CN104027108A - Novel optical electrocardio and pulse comprehensive detection device - Google Patents

Abstract

The invention discloses a novel optical electrocardiogram and pulse comprehensive detection device. The input signal comes from a pair of signal electrodes (1) arranged on the chest of the subject and a pulse sensing test head (5) arranged at the wrist vein. They are respectively used for ECG signal acquisition and pulse signal acquisition; one channel is connected to signal electrode (1) and electro-optic modulator (4) to output ECG measurement results; the other channel is connected to optical fiber sensing test head (5) and optical fiber coupler (3 ), output the measurement result of the pulse wave waveform diagram. Compared with the prior art, the optical electrocardiogram and pulse comprehensive measurement device proposed by the present invention can simultaneously detect human electrocardiogram and pulse signals; the structure is simple, the stability is good, and the requirements for the electromagnetic environment are low, which is conducive to wide popularization.

Description

A new type of optical ECG and pulse comprehensive detection device

technical field

The invention relates to a human body electrocardiogram and pulse signal detection technology, in particular to a device for detecting human body electrocardiogram and pulse signal realized by an optical method.

Background technique

With the improvement of people's material living standards, the incidence and prevalence of cardiovascular diseases caused by unreasonable diet and living habits are showing a rising trend. Today, with the high development of modern science and technology, more and more advanced science and technology are applied to the development of medical devices. The important physiological information of the human body has gradually realized the accurate real-time dynamic monitoring.

The human body contains many physiological parameters that reflect the physiological health status, such as body temperature, blood pressure, pulse, ECG, etc. Among them, ECG and pulse are the two most important and basic physiological parameters that characterize the health of the human cardiovascular system. Electrocardiogram is an important basis for doctors to evaluate cardiac function, and it has a wide range of significance in clinical diagnosis. The change of pulse wave pressure and waveform characteristics is an important basis for evaluating the physiological and pathological state of the human cardiovascular system. Physiological and pathological information can be extracted from TCM pulse pulse or Western medical cardiovascular examination. The combination of ECG signal and pulse signal can provide physiological information reflecting the health status of the cardiovascular system. It brings great significance to the monitoring and prevention of cardiovascular diseases.

In the prior art, the electrocardiographic signal monitoring device based on the principle of photoelectric effect is used in the measurement of electrocardiographic signals. It is a device with small size, light weight, high precision, stable performance, safety and reliability, and has great application potential. . In terms of pulse signal monitoring, the important application of fiber optic sensing technology in the field of intelligent pulse diagnosis and detection is adopted, that is, based on the principle of fiber grating sensitivity to strain, the collection of pulse beating signals is realized by packaging the fiber grating to a certain extent.

Foreign countries have done a lot of research on the measurement of physiological signals such as human ECG and pulse.

1. The US Invention No. US20130102871A1 and the title of the invention "SYSTEM AND METHOD FORWIRELESS GENERRATION OF STANDARD ECG LEADS AND AN ECG SENSINGUNIT THEREFOR" disclose a wireless ECG acquisition device, which adopts a standard 12-lead measurement method. The collected ECG signals are transmitted to the wireless signal transceiver system. The user does not have to be restricted by the ECG machine and can move freely. However, the system receives and receives wireless signals and is affected by distance and environments such as buildings. Due to the limitation of the power of the device itself, it will bring difficulties to signal reception. At the same time, wireless signals are also susceptible to interference from electromagnetic signals.

At present, the domestic methods for ECG signal detection mainly adopt electrical measurement methods, for example: Chinese Invention Number: CN103156592A, Invention Name: "Wireless Optical ECG Detector" discloses a wireless optical ECG detector. The electrocardiogram detector penetrates the blood and blood vessel walls through the red laser diode to form a certain weak reflection. The blood in the blood vessels is pulsating under the action of the heart. The blood absorbs the light signal to a certain extent, and the change of the blood volume affects the change of the light intensity of the signal. The reflected light is converted into a series of periodically changing electrical signals after being received by the photodetector, and the heartbeat frequency can be displayed after the electrical signals are processed. The invention can effectively detect the heart rate. The measurement device has a simple structure, but the signal light is easily affected by the absorption of human tissue, the presence of surrounding stray light and electromagnetic interference, and the measurement accuracy is low. At the same time, the device cannot obtain an accurate electrocardiogram.

