replaces the intracranial blood volume response by utilizing the magnetic induction detection principle, and the excitation and response signals are obtained by a detection system to carry out noninvasive and continuous monitoring on the functions of the cerebrovascular autonomous regulation system.
Example 3:
referring to fig. 1 to 6, a method for using a non-invasive cerebrovascular autonomic regulation function monitoring system based on magnetic induction technology includes:
when blood pressure fluctuates, the cerebrovascular autonomic regulation mechanism can maintain the cerebral blood flow relatively constant by contracting or dilating the tiny artery blood vessels, and ensure the stable blood flow supply required by the brain activity. During this intrinsic neuromodulation, the contraction or relaxation of blood vessels causes a change in intracranial blood volume and thus overall conductivity in the cranium.
When the whole brain is in the excitation alternating magnetic field, the excitation magnetic field of magnetic induction detection covers all small blood vessels in the brain, and due to the magnetic induction effect, an induction magnetic field is generated in the brain, and the size of the induction magnetic field is in direct proportion to the change of the electric conductivity caused by the volume change of each component in the brain. The detection coil can detect the change of the induction magnetic field, and the change of the intracranial integral conductivity caused by the change of the intracranial blood volume during the cerebrovascular autonomous regulation is obtained.
Under the excitation of spontaneous arterial pressure slow wave oscillation, the output response of the cerebrovascular autonomous regulation system, namely cerebral blood volume slow wave oscillation, is replaced by the slow wave oscillation of the conductivity of intracranial integral brain tissue, and a cerebrovascular autonomous regulation index is established by analyzing the variation relations of amplitude, phase and the like between excitation signals and response signals, so that the noninvasive and continuous monitoring of the cerebrovascular autonomous regulation function damage condition in the pathophysiological process is realized.
When radio frequency current is adopted to generate an excitation magnetic field B0 through the spiral coil, an induction magnetic field delta B is generated inside the detected biological tissue in the excitation field, and the detection spiral coil is adopted to measure the induction magnetic field delta B; when the intracranial blood volume is changed, the intracranial integral conductivity is changed, and the induction magnetic field delta B measured by the detection coil is changed along with the change; the induction magnetic field delta B measured by the detection coil can reflect the conductivity change caused by intracranial blood volume change, and the slow wave oscillation in the detection signal is extracted to be used as the response of the cerebrovascular autonomic regulation system.
The magnetic induction signals detected by the detection coil are amplified and filtered, then sent to an upper computer through a collection card, and processed through software, and then slow wave oscillation signals of the detection signals and the excitation signals are extracted. This signal represents the change in intracranial overall conductivity caused by the autonomous regulatory activity of the cerebral vessels in the magnetic field.
Triggering through external electrocardio to obtain arterial blood pressure signals and magnetic induction signals synchronously and noninvasively, taking spontaneous arterial blood pressure slow wave oscillation as excitation, taking magnetic induction slow wave oscillation as response, and then analyzing a cerebrovascular autonomous regulation system according to the relation between arterial blood pressure slow wave excitation and magnetic induction slow wave oscillation response through a software algorithm, and realizing noninvasive and continuous monitoring of cerebrovascular autonomous regulation function damage conditions in a pathophysiological process through established cerebrovascular autonomous regulation indexes.
Example 4:
referring to fig. 1 to 6, a system for monitoring noninvasive cerebrovascular autonomic adjustment based on magnetic induction technology comprises a control module, an excitation module 1, a head magnetic induction sensing device, a noninvasive blood pressure monitoring sensor, a blood pressure acquisition module 3, a magnetic induction signal acquisition module 2, a phase discriminator module, a signal preprocessing module, a characteristic quantity extraction module, a cerebrovascular autonomic adjustment index calculation module 5, a statistical analysis module and a display module 4.
The control module transmits an excitation magnetic field control signal to the excitation source.
And after receiving the excitation magnetic field control signal, the excitation source module 1 transmits an excitation signal to the head magnetic induction sensing device and the magnetic induction signal acquisition module 2 respectively. The amplitude and the frequency of the excitation signal are adjustable.
The excitation source module 1 transmits an excitation signal to the head magnetic induction sensing device and the magnetic induction signal acquisition module 2 to be an alternating sinusoidal current signal.
After the head magnetic induction sensing device receives the excitation signal, an excitation alternating magnetic field is generated in the area where the head of the user is located. Under the action of the excitation alternating magnetic field, the user generates an induction magnetic field in the cranium.
The induced magnetic field strength is proportional to the change in electrical conductivity caused by the change in intracranial volume.
