KR102422529B1 - Invasive Brain Pressure System - Google Patents

Abstract

An invasive intracranial pressure measurement system is disclosed. The invasive intracranial pressure measurement system detects the amount of displacement of the micro-semiconductor pressure sensor diaphragm to invasively measure the intracranial pressure for each measurement position in the cranial cavity of the head, and according to the change in capacitance of the LC resonator, an electrical signal is generated by V = Ed, and the electrical An invasive brain pressure measuring device having one or more micro semiconductor pressure sensors with an LC resonator for measuring the brain pressure corresponding to the signal; And it includes a user terminal for displaying the intracranial pressure for each specific location in the cranial cavity of the one or more micro-semiconductor pressure sensors received through wired and wireless communication from the invasive intracranial pressure sensor.
In the case of an adult, the user terminal has a normal range of pseudotumor cerebri of the intracranial cerebrospinal fluid space of the head in the range of 0 to 15 mmHg, and measures and analyzes the intracranial pressure of the user terminal by measuring the intracranial pressure above a certain value exceeding this range. The brain pressure for each measurement location was displayed by software, and it was visually visualized and outputted on a 2D brain map or a 3D brain map.

Description

Invasive Brain Pressure System

)를 측정하고, 전기 신호에 상응하는 두개강 내 측정 위치별 뇌압을 측정하여 사용자 단말로 전송하며, 사용자 단말은 측정 위치별 뇌압을 표시하고, 정상 뇌압/비정상 뇌압 부위를 표시하며, 일정치 이상의 비정상 뇌압을 2D 뇌지도 또는 3D 뇌지도에 비주얼하게 데이터 시각화하여 출력하는, 침습적 뇌압 측정 시스템에 관한 것이다.The present invention relates to an invasive intracranial pressure measurement system, and more particularly, to open the cranial cavity of the head by surgery to measure the intracranial pressure, and to invasively measure the intracranial pressure in the head by a capacitive method ( Displacement of the upper and lower plates of the diaphragm of one or more micro-semiconductor pressure sensors with LC resonators of capacitance type occurs, the capacitance of the LC resonators is changed, and the electric signal and the LC resonators of the micro-semiconductor pressure sensor are changed by V=Ed resonant frequency (

( It relates to an invasive brain pressure measurement system that visually visualizes and outputs brain pressure on a 2D brain map or a 3D brain map.

The human brain is occupied by the cerebral parenchyma (about 1400 g, 80%), cerebrospinal fluid (150 mL, 10%) and blood (150 mL, 10%) in the solid bones of the skull, and cerebrospinal fluid (CSF) in the skull. ), the brain and spine are connected, and cerebrospinal fluid (CSF) is created on the one hand and absorbed into blood vessels on the other hand to form a constant pressure. The brain and spinal cord are submerged in a clear fluid called cerebrospinal fluid (CSF).

The cranial cavity has a volume of about 1,400 cc and is normally occupied by the cerebral parenchyma (about 1400 g, 80%), cerebrospinal fluid (150 mL, 10%) and blood (150 mL, 10%). The brain does not decrease in volume, and blood and cerebrospinal fluid (CSF) play a major buffer role in maintaining a constant intracranial pressure (pseudotumor cerebri).

Cerebrospinal fluid (CSF) is a fluid that fills the ventricles and central canals of the spine inside the cranial cavity of the head, and serves to supply oxygen and nutrients to brain tissue that cannot receive blood supply. It also serves to protect against the impact of trauma. Cerebrospinal fluid (CSF) is made from blood passing through the choroidal plexus in the ventricles (an open space inside the brain). This fluid ultimately returns to the heart through the superior sagittal sinus, which collects venous blood at the top of the cranial cavity.

Cerebrospinal fluid (CSF) protects the brain and spinal cord in the cranial cavity from changes in the external environment or shock, and at the same time maintains the shape of the brain. The composition of the cerebrospinal fluid is similar to the composition of plasma other than protein, but there is a difference in that the concentration of sodium ion (Na+) or chloride ion (Cl-) is higher and glucose concentration is lower than that of plasma.

Brain pressure is the pressure of the cerebrospinal fluid (CSF) in the cranial cavity of the head. In addition, the intracranial pressure can be directly measured when the cerebrospinal fluid (CSF) is removed from the spine and tested.

또는 0~15 mmHg가 정상 범위이다.The intracranial pressure is 60-180

Or 0-15 mmHg is the normal range.

), 또는 0~15 수은주밀리미터(mmHg)의 범위를 갖는다.Medically, intracranial pressure is the pseudotumor cerebri in the intracranial intracranial space of the head, usually within the normal range of 120 to 180 millimeters in adults.

), or 0 to 15 millimeters of mercury (mmHg).

In physics, pressure is the force (F) acting perpendicularly per unit area (A), where P = F/A.

In the normal range, intracranial pressure is defined as an increase in brain volume, an increase in cerebrospinal fluid (increased intracranial pressure when excessive production of cerebrospinal fluid), and an increase in intracranial blood volume when excessive production of cerebrospinal fluid. abnormal intracranial pressure.

는 그에 상응하는 뇌혈관의 확장을 일으켜 혈관저항이 최소로 되며, 이에 따라 뇌혈류량이 증가하여 뇌압의 상승된다. 이는 이산화탄소의 혈관에 대한 직접적인 작용으로 생각되어지나 Reilly 등은 이러한 변화가 체내 pH나

에 의한 것이라기 보다 뇌 척수액의 pH의 변화에 의한 것이라고 보고하고 있다.'Intracerebral pressure is determined by the cerebral parenchyma, blood volume and cerebrospinal fluid within the confined cranial cavity. acutely increased

causes the corresponding expansion of cerebral blood vessels, which minimizes vascular resistance, and accordingly increases cerebral blood flow and increases intracranial pressure. This is thought to be a direct action of carbon dioxide on blood vessels, but Reilly et al.

It is reported that it is caused by changes in the pH of the cerebrospinal fluid rather than by

Brain disease can be diagnosed with a cerebrospinal fluid test at the time of examination and cause of brain disease. Although the type of meningitis can be estimated by the number of white blood cells in the cerebrospinal fluid, the concentration of protein, and sugar, etc., a cerebrospinal fluid culture test and molecular genetics test (PCR) are needed to find the exact cause.

