CN2669791Y - Human body impedance measuring devices - Google Patents
Human body impedance measuring devices Download PDFInfo
- Publication number
- CN2669791Y CN2669791Y CNU032071140U CN03207114U CN2669791Y CN 2669791 Y CN2669791 Y CN 2669791Y CN U032071140 U CNU032071140 U CN U032071140U CN 03207114 U CN03207114 U CN 03207114U CN 2669791 Y CN2669791 Y CN 2669791Y
- Authority
- CN
- China
- Prior art keywords
- human body
- body impedance
- microcontroller
- loop
- square wave
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Measurement And Recording Of Electrical Phenomena And Electrical Characteristics Of The Living Body (AREA)
Abstract
The utility model discloses a human body impedance measuring device which comprises a microcontroller, an orderly connected measuring circuit, an electronic switch gating device, an alternating current amplifier, a cymoscope and an A/D converter. The output terminal of the A/D converter is connected with the input terminal of the microcontroller. The microcontroller is respectively connected with the electronic switch gating device and the input terminal of the display. The microcontroller can export 1 kHz-100 kHz square wave and the square wave output terminal of the microcontroller is connected with the actuation power input terminal of the measuring circuit. The square wave which is regarded as the actuation power is imported into the measuring circuit. The reference resistance voltage signal and the human body voltage signal which are exported by the measuring circuit pass through the electronic switch gating device, the alternating current amplifier, the cymoscope and the A/D converter and then are processed the microcontroller to obtain the human body impedance value. The human body impedance measuring device can be used for the electronic products such as the human body grease measuring device and the grease-moisture measuring device.
Description
Technical field
This utility model relates to the bioelectronics fields of measurement, especially relates to a kind of device of measuring the live body human body impedance.
Background technology
From U.S. scientist in 1940 first bio-impedance and health are interrelated study since, research, measuring method and the equipment of relevant this respect have had great development.Particularly the eighties, Lukaski HC was applied to the body fat measurement to bio-impedance, and this technology is advanced to the practical stage.Over more than 20 year, the various instruments that relate to biological impedance arise at the historic moment.For example, the BC-300 human body composition analyser of the U.S., the civilian body weight of TBF series-bodily fat measurement instrument of Japanese TANITA company etc.On the other hand, about the document and the patent of biological impedance also continues to bring out, for example, U.S. Patent number is 5611351, and name is called " apparatus for measuring fat in human body and method ", and China Patent No. is 93228321.7, name is called " biological impedance instrument ", China Patent No. is 93204838.2, and name is called the patent of " body fat analyser ", or the like.All these relate to the measurement of bio-impedance, all are based on AC sine wave to carry out as the excitation power supply that feeds the somatometry loop.Can't deny that this method is classical, effectively.But the circuit of whole system is quite complicated, is difficult to simplify.At first, a sine-wave generator and drive circuit must be arranged, perhaps utilize the square wave of microcontroller (MCU) output, become sine wave by change-over circuit again.Its two, this method generally adopts the sine-wave current source as excitation power supply, so will use the voltage-to-current power-switching circuit.Its three, sinusoidal wave detecting circuit linearity is not high, in order to obtain high-quality detection, it is very complicated that detecting circuit is designed to be.Also some scheme adopts the method that increases reference resistance and repeatedly sampling to improve, and for example U.S. Patent number is 5611351 patent, has adopted three reference resistances, needs 4-5 sampling.And make that like this processing of software is more consuming time, more numerous and diverse.
Summary of the invention
It is many that the purpose of this utility model is to solve in the prior art discrete assembly, the circuit complexity, and the problem that the detection linearity is not good, and provide a kind of circuit simple, and measuring cost reduces, and the detection linearity is body impedance measurement devices preferably.
The purpose of this utility model is achieved in that a kind of body impedance measurement devices, comprises microcontroller, electrical switch gate, alternative current amplifier, cymoscope, mould/number (A/D) transducer and measures the loop; Described measurement loop, electrical switch gate, alternative current amplifier, cymoscope, A/D converter are continuous in proper order, the input of the described microcontroller of output termination of described A/D converter; Described microcontroller links to each other with described electrical switch gate, the human body impedance signal of described microcontroller exports the input of the described display of termination, it is characterized in that, described microcontroller can be exported the square wave of 1kHz-100kHz, the square wave outfan of described microcontroller links to each other with the excitation power supply input in described measurement loop, feeds as excitation power supply with this square wave and measures the loop; Reference resistance voltage signal that described measurement loop is exported and body voltages signal are admitted to microcontroller through electrical switch gate, alternative current amplifier, cymoscope and A/D converter successively and handle, thereby draw the human body impedance value.