The head magnetic induction sensing device monitors brain magnetic induction signals and transmits the brain magnetic induction signals to the magnetic induction signal acquisition module.
The head magnetic induction sensing device comprises an excitation coil and a detection coil.
The excitation coil is used for receiving an excitation signal and generating an excitation alternating magnetic field.
The detection coil is used for monitoring brain magnetic induction signals.
The head magnetic induction sensing device is worn on the head of a user, and the head is not in contact with the head magnetic induction sensing device.
The magnetic induction signal acquisition module transmits the received brain magnetic induction signals and the excitation signals to the phase discriminator module.
The magnetic induction signal acquisition module amplifies and filters the received brain magnetic induction signals and the excitation signals.
The phase discriminator module processes the brain magnetic induction signals and the excitation signals to obtain brain magnetic induction phase shift data, and transmits the brain magnetic induction phase shift data to the signal preprocessing module.
The non-invasive blood pressure monitoring sensor monitors arterial pressure signals of a user and transmits the arterial pressure signals to the blood pressure acquisition module 3.
The blood pressure acquisition module 3 transmits the received arterial pressure signal to the signal preprocessing module.
The blood pressure acquisition module 3 amplifies and filters the received arterial pressure signal.
The signal preprocessing module preprocesses the arterial pressure signal and the brain magnetic induction phase shift data and transmits the signals to the characteristic quantity extraction module.
The preprocessing includes normalization, wavelet de-baselining, and filtering.
The characteristic quantity extraction module performs characteristic extraction on the received arterial pressure signal and the brain magnetic induction phase shift data to obtain an electroencephalogram conductivity slow wave signal and a blood pressure pulsation slow wave signal, and transmits the signals to the cerebrovascular autonomic adjustment index calculation module 5.
The cerebrovascular autonomic regulation index calculation module 5 calculates the cerebrovascular autonomic regulation index according to the received brain conductivity slow wave signal and blood pressure pulsation slow wave signal. If the cerebrovascular autonomic regulation index is negative, the cerebrovascular autonomic regulation function is impaired.
The step of calculating a cerebrovascular autonomic modulation index comprises:
1) and windowing to calculate the Pearson correlation coefficient of the brain conductivity slow wave signal and the blood pressure pulsation slow wave signal.
2) Windowing calculates the average of the pearson correlation coefficients. The average value of the Pearson correlation coefficients is the cerebrovascular autonomic regulation index.
The statistical analysis module establishes a magnetic induction phase shift signal, an arterial pressure signal, a cerebrovascular autonomic regulatory index time domain graph and a cerebrovascular autonomic regulatory index frequency spectrogram, and calculates a mean value and a median of the cerebrovascular autonomic regulatory indexes.
The display module 4 displays the magnetic induction phase shift signal, the arterial pressure signal, the cerebrovascular autonomic regulatory index time domain graph, the cerebrovascular autonomic regulatory index frequency spectrum graph, the cerebrovascular autonomic regulatory index mean value and the median.
A use method of a non-invasive cerebrovascular autonomous regulation function monitoring system based on a magnetic induction technology comprises the following steps:
1) the brain is placed in the center of the sensor, the exciting coil is positioned at the position of the eyebrow listening line, namely, an included angle of 22-25 degrees is formed between the exciting coil and the horizontal position, the detecting coil is positioned at the top of the head and is parallel to the exciting coil, and the vertical distance between the centers of the two coils is 5-15 cm. Applying an alternating current to the exciting coil to generate an alternating magnetic field B0The brain is positioned in the alternating magnetic field to form an induced magnetic field delta B due to the action of electromagnetic induction, and the intensity and distribution of the delta B are mainly determined by the conductivity distribution of the whole brain; under the stimulation of blood pressure change, intracranial blood vessels regulate blood flow through contraction or relaxation, and intracranial whole blood volumeChanges are generated, so that the conductivity of the whole brain is changed, and the induction magnetic field delta B is changed; the detection coil is adopted to measure the induction magnetic field delta B, and the measurement signal reflects the whole brain conductivity change caused by intracranial blood volume change under the excitation of blood pressure change. Figure 2 shows an achievable magnetic induction monitoring sensor structure. The magnetic induction sensing device consists of two coils (an exciting coil and a detecting coil), wherein the two coils are coaxially arranged, and the number of turns is 10.
