KR20220066643A - Device to drive blood glucose level using electromagnetic scheme - Google Patents

Abstract

According to one embodiment, provided is a device for driving an electromagnetic wave sensor, which includes: a signal generation unit generating a digital signal having a signal level of at least one of a plurality of frequency bands different from a signal level of another frequency band; a converter which converts the generated digital signal into an OFDM signal, provides the same to a resonator assembly of an electromagnetic wave sensor, and converts a signal returned from the resonator assembly back into the digital signal; a peak detection unit detecting a peak from the returned digital signal; and a processor which determines a blood glucose level of a subject based on the peak.

Description

Electromagnetic wave type blood glucose sensor driving device {DEVICE TO DRIVE BLOOD GLUCOSE LEVEL USING ELECTROMAGNETIC SCHEME}

Hereinafter, a technology for driving a blood glucose sensor using an electromagnetic wave method is provided.

Recently, the number of people suffering from so-called adult diseases such as diabetes, hyperlipidemia, and blood-converted persons is increasing due to the westernization of eating habits. A simple way to determine the severity of these adult diseases is to measure biocomponents in the blood. Bio-component measurement can determine the amount of various components in the blood, such as blood sugar, anemia, and blood clotting, so that the level of a specific component is in the normal or abnormal region, making it easy for the general public to determine whether there is an abnormality without going to the hospital. The advantage is that it is possible.

One of the easy methods for measuring biocomponents is to quantitatively analyze the output signal using electrochemical or photometric methods after injecting blood collected from the fingertip into a test strip. It is suitable for people who do not have

However, since it is painful during blood sampling, a technique for measuring blood sugar in a manner in which there is no blood collection or blood collection is minimized is required.

1 illustrates a frequency scan method.
2 illustrates a digital frequency scan method according to an embodiment.
3 illustrates orthogonal frequency division modulation (OFDM) according to an embodiment.
4 illustrates resonance characteristics of an electromagnetic wave sensor according to an embodiment.
5 illustrates a frequency characteristic inside a living body according to an embodiment.
6 illustrates a distorted sensor output.
7 illustrates a frequency characteristic of a signal adjusted by an equalizer according to an embodiment.
8 illustrates a sensor output from which a frequency characteristic inside a living body is removed, according to an exemplary embodiment.
9 is a block diagram illustrating a system configuration according to an embodiment.
10 is a diagram illustrating a symbol according to an embodiment.
11 is a diagram illustrating a configuration that further includes a band pass filter according to an embodiment.
12 is a diagram illustrating a hardware configuration of an electromagnetic wave sensor according to an embodiment.

Specific structural or functional descriptions of the embodiments are disclosed for purposes of illustration only, and may be changed and implemented in various forms. Accordingly, the actual implementation form is not limited to the specific embodiments disclosed, and the scope of the present specification includes changes, equivalents, or substitutes included in the technical idea described in the embodiments.

Terms such as first or second may be used to describe various elements, but these terms should be interpreted only for the purpose of distinguishing one element from another. For example, a first component may be termed a second component, and similarly, a second component may also be termed a first component.

When a component is referred to as being “connected to” another component, it may be directly connected or connected to the other component, but it should be understood that another component may exist in between.

The singular expression includes the plural expression unless the context clearly dictates otherwise. In this specification, terms such as "comprise" or "have" are intended to designate that the described feature, number, step, operation, component, part, or combination thereof exists, and includes one or more other features or numbers, It should be understood that the possibility of the presence or addition of steps, operations, components, parts or combinations thereof is not precluded in advance.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present specification. does not

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. In the description with reference to the accompanying drawings, the same components are assigned the same reference numerals regardless of the reference numerals, and overlapping descriptions thereof will be omitted.

1 illustrates a frequency scan method.

Since the conventional scan method using the PLL measures the response to one frequency at a time, it takes a lot of time to scan the entire band, and there is a problem in that environmental changes over time directly affect the measurement results. In addition, it is difficult to generate a signal of the same magnitude at all frequencies.

2 illustrates a digital frequency scan method according to an embodiment.

The digital scan method is a technology that measures the sensor response by simultaneously generating all frequency components of the band to be measured. Since all frequency components are generated at once, the measurement time can be dramatically shortened, and the influence of noise or environmental changes over time can be minimized. In addition, since the frequency is generated digitally, it is possible to generate a signal having a constant magnitude at all frequencies.