In terms of joint measurement of ECG pulse, Chinese Invention No.: CN102413761A, Invention Name: "Biological Sensing Device" discloses a biosensor, the surface of the sensor is provided with electrodes for collecting ECG signals, and a finger is placed on the electrodes to detect ECG signals . At the same time, the light emitter installed in the recess or hole on the electrode surface irradiates detection light to the finger, and receives the reflected light of the detection light from the finger through the light receiver installed in the recess or hole on the electrode surface, thereby A photoelectric pulse wave signal corresponding to the received reflected light is acquired. This scheme is simple in structure, but the electrocardiographic signal of the finger is very weak, which brings great difficulties to the acquisition of the signal, and the detection accuracy is relatively low.

Chinese Invention No.: CN101006918, Invention Title: "Comprehensive Detection Device for Blood Pressure, Pulse and ECG" discloses a monitoring device that can simultaneously measure ECG and pulse. The device attaches measuring electrodes to different positions around the human heart respectively, and outputs electrocardiographic signals through two electrodes. The pressure bridge sensor is placed at the radial artery of the human body to collect pulse signals. The measurement method has high sensitivity and is easy to use. However, placing the sensor directly on the human skin for a long time is likely to cause skin discomfort. At the same time, active electronic devices are prone to aging, and the sensitivity will gradually decrease with time.

Although the above invention can measure human ECG and pulse physiological signals, there are inherent limitations in the signal acquisition process. For example, electrical measurement methods are used in some complex electromagnetic environments such as nuclear magnetic resonance and B-ultrasound detection, etc. Active electronic devices are susceptible to electromagnetic interference, resulting in low precision of measurement results, poor accuracy, and difficult signal processing. Therefore, the present invention proposes a comprehensive ECG pulse detection device with good stability, high measurement accuracy and simple structure.

Contents of the invention

In order to overcome the above-mentioned problems in the prior art, the present invention proposes a novel optical ECG and pulse comprehensive detection device, which uses electro-optic crystals, fiber gratings, etc. as sensor materials, and can simultaneously detect human ECG and pulse signals.

The present invention proposes a novel optical ECG and pulse comprehensive detection device. The input signal of the system comes from a pair of signal electrodes 1 arranged on the chest of the subject and a pulse sensing test head 5 arranged at the wrist vein, respectively. It is used for ECG signal collection and pulse signal collection; the system includes signal electrodes 1, lead wires 2, fiber optic couplers 3, electro-optic modulators 4, fiber optic sensing test heads 5, broadband light sources 6, Spectrum demodulator 7, photoelectric detection and amplification and filtering circuit 8, data acquisition card 9, computer 10 and display output unit 11; broadband light source 6 driven by a regulated power supply outputs two broadband light sources, and transmits optical signals through optical fibers; wherein:

In the one way connecting the signal electrode 1 and the electro-optic modulator 4: the electrical signal in the signal electrode 1 is transmitted to the optical fiber coupler 3, the photoelectric detection and amplification filter circuit 8 is transmitted to the computer 10, and then to the display output unit 11 for display and output of the measurement results ECG measurement results;

And in the other road that connects optical fiber sensing test head 5 and fiber optic coupler 3: the measurement grating in the pulse signal measurement sensing head 5 is subjected to pulse pressure to produce strain; The wavelength of the reflected light signal drifts; the reflected light signal is coupled into the transmission fiber 12 through the fiber coupler 3 . After being received by the spectrum demodulator 7, the received wavelength drift signal can be reversely calculated according to the amount of change in the wavelength of the reflected light to obtain the pressure on the contact and convert it into a real-time change in pulse pressure according to the mechanical relationship; the data is processed by the data acquisition card 9 Gather and transmit to computer 10, then to display output unit 11 to carry out the measurement result display output pulse wave waveform diagram measurement result;

The optical fiber sensing test head 5 includes a protective housing 55, a test head base 51, a lever shaft 50 and a shaft bearing 52 arranged on the base, a limiter 53, and a lever shaft 50 which is arranged at one end and probed through the base through hole. Out of the silicone probe 54; measuring grating 56, optical fiber fixing device 57, reference grating 58 are arranged on the other end of the lever shaft 50, and the free end of the reference grating 58 is connected with an optical fiber jumper 59, the optical fiber jumper 59 from the top of the protective housing 55 through-hole protruding.