According to body impedance measurement devices of the present utility model, it is characterized in that, adopt a current-limiting resistance R in the described measurement loop
LWith a reference resistance R
SConnect with tested human body.
According to body impedance measurement devices of the present utility model, it is characterized in that described electrical switch gate is distinguished the magnitude of voltage U of gating reference resistance by microprocessor controls
SSample with the magnitude of voltage Ub of human body impedance.
According to body impedance measurement devices of the present utility model, it is characterized in that, the square wave outfan of described microcontroller and the control signal input of described cymoscope link to each other, described cymoscope is to adopt the synchronous electric sampler cymoscope, and is fed same square wave control the carrying out synchronous detection of measuring the loop.
Implement body impedance measurement devices of the present utility model, owing to adopted the excitation power supply of the square wave of microcontroller output as the measurement loop, and utilize square wave control synchronous detection, thereby whole measuring circuit is simplified, detection is better linear, and sampling number reduces, and software processes is simpler.This utility model is simple in structure, and is with low cost, can be applied to human body bodily fat measurement instrument, on the consumption electronic products such as body fat-drimeter, has very strong practicality and good economic benefits.
Description of drawings
Fig. 1 is the schematic block circuit diagram of the embodiment one of this utility model body impedance measurement devices;
Fig. 2 is the physical circuit connection layout of body impedance measurement devices shown in Figure 1;
Fig. 3 is the schematic block circuit diagram of the embodiment two of this utility model body impedance measurement devices;
Fig. 4 is the schematic block circuit diagram of the embodiment three of this utility model body impedance measurement devices.
The specific embodiment
As depicted in figs. 1 and 2, in embodiment one of the present utility model, body impedance measurement devices comprises microcontroller 101, electrical switch gate 102, alternative current amplifier 103, cymoscope 104, A/D converter 105, measures loop 106 and display 107.
Alternative current amplifier 103 is to adopt the high resistant broadband amplifier, is made up of amplifier IC1, capacitor C 1, C2 and resistance R 1, R2, R3, R4.
Cymoscope 104 is made up of electrical switch K3, capacitor C 3, C6 and resistance R 9.
A/D converter 105 is made up of IC2.
In the present embodiment, adopted four-probe measurement, promptly use four with human body electrode in contact P1, P2, P3, P4, form three human body section impedance Z b1, Zb2, Zb, wherein P1, P4 two electrodes are that excitation power supply feeds end, and P2, P3 two electrodes are that the voltage signal Ub of human body impedance Z b takes out end.Measure loop 106 by current-limiting resistance R
L, reference resistance R
SBe in series with human body.Wherein, current-limiting resistance R
LEffect be the safety range of peak-limitation below 1mA that will flow into the square wave current Ij of human body, reference resistance R
SResistance predict.
Utilize the clock resource of microcontroller IC3, send a constant amplitude square Uj less than the certain frequency of 100kHz from the P2.2 mouth; Through measuring the resistance R in loop 106
L, R
SDirectly feed human body.Square wave current Ij flows through when measuring the loop, at R
SThe voltage of last generation is U
S, the voltage that produces on human body impedance Zb is Ub.The electrical switch K1 and the K2 of the P4.2 mouth control gate 102 of microcontroller IC3, first backgating U
SSample with Ub.When the P4.2 mouth is high level, gating U
SDeliver to amplifier 103, amplifier 103 is formed the high resistant broadband amplifier by amplifier IC1, signal is amplified, and guarantee that the square-wave signal that is exaggerated is undistorted, is not delayed.Square-wave signal after the amplification is admitted to cymoscope 104, and the same square wave power Uj that the electrical switch K3 of cymoscope 104 is measured loop 106 controls, and forms synchronous detection, can be peak value or meansigma methods detection.Work as U
SDuring for positive half-wave, Uj is also for just, and K3 connects U
STo capacitor C 3.Work as U
SDuring for negative half-wave, Uj is also for negative, U
SBe shorted to ground by K3.Like this, after filtering, just preserved U on the capacitor C 6
SThe magnitude of voltage of positive half-wave is about to U
SThe ac square wave rectification become positive direct current signal.Because square-wave signal only amplifies through the one-level broadband, the time that is delayed is very little, obtains better linearity so synchronous detection can intactly detect positive square wave.U after the detection
SDirect current signal is through the IC2 of A/D converter 105, converts to obtain U after digital quantity send microcontroller 101 to handle by the P1.3 mouth of microcontroller 101
SMagnitude of voltage.
