CN211749564U - Portable noninvasive blood oxygen heart rate tester - Google Patents
Portable noninvasive blood oxygen heart rate tester Download PDFInfo
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Abstract
The utility model relates to the technical field of medical equipment, in particular to a portable noninvasive blood oxygen heart rate tester, which comprises a power circuit, a data processing module, a display module, a data transmission module, a driving module, a light source module, a sensor module, a signal conversion module and a filtering amplification module, wherein the power circuit is used for supplying power and outputting power to the tester, the data processing module is used for controlling the driving module and receiving signals of the filtering amplification module, the display module is used for displaying information, the data transmission module is used for outputting processed information, the driving module controls the operation of the light source module, the light source module is used for irradiating light sources at the detected part of a user, the sensor module is used for detecting the irradiated part, the signal conversion module is used for converting signal modes, the filtering amplification module is used for filtering and amplifying the signals output by the signal conversion module and outputting the signals to the data, the utility model has the advantages of portable, low-power consumption, test are accurate.
Description
Technical Field
The utility model relates to the technical field of medical equipment, the concrete field is a portable noninvasive blood oxygen heart rate tester.
Background
Most of blood oxygen and heart rate detection products in the market of medical instruments at present acquire signals based on a transmission type principle, and although a transmission type working mode has the advantages of high signal-to-noise ratio and difficulty in being influenced by movement interference noise, the transmission type working mode is large in general power consumption, only suitable for the tail end of a human body, and small in testable range. In addition, the heart rate and the blood oxygen of most products are not integrated together, and only a single function can be realized, namely, only the heart rate or only the blood oxygen can be measured, so that the use cost is increased.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a portable no wound blood oxygen heart rate tester to solve the problem that equipment function is single, and equipment cost is too high among the prior art.
In order to achieve the above object, the utility model provides a following technical scheme: a portable noninvasive blood oxygen heart rate tester comprises a power circuit, a data processing module, a display module, a data transmission module, a driving module, a light source module, a sensor module, a signal conversion module and a filtering amplification module, wherein the power circuit is used for supplying power to the tester for output, the data processing module is used for controlling the driving module and receiving signals processed by the filtering amplification module, the display module is used for receiving display information output by the data processing module and displaying the information, the data transmission module is used for outputting information output by the data processing module after processing, the driving module receives control signals of the data processing module and controls the operation of the light source module, the light source module is used for irradiating a light source of a detected part of a user, the sensor module is used for detecting the irradiated part of the light source module, the signal conversion module receives detection signals output by the sensor module and performs signal mode conversion, and the filtering and amplifying module is used for filtering and amplifying the signal output by the signal conversion module and outputting the signal to the data processing module.
Preferably, the data processing module is an MSP430F149 single-chip microcomputer.
Preferably, the power circuit comprises an external power port, a 4.5V battery, a diode I, a capacitor II, a capacitor III, a capacitor IV, a resistor I, a resistor II and a TPS76933 low-voltage difference power chip, wherein the diode II, a capacitor V and a capacitor VI are connected with the external power port, the positive end of the external power port is connected with the positive end of the diode II, the negative end of the diode II is connected with the P2.3 port of the MSP430F149 single chip microcomputer after being connected with the resistor I in series, the P2.3 port of the MSP430F149 single chip microcomputer is respectively connected with the capacitor IV in series and then grounded and the resistor II in series and then grounded, the positive end of the external power port is connected with the positive end of the capacitor V, the negative end of the capacitor V is grounded, the capacitor VI is connected with the capacitor V in parallel, the positive end of the battery is connected with the negative end of the diode II and the positive end of the diode I, the negative end of the battery is grounded, one end of, the other end of the second capacitor and the other end of the third capacitor are grounded respectively, the cathode end of the first diode is connected with the anode end of the first capacitor, the cathode end of the first capacitor is grounded, the cathode end of the first diode is connected with the input end of the TPS76933 low-voltage-difference power supply chip, and the output end of the TPS76933 low-voltage-difference power supply chip is used for outputting power supply to the inside of the tester.
Preferably, the first diode and the second diode are schottky diodes.
Preferably, the display module is an OLED liquid crystal display, and the data transmission module is a bluetooth module.