2) The exciting coil generates an alternating exciting magnetic field, and standard sine alternating-current voltage is applied to two ends of the exciting coil; the ac power supply uses a high frequency sinusoidal voltage generator (in the monitoring system shown in fig. 3, PXIe-5451, dual channel output, 400MS/s sampling rate, output signal frequency 0-145MHz, 50 Ω output impedance, 16bit signal resolution, 2GB memory capacity are mainly used). The invention can be used for generating sinusoidal signals with different frequencies, and mainly generates excitation signals below 10MHz by matching with an acquisition card. And one path of the generated two paths of same-frequency sinusoidal signals is loaded on the exciting coil as an exciting signal, and the other path of the same-frequency sinusoidal signals is input into the acquisition card as a phase calculation reference signal.
3) The detection coil is adopted to detect the excitation magnetic field signal and the induction magnetic field signal, and the phase of the excitation magnetic field signal and the induction magnetic field signal contains information reflecting the whole brain volume conductivity change caused by cerebrovascular autonomic regulation. The phase of the detection signal is compared with the phase of the reference signal, so that the position of the detection coil at a certain moment and the size of a disturbing magnetic field caused by the change of the conductivity of the whole brain at the moment of the adjustment activity of the cerebral blood vessel can be obtained. The detection coil measurement signal and the excitation reference signal are synchronously sent into a collection card (in the monitoring system shown in FIG. 3, PXIe-5124 is mainly used, double-channel synchronous sampling is carried out, the resolution is 12 bits, the highest real-time sampling rate is 200MS/s, the denoising and anti-aliasing filtering functions with the bandwidth of 150MHz are adopted, and the standard memory of each channel is 8MB, and the maximum is 512 MB). The acquisition control is integrated in the phase discrimination software. And continuous or interval acquisition of signals is realized through the data acquisition card and the channel parameters selected by the front panel. And a two-dimensional array with the length of the sampling point number is obtained every time the sampling point number is acquired.
4) The acquired signals are subjected to software filtering processing, the filtering is realized by adopting a 3-order Butterworth filter, the filtering bandwidth is set to be 0.5MHz, the detection signals and the reference signals after the software filtering are sent to a phase discrimination module to detect the phase difference, and the detected real-time phase difference information reflects the real-time situation of the conductivity change caused by the brain physiological activity. The phase discrimination algorithm mainly adopts an FFT method. And the magnetic induction phase shift signal obtained after phase discrimination is down-sampled into a 1Hz signal by the phase discrimination module.
5) Peripheral blood pressure signals are collected noninvasively by a noninvasive continuous blood pressure monitor, peripheral blood pressure signals are collected by a collection card 2 at a sampling rate of 50Hz, (in the monitoring system shown in figure 3, another PXIe-5124 is mainly used), and arterial pressure drop is sampled to 1Hz and then is synchronized with magnetic induction phase shift signals.
6) The arterial pressure signal and the magnetic induction signal are preprocessed, as shown in fig. 4, mainly including down-sampling to 1Hz, normalization, wavelet de-baseline, (db 5 wavelet can be used, and 7-layer decomposition is used to reconstruct de-baseline). After the average arterial pressure signal and the average magnetic induction phase shift signal are calculated, the characteristic quantities of the brain conductivity slow wave and the blood pressure pulsation slow wave are extracted through 0.01-0.1Hz band-pass filtering (which can be realized by a 3dB digital filter or an FIR digital filter).
7) The function of the cerebrovascular autonomous regulation system is analyzed through the time domain and frequency domain relation between the spontaneous arterial pressure slow wave oscillation excitation and the magnetic induction phase displacement output response. Fig. 4 shows a time domain correlation analysis flowchart, (after normalization, a 10 second moving window is used to calculate the pearson movement correlation coefficient of the brain conductivity slow wave and the blood pressure pulsation slow wave signal, a 5 minute moving window is used to calculate the average pearson movement correlation coefficient, and if the correlation coefficient is negative, autonomous regulation is damaged), and the function of the cerebrovascular autonomous regulation system can also be analyzed by calculating indexes such as frequency domain amplitude, phase, correlation index or nonlinear entropy.
8) Animal experiments show that noninvasive cerebrovascular autonomic regulation indexes based on magnetic induction technology are correlated with invasive intracranial pressure cerebrovascular autonomic regulation monitoring indexes. Fig. 5(b) (a) shows non-invasive magnetic induction signals, invasive intracranial pressure signals, and arterial pressure signals obtained by monitoring ischemic rabbits and normal rabbits, respectively. Fig. 6 shows the monitoring results of invasive and noninvasive cerebrovascular autonomic regulation indexes of ischemic rabbits, wherein the noninvasive cerebrovascular autonomic regulation index MIPx and the invasive intracranial pressure response index PRx based on the magnetic induction technology are reversely changed.