Similarly, when the P4.2 of microcontroller IC3 mouth is low level, the voltage U b on the gating human body impedance Zb, this moment, sampling obtained the magnitude of voltage of Ub.
The magnitude of voltage U of the measuring resistance that double sampling measured
SCan be calculated as follows out human body impedance Zb with the magnitude of voltage of human body impedance:
Because amplifier 103 is high impedance amplifiers, very little to the shunting of measuring loop 106, can ignore, so the R that flows through
SCan be regarded as same electric current I j with the electric current of Zb, promptly have:
U
S/R
S＝Ub/Zb (1-1)
R wherein
SBe the standard electric resistance of having predicted, so the value of human body impedance Zb is
Zb＝Ub*R
S/U
S (1-2)
In fact, (1-2) formula is for being to be suitable for when measuring power supply with the sine wave, but when being the measurement source with the square wave, also should revise.In theory, square wave can equivalence be sinusoidal fundamental wave and higher hamonic wave, and human body impedance descends to some extent with the rising meeting of measuring frequency.So square wave is compared with the human body impedance that the sine wave of same frequency is measured can be less than normal to some extent.Should multiply by a correction factor j and proofread and correct, that is:
Zb＝j*Ub*R
S/U
S (1-3)
Correction factor j can determine with the method for experiment.If with the sinusoidal wave human body impedance of measuring of 50kHz is with reference to impedance Z bs, the human body impedance that the square wave of same frequency is measured is Zbf, and then correction factor j is:
j＝Zbs/Zbf (1-4)
The value that experiment draws j is about 1.02-1.06 (frequency is 50kHz, and Zb is 100 Ω-1K Ω scope).
When square wave frequency is not 50kHz, also can be and (1-4) calculate human body impedance Zb with reference to (1-3), certain suitability is promptly also arranged.
As shown in Figure 3, in embodiment two of the present utility model, be with the difference of embodiment one, what adopt is the measurement loop of two electrode measurement human body impedances, impedance between two and human body electrode in contact is promptly as measured human body impedance, and asks for human body impedance by the sampling potential value.That this circuit double sampling measures is respectively the potential value Va of human body impedance and reference resistance impedance sum and the potential value Vs of reference resistance, and at this moment, the computing formula of human body impedance Zb is:
Zb＝j*(Va/Vs-1)*R
S (1-5)
Correction factor j equates with (1-4) in the formula.
Because two electrode measurement circuit can't be eliminated the contact resistance of electrode and skin, and the cortex resistance of skin itself, therefore, measuring result error can be bigger.
As shown in Figure 4, in embodiment three of the present utility model, be with the difference of embodiment one, measuring loop 106 is to adopt the current source excitation, the square-wave voltage source that microcontroller 101 is sent is converted to square wave current source feeding measurement loop 106 through voltage/current (U/I) transducer 108, other parts in loop do not become, and above-mentioned principle and computing formula are suitable equally.
Claims (8)
1. a body impedance measurement devices comprises microcontroller, electrical switch gate, alternative current amplifier, cymoscope, mould/number A/D converter and measures the loop; Described measurement loop, electrical switch gate, alternative current amplifier, cymoscope, A/D converter are continuous in proper order, the input of the described microcontroller of output termination of described A/D converter; Described microcontroller links to each other with described electrical switch gate, the human body impedance signal of described microcontroller exports the input of the described display of termination, it is characterized in that, described microcontroller can be exported the square wave of 1kHz-100kHz, the square wave outfan of described microcontroller links to each other with the excitation power supply input in described measurement loop, feeds as excitation power supply with this square wave and measures the loop; Reference resistance voltage signal that described measurement loop is exported and body voltages signal are admitted to microcontroller through electrical switch gate, alternative current amplifier, cymoscope and A/D converter successively and handle, thereby draw the human body impedance value.
2. body impedance measurement devices according to claim 1 is characterized in that, adopts a current-limiting resistance R in the described measurement loop
LWith a reference resistance R
SConnect with tested human body.
3. body impedance measurement devices according to claim 1 and 2 is characterized in that, described electrical switch gate is distinguished the magnitude of voltage U of gating reference resistance by microprocessor controls
SSample with the magnitude of voltage Ub of human body impedance.
4. body impedance measurement devices according to claim 1 and 2 is characterized in that, described alternative current amplifier is to adopt the high resistant broadband amplifier.
5. body impedance measurement devices according to claim 1 and 2, it is characterized in that, the square wave outfan of described microcontroller and the control signal input of described cymoscope link to each other, described cymoscope is to adopt the synchronous electric sampler cymoscope, and is fed same square wave control the carrying out synchronous detection of measuring the loop.