The present invention also proposes a fiber optic sensing test head for a novel optical ECG and pulse comprehensive detection device, including a protective housing 55, a test head base 51, a lever shaft 50 and a shaft bearing 52 arranged on the base, The limiter 53 and the silicone probe 54 that is arranged at one end of the lever shaft 50 and protrudes from the through hole of the base; the measuring grating 56, the optical fiber fixing device 57, and the reference grating 58 are arranged at the other end of the lever shaft 50, and the free end of the reference grating 58 is connected An optical fiber jumper 59 is provided, and the optical fiber jumper 59 protrudes from the through hole at the top of the protective housing 55 .

Compared with the prior art, the optical electrocardiogram and pulse comprehensive measurement device proposed by the present invention can simultaneously detect human body electrocardiogram and pulse signals. Simple structure, good stability, low requirements on electromagnetic environment, conducive to widespread promotion

Description of drawings

Fig. 1 is the structural representation of novel optical ECG of the present invention, pulse comprehensive detection system;

Fig. 2 is the structural diagram of photoelectric modulator;

Fig. 3 is the structural diagram of fiber grating pulse sensing probe;

The reference signs in the figure represent respectively: 1. Signal electrode; 2. Lead wire; 3. Optical fiber coupler; 4. Electro-optic modulator; 5. Optical fiber sensing test head; ;8. Photoelectric detection and amplification filter circuit; 9. Data acquisition card; 10. Computer; 11. Display output unit; 12. Transmission optical fiber; 13. Lithium niobate crystal substrate; 14. Ground electrode 15. Optical waveguide; 50 , lever shaft; 51, test head base; 52, lever shaft bracket; 53, limiter; 54, silicone contact; 55, protective shell; 56, measuring grating; 57, optical fiber fixing device; 59. Optical fiber jumper.

Detailed ways

The ECG signal is the bioelectrical signal of the heart itself, which is transmitted to the surface of the body through the conductive tissue and conductive fluid around the heart. The electrical signals on the surface of various parts of the body change regularly during each cardiac cycle. Electrocardiogram signals can be detected by placing measuring electrodes on specific parts of the human body surface. Pulse detection is based on the principle of traditional Chinese medicine pulse diagnosis, which measures the pulse beating signals of the three pulse positions of Cun, Guan and Chi in the radial artery of the human body. The principle of electrocardiographic signal detection involved in the present invention is based on the linear electro-optic effect in the electro-optic effect. The electrical signal is converted into an optical signal output by an electro-optic modulator. The existing materials suitable for electro-optic modulators are mainly lithium niobate (LiNbO3), gallium arsenide (GaAs) and polymers. The optical waveguides in gallium arsenide and polymer modulators are ridged waveguides, and their loss when connected to single-mode fibers is much larger than that of lithium niobate crystals and single-mode fibers. The long-term stability of polymer modulators is not yet ideal. In contrast, the lithium niobate modulator has small chirp, low transmission loss, and can realize bandwidth modulation. The biggest advantage lies in its high electro-optic coefficient.

The ECG signal measurement involved in the present invention is based on the linear electro-optic effect (Pockels effect) in the electro-optic effect, that is, the effect that the refractive index of the optical waveguide is proportional to the change of the applied electric field. The optical signal in the waveguide produces a phase change under the action of an external electric field, and the output optical signals of the two waveguides are coherently superimposed and converted into a change in light intensity. The optical signal received by the photodetector is converted into an electrical signal, and then the final ECG signal is obtained through steps such as signal amplification, signal filtering, and signal separation.

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings.

As shown in Figure 1, it is a schematic structural diagram of the ECG and pulse comprehensive detection system of the present invention. A pair of signal electrodes 1 arranged on the subject's chest and a pulse sensing test head 5 arranged at the wrist vein are respectively used for ECG signal acquisition and pulse signal acquisition; and the signal electrode 1 is connected to the electro-optic modulator 4; The sensor test head 5 is connected with the fiber coupler 3; the broadband light source 6 driven by a regulated power supply outputs two broadband light sources with a center wavelength of 1550nm and a spectral line width of 1525-1625nm, and transmits optical signals to the electro-optical modulator 4 through optical fibers And pulse sensing test head 5; Wherein connect signal electrode 1 and in the one way of electro-optic modulator 4: the electric signal in the signal electrode 1 is transmitted to optical fiber coupler 3, photoelectric detection and amplification filter circuit 8 are transmitted to computer (10), Go to the display output unit 11 to carry out the measurement results and display the output electrocardiographic measurement results; and in another way connecting the optical fiber sensing test head 5 and the fiber coupler 3: the fiber grating in the pulse signal measurement sensing head 5 is subjected to pulse pressure to produce strain , the wavelength of the optical signal passing through the fiber grating has a certain drift; the reflected optical signal is coupled into the transmission optical fiber 12 through the optical fiber coupler 3 . After being received by the spectrum demodulator 7, the received wavelength shift signal is collected by the data acquisition card 9 and transmitted to the computer 10, and then to the display output unit 11 for measurement results to display and output pulse measurement results.