Preferably, the light source module and the sensor module are SFH7050 type integrated photoelectric sensors, a green LED, a red LED, an infrared LED and a large-area photodiode corresponding to the three LEDs are arranged in the SFH7050 type integrated photoelectric sensors, two ends of the photodiode are PC and PA output ends of the SFH7050 type integrated photoelectric sensors, and the PC and PA output ends are connected to the input end of the signal conversion module.
Preferably, the driving module comprises a first divider resistor, a second divider resistor, a third divider resistor, a first triode, a second triode and a third triode,
the divider resistor I is connected in series between the P1.1 end of the MSP430F149 singlechip and the base end of the triode I, the output power of the power circuit is sequentially connected with the green LED and the collector of the triode I, the emitter of the triode I is grounded,
the divider resistor II is connected in series between the P1.2 end of the MSP430F149 singlechip and the base end of the triode II, the output power supply of the power supply circuit is sequentially connected with the red LED and the collector electrode of the triode, the emitter electrode of the triode is grounded,
the divider resistor III is connected in series between the P1.3 end of the MSP430F149 singlechip and the base end of the triode III, the output power supply of the power supply circuit is sequentially connected with the infrared light LED and the collector electrode of the triode III, and the emitter electrode of the triode III is grounded.
Preferably, the signal conversion module comprises LF353 power operational amplifiers one by one, a resistor three and a resistor four, wherein a cathode of the LF353 power operational amplifier one is connected to a PC end of the SFH7050 integrated photoelectric sensor, an anode of the LF353 power operational amplifier one is connected to a PA end of the SFH7050 integrated photoelectric sensor, the resistor three is connected in series between the cathode and the output of the LF353 power operational amplifier one, and the anode of the LF353 power operational amplifier one is grounded after being connected in series with the resistor four.
Preferably, the filtering and amplifying module includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a seventh capacitor, an eighth capacitor, a ninth capacitor, an OPA349 operational amplifier, and a second LF353 power operational amplifier, an output terminal of the first LF353 power operational amplifier is sequentially connected in series with the fifth resistor and the sixth resistor and then connected to a positive terminal of the OPA349 operational amplifier, an output terminal of the OPA349 transport amplifier is sequentially connected in series with the eighth resistor and then grounded, a connection point between the seventh resistor and the eighth resistor is connected to a negative terminal of the OPA349 transport amplifier, a connection point between the fifth resistor and the sixth resistor and a connection point between the output terminal of the OPA349 transport amplifier are connected in series with a seventh capacitor, and a positive terminal of the OPA349 transport amplifier is,
the output end of the OPA349 transport amplifier is connected with the positive end of the second LF353 power operational amplifier after being connected with the ninth capacitor in series, the positive end of the second LF353 power operational amplifier is connected with the ninth resistor and then grounded, the negative end of the second LF353 power operational amplifier is connected with the tenth resistor in series and then grounded, a resistor eleven is connected between the negative end and the output end of the second LF353 power operational amplifier in series, and the output end of the second LF353 power operational amplifier is connected to the signal receiving end of the MSP430F149 single-chip microcomputer.
Compared with the prior art, the beneficial effects of the utility model are that: the reflection type blood oxygen heart rate detection method based on the low-power-consumption single chip microcomputer MSP430F149STM32 has the advantages of portability, low power consumption, accurate test and the like, is provided with a Bluetooth interface, and has a remote monitoring function;
(1) by adopting the SFH7050 reflective photoelectric sensor of OSRAM company, the body parts which can not be measured in a transmission mode can be measured, including the wrist, the earlobe, the toe, the finger and the like can be selected, and the operation is convenient.
(2) Adopt low-power consumption singlechip MSP430F149, peripheral circuit topology and parameter all adopt the low-power consumption design, set up three kinds of LEDs of green glow, ruddiness and infrared light simultaneously, can detect blood oxygen and heart rate signal respectively alone, reduce system's consumption, portable.