6. body impedance measurement devices according to claim 1 and 2, it is characterized in that, four-probe measurement has been adopted in described measurement loop, promptly use four with human body electrode in contact P1, P2, P3, P4, form three human body section impedance Z b1, Zb2, Zb, wherein P1, P4 two electrodes are that excitation power supply feeds end, and P2, P3 two electrodes are that the voltage signal Ub of human body impedance Z b takes out end.
7. body impedance measurement devices according to claim 1 and 2, it is characterized in that, two electrode measurements have been adopted in described measurement loop, and the impedance between two and human body electrode in contact is promptly as measured human body impedance Zb, and ask for human body impedance by the sampling potential value.
8. body impedance measurement devices according to claim 1 and 2, it is characterized in that, current source excitation also can be adopted in described measurement loop, is about to the square-wave voltage source that described microcontroller sends and feeds the measurement loop after voltage/current U/I transducer is converted to square wave current source.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU032071140U CN2669791Y (en) | 2003-08-05 | 2003-08-05 | Human body impedance measuring devices |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU032071140U CN2669791Y (en) | 2003-08-05 | 2003-08-05 | Human body impedance measuring devices |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2669791Y true CN2669791Y (en) | 2005-01-12 |
Family
ID=34472914
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU032071140U Expired - Fee Related CN2669791Y (en) | 2003-08-05 | 2003-08-05 | Human body impedance measuring devices |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2669791Y (en) |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102955080A (en) * | 2011-08-16 | 2013-03-06 | 重庆融海超声医学工程研究中心有限公司 | Portable measuring instrument and measuring method for electrical parameters |
| CN103063928A (en) * | 2013-01-29 | 2013-04-24 | 湖南继善高科技有限公司 | System for testing earth grounding resistance, and digital coherent detection method |
| CN103344834A (en) * | 2013-06-27 | 2013-10-09 | 成都网动光电子技术股份有限公司 | Device for testing body resistance |
| WO2014190522A1 (en) * | 2013-05-30 | 2014-12-04 | Lee Hou-Chieh | System and method for measuring skin impedance |
| CN104622515A (en) * | 2015-02-27 | 2015-05-20 | 江苏矽望电子科技有限公司 | Body fluid electroconductibility sensor |
| CN104622514A (en) * | 2015-02-27 | 2015-05-20 | 江苏矽望电子科技有限公司 | System and method for testing ovulation on basis of double sensors |
| CN106291114A (en) * | 2016-08-25 | 2017-01-04 | 三诺生物传感股份有限公司 | The ac impedance measurement circuit of a kind of blood glucose meter, method and device |
| CN107157481A (en) * | 2017-05-10 | 2017-09-15 | 湖南海翼电子商务股份有限公司 | Measure circuit, method and the bodily fat measurement device of human body resistance |
| CN107228886A (en) * | 2017-04-24 | 2017-10-03 | 费尔德（北京）科学仪器有限公司 | The measurement apparatus and method of the electrical conductivity Resistivity testing of water |
| CN108378850A (en) * | 2017-12-27 | 2018-08-10 | 诺仪器（中国）有限公司 | Body complex impedance measuring system and method |
| CN108700859A (en) * | 2017-07-31 | 2018-10-23 | 深圳和而泰智能控制股份有限公司 | Human skin water oil analysis circuit and skin detection instrument |
| CN111568419A (en) * | 2020-05-20 | 2020-08-25 | 芯海科技（深圳）股份有限公司 | Detection method, detector and terminal device |
-
2003
- 2003-08-05 CN CNU032071140U patent/CN2669791Y/en not_active Expired - Fee Related
Cited By (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102955080A (en) * | 2011-08-16 | 2013-03-06 | 重庆融海超声医学工程研究中心有限公司 | Portable measuring instrument and measuring method for electrical parameters |
| CN103063928A (en) * | 2013-01-29 | 2013-04-24 | 湖南继善高科技有限公司 | System for testing earth grounding resistance, and digital coherent detection method |
| CN103063928B (en) * | 2013-01-29 | 2015-05-20 | 湖南继善高科技有限公司 | System for testing earth grounding resistance, and digital coherent detection method |
| WO2014190522A1 (en) * | 2013-05-30 | 2014-12-04 | Lee Hou-Chieh | System and method for measuring skin impedance |
| CN103344834A (en) * | 2013-06-27 | 2013-10-09 | 成都网动光电子技术股份有限公司 | Device for testing body resistance |
| CN104622515A (en) * | 2015-02-27 | 2015-05-20 | 江苏矽望电子科技有限公司 | Body fluid electroconductibility sensor |
