阅读说明：本技术 一种基于电感遥测技术的脑血流监测装置 (Cerebral blood flow monitoring device based on inductance remote measuring technology ) 是由 张茂婷 孙建 陈明生 李�根 许佳 陈镜伯 王凤 白泽霖 徐林 庄伟� 张海生 于 2021-08-23 设计创作，主要内容包括：本发明公开一种基于电感遥测技术的脑血流监测装置,包括脑血流传感器(1)、电感遥测芯片(2)、单片机(3)和上位机(4)；本发明提出一种基于电感遥测技术的脑血流监测装置,该装置能够实现无创、实时、床旁长时间监测脑血流。(The invention discloses a cerebral blood flow monitoring device based on an inductance remote measuring technology, which comprises a cerebral blood flow sensor (1), an inductance remote measuring chip (2), a singlechip (3) and an upper computer (4); the invention provides a cerebral blood flow monitoring device based on an inductive telemetry technology, which can realize non-invasive, real-time and bedside long-time monitoring of cerebral blood flow.)

1. A cerebral blood flow monitoring device based on inductance telemetry technology is characterized in that: the brain blood flow sensor comprises a brain blood flow sensor (1), an inductance remote measuring chip (2), the single chip microcomputer (3) and an upper computer (4).

The cerebral blood flow sensor (1) generates an alternating current magnetic field covering the region where the middle cerebral artery is located; the alternating-current magnetic field generates eddy current in the region where the middle cerebral artery is located and generates a secondary magnetic field;

under the action of a magnetic field, cerebral blood flow of a blood vessel in the region of the middle cerebral artery causes the change of the resonance frequency of the cerebral blood flow sensor (1), so that the cerebral blood flow sensor (1) monitors and obtains a cerebral blood flow signal of the blood vessel in the region of the middle cerebral artery and transmits the cerebral blood flow signal to the inductance remote measuring chip (2);

the inductive telemetry chip (2) receives the cerebral blood flow signal and converts the cerebral blood flow signal into a cerebral blood flow digital signal; the inductance remote measuring chip (2) transmits the cerebral blood flow digital signal to the singlechip (3);

the singlechip (3) sends the cerebral blood flow digital signal to the upper computer (4);

and the upper computer (4) displays the change of the cerebral blood flow according to the cerebral blood flow digital signal in the time t.

2. The cerebral blood flow monitoring device based on inductive telemetry according to claim 1, wherein: the cerebral blood flow sensor (1) is attached to the outer side of the skull of a user, and the projection position of the cerebral blood flow sensor (1) is overlapped with the position of a wing point of a hemisphere of the brain.

3. The cerebral blood flow monitoring device based on inductive telemetry according to claim 1, wherein: the cerebral blood flow sensor (1) comprises two layers of PCB coils; the two layers of PCB coils are arranged at intervals and are positioned on the same horizontal line; each layer of PCB coil comprises n turns of coils, and the n turns of coils are n equipotential concentric circles.

4. The cerebral blood flow monitoring device based on inductive telemetry according to claim 3, wherein: the cerebral blood flow sensor (1) is characterized in that the magnetic field intensity is attenuated from the center along the axial direction and the radial direction.

5. The cerebral blood flow monitoring device based on inductive telemetry according to claim 1, wherein: the working frequency range of the inductance telemetering chip (2) is 1KHz-10 MHz.

6. The cerebral blood flow monitoring device based on inductive telemetry according to claim 1, wherein: the resonance frequency of the cerebral blood flow sensor (1) satisfies the following formula:

wherein f is the resonance frequency of the cerebral blood flow sensor (1); l is the resonance inductance of the cerebral blood flow sensor (1); c is the capacitance of the cerebral blood flow sensor (1).

7. The cerebral blood flow monitoring device based on inductive telemetry according to claim 1, wherein: the brain blood flow sensor is characterized by further comprising a power supply module for supplying power to the brain blood flow sensor (1), the inductance remote measurement chip (2) and the single chip microcomputer (3).