Claims (10)
1. The utility model provides a do not have autonomic regulatory function monitoring system of wound blood vessel based on magnetic induction technique which characterized in that: the device comprises a control module, an excitation source module (1), a head magnetic induction sensing device, a non-invasive blood pressure monitoring sensor, a blood pressure acquisition module (3), a magnetic induction signal acquisition module (2), a phase discriminator module, a signal preprocessing module, a characteristic quantity extraction module and a cerebrovascular autonomous regulation index calculation module (5).
The control module transmits an excitation magnetic field control signal to an excitation source;
after receiving the control signal of the excitation magnetic field, the excitation source module (1) respectively transmits an excitation signal to the head magnetic induction sensing device and the magnetic induction signal acquisition module (2);
after the head magnetic induction sensing device receives the excitation signal, an excitation alternating magnetic field is generated in the area where the head of the user is located; under the action of the excitation alternating magnetic field, a user generates an induction magnetic field in the intracranial space;
the head magnetic induction sensing device monitors brain magnetic induction signals and transmits the brain magnetic induction signals to the magnetic induction signal acquisition module;
the magnetic induction signal acquisition module transmits the received brain magnetic induction signals and the excitation signals to the phase discriminator module;
the phase discriminator module processes the brain magnetic induction signals and the excitation signals to obtain brain magnetic induction phase shift data, and transmits the brain magnetic induction phase shift data to the signal preprocessing module;
the non-invasive blood pressure monitoring sensor monitors arterial pressure signals of a user and transmits the arterial pressure signals to the blood pressure acquisition module (3);
the blood pressure acquisition module (3) transmits the received arterial pressure signal to the signal preprocessing module;
the signal preprocessing module is used for preprocessing the arterial pressure signal and the brain magnetic induction phase shift data and transmitting the signals to the characteristic quantity extraction module;
the characteristic quantity extraction module is used for carrying out characteristic extraction on the received arterial pressure signal and the brain magnetic induction phase shift data transmitted by the signal preprocessing module to obtain an electroencephalogram conductivity slow wave signal and a blood pressure pulsation slow wave signal, and transmitting the electroencephalogram conductivity slow wave signal and the blood pressure pulsation slow wave signal to the cerebrovascular autonomic regulation index calculation module (5);
the cerebrovascular autonomic regulation index calculation module (5) calculates a cerebrovascular autonomic regulation index according to the received brain conductivity slow wave signal and blood pressure pulsation slow wave signal; if the cerebrovascular autonomic regulation index is negative, the cerebrovascular autonomic regulation function is damaged;
the step of calculating a cerebrovascular autonomic modulation index comprises:
1) windowing to calculate the Pearson correlation coefficient of the brain electrical conductivity slow wave signal and the blood pressure pulsation slow wave signal;
2) windowing to calculate the average value of the Pearson correlation coefficients; the average value of the Pearson correlation coefficients is the cerebrovascular autonomic regulation index.
2. The system for monitoring the noninvasive cerebrovascular autonomic regulatory function based on the magnetic induction technology as claimed in claim 1, wherein: the induced magnetic field strength is proportional to the change in electrical conductivity caused by the change in intracranial volume.
3. The system for monitoring the noninvasive cerebrovascular autonomic regulatory function based on the magnetic induction technology as claimed in claim 1, wherein: the excitation source module (1) transmits an excitation signal to the head magnetic induction sensing device and the magnetic induction signal acquisition module (2) to form an alternating current signal.
4. The system for monitoring the noninvasive cerebrovascular autonomic regulatory function based on the magnetic induction technology as claimed in claim 1, wherein: the head magnetic induction sensing device comprises an excitation coil and a detection coil;
the excitation coil is used for receiving an excitation signal and generating an excitation alternating magnetic field;
the detection coil is used for monitoring brain magnetic induction signals.
5. The system for monitoring the noninvasive cerebrovascular autonomic regulatory function based on the magnetic induction technology as claimed in claim 1, wherein: the magnetic induction sensing device on the head is worn on the head of a user.
6. The system for monitoring the noninvasive cerebrovascular autonomic regulatory function based on the magnetic induction technology as claimed in claim 1, wherein: the preprocessing includes down-sampling, wavelet de-baselining, normalization, 3dB low pass filter filtering.
7. The system for monitoring the noninvasive cerebrovascular autonomic regulatory function based on the magnetic induction technology as claimed in claim 1, wherein: the characteristic extraction comprises average magnetic induction phase shift signals and average arterial pressure signals, and band-pass filtering is carried out to extract electroencephalogram conductivity slow wave signals and blood pressure pulsation slow wave signals.