(3) And designing an active band-pass filter to filter interference signals in the sampling signals. The high-frequency filtering adopts an RC voltage-controlled voltage source mode to realize a second-order Butterworth low-pass filter with the cut-off frequency of 23Hz, and mainly filters high-frequency interference signals such as electricity and power frequency of the mining machine; low-frequency signals such as baseline drift and the like close to direct current are filtered by first-order active high-pass filtering, so that the test precision is improved.
(4) The test result can be wirelessly transmitted to the intelligent terminals with the Bluetooth function, such as a computer, a Bluetooth host, a mobile phone and the like, so that the system has the remote monitoring function.
Drawings
Fig. 1 is a block diagram of the system structure of the present invention;
FIG. 2 is a schematic diagram of a power circuit of the present invention;
fig. 3 is a schematic circuit diagram of the driving module, the light source module and the sensor module according to the present invention;
FIG. 4 is a green light (400Hz) driving waveform of the present invention;
FIG. 5 is a diagram of the red (800Hz) driving waveform of the present invention;
FIG. 6 is a diagram of an infrared light (1600Hz) driving waveform of the present invention;
fig. 7 is a schematic circuit diagram of the signal conversion module of the present invention;
fig. 8 is a schematic diagram of the second order butterworth low pass filter circuit of the RC voltage controlled voltage source of the present invention;
FIG. 9 is a schematic diagram of the in-phase amplifying and high-pass filtering circuit of the present invention;
FIG. 10 is a main flow chart of the heart rate and blood oxygen detection software according to the embodiment of the present invention;
fig. 11 is a schematic diagram of a heart rate testing principle according to an embodiment of the present invention;
fig. 12 is a flowchart of heart rate calculation software according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
Referring to fig. 1, the present invention provides a technical solution: a portable noninvasive blood oxygen heart rate tester comprises a power circuit, a data processing module, a display module, a data transmission module, a driving module, a light source module, a sensor module, a signal conversion module and a filtering amplification module, wherein the power circuit is used for supplying power to the tester for output, the data processing module is used for controlling the driving module and receiving signals processed by the filtering amplification module, the display module is used for receiving display information output by the data processing module and displaying the information, the data transmission module is used for outputting information output by the data processing module after processing, the driving module receives control signals of the data processing module and controls the operation of the light source module, the light source module is used for irradiating a light source of a detected part of a user, the sensor module is used for detecting the irradiated part of the light source module, the signal conversion module receives detection signals output by the sensor module and performs signal mode conversion, and the filtering and amplifying module is used for filtering and amplifying the signal output by the signal conversion module and outputting the signal to the data processing module.
The data processing module is an MSP430F149 single-chip microcomputer.
As shown in FIG. 2, the power circuit comprises an external power port P3, a 4.5V battery BT1, a diode D1, a capacitor C22, a capacitor C18, a capacitor C19, a capacitor C20, a resistor R28, a resistor R29, a TPS76933 low-voltage difference power chip U9, a diode D2, a capacitor C15 and a capacitor C16, wherein the external power port is connected with an external +5V power supply, the positive terminal of the external power port is connected with the positive terminal of a diode II, the negative terminal of the diode II is connected with the P2.3 port of an MSP430F149 singlechip after being connected with the diode D in series, the P2.3 port of the MSP430F149 singlechip is respectively connected with the four-stage ground of the capacitor and the two-stage ground after being connected with the capacitor, the positive terminal of the external power port is connected with the positive terminal of a capacitor V, the negative terminal of the capacitor V is connected with the ground, the capacitor V is connected with the capacitor V in parallel to the capacitor V, the positive terminal of the battery is connected with the positive terminal of the diode II, the other end of the second capacitor and the other end of the third capacitor are grounded respectively, the cathode end of the first diode is connected with the anode end of the first capacitor, the cathode end of the first capacitor is grounded, the cathode end of the first diode is connected with the input end of the TPS76933 low-voltage-difference power supply chip, and the output end of the TPS76933 low-voltage-difference power supply chip is used for outputting power supply to the inside of the tester.
The first diode and the second diode are Schottky diodes.
The display module is an OLED liquid crystal display, and the data transmission module is a Bluetooth module.
The Bluetooth module adopts an HC-05 high-performance master-slave integrated Bluetooth serial port module, can be matched with various intelligent terminals with Bluetooth functions, such as computers, Bluetooth hosts, mobile phones and the like, and is compatible with a 5V or 3.3V singlechip system.