When frequency signals adjacent to each other are simultaneously generated, each frequency component interferes with each other. To solve this, an Orthogonal Frequency Division Modulation (OFDM) technique is used. OFDM is a technique for modulating a transmission signal using hundreds or more orthogonal narrowband sub-carriers. Using this, since subcarriers do not affect each other (orthogonal), the same result as generating each frequency signal can be obtained.

3 illustrates orthogonal frequency division modulation (OFDM) according to an embodiment.

Referring to FIG. 3 , it can be seen that each subcarrier exhibits the maximum amplitude at its own frequency, and the amplitude becomes 0 at the frequencies of other subcarriers and does not affect other subcarriers.

In the OFDM technique, a Fast Fourier Transform (FFT) or an Inverse Fast Fourier Transform (IFFT) may be used to generate signals without mutual interference. FFT is a method of converting a frequency domain signal into a time domain signal, and IFFT is a method of converting a time domain signal into a frequency domain signal, and is generally used to generate OFDM signals without mutual interference.

4 illustrates resonance characteristics of an electromagnetic wave sensor according to an embodiment. 5 illustrates a frequency characteristic inside a living body according to an embodiment. 6 illustrates a distorted sensor output.

In order to accurately read the resonance characteristics of the sensor, the input signal of the sensor must have the same magnitude for all frequencies. However, as shown in FIGS. 4 to 6 , even when a signal of the same size is generated, the frequency characteristics inside the living body are added, so that the input signal of the sensor does not have the same size for all frequencies, and the sensor output signal is distorted. have. Since the inside of the living body has its own frequency response characteristic, if it is not removed, the measurement result is distorted due to the addition of the resonance characteristic of the sensor during measurement. The figure below shows a waveform in which the sensor output is distorted by adding the frequency characteristics inside the living body.

7 illustrates a frequency characteristic of a signal adjusted by an equalizer according to an embodiment. 8 illustrates a sensor output from which a frequency characteristic inside a living body is removed, according to an embodiment.

In order to solve this problem, the present invention includes an equalizer for compensating for frequency characteristics inside a living body. The equalizer sets the size of each frequency component differently so that the frequency characteristics inside the living body can be identified in advance and corrected. 7 and 8 , it can be seen that the equalizer removes the distortion of the sensor output by correcting the frequency characteristic inside the living body.

The equalizer according to an embodiment may obtain the correction curve as follows. First, 1) Measure the blood glucose in the collection with a blood glucose measurement device through blood collection. 2) Measure the sensor output for the signal output that is not equalized. 3) By obtaining the difference between the measured sensor output waveform and the resonance characteristic waveform of the sensor corresponding to the measured blood sugar, the frequency characteristic inside the living body can be obtained. 4) By inverting the obtained internal frequency characteristic and multiplying it by a predefined coefficient, the correction curve of the equalizer can be obtained.

9 is a block diagram illustrating a system configuration according to an embodiment.

The DATA ARRAY block creates a data array with a constant size in the band to be measured. For example, if you want to measure in units of 10 kHz in the frequency range of 20 MHz, 20 MHz/10 kHz = 2000 data arrays are required. FFT can be most efficiently implemented with 2^N data arrays, so we use 2048 data arrays with 2^N larger than 2000. Among the 2048 data arrays, 2000 required data is set to 1, and the rest is set to 0. As a result, the values of the data array are filled with 1s in the middle and 0s on the left and right. The actual set data array value is D(0)=0, D(1)=0, D(2)=0, ... D(21)=0, D(22)=0, D(23)= 0, D(24)=1, D(25)=1, D(26)=1, ... D(2022)=1, D(2023)=1, D(2024)=0, D(2025) )=0, D(2026)=0, D(2027)=0, ..., D(2045)=0, D(2046)=0, D(2047)=0. Here, D(1024) is a DC (frequency 0 Hz) component, D(0) to D(1023) is a frequency -10.24 MHz to -0.01 MHz, D(1025) to (D(2047) is a frequency 0.01 MHz to 10.23 corresponds to MHz.

The equalizer block generates the input signal of the IFFT block by reflecting the frequency characteristics inside the living body to the uniform signal generated from the DATA ARRAY.