The central wavelength of the broadband light source 6 is 1550nm, and the spectral line width is 1525-1625nm; the lead wire 2 is now widely used as a standard twelve-lead lead. In the present invention, the signal electrode 1 in the figure can be placed in different measurement positions according to actual measurement requirements to obtain ECG signals; the pulse signal measurement sensor head 5 realizes the detection of pulse signals based on the principle that the fiber grating is sensitive to strain.

In addition, the photoelectric detection device can be placed far away from the human body to ensure that the human body measurement area is not interfered by electromagnetic signals. The electrical signal output by the photoelectric detection device is stored by the computer 10 after being amplified and filtered.

The finally detected ECG pulse signal is processed and analyzed by the computer 10, and finally the pulse waveform is displayed and output.

As shown in FIG. 2 , it is a structural diagram of the photoelectric modulator 3 . Wherein: the optical signal is transmitted to the optical waveguide 15 composed of the LiNbO3 crystal substrate 13, and the optical waveguide 15 receives the optical signal transmitted by the broadband light source; the two measuring electrodes 1 are attached to human skin. The electrical excitation signals released by the human body are respectively transmitted to the signal electrode 1 by the lead wire 2. The signal electrode 1 has different potentials and forms a potential difference with the ground electrode 14 respectively. The formed electric field performs electro-optical modulation on the optical signal passing through the waveguide, and then outputs two The column light is coupled into the transmission fiber through the fiber coupler. According to the principle of the electro-optic effect, the optical signal passing through the electro-optic crystal will be modulated by an external electric field.

Various materials and structures can be used for the photoelectric modulator 3 . Introduced in Fig. 2 is a typical LiNbO3 crystal substrate 13 optical waveguide phase modulation. The LiNbO3 substrate that propagates in the x-cut y-direction is selected, the electrodes are located on both sides of the optical waveguide, and the horizontal direction produces modulation on the waveguide. This structure is only one type of photoelectric modulator.

FIG. 3 is a specific structural diagram of the optical fiber sensing test head 5 . As a fiber grating pulse sensor probe, it includes a protective housing 55, a test head base 51, a lever shaft 50 and a shaft bearing 52, a stopper 53, and a through hole arranged at one end of the lever shaft 50 and from the base. The silicone contact 54 protruding; the measuring grating 56, the optical fiber fixing device 57, and the reference grating 58 are arranged at the other end of the lever shaft 50, and the free end of the reference grating 58 is connected with an optical fiber jumper 59, and the optical fiber jumper 59 is connected from the protective shell The through hole of 55 tops sticks out. Because the pulse wave of the human body is very weak, it increases the difficulty of the measurement process. Therefore, the present invention performs sensitivity-increasing packaging on the fiber grating based on the leverage principle. If the distance between the connecting end of the grating and the silicone probe is k times the length of the lever shaft, the force on the grating is amplified or reduced by k times according to the principle of the lever, which increases the sensitivity of the sensor. The value range of k is between 1 and 10

The optical fiber sensing test head 5 packaged according to the above structure is placed at the pulse position of the human body, and the beating of the pulse drives the movement of the sensing probe. Finally, it causes the deformation of the fiber grating. The deformation changes the wavelength reflection condition of the grating, and the wavelength of the reflected light signal received by the grating demodulator drifts. According to the variation of the reflected light wavelength, the pressure on the contact can be calculated in reverse. According to the mechanical relationship, it is converted into real-time changes in pulse pressure. The output signal is amplified, filtered, separated, etc., and the pulse wave waveform is obtained. This is also an optical method proposed by the present invention to detect the pulse signal. The main principle is: based on the fiber grating to accurately measure the pulse signal, it is an intelligent detection method for traditional Chinese medicine pulse diagnosis. The invention adopts the fiber grating as the pulse signal measuring device. A fiber grating is a structure written in an optical fiber, and the refractive index of the fiber core changes periodically. The reflection wavelength of a fiber grating is related to two factors: the effective refractive index of the fiber core and the period of the grating. These two factors are affected by temperature and strain. Therefore, in order to eliminate the interference of temperature on the measurement process, it is necessary to carry out temperature compensation packaging on the fiber grating. The invention designs a reference grating which is only affected by temperature and not acted by stress to realize temperature compensation.