Technical Field

The invention relates to the field of medical equipment, in particular to a cerebral blood flow monitoring device based on an inductance remote measuring technology.

Background

Cerebrovascular disease is a disease that seriously endangers human health and life, and has high morbidity, disability rate and mortality. Normal cerebral blood supply is an important evaluation for the restoration of brain function to normal. Therefore, the real-time detection and monitoring of cerebral blood flow have important clinical significance for improving the diagnosis level and the treatment effect of patients with cerebrovascular diseases.

With the development of medical technology, there are more and more methods for monitoring cerebral blood flow. For example, the Kety-Schmidt method, which measures cerebral blood flow indirectly through inert gas N2O, is a more classical method, but is invasive; transcranial Doppler (TCD) is detected using the Doppler effect of low frequency ultrasound. Is a non-invasive detection method. But the result is influenced by the density of the skull and the operation proficiency of medical staff; the cerebral blood flow value measured by near-infrared spectroscopy (NIRS) is usually low, and each difference is obvious, the average value of repeated measurement needs to be taken as a reliable value, and only superficial cerebral blood flow can be measured; positron Emission Tomography (PET) is known as the "gold standard" for assessing cerebral hemodynamics. However, PET detection techniques are demanding and expensive. In addition, most intensive care units lack bedside equipment capable of monitoring blood supply of a brain area of a patient in real time at present through field research on related departments such as neurology and neurosurgery of a plurality of local hospitals. Only by means of patient's routine vital sign monitoring and daily programmed imaging examination application of doctor, the patient has certain time window effect and is easy to delay the optimal treatment time under the condition of fast disease progress.

Disclosure of Invention

The invention aims to provide a cerebral blood flow monitoring device based on an inductance telemetering technology, which comprises a cerebral blood flow sensor, an inductance telemetering chip, a single chip microcomputer and an upper computer.

The cerebral blood flow sensor is attached to the outer side of the skull of a user, and the projection position of the cerebral blood flow sensor is overlapped with the position of a cerebral hemisphere wing point.

The cerebral blood flow sensor comprises two layers of PCB coils. The two layers of PCB coils are arranged at intervals and are positioned on the same horizontal line. Each layer of PCB coil comprises n turns of coils, and the n turns of coils are n equipotential concentric circles.

The cerebral blood flow sensor magnetic field strength decays from the center in the axial direction and the radial direction.

The resonance frequency of the cerebral blood flow sensor satisfies the following formula:

wherein f is the resonance frequency of the cerebral blood flow sensor; l is the resonance inductance of the cerebral blood flow sensor; and C is the capacitance of the cerebral blood flow sensor.

The cerebral blood flow sensor generates an alternating current magnetic field covering the region of the middle cerebral artery. The alternating magnetic field generates eddy current in the region where the middle cerebral artery is located and generates a secondary magnetic field.

Under the action of a magnetic field, cerebral blood flow of blood vessels in the region of the middle cerebral artery causes the change of the resonance frequency of the cerebral blood flow sensor, so that the cerebral blood flow sensor monitors and obtains cerebral blood flow signals of the blood vessels in the region of the middle cerebral artery and transmits the cerebral blood flow signals to the inductance remote measuring chip.

The inductance telemetering chip receives the cerebral blood flow signal and converts the cerebral blood flow signal into a cerebral blood flow digital signal. The inductance telemetering chip transmits the cerebral blood flow digital signal to the singlechip.

The working frequency range of the inductance telemetering chip is 1KHz-10 MHz.

The singlechip sends the cerebral blood flow digital signals to an upper computer.

And the upper computer displays the change of the cerebral blood flow according to the cerebral blood flow digital signal in the time t.

Further, the device also comprises a power supply module for supplying power to the cerebral blood flow sensor, the inductance remote measurement chip and the single chip microcomputer.

