CN202019342U - Heart sound amplifying circuit based on MAX4465 and LM386 - Google Patents

Heart sound amplifying circuit based on MAX4465 and LM386 Download PDF

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Publication number
CN202019342U
CN202019342U CN 201120152648 CN201120152648U CN202019342U CN 202019342 U CN202019342 U CN 202019342U CN 201120152648 CN201120152648 CN 201120152648 CN 201120152648 U CN201120152648 U CN 201120152648U CN 202019342 U CN202019342 U CN 202019342U
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China
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pin
capacitor
amplifier
resistance
another termination
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Expired - Lifetime
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CN 201120152648
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Chinese (zh)
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夏振宏
袁赞
曾艳芳
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HUANAN MEDICAL ELECTRICAL TECH Co Ltd HENAN
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HUANAN MEDICAL ELECTRICAL TECH Co Ltd HENAN
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Abstract

The utility model discloses a heart sound amplifying circuit based on MAX4465 and LM386. The heart sound amplifying circuit comprises a pre-amplifying circuit and a post-amplifying filter circuit. In the heart sound amplifying circuit, an acquiring and amplifying circuit consists of an MAX4465 amplifier chip and an LM385 amplifier chip; power supply voltage of the whole circuit is from a 5-volt direct-current power supply, and the acquisition and the amplification of a heart sound signal are finished through necessary filtering; the modularization is very high and the heart sound amplifying circuit can be flexibly transplanted into various application circuits, so the heart sound monitoring function is realized and the design requirement of the conventional portable medical product can be met.

