CN104367309B - A kind of reflective wrist cardiotachometer and reflective wrist method for measuring heart rate - Google Patents
A kind of reflective wrist cardiotachometer and reflective wrist method for measuring heart rate Download PDFInfo
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- CN104367309B CN104367309B CN201410609129.2A CN201410609129A CN104367309B CN 104367309 B CN104367309 B CN 104367309B CN 201410609129 A CN201410609129 A CN 201410609129A CN 104367309 B CN104367309 B CN 104367309B
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- 230000003287 optical effect Effects 0.000 claims abstract description 23
- 238000001514 detection method Methods 0.000 claims abstract description 9
- 230000010247 heart contraction Effects 0.000 claims abstract description 7
- 238000012360 testing method Methods 0.000 claims description 9
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- 102100024061 Integrator complex subunit 1 Human genes 0.000 claims description 3
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- 238000005516 engineering process Methods 0.000 description 2
- 238000007689 inspection Methods 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 238000002106 pulse oximetry Methods 0.000 description 2
- 230000003595 spectral effect Effects 0.000 description 2
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/02—Detecting, measuring or recording for evaluating the cardiovascular system, e.g. pulse, heart rate, blood pressure or blood flow
- A61B5/024—Measuring pulse rate or heart rate
- A61B5/0245—Measuring pulse rate or heart rate by using sensing means generating electric signals, i.e. ECG signals
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/0059—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
- A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
- A61B5/6813—Specially adapted to be attached to a specific body part
- A61B5/6824—Arm or wrist
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Abstract
The invention discloses a kind of reflective wrist cardiotachometer, including microprocessor, charactron, LED flashing circuit, light emitting diode, light source driving circuit, reflection optical receiving circuit, low pass amplifying circuit, high-pass filtering circuit and voltage comparator circuit；Described microprocessor is STC89C52 chip；The heart rate value that described charactron detects for display；Reflection optical receiving circuit, low pass amplifying circuit, high-pass filtering circuit and voltage comparator circuit are sequentially connected, the external interrupt interface of the output termination microprocessor of voltage comparator circuit；External interrupt occurs the most corresponding heart beating to occur each time；Microprocessor number of times based on the external interrupt in default T time calculates heart rate value, and is shown on charactron by calculated heart rate value；When external interrupt occurs each time, microprocessor control the LED in LED flashing circuit and flash once.The present invention is easy to implement, and accuracy of detection is high.
Description
Technical field
The present invention relates to a kind of reflective wrist cardiotachometer and reflective wrist method for measuring heart rate.
Background technology
Heart rate, is used for describing the technical term of cardiac cycle, refers to the heart number of times beated per minute.Heart rate
Not only reflect the health status of cardiovascular system of human body, also reflect human-body biological motion severity, in motion
The heart rate monitoring to exercise intensity, is domestic and international sports medical science, athletic physiology, theories of sport training, Yi Jiyun
The problem that aroused in interest boundary of science is interested.
Recent domestic is devoted to develop noncontacting proximity sensor, and the key character of this kind of sensor is measurement portion
Dividing and do not invade body, do not result in body wound, system sensor degree of integration is more and more higher.The most at home
On market most this type of pulse blood oxygen instrument or finger cot type, the transmittance type pulse oximetry instrument of employing, this kind of dress
Put and cannot be played measurement easily act on by concrete position limitation in actual measurement, and the measured exists
It is difficult to carry out other work during measurement, hence in so that transmittance type pulse oximetry instrument need to improve simultaneously.
According to the difference of the sensor sample mode that heart rate monitoring system is used, transmission-type and reflection can be divided into
Formula two kinds.
According to Lambert-Beer law, utilizing light to pass through the decay after one section of known paths L can be quantitative
Description extinction material concentration C and absorptance μ a:
Wherein, ε is specific absorbance (extinction coefficient, cm-1mM-1)；C is extinction thing
Matter concentration (mM)；I0 and I respectively incident illumination and the light intensity detected；μ a is absorptance, i.e. photon exists
Absorbed probability in unit path (cm-1).