It is worth to be noted that the invention combines the electrical characteristic basis of the rhythmic beating of cerebral blood flow and the inductance measurement principle of the industrial inductance remote measuring chip. The change of cerebral blood flow volume and rhythmic pulsation thereof have great influence on the resonance circuit, and when the cerebral blood flow velocity changes, the blood flow volume passing through a certain section of blood vessel in unit time changes. Thus, a rhythmic cerebral blood flow velocity change will bring about a rhythmic cerebral blood flow volume change, which in turn will bring about a change in the resonant frequency of the circuit. The change of the cerebral blood flow is obtained by detecting the change of the resonance frequency through an inductance telemetering chip.

The technical effect of the invention is undoubted, and the invention provides the cerebral blood flow monitoring device based on the inductive telemetry technology, which can realize non-invasive, real-time and bedside long-time monitoring of cerebral blood flow. The invention has the advantages of low cost, wide application range, low operation technical requirement and the like, and is expected to realize simple and quick bedside monitoring on patients with cerebrovascular diseases and break the time window effect. The invention can provide a device for monitoring cerebral blood flow with low cost, small volume, simplicity and rapidness for old families, community hospitals, primary level and remote medical units, reduces the burden of diseases and saves social resources.

The invention has small volume and low power consumption, and can realize long-time bedside monitoring. The invention adopts a non-invasive non-contact technology, is friendly to medical staff, has low operation difficulty, saves tedious work such as skin preparation and the like, and reduces the workload of the medical staff.

Drawings

FIG. 1 is a system diagram of a cerebral blood flow monitoring device based on inductive telemetry according to the present invention;

FIG. 2 is a cerebral blood flow sensor;

FIG. 3 is a schematic diagram of a mutual inductance circuit;

FIG. 4 is a cerebral blood flow monitoring device based on inductive telemetry;

FIG. 5 is a realistic view of cerebral blood flow in healthy volunteers;

FIG. 6 is a TCD profile in healthy volunteers;

FIG. 7 is a time domain plot of cerebral blood flow in healthy volunteers compared to TCD;

in the figure: the device comprises a cerebral blood flow sensor 1, an inductance remote measuring chip 2, a singlechip 3 and an upper computer 4.

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:

a cerebral blood flow monitoring device based on an inductance telemetering technology comprises a cerebral blood flow sensor 1, an inductance telemetering chip 2, a single chip microcomputer 3 and an upper computer 4.

The cerebral blood flow sensor 1 is attached to the outer side of the skull of a user, and the projection position of the cerebral blood flow sensor 1 is overlapped with the position of a cerebral hemisphere wing point.

The cerebral blood flow sensor 1 comprises two layers of PCB coils. The two layers of PCB coils are arranged at intervals and are positioned on the same horizontal line. Each layer of PCB coil comprises n turns of coils, and the n turns of coils are n equipotential concentric circles.

The cerebral blood flow sensor 1 attenuates the magnetic field strength from the center in the axial direction and the radial direction.

The resonance frequency of the cerebral blood flow sensor 1 satisfies the following equation:

where f is the resonance frequency of the cerebral blood flow sensor 1. L is the resonance inductance of the cerebral blood flow sensor 1. C is the capacitance of the cerebral blood flow sensor 1.

The cerebral blood flow sensor 1 generates an alternating magnetic field covering the region of the middle cerebral artery. The alternating magnetic field generates eddy current in the region where the middle cerebral artery is located and generates a secondary magnetic field.

Under the action of a magnetic field, cerebral blood flow of blood vessels in the region of the middle cerebral artery causes the change of the resonance frequency of the cerebral blood flow sensor 1, so that the cerebral blood flow sensor 1 monitors and obtains cerebral blood flow signals of the blood vessels in the region of the middle cerebral artery and transmits the cerebral blood flow signals to the inductance remote measuring chip 2.