1 is a brain MRI photograph taken at the Department of Neurology at a certain university hospital in Seoul, and is a brain MRI photograph comparing a left normal brain and a right normal pressure hydrocephalus (NPH).

In general, if you exercise excessively, your heart blood pressure rises and your brain pressure rises.

For reference, if the cerebral blood vessels are dilated due to extreme stress and the intracranial pressure rises, headaches, vomiting, dizziness, movement disorders, and visual field defects occur. state can also be reached.

In particular, if the brain is severely impacted by a car accident or bruise or is damaged in the head, brain oxygen deficiency and brain swelling occur. and the patient dies.

According to the Department of Neurosurgery at a university hospital in Seoul, the intracranial pressure measuring device has been continuously studied for the past 30 years since Lundberg4 measured the ventricular pressure in 1960, and it has been widely implemented in the field of neurosurgery. have.

Recently, with the development of cranial perfusion pressure therapy, intracranial pressure measurement is classified into epidural and intrathecal measurement according to the measurement location, and intrathecal measurement is further classified into subarachnoid measurement, intraparenchymal measurement, and intraventricular measurement. Among the various measurement methods, the intraventricular method is recognized as the standard method for intracranial pressure measurement as its measurement is the most accurate and is the most commonly used. However, the intraventricular measurement method also always requires the setting of a reference point, and it is not easy to install when the position of the ventricle is changed or the size of the ventricle is small, and in some cases, infection or bleeding can occur during installation. . Recently, an epidural measurement device that does not require setting of a reference point and is relatively safe and easy to install in view of the risk of infection, epilepsy, and bleeding has been developed and used in clinical practice. However, the epidural measurement device is located on the epidural and can reduce brain damage, but according to several studies, it is higher than the measurement value in the ventricle, so the accuracy is questionable. The most commonly used non-invasive measurement method using the fibroptic transducer is easy to measure in the ventricle, ventricle, and subdural locations, and has the advantage that the transducer is located near the measurement area. It is recognized as a reliable method without It is reported that the method using a lumbar puncture method and a non-invasive measurement method that can be limitedly applicable to newborns are measures that reflect changes in intracranial pressure, and numerical measurements are unreliable.

[Internal pressure sensor, brain pressure measurement method]

For reference, an intracranial pressure sensor is an intracranial pressure sensor used for post-operative management of patients in the field of brain surgery. There are three methods for measuring intracranial pressure. The first is a method of measuring the pressure of the ventricle by inserting a tube directly into the ventricle, and the second is a method of measuring the pressure of the balloon from the outside by inserting a balloon between the skull and the dura mater. The third method is to measure the intracranial pressure by pushing the sensor on the dura mater. The first and second measurement methods are to measure the pressure with a pressure gauge installed outside the body, and a general pressure gauge is used.

The sensor used for the third measurement method is collectively referred to as an intracranial pressure sensor. Since this method can measure intracranial pressure without damaging the dura mater, it can be monitored for a long time without fear of bacterial infection. The intracranial pressure sensor should measure the pressure accurately by reducing the effect of the tension of the dura mater.

In addition, it was reported in the scientific journal 'Nature' that the team led by Professor John Rogers of the Department of Materials Science and Engineering at the University of Illinois in the US developed a sensor that can measure pressure and temperature in the brain in collaboration with Washington Medical School. The US research team has developed an implantable wireless sensor that can measure the pressure and temperature in the brain, and the implantable sensor for measuring brain pressure using biodegradable polymer melts away by itself after a few days after being inserted into the brain. It is smaller than a pencil lead and smaller than a grain of rice. It's a light sensor, and the sensor has a thin wire about one-tenth the thickness of a human hair. This wire serves to connect the sensor and the wireless transmitter attached to the outside of the skull. Brain pressure and temperature data measured by the sensor can be wirelessly transmitted in real time.

All the materials used in the sensor will melt and be absorbed by itself after a few days in the body. When the research team immersed the device in saline with a concentration similar to that of cerebrospinal fluid and observed it, it was found that after 30 hours, the shape began to flow.

It was also confirmed that the sensor could be inserted into the brain of a mouse and observed for three days. Inflammation, which has been pointed out as a problem with other implantable devices so far, has not occurred.

For reference, an invasive blood pressure measurement sensor is a blood pressure monitor and blood contact when measuring blood pressure, and is referred to as a direct method. In this method, the blood pressure is measured by inserting a needle or catheter into the blood vessel and connecting the electro-sphygmomanometer through a connection tube filled with heparin water. Alternatively, the blood pressure can be measured by directly inserting a catheter tip-type manometer into the blood vessel, and the blood pressure can be measured with high precision. In this method, since the pressure gauge and blood come into contact, it is necessary to consider disinfection or electrical safety.

2 is a photograph showing an invasive brain pressure measuring method (left) and a non-invasive intracranial pressure measuring method (right).

The manometer is an invasive manometer that measures intracranial pressure by inserting a probe that measures the intracranial pressure of a person's head into the skull of a person, and a non-invasive instrument that measures the intracranial pressure indirectly without inserting the probe into the skull. Non-invasive pressure gauges exist.

; 1 mm Hg = 136

)를 갖는다. 정상 범위를 초과하는 뇌압은 뇌조직에 이차적인 손상을 가져올 수 있는데, 뇌압 상승에 의해 뇌관류압이 감소하면서 뇌허혈이 초래되거나, 뇌압의 압력경사에 의해 뇌탈출이 일어나면서 이차적인 뇌손상이 발생한다.According to the "brain pressure and hematology (J Neurocrit Care 2011; 4:35-41)" of the Department of Neuroscience, Seoul National University, the range of normal intracranial pressure and normal intracranial pressure in adults is in the range of 5 mmHg to 15 mmHg (75-20 mmHg).

; 1 mm Hg = 136

) has Brain pressure exceeding the normal range can cause secondary damage to brain tissue. Cerebral perfusion pressure decreases due to increase in intracranial pressure, resulting in cerebral ischemia, or secondary brain damage occurs as brain prolapse occurs due to pressure gradient of intracranial pressure.

Although non-invasive methods of measuring intracranial pressure have been recently studied a lot, there is no risk of bacterial infection because the intracranial pressure is measured outside the brain. In order to measure accurately, an invasive intracranial pressure measurement method is mainly used.