Organized according to diffusion transport theory or in turbid medium, at the r of position, general photon during time t is expanded
Scattered equation is:
In formula, (r t) is (r, t) optical density at point, μ to φaFor absorptance, (r, t) is light source amount to S, and c is light
Sub-gait of march (constant).D is diffusion coefficient, is from macroscopically reflect biological tissue's diffusive property one
Basic characterisitic parameter, unit m or cm；For photon transport, diffusion coefficient is equal to following formula:
Wherein, μ a is absorptance；μ s be scattering coefficient (cm-1), g be the meansigma methods of angle of scattering cosine,
It is referred to as scattering anisotropy factor；(1-g) μ s item is referred to as effective scattering coefficients or effective homogeneity scattering is
Number.Formula (3) is general heat and the diffusion equation of quality transmission, is by describing uncharged particle motion
Equation of radiative transfer be derived by, therefore be applicable to light propagation strong scattering medium.
According to photon diffusion equation (2) and time resolved spectroscopy technology, Patterson et al. is according to reality
Boundary condition solved light pulse encourage after photon flow distribution formula, mainly include transmission-type and reflection
Two kinds of situations of formula.Wherein, the formula of transmitted light intensity is:
In formula, z0 is equal to [(1-g) μ s]-1, and ρ is the distance in cylindrical coordinates between light source and detector；D is
Transmitting terminal is to the distance of receiving terminal.
The formula of the reflective light intensity simultaneously obtained:
In formula, z0 is equal to [(1-g) μ s]-1, and ρ is the distance in cylindrical coordinates between light source and detector.
Formula (4) and formula (5) are sought ln and respectively to t derivation, obtain following two formulas:
During elapsed time long enough, the above two formula left sides are all by close-μ ac, it may be assumed that
Therefore, can show that reflective light intensity is directly proportional to absorptance by above-mentioned derivation.Thus, we are by reason
Opinion derivation demonstrates: in biological tissues, utilizes reflection detection formula detection light intensity, represents the change of light intensity with W
Rate, obtain light intensity change formula: W=-μac
I.e. when specific absorbance one timing, in bio-tissue, reflective light intensity is directly proportional to extinction material concentration,
Cleaning Principle as the reflective heart rate sensor of principle is use light sensitive diode detection reflective light intensity,
Connect and present the cycle variation law of extinction material concentration in tremulous pulse, thus reach to detect the purpose of heart rate wave frequency.
Existing cardiotachometer structure is complicated, and accuracy is low, therefore, it is necessary to design a kind of novel reflective
Wrist cardiotachometer and reflective wrist method for measuring heart rate.
Summary of the invention
The technical problem to be solved is to provide a kind of reflective wrist cardiotachometer and the reflective wrist heart
Rate measuring method, this reflective wrist cardiotachometer and reflective wrist method for measuring heart rate are easy to implement, detection essence
Degree height.
The technical solution of invention is as follows:
A kind of reflective wrist cardiotachometer, including microprocessor, charactron, LED flashing circuit, light-emitting diodes
Pipe, light source driving circuit, reflection optical receiving circuit, low pass amplifying circuit, high-pass filtering circuit and voltage ratio are relatively
Circuit；
Described microprocessor is STC89C52 chip；
Described charactron and LED flashing circuit all connect with microprocessor, and described charactron is used for showing inspection
The heart rate value measured；
Reflection optical receiving circuit, low pass amplifying circuit, high-pass filtering circuit and voltage comparator circuit are sequentially connected,
The external interrupt interface of the output termination microprocessor of voltage comparator circuit；
Light source driving circuit is used for driven for emitting lights LED lighting；
Reflection optical receiving circuit is for detecting the lumination of light emitting diode light intensity through the reflection light of the wrist of detected person
Signal；
External interrupt occurs the most corresponding heart beating to occur each time；Microprocessor is based on outside in default T time
The number of times that portion interrupts calculates heart rate value, and is shown on charactron by calculated heart rate value；
When external interrupt occurs each time, microprocessor control the LED in LED flashing circuit and flash once.
Light emitting diode model is DLED-660/905-CSL-2, the light-intensity test element in reflection optical receiving circuit
Using light sensitive diode model is PIN-4.0CSL.