The inductance telemetering chip 2 receives the cerebral blood flow signal and converts the cerebral blood flow signal into a cerebral blood flow digital signal. The inductance telemetering chip 2 transmits the cerebral blood flow digital signal to the singlechip 3.

The working frequency range of the inductance telemetering chip 2 is 1KHz-10 MHz.

The singlechip 3 sends the cerebral blood flow digital signal to the upper computer 4.

And the upper computer 4 displays the change of cerebral blood flow according to the cerebral blood flow digital signal in the time t.

The cerebral blood flow monitoring device also comprises a power supply module for supplying power to the cerebral blood flow sensor 1, the inductance telemetering chip 2 and the singlechip 3.

Example 2:

a cerebral blood flow monitoring device based on an inductance telemetering technology comprises a cerebral blood flow sensor 1, an inductance telemetering chip 2, a single chip microcomputer 3 and an upper computer 4.

The cerebral blood flow sensor 1 generates an alternating magnetic field covering the region of the middle cerebral artery. The alternating magnetic field generates eddy current in the region where the middle cerebral artery is located and generates a secondary magnetic field.

Under the action of a magnetic field, cerebral blood flow of blood vessels in the region of the middle cerebral artery causes the change of the resonance frequency of the cerebral blood flow sensor 1, so that the cerebral blood flow sensor 1 monitors and obtains cerebral blood flow signals of the blood vessels in the region of the middle cerebral artery and transmits the cerebral blood flow signals to the inductance remote measuring chip 2.

The inductance telemetering chip 2 receives the cerebral blood flow signal and converts the cerebral blood flow signal into a cerebral blood flow digital signal. The inductance telemetering chip 2 transmits the cerebral blood flow digital signal to the singlechip 3.

The singlechip 3 sends the cerebral blood flow digital signal to the upper computer 4.

And the upper computer 4 displays the change of cerebral blood flow according to the cerebral blood flow digital signal in the time t.

Example 3:

a cerebral blood flow monitoring device based on an inductance telemetry technology is mainly structurally shown in an embodiment 2, wherein a cerebral blood flow sensor 1 is attached to the outer side of a skull of a user, and the projection position of the cerebral blood flow sensor 1 is overlapped with the position of a wing point of a hemisphere of the brain.

Example 4:

a cerebral blood flow monitoring device based on an inductance telemetry technology is mainly structurally shown in an embodiment 2, wherein the cerebral blood flow sensor 1 comprises two layers of PCB coils. The two layers of PCB coils are arranged at intervals and are positioned on the same horizontal line. Each layer of PCB coil comprises n turns of coils, and the n turns of coils are n equipotential concentric circles.

Example 5:

a cerebral blood flow monitoring device based on inductive telemetry is mainly structured as shown in embodiment 2, wherein the magnetic field intensity of the cerebral blood flow sensor 1 is attenuated from the center along the axial direction and the radial direction.

Example 6:

a cerebral blood flow monitoring device based on an inductance telemetry technology is mainly structurally shown in an embodiment 2, wherein the working frequency range of an inductance telemetry chip 2 is 1KHz-10 MHz.

Example 7:

a cerebral blood flow monitoring device based on an inductive telemetry technology is disclosed in an embodiment 2, wherein a resonant frequency of the cerebral blood flow sensor 1 satisfies the following formula:

where f is the resonance frequency of the cerebral blood flow sensor 1. L is the resonance inductance of the cerebral blood flow sensor 1. C is the capacitance of the cerebral blood flow sensor 1.

Example 8:

the utility model provides a cerebral blood flow monitoring devices based on inductance telemetering measurement technique, the major structure sees embodiment 2, wherein, still includes the power module for cerebral blood flow sensor 1, inductance telemetering measurement chip 2, 3 power supplies power of singlechip.

Example 9:

a cerebral blood flow monitoring device based on an inductance telemetry technology is mainly structurally shown in an embodiment 2, wherein an inductance telemetry chip 2 is LDC 1612.