As shown in fig. 3, the light source module and the sensor module are SFH7050 type integrated photoelectric sensors U2, a green LED, a red LED, an infrared LED, and a large-area photodiode corresponding to the three LEDs are disposed in the SFH7050 type integrated photoelectric sensors, two ends of the photodiode are PC and PA output ends of the SFH7050 type integrated photoelectric sensors, and the PC and PA output ends are connected to the input end of the signal conversion module.
The driving module comprises a first divider resistor R4, a second divider resistor R5, a third divider resistor R6, a first triode Q1, a second triode Q2 and a third triode Q3,
the divider resistor I is connected in series between the P1.1 end of the MSP430F149 singlechip and the base end of the triode I, the output power of the power circuit is sequentially connected with the green LED and the collector of the triode I, the emitter of the triode I is grounded,
the divider resistor II is connected in series between the P1.2 end of the MSP430F149 singlechip and the base end of the triode II, the output power supply of the power supply circuit is sequentially connected with the red LED and the collector electrode of the triode, the emitter electrode of the triode is grounded,
the divider resistor III is connected in series between the P1.3 end of the MSP430F149 singlechip and the base end of the triode III, the output power supply of the power supply circuit is sequentially connected with the infrared light LED and the collector electrode of the triode III, and the emitter electrode of the triode III is grounded.
As shown in fig. 7, the signal conversion module includes an LF353 power operational amplifier one U3A, a resistor three R8, a resistor four R7,
the negative end of the first LF353 power operational amplifier is connected with the PC end of the SFH7050 type integrated photoelectric sensor, the positive end of the first LF353 power operational amplifier is connected with the PA end of the SFH7050 type integrated photoelectric sensor, a third resistor is connected between the negative end and the output end of the first LF353 power operational amplifier in series, and the positive end of the first LF353 power operational amplifier is grounded after being connected with the fourth resistor in series.
As shown in fig. 8 and 9, the filtering and amplifying module includes a resistor five R9, a resistor six R10, a resistor seven R11, a resistor eight R12, a resistor nine R17, a resistor ten R19, a resistor eleven R18, a capacitor seven C6, a capacitor eight C5, a capacitor nine C11, an OPA349 operational amplifier U4, and an LF353 power operational amplifier two U3B, an output terminal of the LF353 power operational amplifier is sequentially connected in series with the resistor five, a positive terminal of the OPA349 operational amplifier is connected after the resistor six, an output terminal of the OPA349 transport amplifier is sequentially connected in series with the resistor eight and the resistor seven and then grounded, a connection point between the resistor seven and the resistor eight is connected with a negative terminal of the OPA349 transport amplifier, a capacitor seven is connected in series between the connection point between the resistor five and the resistor six and the output terminal of the OPA349 transport amplifier, a positive terminal of the OPA349 transport amplifier,
the output end of the OPA349 transport amplifier is connected with the positive end of the second LF353 power operational amplifier after being connected with the ninth capacitor in series, the positive end of the second LF353 power operational amplifier is connected with the ninth resistor and then grounded, the negative end of the second LF353 power operational amplifier is connected with the tenth resistor in series and then grounded, a resistor eleven is connected between the negative end and the output end of the second LF353 power operational amplifier in series, and the output end of the second LF353 power operational amplifier is connected to the signal receiving end of the MSP430F149 single-chip microcomputer.
According to the technical scheme, in the specific implementation process, the resistance value of a resistor, the capacity of a capacitor and the type of a triode in the circuit all adopt specific information shown in the attached drawing of the specification;
the blood oxygen heart rate detection system is shown in a structural block diagram in fig. 1, an MSP430F149 single chip microcomputer is used as a core, when a heart rate test is carried out, a green light (535nm) LED is driven to independently emit light, the light reflected by a tested part of a human body is received by an SFH7050 photoelectric sensor, the light is sent to an AD conversion module for sampling through circuits such as I/V conversion, filtering amplification and the like, and heart rate data can be obtained through a heart rate calculation algorithm; when the blood oxygen test is carried out, red light (660nm) and infrared (940nm) LEDs need to be driven alternately to emit light, collected signals are filtered and amplified respectively and then enter A/D conversion sampling, and blood oxygen data are obtained through a blood oxygen calculation algorithm. The test result can be displayed on the OLED and can be uploaded to the intelligent terminal through the Bluetooth module.