The IFFT block converts an input frequency domain signal into a time domain signal. This signal includes each of the frequency components set above, and is output to a real part (I) and an imaginary part (Q).

In the IF Up Converter, the real part and the imaginary part generated by IFFT are multiplied by a sine wave with the same frequency and a phase difference of 90 degrees to generate an IF signal. At this time, the frequency of the multiplied sine wave becomes the center frequency of the IF signal. If the frequency of the sine wave is set to 120MHz, the generated IF signal becomes a signal having a left and right 10MHz band centered at 120MHz.

The IF signal generated above contains several harmonic components in addition to the 120MHz signal. Use FILTER to remove it. Filter can use Low Pass Filter or Band Pass Filter, and set Cut Off Frequency to effectively remove harmonic components.

Finally, the real and imaginary parts of the generated IF signal are added to form a single signal and output through the DAC.

The transmitting IF signal output through the DAC goes through the RF Up Converter and is converted into a signal in the RF band where the sensor operates. In this case, the center frequency of the RF signal is determined by the sum of the IF frequency and the local PLL frequency of the RF Up Converter. If the transmitting IF frequency is 120MHz and the local PLL frequency is 2.4GHz, the center frequency of the RF band becomes 0.12GHz+2.4GHz=2.52GHz.

The generated RF signal is input to the sensor, and a signal having a different magnitude of each frequency component is output according to the resonance characteristic of the sensor.

The signal output from the sensor is again converted into an IF signal on the receiving side through the RF Down Converter. In this system configuration, since the RF Down Converter uses the same Local PLL frequency as the RF Up Converter, the receiving IF signal has the same frequency band as the transmitting IF signal. That is, if the transmitting-side IF frequency is 120MHz, the transmitting-side IF frequency is also 120MHz. However, the IF frequency of the transmitter and the IF frequency of the receiver may be designed differently. In this case, the local PLL frequencies of the RF Up Converter and the RF Down Converter may be set differently.

The receiving IF signal is converted into a digital signal through the ADC and is input to the digital block.

The first input stage of DIGITAL BLOCK is IF Down Converter. The IF Down Converter divides the input IF signal into a real part and an imaginary part and converts it into a base band signal. As with the IF Up Converter, two sine waves with the same frequency and 90 degrees out of phase are used here. At this time, the frequency of the sine wave uses the same frequency as the IF signal on the receiving side.

Harmonic components are added to the signal through the IF Down Converter, and a Low Pass Filter is used to remove it.

The base band signal thus created is converted into a frequency domain signal through FFT.

The frequency domain signal generated through FFT is input to the PEAK SEARCH block for calculating the blood glucose by finding the resonance frequency.

The PEAK SEARCH block determines the resonant frequency by finding the peak point of the received frequency domain signal. The received signal is a signal in which the value of each frequency component is changed according to the resonance characteristic of the sensor as it passes through the sensor. The received signal has a maximum or minimum data value at the resonant frequency of the sensor according to the configuration of the sensor. The PEAK SEARCH block finds the frequency corresponding to the maximum or minimum point in the received signal and determines it as the resonant frequency of the sensor.

When the resonant frequency of the sensor is determined, the blood glucose value corresponding to the determined frequency is calculated in the GLUCOSE LEVEL MAPPING block. The GLUCOSE LEVEL MAPPING block has a resonance frequency mapping table according to blood sugar values, and when a resonance frequency is input, a blood sugar value corresponding to the resonance frequency is found in the table and output. The GLUCOSE LEVEL MAPPING block can additionally have a separate table or calculation formula for compensation according to the surrounding environment such as temperature.

10 is a diagram illustrating a symbol according to an embodiment.

There may be a time difference between the signal output from the digital block and the input signal, which may cause a problem in signal detection. In this case, the synchronization of the received signal can be found by adding a TIMING block. To this end, when outputting a transmission signal, a CP (Cyclic Prefix) that first copies the last predetermined section of the transmission signal and outputs it first is inserted. Thereafter, when the receiving end compares the repeated sections of the received signal to find the CP, the starting point of the actual data can be found. The CP structure is as follows. When CP is used, the data transmission time increases by the length of the CP section, but signal detection is facilitated by the receiving side.

11 is a diagram illustrating a configuration that further includes a band pass filter according to an embodiment.