Description

Hear sounds amplifying circuit based on MAX4465 and LM386
Technical field
The utility model relates to a kind of amplifying circuit, is mainly used in medical instruments field, is used for the monitoring and the diagnostic system of the various physiology sign of human body parameter, is specifically related to a kind of hear sounds amplifying circuit based on MAX4465 and LM386.
Background technology
Along with developing rapidly of medical electronics industry, portable medical device also more and more is subjected to people in the industry's attention and favor.So-called portable equipment is meant treatment usefulness or the sub-apparatus product of detection that volume is small and exquisite, the complete machine deal is light, power-saving, moderate.Portable medical electronic devices mainly is divided into portable medical treatment electronic equipment of family expenses and medical portable medical treatment electronic equipment, and the former comprises electrosphygmomanometer, electronics blood glucose meter, electronic hearing aid etc.; The latter comprises portable electrocardiograph, Portable, multiple parameter patient monitor, portable ultrasonic surveymeter etc.The parameter that Portable, multiple parameter patient monitor is in the market mainly guarded is parameters such as electrocardio, blood pressure, blood oxygen, breathing, body temperature, pulse frequency, and the multi-parameter monitor of monitoring hear sounds is seldom arranged.Much research and develop producer for the demand that adapts to market and all want hear sounds detected to add in the multi-parameter monitor to go, this just needs the collection of relevant cardiechema signals and the monitoring that amplifying circuit is realized hear sounds.
The utility model content
In view of above background, the purpose of this utility model is to provide a kind of hear sounds amplifying circuit based on MAX4465 and LM386, can be applied in the multiple portable medical device, realizes portability, miniaturization, the multifunction and integrated of Medical Devices.
The utility model is by the following technical solutions:
A kind of hear sounds amplifying circuit based on MAX4465 and LM386, wherein, comprise preamplifying circuit and back level amplification filtering circuit, described preamplifying circuit comprises resistance R 1, R2, R3, R4, R8, R9, capacitor C 1, C3, C7, C10, C11 and amplifier, the end of one pin connecting resistance R3, the R4 of amplifier and capacitor C 3, C7, pin 2 ground connection, the end of pin 3 connecting resistance R8, R9 and C10, the other end of pin 4 connecting resistance R8, C10 and back level amplification filtering circuit, pin 5 connects the 5V power supply; Another termination capacitor C 11 of resistance R 9, the other end ground connection of C11; Another termination 5V power supply of resistance R 3, the other end ground connection of resistance R 4, the input of another termination electrocardiosignal of capacitor C 3 and C7 and resistance R 2, the other end connecting resistance R1 of resistance R 2 and capacitor C 1, another termination 5V power supply of resistance R 1, the other end ground connection of capacitor C 1; Described back level amplification filtering circuit comprises polar capacitor C4, adjustable rheostat W1, polarity free capacitor C2, C5, C6, C8, C9, resistance R 5, R6, R7, and amplifier; The pin 1 tape splicing resistance R 6 of amplifier and the end of R5, another termination capacitor C 9 of R5, the pin 8 of another termination amplifier of C9; Another termination C5 of R6, the pin 5 of another termination amplifier of C5, the pin 5 of amplifier has also connected capacitor C 6 and C2; Pin 4 ground connection of amplifier, pin 6 connects the 5V power supply; The pin 7 of amplifier connects capacitor C 8, the pin 2 of another termination amplifier of C8 and ground; Amplifier pin 3 connects the centre tap end of adjustable resistor W1, other two ends difference ground connection of W1 and the end of polar capacitor C4, another termination preamplifying circuit of C4; The other end connecting resistance R7 of capacitor C 6, the other end ground connection of R7, the other end of capacitor C 2 is the cardiechema signals of output.
Further, the amplifier of described preamplifying circuit is the MAX4465 chip.
Further, the amplifier of described back grade amplification filtering circuit is the LM386 chip.
Collection and amplifying circuit that this circuit is made up of MAX4465 amplifier chip and LM385 amplifier chip, the supply power voltage of entire circuit are the 5V DC power supply.Chip MAX4465 is a kind of low cost of MAXIM company research and development, the microphone and the full cut-off chip of little power consumption, and it is mainly used in the equipment such as loudspeaker amplification, hearing aids, portable phone, sound discriminator, digital audio detection, earphone and portable computer.The advantage of its uniqueness is exactly that high cmrr and good power supply suppress, and amplifying this chip for the signal in the noisy environment is optimal selection, and this chip can lower the power consumption and the cost of whole instrument simultaneously.This chip has been finished the prime amplification and the part filter function of cardiechema signals in this circuit module, and we have adopted the filter circuit that electric capacity and resistance are formed at its input, and signal is carried out simple filtering.Regulate multiplication factor by the feedback resistance between the configuration input and output.The signal that this chip comes out is isolated the input of sending into the LM386 chip through electric capacity, carries out next step processing.
The LM386 that uses in this circuit is the low-voltage audio frequency amplifier of UTC company design research and development, and its internal gain is 20, but by the size of resistance between configuration pin 1 and the pin 8 its gain is changed between 20-200.The main feature of this chip is exactly the supply power voltage that can use powered battery, peripheral components few, wide, adjustable voltage gain etc.This circuit adopts this chip to amplify as the secondary of cardiechema signals, simultaneously capacitance-resistance filter is arranged also, and signal is carried out further filtering.This circuit has added adjustable resistance in the middle of the input of signal and this chip, can change the size of output signal by regulating this resistance.The coupling of amplifier chip He their peripheral components by above two special uses, cardiechema signals is finally sent the electrocardiosignal of relative clean by filtering and amplification, uses for the designer of Medical Devices.