The invasive method of measuring intracranial pressure uses two methods, such as measuring ventricular pressure using an extraventricular drainage catheter or directly measuring brain tissue pressure by inserting a pressure monitor into the cerebral parenchyma. If you use an extraventricular drainage catheter, you can measure the intraventricular pressure, so you can get a value that reflects the overall pressure in the cranial cavity. However, when there is a localized mass, the intracranial pressure around the mass is increased, but there are cases where the pressure in the area far from the brain lesion site is normal. When the intracranial pressure is compartmentalized in this way, the overall intraventricular pressure is measured lower than the local tissue pressure, so the actual level of the increased intracranial pressure may be underestimated. Advantages are that it can be used for therapeutic purposes, such as draining cerebrospinal fluid through a drainage catheter or injecting drugs, and if there is any doubt about the reliability of the pressure measurement, the intracranial pressure can be zeroed at any time. As a disadvantage, continuous intracranial pressure measurement is impossible for a long period of time because the intracranial pressure can be measured only after the catheter is closed, and the complications of bleeding or infection occur higher than the method of inserting an intraparenchymal monitor. In order to reduce the complications of infection, a catheter made of a new material coated with antibiotics or particles having an antibacterial effect is being used.

The method of measuring the intracranial pressure using the intracerebral parenchyma monitor mainly measures the pressure using fiberoptics, and is fixed using a bolt on the skull. The Caminoⓡ monitor commonly used in Korea uses this method. As a disadvantage, the longer the time after inserting the monitor, the more it drifts from the true value. When used for a long period of time, there may be a problem in the reliability of the measured value. none. However, in patients with focal brain lesions, local brain tissue pressure can be directly measured and the intracranial pressure can be continuously monitored.

As a related prior art, the non-invasive intracranial pressure gauge is a device for measuring cerebral blood flow using ultrasound, and existing devices use a wire-type controller (Patent 2003-0081346: Doppler ultrasound method for blood flow monitoring and embolism detection) and Apparatus, Special 2003-0036137: Method and apparatus for combining diagnostic ultrasound and therapeutic ultrasound for enhancing thrombus dissolution, US005348015A: Method and apparatus for ultrasonically detecting, counting and/or characterizing emboli, US006196972B1: Doppler ultrasound method and apparatus for monitoring blood flow), etc. have been published.

In general, a cerebral blood flow measurement device using a wire-type ultrasound puts the ultrasound probe head on a specific part of the patient's head (Window) and presses buttons on the controller panel with the other hand to control the window depth, scale, sample volume, etc. It is controlled to obtain the desired optimal output, but there are restrictions on overlapping and distance of cables and restrictions on movement.

Referring to FIG. 3 , a non-invasive brain manometer that wirelessly communicates with a measuring device and a controller ergonomically, Korean Patent Laid-Open No. 10-2005-0056100 discloses an ultrasonic cerebral blood flow measuring device using a wireless charging controller. are doing

The method of measuring intracranial pressure and cerebral perfusion pressure is to insert a pressure transducer, a pressure transducer, into the brain. However, insertion of a pressure transducer for measuring intracranial pressure cannot be performed in all patients because it may cause intracerebral hemorrhage as a complication.

Therefore, the control unit used in the non-invasive ultrasonic cerebral blood flow measuring device [ultrasonic TCD (Transcranial Doppler) apparatus] provides a method of driving with a rechargeable infrared remote controller. As a 2MHz pulsed ultrasound probe, it measures the blood flow velocity of the cerebral blood vessels through the window and adjusts the position using a wireless controller, so that when diagnosing stroke, which is a cerebrovascular disease, cerebrovascular stenosis and occlusion are non-invasively accurate and quick. In addition to being able to diagnose quickly, the results can be viewed in detail.

The conventional cerebral blood flow measuring device calculates the intracranial pressure by analyzing the returned waveform by mainly emitting ultrasound to the middle cerebral artery and cerebral blood vessels.

The operating principle of the entire ultrasonic cerebral blood flow measurement device will be described with reference to the block diagram of FIG. 3 . By controller, Direction sets the blood flow forward/reverse direction, Probe selects 2MHz PW probe, Delete modifies, Sample adjusts sample volume size, Zero adjusts zero position, Amplitude adjusts signal amplitude increase/decrease, Sweep repeats constant Set the output time of the received signal waveform of the period, Depth adjusts the size of the window depth, Scale adjusts the size of the scale when displaying the output waveform, and Window selects one of the windows (MCA, ACA, PCA, VA). It provides a selection function.

Transmitter and Receiver is a device that sends a 2MHz PW signal to the skull through a probe and receives the returned Doppler signal. The received signal enters the TGC AMP. TGC AMP is a TGC (Time Gain Control) Amplifier that amplifies the reflected wave received through the Pre-Amp. The next step is Quadrature Detection. Quadrature Detection is a demodulation circuit for detecting the movement direction of blood flow. Using an analog multiplier, the received signal and the signal with a phase difference of 90° are multiplied respectively and the cutoff frequency is passed to the LPF. After that, it enters the S/H (Sample and Hold) circuit. Sample and Hold detects the Doppler frequency shift of the sample volume as a sample & hold (S/H) of two demodulated In-Phase and Quadrature-Phase signals, respectively. After that, the stationary canceller removes unwanted clutter and 50~150Hz components of the signal due to harmonics by the sampling frequency among the signals detected by S/H with HPF having a cutoff frequency of 200Hz. Here it goes through the filter. Optionally, the Nyquist Filter removes signals above PRF/2 among the harmonics of the PRF-sampled signal so that the audible frequency can be heard by the diagnostician through the amplifier and speaker. In the next step, the comparator compares the phases of the two signals of Quadrature and In-Phase in the conversion of Doppler frequency proportional to the speed of the sample volume to frequency-to-voltage. will produce a positive or negative pulse. Finally, the integral integrates the pulse trains of different polarities in both directions, and the LPF passes the output of the integrating circuit through the LPF having a cut-off frequency, and the average speed signal is output and displayed on the TFT-LCD display.

In the conventional cerebral blood flow measurement device, the patient's brain pressure must be measured by contacting the head of a person in a state of holding the measuring device directly by an experienced operator, and the patient's brain pressure must be calculated based only on information obtained from the cerebral blood vessels. An accurate intracranial pressure value cannot be calculated.