In addition, by adding BPF (Band Pass Filter) before and after RF Up Converter and RF Down Converter, noise and harmonic components can be removed to improve performance.

12 is a diagram illustrating a hardware configuration of an electromagnetic wave sensor according to an embodiment.

The hardware configuration of the present invention is shown in FIG. 12 . The FPGA is responsible for generating and detecting the IF signal. Algorithm processing such as equalizer is also performed in FPGA.

The DAC converts the digital signal generated in the FPGA into an analog signal and outputs it, and the ADC converts the input analog signal into a digital signal and delivers it to the FPGA.

MIXER converts an IF frequency to an RF frequency or converts an RF frequency to an IF frequency.

BPF is located before and after MIXER to remove harmonic components.

The PLL generates the reference frequency of the MIXER.

AMP amplifies the signal in each part.

VGA keeps the magnitude of the input signal at a constant level to prevent the ADC from saturating. In VGA, the gain is changed according to the control of the FPGA.

The COUPLER separates the sensor's input and output signals. The TX PATH signal is input to the sensor through the COUPLER, and the signal reflected from the sensor is transmitted to the RX PATH through the COUPLER.

As the time passes after the sensor is inserted into the body, the resonant frequency of the sensor gradually shifts, which may deviate from the initial frequency detection range. To compensate for this, the detection range can be adjusted by controlling the frequency of the MIXER's REFERENCE PLL.

The embodiments described above may be implemented by a hardware component, a software component, and/or a combination of a hardware component and a software component. For example, the apparatus, methods and components described in the embodiments may include, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate (FPGA) array), a programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions, may be implemented using a general purpose computer or special purpose computer. The processing device may execute an operating system (OS) and a software application running on the operating system. A processing device may also access, store, manipulate, process, and generate data in response to execution of the software. For convenience of understanding, although one processing device is sometimes described as being used, one of ordinary skill in the art will recognize that the processing device includes a plurality of processing elements and/or a plurality of types of processing elements. It can be seen that can include For example, the processing device may include a plurality of processors or one processor and one controller. Other processing configurations are also possible, such as parallel processors.

Software may comprise a computer program, code, instructions, or a combination of one or more thereof, which configures a processing device to operate as desired or is independently or collectively processed You can command the device. The software and/or data may be any kind of machine, component, physical device, virtual equipment, computer storage medium or apparatus, to be interpreted by or to provide instructions or data to the processing device. , or may be permanently or temporarily embody in a transmitted signal wave. The software may be distributed over networked computer systems and stored or executed in a distributed manner. Software and data may be stored in a computer-readable recording medium.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination, and the program instructions recorded on the medium are specially designed and configured for the embodiment, or are known and available to those skilled in the art of computer software. may be Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic such as floppy disks. - includes magneto-optical media, and hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like.

The hardware devices described above may be configured to operate as one or a plurality of software modules to perform the operations of the embodiments, and vice versa.

As described above, although the embodiments have been described with reference to the limited drawings, a person skilled in the art may apply various technical modifications and variations based thereon. For example, the described techniques are performed in an order different from the described method, and/or the described components of the system, structure, apparatus, circuit, etc. are combined or combined in a different form than the described method, or other components Or substituted or substituted by equivalents may achieve an appropriate result.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

Claims (4)

A device for driving an electromagnetic wave sensor, comprising:
a signal generator generating a digital signal having a signal level of at least one of the plurality of frequency bands different from a signal level of another frequency band;
a converter that converts the generated digital signal into an OFDM signal, provides it to a resonator assembly of an electromagnetic wave sensor, and converts a signal returned from the resonator assembly back into a digital signal;
a peak detector for detecting a peak from the returned digital signal; and
A processor that determines a blood sugar level of a subject based on the peak
A device for driving an electromagnetic wave sensor comprising a.
According to claim 1,
The signal generator,
equalizing the signal level of the digital signal based on the frequency response characteristic of the subject,
A device that drives an electromagnetic wave sensor.
According to claim 1,
The signal generator,
equalizing the signal level of the digital signal based on the frequency response characteristic of the electromagnetic wave sensor,
A device that drives an electromagnetic wave sensor.
According to claim 1,
A bandpass filter that removes harmonic components from the OFDM signal
Device for driving the electromagnetic wave sensor further comprising.

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