Reflection optical receiving circuit and low pass amplifying circuit are as follows: the negative pole of light sensitive diode meets positive source VCC,
The positive pole of light sensitive diode connects the input in the same direction of the first operational amplifier；The outfan of the first operational amplifier and
Being parallel with electric capacity C1 and resistance R5 between reverse input end, the outfan of the first operational amplifier is that low pass is amplified
The outfan of circuit；First operational amplifier is LM324 type operational amplifier；First operational amplifier is the most defeated
Enter end and reverse input end respectively by resistance R3 and R4 ground connection；Resistance R3, R4 and R5 be respectively 56K Ω,
4.7K Ω and 1M Ω；Electric capacity C1 is 47nF.
The structure of high-pass filtering circuit is: signal input part connects the input in the same direction of the second operational amplifier through electric capacity C2
End；The input in the same direction of the second operational amplifier is through resistance R6 ground connection；The reverse input of the second operational amplifier
End and the outfan short circuit of the second operational amplifier, the reverse input end of the second operational amplifier is high-pass filtering
The outfan of circuit；Second operational amplifier is LM324 type operational amplifier；R6 is 1M Ω, and C2 is 1uF.
Voltage comparator circuit is as follows: the signal that input in the same direction is voltage comparator circuit of the 3rd operational amplifier is defeated
Enter end, i.e. connect the outfan of high-pass filtering circuit；The reverse input end of the 3rd operational amplifier connects through resistance R7
VCC, the reverse input end of the 3rd operational amplifier is also through resistance R8 ground connection；The outfan of voltage comparator circuit
And being connected to resistance R9 between the outfan of the 3rd operational amplifier, the outfan of voltage comparator circuit is through resistance R10
Ground connection；The external interrupt interface INT1 of the output termination microprocessor of voltage comparator circuit；
3rd operational amplifier use LM324 amplifier chip, R7, R8, R9 and R10 be respectively 3.3K
Ω, 2.7K Ω, 3.9K Ω and 2.4K Ω；
T is 15 seconds.VCC is 5V.
A kind of reflective wrist method for measuring heart rate, uses aforesaid reflective wrist cardiotachometer to human body wrist portion
Position measures to obtain heart rate value, first, opens light source driving circuit driven for emitting lights LED lighting and irradiates
At human body wrist position；
Reflection optical receiving circuit detection lumination of light emitting diode is through the light intensity letter of the reflection light of the wrist of detected person
Number；Light intensity signal sequentially passes through after low pass amplifying circuit, high-pass filtering circuit and voltage comparator circuit process and enters
The external interrupt port of microprocessor；
There is the most corresponding heart beating in external interrupt each time；Microprocessor is based in the outside in default T time
Disconnected number of times calculates heart rate value, and is shown on charactron by calculated heart rate value；
When external interrupt occurs each time, microprocessor control the LED in LED flashing circuit and flash once.
T is 15 seconds.
Beneficial effect:
The reflective wrist cardiotachometer of the present invention and reflective wrist method for measuring heart rate, use the luminescence two of specific wavelength
Pole pipe is placed near human body wrist superficial arterial for launching near-infrared fibre-optical, and photodiode is used for collecting process
The reflection light with human heart rate's ripple signal of arterial blood modulation；Low-pass filter circuit is used to be used for filtering
The influence of noise that heart rate ripple signal is caused by the high-frequency signals such as 50Hz power frequency, high-pass filtering circuit is used for filtering ring
The impact of some DC quantity such as border light.Finally, the heart rate ripple signal with near sinusoidal signal is more electric through voltage ratio
Road forms the square-wave signal that can be used for triggering external interrupt INIT1；Reliability is high.By single-chip microcomputer by timing
Device, external interrupt counting etc. realize the statistics of beats in a period of time, and are converted into heart rate and show
On charactron, represent beating of human heart with the flicker of LED.The present invention uses conventional components and parts and monolithic
Mechanism makes test system, low cost, it is easy to implement, it addition, test shows, the test accuracy rate of the present invention is high.
Accompanying drawing explanation
Fig. 1 is the population structure block diagram of reflective wrist cardiotachometer.
Fig. 2 is LED driving circuit figure.
Fig. 3 is light sensitive diode operating circuit and the circuit theory diagrams of low-pass filtering amplifying circuit.
Fig. 4 is the schematic diagram of high-pass filtering circuit.
Fig. 5 is the circuit theory diagrams of comparator.