In addition, with the aging of the population, elderly patients suffering from central nervous system diseases are increasing, and they suffer from diseases such as degenerative brain diseases such as Alzheimer's disease and Parkinson's disease, and blood circulation disorders such as epilepsy and stroke.

In the case of the elderly over the age of 65, it is called normal pressure hydrocephalus (NPH), in which the brain pressure does not rise but brain function is abnormal as the amount of cerebrospinal fluid increases. have. In addition, in the case of elderly patients, there are more than 30% of cases where ultrasound does not pass through the skull. In patients whose skull has been destroyed by damage to the skull, intracranial pressure cannot be measured.

Recently, research and development of an implantable intracranial pressure measuring device has been developed for invasive intracranial pressure measurement rather than non-invasive in vitro measurement to measure intracranial pressure and brain temperature biosignals.

Figure 1b shows a resistive temperature sensor using a capacitive lightning pressure sensor and a temperature coefficient resistance (TCR) on a low resistance silicon wafer substrate (0001 ~ 0005 Ωcm) and a lower electrode using conventional poly silicon. It is a cross-sectional view of the lightning pressure/temperature sensor device implemented in one semiconductor chip through the MEMS process.

The brain pressure sensor is a low-resistance (silicon wafer: 0001 ~ 0005Ωcm) using LPCVD equipment to deposit a silicon-nitride film (2000 Å), and then using an LPCVD process on it to form poly-silicon (poly-silicon). A sacrificial layer was deposited to a thickness of 1 μm using the film, and boron doping was performed during deposition. In the poly-silicon film, the pressure sensor unit acts as a sacrificial layer, and the temperature sensor unit acts as a resistance type temperature sensor that detects changes in ambient temperature.

The deposited poly-silicon film was etched (1 μm) using patterning and deep-RIE processes to form the cavity of the pressure sensor and the resistor of the temperature sensor.

A low stress silicon nitride is again deposited (1 μm) on the formed sacrificial layer (poly-silicon) to form a support layer for the upper electrode, and then a thin film is deposited using a gold sputtering process (Ti/Au 200/2000). Å) and then an upper electrode was formed using an exposure process.

Thereafter, in order to etch the sacrificial layer, silicon nitride, which is a support layer of the upper electrode, was partially removed through a patterning process, and then the sacrificial layer was removed by isotropy etching of silicon of XeF2. In addition, to maintain the pressure of the capacitive pressure sensor, SU-8 2000 photo resist was used (2 μm).

Recently, the wireless brain pressure/brain temperature measurement sensor is harmless to the human body and is a bio-insertable electronic device composed of a material that can be decomposed and absorbed by the cerebrospinal fluid in the skull to measure the brain pressure and brain temperature wirelessly for a certain period of time in vivo. A wireless type of brain pressure/brain temperature measurement sensor using an implantable electronic device is being studied.

Professor Hwang's team at the KU-KIST Graduate School of Convergence at Korea University has developed a 'wireless brain pressure and brain temperature sensor' that melts in the body. absorbed by the body and eliminated.

The results of this study were published in the world-renowned scientific journal 'Nature'.

Professor Hwang's team emphasized, "Existing brain pressure and brain temperature sensors require reoperation because they have to be inserted into the brain and then taken out again, so it was risky.

The bio-insertable electronic device is composed/designed with a material that can be completely decomposed and reabsorbed in the body within the cranial cavity. , molybdenum (Mo), and biodegradable polymer (PLGA; poly(lactic-co-glycolic acid)).

However, although non-invasive methods for measuring intracranial pressure have been studied a lot, there is no risk of bacterial infection because the intracranial pressure is measured from the outside of the head, but the intracranial pressure measurement is inaccurate and there are few medical devices that can be applied clinically.

On the other hand, the invasive method of measuring the brain opening of the head by surgery to measure the intracranial pressure causes bleeding and there is a risk of bacterial infection. However, the intracranial pressure measurement is relatively accurate.

Patent Publication No. 10-2005-0056100 (published on June 14, 2005), "Ultrasound cerebral blood flow measuring device using a wireless charging controller", B.M.Tech 21

)를 측정하고 전기 신호에 상응하는 두개강 내 측정 위치별 뇌압을 측정하여 사용자 단말로 전송하며, 사용자 단말은 측정 위치별 뇌압을 표시하고, 정상 뇌압/비정상 뇌압 부위를 표시하며, 일정치 이상의 비정상 뇌압을 2D 뇌지도 또는 3D 뇌지도에 비주얼하게 데이터 시각화하여 출력하는, 침습적 뇌압 측정 시스템을 제공한다. An object of the present invention to solve the above problem is to open the cranial cavity of the head by surgery to measure the intracranial pressure, and to invasively measure the intracranial pressure at each location in the head of the head by a capacitance type. Displacement of the upper and lower plates of the diaphragm of at least one micro semiconductor pressure sensor having an LC resonator occurs, the capacitance of the LC resonator is changed, and the electric signal and the resonance frequency of the LC resonator of the micro semiconductor pressure sensor (V = Ed)

) is measured and the intracranial pressure corresponding to the electrical signal is measured and transmitted to the user terminal. Provides an invasive brain pressure measurement system that visually visualizes and outputs data on a 2D brain map or a 3D brain map.

)의 변화를 측정하고 상기 전기 신호에 상응하는 뇌압을 측정하는 생체삽입형 정전용량 방식(capacitance type)의 LC 공진기를 구비한 초소형 압력 센서; 및 상기 압력 센서 위에 구비되는 상부 전극을 포함하며,
상기 기판은 유리 기판 또는 유연성이 있는 플렉시블 기판을 사용하며,
상기 플렉시블 기판은 폴리이미드(polyimid) 또는 폴리 실리콘(polysilicon)을 사용한다. In order to achieve the object of the present invention, the invasive intracranial pressure measurement system detects the displacement amount of the diaphragm of the micro semiconductor pressure sensor so as to invasively measure the intracranial pressure at each measurement position in the cranial cavity of the head, and V = Ed according to the change in the capacitance of the LC resonator An electrical signal is generated by the invasive brain pressure measuring instrument having at least one micro semiconductor pressure sensor having an LC resonator for measuring the brain pressure corresponding to the electrical signal; and a user terminal for displaying the intracranial pressure for each specific location in the cranial cavity of the micro-semiconductor pressure sensor received from the invasive brain pressure sensor through wired/wireless communication,
The ultra-small semiconductor pressure sensor having the LC resonator is
Board; a lower electrode provided on the substrate; It is formed on the lower electrode and includes, for example, a first metal line using gold (Au), a first stub, and a second metal line and a second stub using gold (Au) facing each other, and the an input/output port respectively connected to the first stub and the second stub; The amount of displacement of the diaphragm (thickness d of the upper and lower plates) is detected according to the pressure at each location in the cranial cavity of the head, and the electric signal is measured by V=Ed, and the resonance frequency (

) and a micro-pressure sensor equipped with an LC resonator of a bio-insertable capacitance type for measuring the change in the brain pressure corresponding to the electrical signal; and an upper electrode provided on the pressure sensor,
The substrate uses a glass substrate or a flexible flexible substrate,
The flexible substrate uses polyimide or polysilicon.