Example 10:

a cerebral blood flow monitoring device based on an inductance telemetry technology is shown in an embodiment 2, wherein a single chip microcomputer 3 is a master MSP430F 5528.

Example 11:

a cerebral blood flow monitoring device based on an inductance telemetry technology. The brain blood flow sensor is composed of a brain blood flow sensor, an inductance remote measuring chip (LDC1612), a single chip microcomputer and a tablet personal computer. The device can realize non-invasive, real-time and bedside long-time monitoring of cerebral blood flow.

The cerebral blood flow sensor is designed according to the anatomical structure of the winged points of the human skull and the cerebral blood flow signal characteristics of the artery area in the hemisphere, and accords with the human engineering. A PCB coil is made of epoxy resin, a double-layer PCB coil with a copper layer of 0.035mm in thickness and a 6cm geometric dimension has 5 upper and lower concentric circles (radius: 5mm,10mm,15mm,20mm and 25mm) with equal positions (substrate thickness 1.6 mm). The magnetic field intensity of the cerebral blood flow sensor is attenuated from the center along the axial direction and the radial direction, and the size of a high field intensity area is equivalent to the geometric dimension of a coil, so that the cerebral blood flow sensor is suitable for measuring the cerebral blood flow at a medium depth. The cerebral blood flow sensor is arranged at the wing point of the cerebral hemisphere to sense cerebral blood flow signals of the middle cerebral artery and the vicinity of the middle cerebral artery.

The frequency range of the LDC1612 is 1KHz-10 MHz. The higher the system excitation frequency, the higher the sensitivity. On the premise of meeting the national standard of electromagnetic radiation, 8MHz is selected as the working frequency of the cerebral blood flow sensor by the project group for combining the model selection of the inductive accessories of the matching circuit, and the simulation design and matching of the sensor are carried out according to the working frequency. The sensor measured an inductance of 2.78 uH.

Law of LC resonance

Then there is

It can be calculated that at 8MHz resonance, a 142pF capacitor is required, and a 150pF (+ -10%) capacitor is selected for use by the 0402 or 0603 patch capacitor specifications.

The LDC1612 is used for collecting and processing cerebral blood flow signals sensed by the cerebral blood flow sensor, converting the cerebral blood flow signals into digital signals and transmitting the digital signals to the single chip microcomputer through an I2C interface. The working principle of the LDC1612 is as follows: the external wiring coil (cerebral blood flow sensor) generates an alternating magnetic field to cover the middle cerebral artery which is a main blood supply source of the cerebral hemisphere and other blood vessels nearby, the alternating magnetic field generates eddy current near the middle cerebral artery, and a secondary magnetic field is generated. Rhythmic changes in cerebral blood flow will result in rhythmic changes in the resonant frequency. The inductance telemetering chip measures the oscillation frequency of the resonant circuit and converts the oscillation frequency into a digital signal to be displayed. Therefore, the change of cerebral blood flow can be obtained by detecting the change of the resonant frequency through the inductive telemetry chip.

The single chip microcomputer is connected with the tablet personal computer through a USB interface. And displaying the cerebral blood flow signals acquired in real time on a tablet personal computer.

Example 12:

referring to fig. 1 to 5, a cerebral blood flow monitoring device based on an inductance telemetry technology comprises a cerebral blood flow sensor, an LDC1612, a single chip microcomputer and a tablet computer. The cerebral blood flow sensor and the measuring module are only 6cm in diameter and 1.2cm in thickness, and the cerebral blood flow signals can be monitored in real time by connecting the cerebral blood flow sensor and the measuring module with a tablet personal computer through a USB interface. The device is small and exquisite and is convenient to be placed beside a bed or carried about.