The beneficial effects of the utility model are:
This circuit adopts special-purpose amplifier chip, the collection and the amplification of cardiechema signals have been finished by essential filtering, the degree of modularity is very strong can be transplanted in the various application circuits neatly, realize the monitoring function of hear sounds, for the designer has saved the valuable research and development time, can satisfy the designing requirement of present portable medical product.
This circuit is a modular circuit, can be applied in the design of various electrostethophones, can clearly hear the sound that human heart is beated by external earphone or loudspeaker, in addition by regulating the lungs sound that adjustable resistance also can human body.This circuit is easy to use and low-cost design principle in line with the designer, adopt special audio frequency to amplify chip, also select simultaneously the components and parts of low-voltage and little power consumption for use, and reduce the peripheral cell of device as far as possible, this circuit can simply be transplanted in the portable medical device, make the with better function of portable medical device, integrated level is higher.
Description of drawings
Fig. 1 is circuit theory diagrams of the present utility model.
Fig. 2 is an application block diagram of the present utility model.
Embodiment
Below in conjunction with drawings and Examples the utility model is further described:
As shown in Figure 1, the utility model mainly is made up of prime amplification filtering circuit 1 and back level amplification filtering circuit 2, and " IN " among the figure is the input of cardiechema signals source, and " OUT " is final output signal.
Preamplifying circuit 1 comprises resistance R 1, R2, R3, R4, R8, R9, polarity free capacitor C1, C3, C7, C10, C11, also has an amplifier chip MAX4465, the end of a pin connecting resistance R3, the R4 of chip MAX4465 and capacitor C 3, C7, pin 2 ground connection, the end of pin 3 connecting resistance R8, R9 and C10, the other end of pin 4 connecting resistance R8, C10 and back level amplification filtering circuit 2, pin 5 connects the 5V power supply.Another termination capacitor C 11 of resistance R 9, the other end ground connection of C11.Another termination 5V power supply of resistance R 3, the other end ground connection of resistance R 4, the input of another termination electrocardiosignal of capacitor C 3 and C7 and resistance R 2, the other end connecting resistance R1 of resistance R 2 and capacitor C 1, another termination 5V power supply of resistance R 1, the other end ground connection of capacitor C 1.
Back level amplification filtering circuit 2 comprises polar capacitor C4, adjustable rheostat W1, and polarity free capacitor C2, C5, C6, C8, C9 and resistance R 5, R6, R7 also have amplifier chip LM386.The pin 1 tape splicing resistance R 6 of amplifier chip and the end of R5, another termination capacitor C 9 of R5, the pin 8 of another termination amplifier chip LM386 of C9.Another termination C5 of R6, the pin 5 of another termination amplifier chip of C5, the pin 5 of amplifier chip has also connected capacitor C 6 and C2.Pin 4 ground connection of amplifier, pin 6 connects the 5V power supply.The pin 7 of amplifier connects capacitor C 8, the pin 2 of another termination amplifier chip of C8 and ground.Amplifier chip pin 3 connects the centre tap end of adjustable resistor W1, other two ends difference ground connection of W1 and the end of polar capacitor C4, another termination preamplifying circuit 1 of C4.The other end connecting resistance R7 of capacitor C 6, the other end ground connection of R7.The other end of capacitor C 2 is the cardiechema signals of output.
The supply power voltage of entire circuit is 5V as can be seen from Figure 1, cardiechema signals enters prime amplification filtering circuit 1, carries out the signal filtering and the amplification of one-level, enters back level amplification filtering circuit 2 then, signal is carried out secondary filtering and amplification, the clean effectively cardiechema signals of final output.Can change the strong and weak degree of output signal by adjusting adjustable resistance W1.The yield value that the resistance R 5 among change Fig. 1 between LM386 pin of chip 1 and the pin 8 and the value of capacitor C 9 can change the LM386 chip is between 20 to 200.Can the cardiechema signals intensity of output be compensated by the value that disposes rational C5 and R6.
Fig. 2 is the concrete application in practice of the utility model circuit.Obtaining of cardiechema signals among Fig. 2 can be passed through old-fashioned stethoscopic vibrating diaphragm head, on vibrating diaphragm ear handle, put 1 ~ 2 inch long rubber tube, the microminiature Electret condenser microphone of one 1/4 inch diameter is clamp-oned in the other end, two leads of microphone are received IN and GND place in the circuit with shielded type cable, the Electret condenser microphone place available heat draw is reinforced, in case produce unnecessary noise jamming.Handle through signal being sent into microprocessor behind the amplifying circuit, externally connected with display screen can show the waveform of cardiechema signals, if but want to listen heartbeat sound lug machine.If wave-shape amplitude is less or the very low W1 that can regulate Fig. 1 of sound regulates, perhaps disposes C5 and C6 and carry out the weak signal compensation.
Explanation is at last, above embodiment is only unrestricted in order to the explanation the technical solution of the utility model, other modifications that those of ordinary skills make the technical solution of the utility model or be equal to replacement, only otherwise break away from the spirit and scope of technical solutions of the utility model, all should be encompassed in the middle of the claim scope of the present utility model.