)를 측정하고 전기 신호에 상응하는 두개강 내 측정 위치별 뇌압을 측정하여 사용자 단말로 전송하며, 사용자 단말은 측정 위치별 뇌압을 표시하고, 정상 뇌압/비정상 뇌압 부위를 표시하며, 일정치 이상의 비정상 뇌압을 2D 뇌지도 또는 3D 뇌지도에 비주얼하게 데이터 시각화하여 출력하는 효과가 있다. The invasive intracranial pressure measurement system of the present invention uses an LC resonator of a capacitance type to open the cranial cavity of the head by surgery to measure the intracranial pressure, and to invasively measure the intracranial pressure at each location in the head. One or more micro-semiconductor pressure sensors provided are positioned, and the displacement of the upper and lower plates of the diaphragm of the micro-semiconductor pressure sensor occurs according to the pressure for each measurement position in the cranial cavity, and the capacitance of the LC resonator is changed, and the electric The resonance frequency of the signal and the LC resonator of the micro semiconductor pressure sensor (

) is measured and the intracranial pressure corresponding to the electrical signal is measured and transmitted to the user terminal. It has the effect of visualizing and outputting data on a 2D brain map or a 3D brain map.

At least one ultra-small semiconductor pressure sensor equipped with an implantable LC resonator for each measurement position in the cranial cavity of the head is a medical device that can be used for diagnosing patients with brain diseases, patients with head injuries, cerebral hemorrhage, cerebral infarction, meningitis, and brain tumors.

1A is a brain MRI image taken at the Department of Neurology at a university hospital in Seoul, and is a brain MRI image comparing a left normal brain and a right normal pressure hydrocephalus (NPH).
Figure 1b shows a resistive temperature sensor using a capacitive lightning pressure sensor and a temperature coefficient resistance (TCR) on a low resistance silicon wafer substrate (0001 ~ 0005 Ωcm) and a lower electrode using conventional poly silicon. It is a cross-sectional view of the lightning pressure/temperature sensor device implemented in one semiconductor chip through the MEMS process.
2 is a photograph showing an invasive brain pressure measuring method (left) and a non-invasive intracranial pressure measuring method (right).
3 is a block diagram and a view showing a measurement principle of a conventional all ultrasonic cerebral blood flow measurement device.
4 is a block diagram of a system for measuring brain pressure according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

)를 측정하고 전기 신호에 상응하는 두개강 내 측정 위치별 뇌압을 측정하여 사용자 단말로 전송하며, 사용자 단말은 측정 위치별 뇌압을 표시하고, 정상 뇌압/비정상 뇌압 부위를 표시하며, 일정치 이상의 비정상 뇌압을 2D 뇌지도 또는 3D 뇌지도에 비주얼하게 데이터 시각화하여 출력한다. The invasive intracranial pressure measuring system of the present invention opens the cranial cavity of the head by surgery to measure the intracranial pressure, and in order to invasively measure the intracranial pressure at each position in the head, the capacitive method according to the pressure at each position in the cranial cavity Displacement of the upper and lower plates of the diaphragm of one or more micro-semiconductor pressure sensors having a (capacitance type) LC resonator occurs, and the capacitance of the LC resonator is changed, and the electric signal and the LC of the micro-semiconductor pressure sensor are changed by V=Ed. The resonant frequency of the resonator (

) is measured and the intracranial pressure corresponding to the electrical signal is measured and transmitted to the user terminal. Visualize and output data on a 2D brain map or a 3D brain map.

For reference, in the EEG test using 32~128 EEG electrodes, it is possible to know the local location of the brain lesion where abnormal EEG is generated by using an EEG test device on the outside of the head.

)의 변화에 상응하는 뇌압[뇌 척수액 공간의 두개강 내압(pseudotumor cerebri)]을 측정한다. The cranial cavity of the head is opened by surgery, and a plurality of bio-insertable capacitance type micro semiconductor pressure sensors are provided at the local location of the brain lesion in the cranial cavity of the head, and micro semiconductor pressure of the bio-inserable capacitive type is provided. The sensor measures the change in capacitance of the LC resonator of the ultra-small semiconductor pressure sensor according to the concentration of cerebrospinal fluid at each measurement location, and the resonant frequency (

) corresponding to the change in intracranial pressure (pseudotumor cerebri) is measured.

)의 변화에 상응하는 뇌압[뇌 척수액 공간의 두개강 내압(pseudotumor cerebri)]을 측정한다.A bio-implantable capacitance type micro semiconductor pressure sensor is a micro semiconductor pressure sensor composed of an LC resonator, a micro pressure sensor chip made with MEMS technology on a glass substrate or a flexible polyimide substrate. By measuring the change in the capacitance of the LC resonator of the star ultra-small semiconductor pressure sensor, the characteristic impedance changes and the resonant frequency of the LC resonator (

) corresponding to the change in intracranial pressure (pseudotumor cerebri) is measured.

For reference, the pressure sensor is classified into a mechanical pressure sensor and a semiconductor pressure sensor. The mechanical pressure sensor uses a Bourdon tube, a metal plate diaphragm, etc., and has a disadvantage in that the device size of the pressure sensor is large. The semiconductor pressure sensor uses a silicon diaphragm, and the size of the device is measured using MEMS (Micro Electro Mechanical Systems) technology. can be made small. The silicon diaphragm pressure sensor using MEMS technology is classified into a piezo-resistive type and a capacitive type semiconductor pressure sensor according to the detection method.