Detailed description of the invention
Below with reference to the drawings and specific embodiments, the present invention is described in further details:
As Figure 1-5, a kind of reflective wrist cardiotachometer, including microprocessor, charactron, LED flicker
Circuit, light emitting diode, light source driving circuit, reflection optical receiving circuit, low pass amplifying circuit, high-pass filtering
Circuit and voltage comparator circuit；
Described microprocessor is STC89C52 chip；
Described charactron and LED flashing circuit all connect with microprocessor, and described charactron is used for showing inspection
The heart rate value measured；
Reflection optical receiving circuit, low pass amplifying circuit, high-pass filtering circuit and voltage comparator circuit are sequentially connected,
The external interrupt interface of the output termination microprocessor of voltage comparator circuit；
Light source driving circuit is used for driven for emitting lights LED lighting；
Reflection optical receiving circuit is for detecting the lumination of light emitting diode light intensity through the reflection light of the wrist of detected person
Signal；
External interrupt occurs the most corresponding heart beating to occur each time；Microprocessor is based on outside in default T time
The number of times that portion interrupts calculates heart rate value, and is shown on charactron by calculated heart rate value；
When external interrupt occurs each time, microprocessor control the LED in LED flashing circuit and flash once.
Light emitting diode model is DLED-660/905-CSL-2, the light-intensity test element in reflection optical receiving circuit
Using light sensitive diode model is PIN-4.0CSL.
Reflection optical receiving circuit and low pass amplifying circuit are as follows: the negative pole of light sensitive diode meets positive source VCC,
The positive pole of light sensitive diode connects the input in the same direction of the first operational amplifier；The outfan of the first operational amplifier and
Being parallel with electric capacity C1 and resistance R5 between reverse input end, the outfan of the first operational amplifier is that low pass is amplified
The outfan of circuit；First operational amplifier is LM324 type operational amplifier；First operational amplifier is the most defeated
Enter end and reverse input end respectively by resistance R3 and R4 ground connection；Resistance R3, R4 and R5 be respectively 56K Ω,
4.7K Ω and 1M Ω；Electric capacity C1 is 47nF.
The structure of high-pass filtering circuit is: signal input part connects the input in the same direction of the second operational amplifier through electric capacity C2
End；The input in the same direction of the second operational amplifier is through resistance R6 ground connection；The reverse input of the second operational amplifier
End and the outfan short circuit of the second operational amplifier, the reverse input end of the second operational amplifier is high-pass filtering
The outfan of circuit；Second operational amplifier is LM324 type operational amplifier；R6 is 1M Ω, and C2 is 1uF.
Voltage comparator circuit is as follows: the signal that input in the same direction is voltage comparator circuit of the 3rd operational amplifier is defeated
Enter end, i.e. connect the outfan of high-pass filtering circuit；The reverse input end of the 3rd operational amplifier connects through resistance R7
VCC, the reverse input end of the 3rd operational amplifier is also through resistance R8 ground connection；The outfan of voltage comparator circuit
And being connected to resistance R9 between the outfan of the 3rd operational amplifier, the outfan of voltage comparator circuit is through resistance R10
Ground connection；The external interrupt interface INT1 of the output termination microprocessor of voltage comparator circuit；
3rd operational amplifier use LM324 amplifier chip, R7, R8, R9 and R10 be respectively 3.3K
Ω, 2.7K Ω, 3.9K Ω and 2.4K Ω；
T is 15 seconds.VCC is 5V.
A kind of reflective wrist method for measuring heart rate, uses aforesaid reflective wrist cardiotachometer to human body wrist portion
Position measures to obtain heart rate value, first, opens light source driving circuit driven for emitting lights LED lighting and irradiates
At human body wrist position；
Reflection optical receiving circuit detection lumination of light emitting diode is through the light intensity letter of the reflection light of the wrist of detected person
Number；Light intensity signal sequentially passes through after low pass amplifying circuit, high-pass filtering circuit and voltage comparator circuit process and enters
The external interrupt port of microprocessor；
There is the most corresponding heart beating in external interrupt each time；Microprocessor is based in the outside in default T time
Disconnected number of times calculates heart rate value, and is shown on charactron by calculated heart rate value；
When external interrupt occurs each time, microprocessor control the LED in LED flashing circuit and flash once.
T is 15 seconds.
Embodiment 1:
Overall construction drawing such as Fig. 1 of reflective wrist cardiotachometer.