As shown in FIG. 2, the test instrument is normally powered by a battery, and can also be powered by 5V voltage input from the outside through a socket P1, as shown in FIG. 2. The battery voltage is monitored by connecting the voltage divider resistor to the input CA0 of the internal comparator of the MSP 430. When the voltage is normal, the CA1 terminal of the comparator is connected to the reference voltage 0.5Vcc inside the MSP 430. When the battery is dropped and the voltage at the point VA is dropped to 0.5Vcc, the battery voltage is:
that is, when the battery voltage drops to 3.6V, which causes the VA point voltage to drop to 0.5Vcc, an interrupt of the comparator a, called an under-voltage interrupt, occurs inside the MSP 430. In the under-voltage interruption subroutine, CA1 is connected to the reference voltage 0.25Vcc terminal, when the battery voltage continues to drop to VbatAt 3.6V, when the VA point voltage is 0.25Vcc, comparator a interrupt occurs again, and is called system power down interrupt. When the battery is taken down, the single chip microcomputer can work for a period of time due to the energy storage effect of the super capacitor. Therefore, the AD conversion is required to be started regularly to acquire the voltage of the VA point voltage monitoring battery during the heartbeat design. When the voltage of the battery is reduced to a certain limit, the system is subjected to power-down protection;
the TPS76933 is a low-dropout power supply chip and outputs 3.3V voltage as a system power supply. The Schottky diode D1 prevents the super capacitor C22 from discharging R28 and R29, and reverse leakage current is small and only reaches nA level.
The circuit design of the signal acquisition part of the photoelectric sensor is shown in fig. 3, the SFH7050 has the working principle of reflected photoplethysmography (PPG), is an integrated photoelectric sensor specially designed for blood oxygen and heart rate detection equipment, can measure body parts which cannot be measured in a transmission mode, is convenient to operate, and has better performance in wearable equipment than that in a transmission mode. The SFH7050 is provided with three LEDs-green (535nm), red (660nm) and infrared (940nm) and one large area photodiode. Measuring heart rate, and only driving green LED to emit light (the duty ratio of the driving waveform is 10% (as shown in FIG. 4), wherein the DC component of the photocurrent can be ignored, and only the AC component is useful; for measuring blood oxygen, red light and infrared LEDs are required to be alternately driven to emit light (the duty ratio of a driving waveform is 10 percent, as shown in fig. 5 and 6), the collected signals are filtered and amplified respectively and then enter the a/D conversion module together for sampling, where both the dc and ac components of the photocurrent are necessary, and, at the same time, because the photodiode of the SFH7050 has lower dark current ratio and strong anti-jamming capability, and the low capacitance and the quick response time of the photodiode ensure that the power consumption during working is very low, considering the influence of the sink current on a singlechip, before the PWM wave is input into the LED, the triode is added, so that the possible damage to the singlechip caused by overlarge current which is filled for a long time can be effectively prevented.
The PC end of the photosensor outputs a current, the typical value of the output current is microampere, and the current signal cannot be directly processed when the signal is filtered, amplified and the like, so that the output current signal needs to be converted into a voltage signal, the current is converted into a voltage, interference can be reduced, and accuracy is improved, and the circuit is shown in fig. 7;
by the formula Vsen＝IRfThe output voltage can be obtained, I is PC terminal current, typical value is microampere, feedback resistance Rf200k, so the output voltage VsenIs hundreds of millivolts, and is convenient for subsequent amplification and filtering.