The capacitive semiconductor pressure sensor can use a flat diaphragm or a ring-type diaphragm with a thickness of 200 to 300 μm, and when the pressure changes, the capacitance changes and an electric signal changes accordingly to measure the pressure.

에 의해 커패시턴스(capacitance)가 변화되며, V = Ed [v] 식에 전기 신호를 측정한다. That is, when pressure is applied to the upper plate, the distance d between the upper and lower plates changes in proportion to the magnitude of the force due to the piezoelectric phenomenon (pressure -> electric signal).

The capacitance is changed by , and the electric signal is measured according to the equation V = Ed [v].

For reference, in order to invasively measure the intracranial pressure of the head, the invasive pressure sensor changes the piezo resistance value of the semiconductor when a force is applied to the semiconductor pressure sensor. Without using a piezo resistance type pressure sensor to measure

에 의해 커패시턴스 값이 측정된다.

는 진공의 유전율(permittivity of vacuum), ε는 물질의 비유전율(relative permittivity), A는 평행판 콘덴서 면적(sensing area)이며, d는 감지층의 두께(thickness of the sensing layer)이다.The miniature pressure sensor of the present invention uses a miniature semiconductor pressure sensor using an electrostatic capacitance type LC resonator. As a basic concept, the capacitance between two electrodes with a cross-sectional area A of a parallel plate capacitor and a distance d between the upper and lower plates of a parallel plate capacitor is

The capacitance value is measured by

is the permittivity of vacuum, ε is the relative permittivity of the material, A is the parallel plate sensing area, and d is the thickness of the sensing layer.

V is the potential difference between the two conductor plates of the upper and lower plates, E is the uniform magnetic field strength generated between the two conductor plates, and d is the distance between the two conductor plates of the upper and lower plates.

4 is a block diagram of an invasive brain pressure measurement system according to the present invention.

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The invasive intracranial pressure measurement system of the present invention comprises:

In order to invasively measure the intracranial pressure at each measurement position in the head of the head, the displacement amount of the diaphragm with a thickness of several ㎛ ~ tens of ㎛ of the micro semiconductor pressure sensor 11 for each measurement position is sensed, and according to the change in the capacitance of the LC resonator, V = An electrical signal is generated by Ed, the invasive brain pressure measuring instrument 10 having at least one micro semiconductor pressure sensor having an LC resonator for measuring the brain pressure corresponding to the electrical signal; and

A user terminal 20 (PC, smartphone/tablet PC) that displays the intracranial pressure for each specific location in the cranial cavity of the ultra-small semiconductor pressure sensor received from the invasive intracranial pressure sensor 10 through wired/wireless communication. ,

)의 변화를 측정하고 상기 전기 신호에 상응하는 뇌압을 측정하는 생체삽입형 정전용량 방식(capacitance type)의 LC 공진기를 구비한 초소형 압력 센서; 및 상기 압력 센서 위에 구비되는 상부 전극을 포함하며,
상기 기판은 유리 기판 또는 유연성이 있는 플렉시블 기판을 사용하며,
상기 플렉시블 기판은 폴리이미드(polyimid) 또는 폴리 실리콘(polysilicon)을 사용한다. The user terminal displays the intracranial pressure for each location measured in the cranial cavity on the display unit, displays abnormal intracranial pressure above a certain value, and visually visualizes and outputs it on a 2D brain map or a 3D brain map,
The micro semiconductor pressure sensor having the LC resonator is
Board; a lower electrode provided on the substrate; It is formed on the lower electrode and includes, for example, a first metal line using gold (Au), a first stub, and a second metal line and a second stub using gold (Au) facing each other, and the an input/output port respectively connected to the first stub and the second stub; The amount of displacement of the diaphragm (thickness d of the upper and lower plates) is detected according to the pressure at each position in the cranial cavity of the head, and the electric signal is measured by V=Ed, and the resonance frequency (

) and a micro-pressure sensor equipped with an LC resonator of a bioinserable capacitance type for measuring the change in the brain pressure corresponding to the electrical signal; and an upper electrode provided on the pressure sensor,
The substrate uses a glass substrate or a flexible flexible substrate,
The flexible substrate uses polyimide or polysilicon.

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A micro-semiconductor pressure sensor 11 equipped with an invasive bio-insertable LC resonator in the cranial cavity of the head uses an interdigital capacitor and an inductor (micro electro mechanical system) on a glass substrate or a flexible flexible substrate ( Inductor) using MEMS technology to design/manufacture, and use the ultra-small semiconductor pressure sensor 11 equipped with a tube-shaped capacitance type LC resonator manufactured by semiconductor packaging.

Pressure sensors that measure intracranial pressure are classified into intrathecal measurement methods (subarachnoid measurement, intraventricular measurement, and intraventricular measurement). have.

An intracranial pressure sensor used as an intracranial pressure sensor is

i) the ventricular pressure is measured by inserting a tube directly into the ventricle, measured with a manometer from the outside of the head, or

ii) By inserting a balloon between the base of the skull and the dura mater, the pressure of the balloon is measured from the outside of the head, and the pressure of the balloon is measured from the outside of the head with a manometer.

iii) Third, since the intracranial pressure sensor used in the method of measuring the intracranial pressure by pushing the intracranial pressure sensor above the dura mater can measure the intracranial pressure without damaging the dura mater, it can be monitored for a long time without fear of bacterial infection. have. The intracranial pressure sensor should measure the pressure accurately by reducing the influence of the tension of the dura mater.

In the embodiment, the ultra-small semiconductor pressure sensor 11 having an LC resonator of a capacitance type will be described as an example.

[Example]

For example, as an RF Bio Sensor for measuring intracranial pressure, the micro semiconductor pressure sensor 11 equipped with an LC resonator of a capacitance type is symmetrical on a glass substrate or a flexible polyimid flexible substrate. The LC resonator is provided and may be implemented as a BPF having an octagonal structure (spiral structure) cross-connected in an air bridge structure.

Cuc = Cg + Cs

Here, Cuc is the unit cell capacitance forming each turn of the octagonal resonator, Cg is the gap capacitance, and Cs is the substrate mapping capacitance.