(1) hardware components
Research shows, impacts measurement structure to reduce tissue absorbing light photograph, and selecting wavelength is should
Note making blood tissues that the absorptance of light intensity is more than the absorption to light intensity of the non-blood tissue, and main in blood
Extinction material is hemoglobin (Hb) and Oxygenated blood Lactoferrin (HbO2), and the two concentration can be along with the receipts of heart
Contracting and relaxation cycle change.Fig. 5 is the specific absorbance contrast of Hb and HbO2 in blood, in order to ensure to reflect light
By force according to incident intensity linear change, the wavelength that Hb with HbO2 specific absorbance is identical should be chosen as far as possible, can
To be seen to be at about 805nm, but the specific absorbance near this point is relatively big, so with the variable gradient of wavelength
When luminous tube exists individual difference, it is unfavorable for that debugging is replaced, such that it is able to consider to choose 805～950nm wave bands
Light emitting diode.This example is selected 905nm as detection wavelength.
The light emitting diode model that the design uses is DLED-660/905-CSL-2, and light sensitive diode model is
PIN-4.0CSL。
A. light emitting diode performance parameter
B. light sensitive diode performance parameter
The spectral bandwidth of the light emitting diode of this model is 50nm, and peak wavelength is 905nm, is considering cost
In the case of, spectral wavelength unicity is preferable, therefore selects the light emitting diode of this model, table 1 (a) to provide
The performance parameter of light emitting diode, the near infrared light of 900～1000nm is had higher sensitive by PIN-4.0CSL
Degree, table 1 (b) gives the critical performance parameters of light sensitive diode, and it is near 900nm peak wavelength
Sensitivity has reached 0.55A/W, meets application requirement.
Fig. 2 is the drive circuit of light emitting diode, owing to the source of stable pressure quality used is fine, and voltage stabilization, no
Consider to use Zener diode to carry out voltage stabilizing.Forward bias current in view of light emitting diode is less than 2.4V,
Resistor voltage divider circuit is used to carry out dividing potential drop.
The optical signal that light emitting diode is launched is after arterial blood is modulated, with the transmitting light quilt of heart rate ripple signal
Light sensitive diode near light emitting diode receives, and has converted optical signals into the signal of telecommunication.
The initial heart rate signal of telecommunication is the faintest, the most only tens millivolts, and along with 50Hz Hz noise,
Low-frequency d signal etc. disturbs, and will obtain the good heart rate signal being similar to sine wave, needs heart rate electricity
Signal is filtered, amplify and the various analog circuitry processes such as noise reduction.
By circuit as shown in Figure 3, the signal of telecommunication is converted to voltage signal, utilizes the voltage that LM324 builds
Amplifier carries out initial low-pass filtering and amplification to voltage signal.
With the high-pass filtering circuit of LM324 operational amplifier composition suggestion, filtering environmental light, light emitting diode etc.
The direct current signal that ambient lighting brings, retains heart rate ripple signal.As shown in Figure 4, filter for the active high pass of single order
Ripple device, is completed by single order RC filter circuit, can filter low-frequency noise, eliminates the interference to heart rate signal.
Heart rate ripple is added up by the trailing edge counting mode using external interrupt 1, then need being similar to sine
The heart rate signal of ripple is modulated into the square-wave signal of standard for triggering interruption counting.Still use LM324 type computing
Amplifying device builds comparator circuit, as shown in Figure 5.
(2) software section
Software section main completion timing device timing, counter technique, numeral method heart rate, LED light on and off are dodged
Bright luminaire body function.After Single Chip Microcomputer (SCM) system powers on, system initialization, automatically into duty.
Timer interruption and external interrupt 1 cooperative cooperating achieve the accurate timing to the time and the meter of heart rate signal
Number function.
In the program of timer interruption, when 50ms is timed to, when Timer Register overflows, enter in intervalometer
Disconnected service routine, intervalometer is deposited with 50ms timing initial value of reloading, and time adds one, it is judged that 50ms is fixed
Time number of times, if time is equal to 300, then 15 seconds arrive, calculate x, y, z (the individual position of heart rate value, ten
Position and hundred) show on the charactron, jump out mastery routine, perform mastery routine；If being not equal to 300, jump out
Interrupt routine, performs mastery routine.