Fig. 1 is a system overall framework diagram, a cerebral blood flow sensor arranged at a wing point of a craniocerebral hemisphere firstly senses cerebral blood flow signals of a middle cerebral artery and the vicinity thereof, an LDC1612 converts the cerebral blood flow signals into digital signals and transmits the digital signals to a single chip microcomputer, the single chip microcomputer is connected with a tablet personal computer through a USB interface, and finally the cerebral blood flow signals are displayed on the tablet personal computer in real time.

Fig. 2 is a cerebral blood flow sensor, which is designed according to the human skull wing point anatomical structure and the cerebral blood flow signal characteristics of the artery region in the cerebral hemisphere and accords with the human engineering. A PCB coil is made of epoxy resin, a double-layer PCB coil with a copper layer of 0.035mm in thickness and a 6cm geometric dimension has 5 upper and lower concentric circles (radius: 5mm,10mm,15mm,20mm and 25mm) with equal positions (substrate thickness 1.6 mm). The magnetic field intensity of the sensor is attenuated from the center along the axial direction and the radial direction, and the size of a high field intensity area is equivalent to the geometric dimension of a coil, so that the sensor is suitable for measuring the cerebral blood flow at medium depth. 8MHz is the working frequency of the sensor.

Fig. 3 is a schematic diagram of a mutual inductance circuit, when the LDC1612 is in operation, the external coil (cerebral blood flow sensor) generates an ac magnetic field B1 to cover the middle cerebral artery and other blood vessels around the middle cerebral artery, which are the main blood supply sources of the hemisphere, and the ac magnetic field B1 generates an eddy current around the middle cerebral artery and a secondary magnetic field B1'. When the cerebral blood flow speed is increased, the blood flow passing through a certain section of blood vessel in unit time is increased, which causes B1' to be reduced, and further brings the resonance inductance L of the circuit_coilBecome smaller according to the formulaThe resonance frequency f will increase. When the cerebral blood flow rate slows, the blood flow per unit time through a certain segment of the vessel will decrease, eventually resulting in a decrease in f. Rhythmic changes in cerebral blood flow will result in rhythmic changes in the resonant frequency. The LDC1612 may measure the oscillation frequency of the resonant tank and convert it to a digital signal. Therefore, the change of cerebral blood flow can be obtained by detecting the change of the resonant frequency through the LDC 1612.

Fig. 4 shows a cerebral blood flow monitoring device based on inductive telemetry, which uses a cerebral blood flow sensor to replace a primary coil, and connects an LDC1612 with a tablet computer through a USB interface. The cerebral blood flow sensor is placed at the position of a cerebral wing point to detect cerebral blood flow signals, then the sensed cerebral blood flow signals are transmitted to the single chip microcomputer through the LDC1612, and finally the cerebral blood flow signals monitored in real time are displayed on a GUI software display interface of the tablet personal computer.

FIG. 5 is a pictorial view of cerebral blood flow of healthy volunteers, selected from healthy volunteers aged 18-85 years, with unlimited gender. Inclusion criteria (subjects must meet all of the following requirements before the trial) were: 1) the health of the body; 2) no history of heart disease, hypertension and other related diseases; 3) no implantable medical device in vivo; 4) healthy volunteers without relevant diseases such as brain and the like, which are confirmed by magnetic resonance SWAN sequence gold standard; the cerebral blood flow sensor was fixed at the right lateral wing point position of the subject as shown in fig. 5. And setting GUI software parameters. The data measurement time was 5 minutes.

FIG. 7 is a time domain plot of cerebral blood flow in healthy volunteers compared to TCD. The frequency of the cerebral blood flow waveform obtained by the spectrum analysis is 1.071Hz, and the heart rate is calculated to be HR1 ═ 1.071 × 60 ≈ 64 bmp. From the same volunteer TCD test results (fig. 6), the volunteer had a heart rate of 58bmp at this time. The heart rate that this device calculated through cerebral blood flow is unanimous basically with the actual measurement heart rate. Through comparison and analysis with TCD, the detection result of the cerebral blood flow monitoring device based on the inductive telemetry technology can be verified to be cerebral blood flow.