Claims (3)

1. hear sounds amplifying circuit based on MAX4465 and LM386, it is characterized in that: comprise preamplifying circuit and back level amplification filtering circuit, described preamplifying circuit comprises resistance R 1, R2, R3, R4, R8, R9, capacitor C 1, C3, C7, C10, C11 and amplifier, the end of one pin connecting resistance R3, the R4 of amplifier and capacitor C 3, C7, pin 2 ground connection, the end of pin 3 connecting resistance R8, R9 and C10, the other end of pin 4 connecting resistance R8, C10 and back level amplification filtering circuit, pin 5 connects the 5V power supply; Another termination capacitor C 11 of resistance R 9, the other end ground connection of C11; Another termination 5V power supply of resistance R 3, the other end ground connection of resistance R 4, the input of another termination electrocardiosignal of capacitor C 3 and C7 and resistance R 2, the other end connecting resistance R1 of resistance R 2 and capacitor C 1, another termination 5V power supply of resistance R 1, the other end ground connection of capacitor C 1; Described back level amplification filtering circuit comprises polar capacitor C4, adjustable rheostat W1, polarity free capacitor C2, C5, C6, C8, C9, resistance R 5, R6, R7, and amplifier; The pin 1 tape splicing resistance R 6 of amplifier and the end of R5, another termination capacitor C 9 of R5, the pin 8 of another termination amplifier of C9; Another termination C5 of R6, the pin 5 of another termination amplifier of C5, the pin 5 of amplifier has also connected capacitor C 6 and C2; Pin 4 ground connection of amplifier, pin 6 connects the 5V power supply; The pin 7 of amplifier connects capacitor C 8, the pin 2 of another termination amplifier of C8 and ground; Amplifier pin 3 connects the centre tap end of adjustable resistor W1, other two ends difference ground connection of W1 and the end of polar capacitor C4, another termination preamplifying circuit of C4; The other end connecting resistance R7 of capacitor C 6, the other end ground connection of R7, the other end of capacitor C 2 is the cardiechema signals of output.
2. a kind of hear sounds amplifying circuit based on MAX4465 and LM386 according to claim 1, it is characterized in that: the amplifier of described preamplifying circuit is the MAX4465 chip.
3. a kind of hear sounds amplifying circuit based on MAX4465 and LM386 according to claim 2 is characterized in that: the amplifier of described back level amplification filtering circuit is the LM386 chip.
CN 201120152648 2011-05-13 2011-05-13 Heart sound amplifying circuit based on MAX4465 and LM386 Expired - Lifetime CN202019342U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN 201120152648 CN202019342U (en) 2011-05-13 2011-05-13 Heart sound amplifying circuit based on MAX4465 and LM386

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102158185A (en) * 2011-05-13 2011-08-17 河南华南医电科技有限公司 Cardiac sound amplifying circuit based on MAX 4465 amplifier chip and LM 386 amplifier chip
CN104967963A (en) * 2015-06-30 2015-10-07 傅明尧 Audio amplifier integrated circuit
WO2018176289A1 (en) * 2017-03-29 2018-10-04 深圳市大疆创新科技有限公司 Amplification circuit, laser measurement device, and mobile platform
US10539663B2 (en) 2017-03-29 2020-01-21 SZ DJI Technology Co., Ltd. Light detecting and ranging (LIDAR) signal processing circuitry
US11529102B2 (en) 2019-12-02 2022-12-20 Analog Devices, Inc. Heart sound normalization

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102158185A (en) * 2011-05-13 2011-08-17 河南华南医电科技有限公司 Cardiac sound amplifying circuit based on MAX 4465 amplifier chip and LM 386 amplifier chip
CN104967963A (en) * 2015-06-30 2015-10-07 傅明尧 Audio amplifier integrated circuit
WO2018176289A1 (en) * 2017-03-29 2018-10-04 深圳市大疆创新科技有限公司 Amplification circuit, laser measurement device, and mobile platform
CN108700648A (en) * 2017-03-29 2018-10-23 深圳市大疆创新科技有限公司 A kind of amplifying circuit and laser measuring device for measuring, mobile platform
US10539663B2 (en) 2017-03-29 2020-01-21 SZ DJI Technology Co., Ltd. Light detecting and ranging (LIDAR) signal processing circuitry
US11529102B2 (en) 2019-12-02 2022-12-20 Analog Devices, Inc. Heart sound normalization

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AV01 Patent right actively abandoned

Granted publication date: 20111026

Effective date of abandoning: 20120926