8. The system for monitoring the noninvasive cerebrovascular autonomic regulatory function based on the magnetic induction technology as claimed in claim 1, wherein: the magnetic induction signal acquisition module amplifies and filters the received brain magnetic induction signals and the excitation signals;
the blood pressure acquisition module (3) amplifies and filters the received arterial pressure signal.
9. The system for monitoring the noninvasive cerebrovascular autonomic regulatory function based on the magnetic induction technology as claimed in claim 1, wherein: the system also comprises a statistical analysis module;
the statistical analysis module establishes a magnetic induction phase shift signal, an arterial pressure signal, a cerebrovascular autonomic regulatory index time domain graph and a cerebrovascular autonomic regulatory index frequency spectrogram, and calculates a mean value and a median of the cerebrovascular autonomic regulatory indexes.
10. The system for monitoring the noninvasive cerebrovascular autonomic regulatory function based on the magnetic induction technology as claimed in claim 1, wherein: also comprises a display module (4);
the display module (4) displays the magnetic induction phase shift signal, the arterial pressure signal, the cerebrovascular autonomic regulatory index time domain graph, the cerebrovascular autonomic regulatory index frequency spectrum graph, the cerebrovascular autonomic regulatory index mean value and the median.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012104799A1 (en) * | 2011-02-03 | 2012-08-09 | Koninklijke Philips Electronics N.V. | Planar coil arrangement for a magnetic induction impedance measurement apparatus |
| CN103006334A (en) * | 2013-01-05 | 2013-04-03 | 中国科学院深圳先进技术研究院 | Individualized real-time measuring system for noninvasive cerebral blood flow automatic adjusting function |
| CN103598883A (en) * | 2013-12-03 | 2014-02-26 | 中国人民解放军第三军医大学 | Intracranial pressure monitoring method based on magnetic induction phase difference change |
| US20150238114A1 (en) * | 2014-02-27 | 2015-08-27 | Kimberly-Clark Worldwide, Inc. | Methods for Assessing Health Conditions Using Single Coil Magnetic Induction Tomography Imaging |
| WO2017109484A1 (en) * | 2015-12-22 | 2017-06-29 | The University Of Sheffield | Apparatus and methods for determining electrical conductivity of tissue |
| CN109730668A (en) * | 2018-11-30 | 2019-05-10 | 上海浩聚医疗科技有限公司 | Signal processing method based on histogram estimation brain self-regulation ability |
| US20200049778A1 (en) * | 2018-08-10 | 2020-02-13 | Beijing Boe Optoelectronics Technology Co., Ltd. | Phase compensation circuit, magnetic induction imaging device and phase compensation method |
| CN112754521A (en) * | 2021-01-12 | 2021-05-07 | 上海交通大学 | Method and system for evaluating brain blood flow automatic regulation capability |
| CN113288102A (en) * | 2021-06-11 | 2021-08-24 | 中国人民解放军陆军军医大学 | System for monitoring cerebral blood flow without wound |
-
2021
- 2021-08-30 CN CN202111006937.6A patent/CN113768475B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012104799A1 (en) * | 2011-02-03 | 2012-08-09 | Koninklijke Philips Electronics N.V. | Planar coil arrangement for a magnetic induction impedance measurement apparatus |
| CN103006334A (en) * | 2013-01-05 | 2013-04-03 | 中国科学院深圳先进技术研究院 | Individualized real-time measuring system for noninvasive cerebral blood flow automatic adjusting function |
| CN103598883A (en) * | 2013-12-03 | 2014-02-26 | 中国人民解放军第三军医大学 | Intracranial pressure monitoring method based on magnetic induction phase difference change |
| US20150238114A1 (en) * | 2014-02-27 | 2015-08-27 | Kimberly-Clark Worldwide, Inc. | Methods for Assessing Health Conditions Using Single Coil Magnetic Induction Tomography Imaging |
| WO2017109484A1 (en) * | 2015-12-22 | 2017-06-29 | The University Of Sheffield | Apparatus and methods for determining electrical conductivity of tissue |
| US20200049778A1 (en) * | 2018-08-10 | 2020-02-13 | Beijing Boe Optoelectronics Technology Co., Ltd. | Phase compensation circuit, magnetic induction imaging device and phase compensation method |
| CN109730668A (en) * | 2018-11-30 | 2019-05-10 | 上海浩聚医疗科技有限公司 | Signal processing method based on histogram estimation brain self-regulation ability |
| CN112754521A (en) * | 2021-01-12 | 2021-05-07 | 上海交通大学 | Method and system for evaluating brain blood flow automatic regulation capability |
| CN113288102A (en) * | 2021-06-11 | 2021-08-24 | 中国人民解放军陆军军医大学 | System for monitoring cerebral blood flow without wound |
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