The signals collected by the SFH7050 photoelectric sensor contain a large amount of interference components such as baseline drift, electromechanical interference, power frequency interference and the like. Wherein the baseline disturbance is caused by motion or respiration and is low frequency sinusoidal noise having a frequency less than 0.5 Hz; the electromechanical interference is caused by limb shaking, and the frequency and the amplitude can be changed in different environments; the frequency of the power frequency interference is 50Hz and harmonic components thereof, and the amplitude and the frequency of the power frequency interference are basically kept stable in a fixed environment; and also interference caused by ambient light changes. In order to improve the testing precision, an active band-pass filter is designed to filter interference signals in the sampling signals. The high-frequency filtering adopts an RC voltage-controlled voltage source mode to realize a second-order Butterworth low-pass filter with the cut-off frequency of 23Hz, and mainly filters high-frequency interference signals such as electricity and power frequency of the mining machine; low-frequency signals such as baseline drift and the like close to direct current are filtered by first-order active high-pass filtering.
The design adopts RC voltage-controlled voltage source mode to realize a second-order Butterworth low-pass filter, as shown in FIG. 8, the cut-off frequency is
Substituting data to obtain f H23 Hz. The pulse wave signal belongs to a bioelectricity signal, the frequency and the intensity of the signal are very small, and the acquired signal passes through a filter to filter out the interference of high-frequency components in the signal.
In the high-pass filter and amplifier circuit shown in FIG. 9, fLThe device is used for filtering extremely low frequency noise close to direct current, such as baseline interference, and outputting a low frequency signal containing frequency components (within 10Hz and more than 1Hz) of heart rate and blood oxygen saturation information. Meanwhile, the high-pass filtering and in-phase amplifying circuit in fig. 9 provides 10 times of voltage gain, the second-order butterworth low-pass filter in fig. 8 provides 2.5 times of voltage gain, the total voltage gain is 25 times, and hundred millivolts of voltage output by the voltage-current conversion circuit can be amplified to be about 2V, so that sampling is facilitated.
In the using process of the tester, the flow chart of the blood oxygen and heart rate detection software is shown in fig. 10, after the system is powered on, variables and peripheral equipment are initialized, and if a set key is pressed, parameters are required to be set and stored. Then judging whether the heart rate detection is the blood oxygen detection or the heart rate detection, wherein the heart rate detection drives a green light LED; blood oxygen detection drives the red and infrared LEDs. And then, collecting the filtered and amplified analog voltage, obtaining test results according to the heart rate and the blood oxygen algorithm respectively, displaying the test results on an OLED (organic light emitting diode), and uploading test data by Bluetooth if necessary.
Heart rate measurement principle-extraction of pulse wave feature points
The key of heart rate measurement is the extraction of pulse wave characteristic points, and based on the thought, the optical signal needs to be converted into an electric signal, and the pulse heart rate signal can be indirectly obtained by analyzing the frequency amplitude of the electric signal.
As shown in fig. 11, after denoising the acquired original signal and amplifying the signal, a pulse signal with low noise interference can be obtained. The heart rate detection is mainly the detection of the R wave, and if the time interval between two occurrences of the R wave is Δ t, the heart rate is determined as f ═ 1/Δ t.
For each pulse wave, although the peak value is different in size, the value of the peak value is always changed within a range, and the change amplitude is not more than 0.4 times of the maximum waveform, so that in one pulse period, the value of the peak value is larger than the maximum value point of all points in the surrounding neighborhood, namely the peak value point of the pulse wave, more than two continuous peak value points are found, and the heart rate can be calculated according to the sampling period and the number of sampling points. When the pulse wave is relatively stable, a time period greater than a time period can be taken, the numerical points in the time period are compared to find the maximum value and the minimum value, the difference between the maximum value and the minimum value and the alternating current component of the signal required by people are found, and the detection flow chart is shown in fig. 12.
Measurement of blood oxygen saturation
According to the relevant literature, the blood oxygen saturation SpO2The calibration formula of (a) is as follows:
SpO2＝AR+B (1)
two quantities in equation (1) need to be calibrated, one for R, and the other for A and B.
(1) Calibration of R
The value of R is determined by
Wherein
And
is the wavelength lambda1Red light at 660nm detects the ac and dc components of the light intensity, and
and
is the wavelength lambda2Infrared light at 940nm detects both ac and dc components of light intensity.
(2) Calibration of A and B values
Both the red light and the infrared light have a direct current component and an alternating current component, and a linear regression line is calculated from the R value and the blood oxygen saturation level based on the proportional relationship between the alternating current and the direct current in the signal, thereby obtaining a value of A, B. Although the differences of human bodies, such as gender, skin color, distribution of fingertip blood vessels and the like all influence the numerical value in the experimental result, the R value calculated by the formula (2) has no great difference.