Although the present invention has been described above in conjunction with the drawings, the present invention is not limited to the above-mentioned specific embodiments, and the above-mentioned specific embodiments are only illustrative, rather than restrictive. Under the inspiration, many modifications can be made without departing from the gist of the present invention, and these all belong to the protection of the present invention.

Claims (6)

1. A new type of optical ECG and pulse comprehensive detection device. The input signal of the system comes from a pair of signal electrodes (1) arranged on the chest of the subject and a pulse sensor test head (5) arranged at the wrist vein. , which are respectively used for ECG signal acquisition and pulse signal acquisition; it is characterized in that the system includes signal electrodes (1), lead wires (2), fiber optic couplers (3), electro-optical modulation device (4), optical fiber sensing test head (5), broadband light source (6), spectrum demodulator (7), photoelectric detection and amplification filter circuit (8), data acquisition card (9), computer (10) and The display output unit (11); the broadband light source (6) driven by a regulated power supply outputs two broadband light sources, and transmits optical signals through optical fibers; wherein: One way connects the signal electrode (1) and the electro-optic modulator (4): the electrical signal in the signal electrode (1) is transmitted to the optical fiber coupler (3), the photoelectric detection and amplification filter circuit (8) is transmitted to the computer (10), and then Go to the display output unit (11) to carry out the measurement result display and output the ECG measurement result; The other is connected to the optical fiber sensing test head (5) and the fiber optic coupler (3): the measuring grating in the pulse signal measuring sensing head (5) is strained by the pulse pressure; this strain changes the wavelength reflection condition of the grating, and the grating demodulator The wavelength of the received reflected light signal drifts; the reflected light signal is coupled into the transmission fiber (12) through the fiber coupler (3); after being received by the spectrum demodulator (7), the received wavelength shift signal is based on the reflected light The change in wavelength is back-calculated to the pressure on the contact and converted into real-time changes in pulse pressure according to the mechanical relationship; the data is collected by the data acquisition card (9) and transmitted to the computer (10), and then to the display output unit (11) for further processing. The measurement results display the measurement results of the output pulse wave waveform diagram; The optical fiber sensing test head (5) includes a protective shell (55), a test head base (51), a lever rotating shaft (50) and a rotating shaft bearing (52), a stopper (53) and a rotating shaft bearing (52) arranged on the base. The silicone probe (54) which is arranged at one end of the lever shaft (50) and protrudes from the through hole of the base; the measuring grating (56), the optical fiber fixing device (57), and the reference grating (58) are arranged at the other end of the lever shaft (50), And a fiber jumper (59) is connected to the free end of the reference grating (58), and the fiber jumper (59) protrudes from a through hole at the top of the protective housing (55). 2. novel optical electrocardiograph as claimed in claim 1, pulse comprehensive detection device is characterized in that, the distance of the connecting end of described measurement grating (56) and lever rotating shaft (50) and the silica gel probe (54) is the lever rotating shaft K times the length, the force on the grating is enlarged or reduced by k times according to the principle of leverage. 3. The novel optical ECG and pulse comprehensive detection device according to claim 2, characterized in that, the value range of k is between 1 and 10. 4. An optical fiber sensing test head is characterized in that it comprises a protective housing 55, a test head base (51) and a lever rotating shaft (50) and a rotating shaft bearing (52) and a stopper (53) arranged on the base. ) and the silicone probe (54) that is arranged on one end of the lever shaft (50) and protrudes from the through hole of the base; the measurement grating (56), the optical fiber fixing device (57), and the reference grating (58) are arranged on the other end of the lever shaft (50). One end, and the free end of the reference grating (58) is connected with an optical fiber jumper (59), and the optical fiber jumper (59) protrudes from a through hole at the top of the protective housing (55). 5. optical fiber sensing test head as claimed in claim 4, is characterized in that, the distance of the connecting end of described measuring grating (56) and lever rotating shaft (50) and the silica gel probe (54) is k times of lever rotating shaft length , the force on the grating is amplified or reduced by k times according to the principle of leverage. 6 . The optical fiber sensing test head according to claim 5 , wherein the value range of k is between 1 and 10.