In the interrupt service routine flow process of external interrupt 1, when heart rate signal trailing edge comes interim, trigger outside entering
1 interrupt service routine is interrupted in portion, lights LED, of short duration time delay, adds one, in exiting extinguishing LED, hbr
Disconnected program, performs mastery routine.
Test result
Measure human heart rate under practical situation with heart rate meter systems, and contrast with heart rate correct value, test
Result is as shown in table 2.
Table 2 cardiotachometer test result
Above-mentioned data are carried out error analysis: error is 1.33%, absolutely prove that the accuracy rate of the present invention is high.
Claims (6)
1. a reflective wrist cardiotachometer, it is characterised in that include microprocessor, charactron, LED flashing circuit, light emitting diode, light source driving circuit, reflection optical receiving circuit, low pass amplifying circuit, high-pass filtering circuit and voltage comparator circuit；
Described microprocessor is STC89C52 chip；
Described charactron and LED flashing circuit all connect with microprocessor, the heart rate value that described charactron detects for display；
Reflection optical receiving circuit, low pass amplifying circuit, high-pass filtering circuit and voltage comparator circuit are sequentially connected, the external interrupt interface of the output termination microprocessor of voltage comparator circuit；
Light source driving circuit is used for driven for emitting lights LED lighting；
Reflection optical receiving circuit is for detecting the lumination of light emitting diode light intensity signal through the reflection light of the wrist of detected person；
External interrupt occurs the most corresponding heart beating to occur each time；Microprocessor number of times based on the external interrupt in default T time calculates heart rate value, and is shown on charactron by calculated heart rate value；
When external interrupt occurs each time, microprocessor control the LED in LED flashing circuit and flash once；
Light emitting diode model is DLED-660/905-CSL-2, and the light-intensity test element in reflection optical receiving circuit uses light sensitive diode model to be PIN-4.0CSL；
Reflection optical receiving circuit and low pass amplifying circuit are as follows: the negative pole of light sensitive diode meets positive source VCC, and the positive pole of light sensitive diode connects the input in the same direction of the first operational amplifier；Being parallel with electric capacity C1 and resistance R5 between outfan and the reverse input end of the first operational amplifier, the outfan of the first operational amplifier is the outfan of low pass amplifying circuit；First operational amplifier is LM324 type operational amplifier；First operational amplifier input in the same direction and reverse input end are respectively by resistance R3 and R4 ground connection；Resistance R3, R4 and R5 are respectively 56K Ω, 4.7K Ω and 1M Ω；Electric capacity C1 is 47nF.
Reflective wrist cardiotachometer the most according to claim 1, it is characterised in that the structure of high-pass filtering circuit is: signal input part connects the input in the same direction of the second operational amplifier through electric capacity C2；The input in the same direction of the second operational amplifier is through resistance R6 ground connection；The reverse input end of the second operational amplifier and the outfan short circuit of the second operational amplifier, the reverse input end of the second operational amplifier is the outfan of high-pass filtering circuit；Second operational amplifier is LM324 type operational amplifier；R6 is 1M Ω, and C2 is 1uF.
Reflective wrist cardiotachometer the most according to claim 2, it is characterised in that voltage comparator circuit is as follows: the signal input part that input in the same direction is voltage comparator circuit of the 3rd operational amplifier, i.e. connects the outfan of high-pass filtering circuit；The reverse input end of the 3rd operational amplifier meets VCC through resistance R7, and the reverse input end of the 3rd operational amplifier is also through resistance R8 ground connection；Being connected to resistance R9 between outfan and the outfan of the 3rd operational amplifier of voltage comparator circuit, the outfan of voltage comparator circuit is through resistance R10 ground connection；The external interrupt interface INT1 of the output termination microprocessor of voltage comparator circuit；
3rd operational amplifier uses LM324 amplifier chip, and R7, R8, R9 and R10 are respectively 3.3K Ω, 2.7K Ω, 3.9K Ω and 2.4K Ω.
Reflective wrist cardiotachometer the most according to claim 3, it is characterised in that T is 15 seconds.