In the specific calibration, a certain amount of sample data can be taken to calculate a linear regression line to obtain an average value of A and B, 10 sample data are adopted for calibration (specific data are omitted), and the obtained value of A is-27.582, and B is 118.583, namely, the blood oxygen saturation formula 2 can be rewritten as follows:
SpO2＝-27.582R+118.583 (3)
when the blood oxygen saturation index is tested, only the blood oxygen saturation index needs to be tested respectively
And
then, the R value is obtained by substituting the formula (2), and then the final blood oxygen saturation value can be obtained by the formula (3).
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (9)
1. The utility model provides a portable noninvasive blood oxygen heart rate tester which characterized in that: the tester comprises a power circuit, a data processing module, a display module, a data transmission module, a driving module, a light source module, a sensor module, a signal conversion module and a filtering amplification module, wherein the power circuit is used for supplying power to the tester for output, the data processing module is used for controlling the driving module and receiving signals processed by the filtering amplification module, the display module is used for receiving display information output by the data processing module and displaying information, the data transmission module is used for outputting information output by the data processing module after processing, the driving module is used for receiving control signals of the data processing module and controlling the operation of the light source module, the light source module is used for irradiating a light source at a detected part of a user, the sensor module is used for detecting the irradiated part of the light source module, the signal conversion module is used for receiving detection signals output by the sensor module and performing signal mode conversion, and the filtering and amplifying module is used for filtering and amplifying the signal output by the signal conversion module and outputting the signal to the data processing module.
2. The portable noninvasive blood oxygen heart rate tester of claim 1, characterized in that: the data processing module is an MSP430F149 single-chip microcomputer.
3. The portable noninvasive blood oxygen heart rate tester of claim 2, characterized in that: the power supply circuit comprises an external power supply port, a 4.5V battery, a first diode, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a first resistor, a second resistor and a TPS76933 low-voltage difference power supply chip, a second diode, a fifth capacitor and a sixth capacitor, wherein the external power supply port is connected with an external +5V power supply, the positive electrode of the external power supply port is connected with the positive electrode of the second diode, the negative electrode of the second diode is connected with the P2.3 port of the MSP430F149 single chip microcomputer after being connected with the first resistor in series, the P2.3 port of the MSP430F149 single chip microcomputer is respectively connected with the fourth capacitor and the second resistor in series and then grounded, the positive electrode of the external power supply port is connected with the positive electrode of the fifth capacitor, the negative electrode of the fifth capacitor is grounded, the sixth capacitor is connected with the fifth capacitor in parallel, the positive electrode of the battery is connected with the negative electrode of the second diode and the positive electrode of the first diode, the negative, the other end of the second capacitor and the other end of the third capacitor are grounded respectively, the cathode end of the first diode is connected with the anode end of the first capacitor, the cathode end of the first capacitor is grounded, the cathode end of the first diode is connected with the input end of the TPS76933 low-voltage-difference power supply chip, and the output end of the TPS76933 low-voltage-difference power supply chip is used for outputting power supply to the inside of the tester.
4. A portable noninvasive blood oxygen heart rate tester as set forth in claim 3, characterized in that: the first diode and the second diode are Schottky diodes.
5. The portable noninvasive blood oxygen heart rate tester of claim 1, characterized in that: the display module is an OLED liquid crystal display, and the data transmission module is a Bluetooth module.
6. The portable noninvasive blood oxygen heart rate tester of claim 2, characterized in that: the light source module and the sensor module are SFH7050 type integrated photoelectric sensors, green light LEDs, red light LEDs, infrared light LEDs and a large-area photodiode corresponding to the three LEDs are arranged in the SFH7050 type integrated photoelectric sensors, the two ends of the photodiode are PC and PA output ends of the SFH7050 type integrated photoelectric sensors, and the PC and PA output ends are connected with the input end of the signal conversion module.