The capacitance of the LC resonator changes according to the amount of displacement of the diaphragm for each measurement position in the two cranial cavity of the head, and the resonant frequency change, reflection coefficient, and gap capacitance due to the spiral-coupled BPF capacitance with two symmetrical resonators. capacitance, by measuring the change in complex permittivity,

The BPF of the octagonal structure is

Two symmetrical LC resonators cross below the air-bridge structure and form an LC resonator having a plurality of turns of an octagonal structure symmetrical to each other, and induction between mutually wound resonators each having an inductance of L/2 coupling (inductive coupling) (Lm), and

Capacitive coupling that occurs between the gap capacitances (Cg) of two open-ended interwound resonators (Cg) and the fringe capacitance (Cs) developed through a flexible substrate ) becomes,

The resistance characteristic of the LC resonator is modeled as Rs, and the unit cell capacitance Cuc forming each turn of the octagonal structure is the capacitance value added by the gap capacitance (Cg) and the substrate mapping capacitance (Cs). ,

)는

에 의해 계산된다.The fundamental resonant frequency of the BPF of the octagonal structure (

)Is

is calculated by

Here, Leq is the inductance of the equivalent circuit, and Ceq is the capacitance of the equivalent circuit.

The capacitive type micro semiconductor pressure sensor 11 may be provided in the invasive brain pressure meter 10 having a control unit, a storage unit, and a communication unit through an amplifier and an ADC.

The invasive intracranial pressure meter 10 is

In order to open the cranial cavity of the head by surgery and invasively measure the intracranial pressure, a micro semiconductor pressure sensor 11 equipped with a bioinserable capacitive LC resonator at one or more specific locations of the brain within the cranial cavity Detects the amount of displacement of the diaphragm according to the intracranial pressure for each intracranial measurement location and measures the change in the capacitance of the LC resonator of the micro semiconductor pressure sensor. A micro semiconductor pressure sensor 11 having at least one LC resonator for measuring;

a control unit 12 connected to the miniature semiconductor pressure sensor 11 having the at least one LC resonator;

a storage unit (13) connected to the control unit and storing information on brain pressure measured for each measurement location in the cranial cavity of the head; and a battery 19 .

Additionally, the invasive intracranial pressure meter 10 is connected to the control unit 12, and further includes a display unit (not shown) for displaying the measured intracranial pressure information for each measurement position in the cranial cavity of the head.

Additionally, the invasive intracranial pressure meter 10 is connected to the control unit 12 and transmits the measurement position inserted into the living body for each measurement position in the cranial cavity of the head and the measured brain pressure information through wired/wireless communication (USB cable, Bluetooth, Wi-Fi, etc.) It further includes a communication unit for transmitting to the user terminal 20 through the.

The micro semiconductor pressure sensor with the capacitive type LC resonator is a bio-insertable RF biosensor in the two cavities of the head,

After opening the cranial cavity of the head by surgery, a micro semiconductor pressure sensor is provided so as to invasively measure the intracranial pressure at one or more specific locations of the brain, and a bioinserable capacitance in the intracranial cerebrospinal fluid (CSF). A micro semiconductor pressure sensor equipped with a capacitance type LC resonator is used, and the displacement of the diaphragm with a thickness of several μm to tens of μm occurs depending on the pressure at each measurement location in the cranial cavity, and changes in the capacitance of the LC resonator are detected. By measuring, an electric signal is generated by V=Ed, and the resonance frequency of the LC resonator is measured, and the corresponding intracranial pressure [pseudotumor cerebri in the cerebrospinal fluid space] is measured.

The miniature semiconductor pressure sensor 11 having the LC resonator is

a substrate;

a bottom electrode provided on the substrate;

)의 변화를 측정하고 상기 전기 신호에 상응하는 뇌압을 측정하는 생체삽입형 정전용량 방식(capacitance type)의 LC 공진기를 구비한 초소형 압력 센서; 및It is formed on the lower electrode and includes, for example, a first metal line using gold (Au), a first stub, and a second metal line and a second stub using gold (Au) facing each other, and the an input/output port respectively connected to the first stub and the second stub; The amount of displacement of the diaphragm (thickness d of the upper and lower plates) is detected according to the pressure at each position in the cranial cavity of the head, and the electric signal is measured by V=Ed, and the resonance frequency (

) and a micro-pressure sensor equipped with an LC resonator of a bioinserable capacitance type for measuring the change in the brain pressure corresponding to the electrical signal; and

It includes a top electrode (top electrode) provided on the pressure sensor,

The substrate uses a glass substrate or a flexible flexible substrate,

The flexible substrate uses polyimide or polysilicon.

The micro-semiconductor pressure sensor with the LC resonator of the bio-insertable capacitance type is inserted into the living body with three materials: SU-8, silicon nitride, and gold (Au) exposed to the living tissue in the cranial cavity of the head. A material that is stable and has excellent biocompatibility was used.

The user terminal 20 uses a PC, a smartphone or a tablet PC, the brain pressure measurement and analysis SW is installed, and the intracranial pressure for each location of the head is displayed.

The user terminal 20 provides information on the resonance frequency of the LC resonator measured according to the change in capacitance of the LC resonator according to the displacement amount of the diaphragm of the micro semiconductor pressure sensor 11 having the LC resonator for each measurement position in the cranial cavity of the head. a communication unit 21 for receiving a signal through wired/wireless communication (USB cable, Bluetooth, Wi-Fi, etc.); a control unit 22 connected to the communication unit 21 and controlling to be displayed on the display unit 27 by analyzing the intracranial pressure for each measurement position in the cranial cavity; It is connected to the control unit 22, stores brain pressure measurement and analysis software, and V = Ed measured according to a change in the capacitance of the LC resonator of the micro semiconductor pressure sensor 11 having the LC resonator. a storage unit 23 for storing the measured electrical signal (in addition, the resonance frequency of the LC resonator) and corresponding brain pressure information; and a display unit 27 that is connected to the control unit 22 and displays the measured intracranial pressure for each position in the cranial cavity of the head of the micro semiconductor pressure sensor 11 using a living body implantable LC resonator.

When a person's head is scanned using a 3D scanner, a 3D modeled and rendered 3D brain map can be generated.

In the case of an adult, the normal range of intracranial pressure (pseudotumor cerebri) in the intracranial intracranial cerebrospinal fluid space has a range of 0 to 15 mmHg, and the intracranial pressure of the user terminal 20 is measured and analyzed at the area of intracranial pressure exceeding the normal range of intracranial pressure. By software, the intracranial pressure for each measurement location is displayed, and the 2D brain map or 3D brain map is visually visualized and output.