| CN104622514A (en) * | 2015-02-27 | 2015-05-20 | 江苏矽望电子科技有限公司 | System and method for testing ovulation on basis of double sensors |
| CN106291114B (en) * | 2016-08-25 | 2019-02-01 | 三诺生物传感股份有限公司 | A kind of ac impedance measurement circuit of blood glucose meter, method and device |
| CN106291114A (en) * | 2016-08-25 | 2017-01-04 | 三诺生物传感股份有限公司 | The ac impedance measurement circuit of a kind of blood glucose meter, method and device |
| CN107228886A (en) * | 2017-04-24 | 2017-10-03 | 费尔德（北京）科学仪器有限公司 | The measurement apparatus and method of the electrical conductivity Resistivity testing of water |
| CN107228886B (en) * | 2017-04-24 | 2019-09-10 | 费尔德（北京）科学仪器有限公司 | The measuring device and method of the conductivity Resistivity testing of water |
| CN107157481A (en) * | 2017-05-10 | 2017-09-15 | 湖南海翼电子商务股份有限公司 | Measure circuit, method and the bodily fat measurement device of human body resistance |
| CN107157481B (en) * | 2017-05-10 | 2020-09-15 | 安克创新科技股份有限公司 | Circuit and method for measuring human body resistance and body fat measuring device |
| CN108700859A (en) * | 2017-07-31 | 2018-10-23 | 深圳和而泰智能控制股份有限公司 | Human skin water oil analysis circuit and skin detection instrument |
| WO2019023881A1 (en) * | 2017-07-31 | 2019-02-07 | 深圳和而泰智能控制股份有限公司 | Human skin water and oil analysis circuit and skin testing instrument |
| CN108378850A (en) * | 2017-12-27 | 2018-08-10 | 诺仪器（中国）有限公司 | Body complex impedance measuring system and method |
| CN111568419A (en) * | 2020-05-20 | 2020-08-25 | 芯海科技（深圳）股份有限公司 | Detection method, detector and terminal device |
| CN111568419B (en) * | 2020-05-20 | 2023-11-03 | 芯海科技（深圳）股份有限公司 | Detection method, detector and terminal equipment |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN2669791Y (en) | Human body impedance measuring devices | |
| CN207215905U (en) | A kind of high-precision AC microresistivity survey instrument | |
| CN1928540A (en) | Portable smart water quality conductive detection device | |
| CN104062507A (en) | Battery internal resistance measuring instrument | |
| CN201269859Y (en) | Measurement device for capacitor coupling type non-contact conductor based on series resonance | |
| WO2011100253A3 (en) | Carbon quantifying apparatus and method | |
| WO2003010546A1 (en) | Capacitor insulation resistance measuring method and insulation resistance measuring instrument | |
| WO2018186506A1 (en) | Skin measurement device for measuring skin hydration using voltage application electrode and current detection electrode | |
| CN204595180U (en) | A kind of supervising device being applied to high-power DC power supply system | |
| CN111964749A (en) | Anti-scaling electrode type conductive liquid level sensor and conductive liquid level detection device comprising same | |
| DE50001612D1 (en) | MEASURING METHOD FOR CAPACITIVE MEASURING SYSTEM | |
| CN206892187U (en) | A kind of AC harmonic source | |
| CN203591258U (en) | Human body electrical impedance measuring instrument | |
| CN106137192A (en) | A kind of body impedance measurement devices and bioelectrical impedance analysis instrument thereof | |
| CN110954577B (en) | Rapid nondestructive injection quality detection system and detection method | |
| CN111879847A (en) | Magnetic flux leakage detection method and detection device | |
| CN202041488U (en) | Ion measuring device for biological product | |
| CN204241570U (en) | The proving installation of conductivity and consumer | |
| Hedayatipour et al. | CMOS integrated impedance to frequency converter for biomedical applications | |
| CN201226003Y (en) | Apparatus for detecting liquid electrical parameter | |
| CN206183266U (en) | Human impedance measuring device and human body component analyzer thereof | |
| CN103063928B (en) | System for testing earth grounding resistance, and digital coherent detection method | |
| CN2821570Y (en) | Electromechanical integrated detector for digital weak electrolyte dissociation constant | |
| CN1127628A (en) | Organism body fluid distribution measuring analyzer | |
| CN2681144Y (en) | Conductance/voltage converter based on bipolar pulse current excitation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| DD01 | Delivery of document by public notice |
Addressee: Peng Fei Document name: Notification of Approving Refund |
|
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20050112 Termination date: 20100805 |