7. The portable noninvasive blood oxygen heart rate tester of claim 6, characterized in that: the driving module comprises a first divider resistor, a second divider resistor, a third divider resistor, a first triode, a second triode and a third triode,
the divider resistor I is connected in series between the P1.1 end of the MSP430F149 singlechip and the base end of the triode I, the output power of the power circuit is sequentially connected with the green LED and the collector of the triode I, the emitter of the triode I is grounded,
the divider resistor II is connected in series between the P1.2 end of the MSP430F149 singlechip and the base end of the triode II, the output power supply of the power supply circuit is sequentially connected with the red LED and the collector electrode of the triode, the emitter electrode of the triode is grounded,
the divider resistor III is connected in series between the P1.3 end of the MSP430F149 singlechip and the base end of the triode III, the output power supply of the power supply circuit is sequentially connected with the infrared light LED and the collector electrode of the triode III, and the emitter electrode of the triode III is grounded.
8. The portable noninvasive blood oxygen heart rate tester of claim 6, characterized in that: the signal conversion module comprises LF353 power operational amplifiers one by one, a third resistor and a fourth resistor, wherein the cathode end of the LF353 power operational amplifier I is connected with the PC end of the SFH7050 type integrated photoelectric sensor, the anode end of the LF353 power operational amplifier I is connected with the PA end of the SFH7050 type integrated photoelectric sensor, the third resistor is connected between the cathode end and the output end of the LF353 power operational amplifier I in series, and the anode end of the LF353 power operational amplifier I is grounded after being connected with the fourth resistor in series.
9. The portable noninvasive blood oxygen heart rate tester of claim 8, wherein: the filtering and amplifying module comprises a resistor five, a resistor six, a resistor seven, a resistor eight, a resistor nine, a resistor ten, a resistor eleven, a capacitor seven, a capacitor eight, a capacitor nine, an OPA349 operational amplifier and an LF353 power operational amplifier II, wherein the output end of the LF353 power operational amplifier I is sequentially connected with the resistor five in series and the resistor six in series and then connected with the positive electrode end of the OPA349 operational amplifier, the output end of the OPA349 transport amplifier is sequentially connected with the resistor eight in series and then grounded, the connecting point between the resistor seven and the resistor eight is connected with the negative electrode end of the OPA349 transport amplifier, the connecting point between the resistor five and the resistor six is connected with the capacitor seven in series and the positive electrode end of the OPA349 transport amplifier is connected with the capacitor eight in series and then,
the output end of the OPA349 transport amplifier is connected with the positive end of the second LF353 power operational amplifier after being connected with the ninth capacitor in series, the positive end of the second LF353 power operational amplifier is connected with the ninth resistor and then grounded, the negative end of the second LF353 power operational amplifier is connected with the tenth resistor in series and then grounded, a resistor eleven is connected between the negative end and the output end of the second LF353 power operational amplifier in series, and the output end of the second LF353 power operational amplifier is connected to the signal receiving end of the MSP430F149 single-chip microcomputer.
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| CN201922437006.6U CN211749564U (en) | 2019-12-30 | 2019-12-30 | Portable noninvasive blood oxygen heart rate tester |
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| CN201922437006.6U CN211749564U (en) | 2019-12-30 | 2019-12-30 | Portable noninvasive blood oxygen heart rate tester |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111227811A (en) * | 2019-12-30 | 2020-06-05 | 浙江机电职业技术学院 | Portable noninvasive blood oxygen heart rate tester |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111227811A (en) * | 2019-12-30 | 2020-06-05 | 浙江机电职业技术学院 | Portable noninvasive blood oxygen heart rate tester |
| CN111227811B (en) * | 2019-12-30 | 2023-09-26 | 浙江机电职业技术学院 | Portable noninvasive blood oxygen heart rate tester |
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Effective date of registration: 20211126 Address after: 310017 room 606-4, building 3, Zhonghao international business center, No. 672, Xintang Road, Jianggan District, Hangzhou City, Zhejiang Province Patentee after: Hangzhou moju Technology Co.,Ltd. Address before: 310000 Binjiang District binwen Road, Hangzhou, Hangzhou, Zhejiang Patentee before: ZHEJIANG INSTITUTE OF MECHANICAL & ELECTRICAL ENGINEERING |
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Granted publication date: 20201027 |