In adults, the normal range of intracranial pressure (pseudotumor cerebri) ranges from 0 to 15 mmHg.

The invasive intracranial pressure measurement system of the present invention opens the cranial cavity of the head by surgery, and at least one ultra-small semiconductor pressure sensor equipped with a capacitive LC resonator for each position in the cranial cavity of the head is located, and the diaphragm for each position in the cranial cavity is located. By detecting the amount of displacement, the change in capacitance of the LC resonator of the micro semiconductor pressure sensor is measured, and an electric signal is generated by V=Ed, and the intracranial pressure corresponding to the electric signal is measured and transmitted to the user terminal, and the intracranial pressure is measured and transmitted to the user. The terminal displays the intracranial pressure for each position measured in the cranial cavity on the display unit, and visually visualizes and outputs the abnormal intracranial pressure above a certain value on a 2D brain map or a 3D brain map.

At least one ultra-small semiconductor pressure sensor equipped with a bio-insertable LC resonator for each position in the cranial cavity of the head is a medical device that can be used for diagnosing patients with brain diseases, patients with head injuries, cerebral hemorrhage, cerebral infarction, meningitis, and brain tumors.

Although described with reference to the preferred embodiment of the present invention, those of ordinary skill in the art can variously modify or modify the present invention within the scope without departing from the spirit and scope of the present invention described in the claims below. It will be understood that this can be done.

10: pressure gauge
11: Ultra-small semiconductor pressure sensor using LC resonator
12: control unit 13: storage unit
17: communication unit 19: battery
20: user terminal 21: communication unit
22: control unit 23: storage unit
27: display unit

Claims (9)

The amount of displacement of the diaphragm of the micro-semiconductor pressure sensor is sensed to invasively measure the intracranial pressure at each location of the head, and an electric signal is generated by V=Ed according to the change in the capacitance of the LC resonator, and the brain pressure corresponding to the electric signal An invasive intracranial pressure meter having one or more miniature semiconductor pressure sensors with an LC resonator for measuring; and
It includes a user terminal that displays the intracranial pressure for each specific location in the cranial cavity of the one or more micro-semiconductor pressure sensors received from the invasive intracranial pressure sensor through wired/wireless communication,
The micro semiconductor pressure sensor having the LC resonator is
Board; a lower electrode provided on the substrate; It is formed on the lower electrode and includes, for example, a first metal line using gold (Au), a first stub, and a second metal line and a second stub using gold (Au) facing each other, and the an input/output port respectively connected to the first stub and the second stub; The amount of displacement of the diaphragm (thickness d of the upper and lower plates) is detected according to the pressure at each position in the cranial cavity of the head, and the electric signal is measured by V=Ed, and the resonance frequency (

) and a micro-pressure sensor equipped with an LC resonator of a bioinserable capacitance type for measuring the change in the brain pressure corresponding to the electrical signal; and an upper electrode provided on the pressure sensor,
The substrate uses a glass substrate or a flexible flexible substrate,
The flexible substrate is using a polyimide (polyimid) or polysilicon (polysilicon), invasive brain pressure measurement system. According to claim 1,
The micro semiconductor pressure sensor having the LC resonator is
After the cranial cavity of the head is opened by surgery, it is provided to invasively measure the intracranial pressure at one or more specific locations, and a micro-semiconductor pressure sensor equipped with an LC resonator of a bio-insertable capacitance type in the cranial cavity of the head is used. An invasive intracranial pressure measurement system that measures intracranial pressure. delete According to claim 1,
The invasive intracranial pressure meter
In order to open the cranial cavity of the head by surgery and invasively measure the intracranial pressure, a micro semiconductor pressure sensor 11 equipped with a bioinserable capacitive LC resonator at one or more specific locations of the brain within the cranial cavity Detects the amount of displacement of the diaphragm according to the intracranial pressure for each intracranial measurement location and measures the change in the capacitance of the LC resonator of the micro semiconductor pressure sensor. A micro semiconductor pressure sensor having at least one LC resonator for measuring;
a control unit connected to the miniature semiconductor pressure sensor 11 having the at least one LC resonator;
a storage unit connected to the control unit and storing the measured intracranial pressure information for each measurement position within the cranial cavity of the head; and
An invasive intracranial pressure measurement system comprising a battery. 5. The method of claim 4,
The invasive intracranial pressure measuring device is connected to the control unit, the invasive intracranial pressure measuring system further comprising a display unit for displaying the measured intracranial pressure information for each measurement position in the cranial cavity of the head. 5. The method of claim 4,
The invasive brain pressure measuring device is connected to the control unit, the invasive brain pressure measuring system further comprising a communication unit for transmitting the measured position and the measured brain pressure information for each position in the cranial cavity of the head to the user terminal through wired or wireless communication. delete According to claim 1,
The user terminal transmits the resonant frequency information of the LC resonator measured according to the change in capacitance of the LC resonator according to the displacement amount of the diaphragm of the micro semiconductor pressure sensor having the LC resonator for each measurement position in the cranial cavity of the head through wired/wireless communication ( a communication unit that receives via a USB cable, Bluetooth, Wi-Fi, etc.);
a control unit connected to the communication unit and controlling to be displayed on the display unit 27 by analyzing the intracranial pressure for each measurement position in the cranial cavity;
It is connected to the control unit, stores brain pressure measurement and analysis software, and an electrical signal measured by V=Ed measured according to the change in capacitance of the LC resonator of the micro semiconductor pressure sensor having the LC resonator (additionally, the LC resonator) of a resonant frequency) and a storage unit for storing brain pressure information corresponding thereto; and
Connected to the control unit, including a display unit for displaying the measured intracranial pressure for each position in the cranial cavity of the head of the micro-semiconductor pressure sensor using a living body implantable LC resonator, invasive intracranial pressure measurement system. 9. The method of claim 8,
In the case of an adult, the intracranial pressure (pseudotumor cerebri) of the normal range of the intracranial cerebrospinal fluid space of the head has a range of 0 to 15 mmHg, and the part of the intracranial pressure exceeding this range is measured by the intracranial pressure measurement and analysis software of the user terminal. An invasive brain pressure measurement system that displays the intracranial pressure by measurement location and visually visualizes it on a 2D brain map or a 3D brain map

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