5. a reflective wrist method for measuring heart rate, it is characterized in that, use the reflective wrist cardiotachometer described in claim 3 to measure to obtain heart rate value to human body wrist position, first, open light source driving circuit driven for emitting lights LED lighting and be radiated at human body wrist position；
Reflection optical receiving circuit detection lumination of light emitting diode is through the light intensity signal of the reflection light of the wrist of detected person；Light intensity signal sequentially passes through low pass amplifying circuit, high-pass filtering circuit and voltage comparator circuit process laggard enter microprocessor external interrupt port；
There is the most corresponding heart beating in external interrupt each time；Microprocessor number of times based on the external interrupt in default T time calculates heart rate value, and is shown on charactron by calculated heart rate value；
When external interrupt occurs each time, microprocessor control the LED in LED flashing circuit and flash once.
Kind the most according to claim 5 reflective wrist method for measuring heart rate, it is characterised in that T is 15 seconds.
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| CN105433935A (en) * | 2015-12-29 | 2016-03-30 | 深圳贝特莱电子科技股份有限公司 | Integrated chip for detecting human body heart rate in photoelectric mode |
| CN107171734B (en) * | 2016-03-08 | 2020-03-06 | 深圳光启智能光子技术有限公司 | Optical chip for optical communication |
| WO2017152811A1 (en) | 2016-03-08 | 2017-09-14 | 深圳光启智能光子技术有限公司 | Optical noise removal circuit, optical receiver, and optical chip |
| CN107171737B (en) * | 2016-03-08 | 2020-03-06 | 深圳光启智能光子技术有限公司 | Optical chip for optical communication and authentication device |
| CN107411702A (en) * | 2016-05-23 | 2017-12-01 | 工业和信息化部电信研究院 | A kind of method and system for testing Wrist wearable type terminal heart rate detection precision |
| CN105944217A (en) * | 2016-07-04 | 2016-09-21 | 中国计量大学 | Intelligent sleeping device based on human-computer interaction |
| CN106473729A (en) * | 2016-11-14 | 2017-03-08 | 广东思派康电子科技有限公司 | A laser flashing earphone based on heart rate beating and its implementation method |
| CN106773606B (en) * | 2016-11-28 | 2019-02-19 | 深圳市奋达科技股份有限公司 | A kind of test device and its test method of product heart rate function |
| CN109044294A (en) * | 2018-08-09 | 2018-12-21 | 珠海格力电器股份有限公司 | Intelligent terminal for changing interface color along with human health condition and control method thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102626307A (en) * | 2012-01-16 | 2012-08-08 | 兰州理工大学 | Dynamic pulse signal real-time detection system and detection method |
| CN104055499A (en) * | 2014-06-16 | 2014-09-24 | 朱宇东 | Wearable intelligent hand ring and method for continuously monitoring human body physiological signs |
| CN203858463U (en) * | 2014-04-10 | 2014-10-01 | 福州宜美电子有限公司 | Sports watch with watchband capable of measuring heart rate |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5672709B2 (en) * | 2010-02-04 | 2015-02-18 | セイコーエプソン株式会社 | Biological information detector, biological information measuring device, and method for designing reflector in biological information detector |
| US9039614B2 (en) * | 2013-01-15 | 2015-05-26 | Fitbit, Inc. | Methods, systems and devices for measuring fingertip heart rate |
-
2014
- 2014-11-03 CN CN201410609129.2A patent/CN104367309B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102626307A (en) * | 2012-01-16 | 2012-08-08 | 兰州理工大学 | Dynamic pulse signal real-time detection system and detection method |
| CN203858463U (en) * | 2014-04-10 | 2014-10-01 | 福州宜美电子有限公司 | Sports watch with watchband capable of measuring heart rate |
| CN104055499A (en) * | 2014-06-16 | 2014-09-24 | 朱宇东 | Wearable intelligent hand ring and method for continuously monitoring human body physiological signs |
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Effective date of registration: 20221027 Address after: 413000 No. 07, Lida Road, Changchun Economic Development Zone, Ziyang District, Yiyang City, Hunan Province Patentee after: Hunan Laitong Optical Technology Co.,Ltd. Address before: 518000 The first floor of plant 11, Donghai Science and Technology Industrial Park, No. 2, Shanzixia Road, Dakang Community, Henggang Street, Longgang District, Shenzhen, Guangdong Patentee before: SHENZHEN LAITONG OPTICAL TECHNOLOGY Co.,Ltd. |