CN108378850A - Body complex impedance measuring system and method - Google Patents
Body complex impedance measuring system and method Download PDFInfo
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- CN108378850A CN108378850A CN201810154762.5A CN201810154762A CN108378850A CN 108378850 A CN108378850 A CN 108378850A CN 201810154762 A CN201810154762 A CN 201810154762A CN 108378850 A CN108378850 A CN 108378850A
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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
- A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves
- A61B5/053—Measuring electrical impedance or conductance of a portion of the body
- A61B5/0537—Measuring body composition by impedance, e.g. tissue hydration or fat content
Abstract
A kind of body complex impedance measuring system of present invention proposition and method, the system include：Signal generator, differential operational amplifier, the first signal isolator, second signal isolator, measuring resistance, third signal isolator, fourth signal isolator, the first phase shifter, the first signal conditioning circuit, second signal modulate circuit and signal processing circuit；Phase shifter connection carries out phase shift to normal voltage and/or test voltage, so that the signal phase on the first signal conditioning circuit and second signal modulate circuit differs 90 degree；Signal processing circuit is calculating the normal voltage of reception and the phase difference of test voltage, and the phase difference is compensated according to the phase shift phase on phase shifter, according to after compensation phase difference and the normal voltage and test voltage calculate the human body body complex impedance of one position under the frequency.The frequency corresponding to abnormal conditions can be directly learnt from measurement result, convenient for investigation, and measurement data is more accurate.
Description
Technical field
The present invention relates to field of measuring technique more particularly to a kind of body complex impedance measuring systems and method.
Background technology
Bodily fat measurement instrument is theoretical using bio-electrical impedance, can monitor nutrition condition, the isohydria situation of human body in real time,
Human body component range of normal value is provided, and evaluates human body growth and development state etc..Body complex impedance can more accurate Characterization human body
Physical condition, such as body fat, internal water, sugar, protein content etc..The ultra-weak electronic signal of different frequency passes through same people
When body tissue, path difference so that body complex impedance is different, and capacitive is presented in low frequency range, and perception is presented in high frequency region.Same frequency
When the ultra-weak electronic signal of rate is by different tissues, body complex impedance is also different.
The prior art generally measures body complex impedance by the following method, that is, uses the ultra-weak electronic signal of multiple frequencies simultaneously
Same tissue is measured, it is multiple to calculate human body later for the data of acquisition current signal transfer delay and current signal virtual value
Impedance.When bodily fat measurement instrument is calibrated, if it is abnormal to find that the complex impedance of tissue exists, need for each frequency
The electric signal of rate is debugged, and eventually finds that frequency of tissue complex impedance exception, and the debugging process is complicated, take compared with
It is long；And when measurement, due to the imperfection of the waveform of signal, with the method for zero-crossing examination when calculating phase, there are larger
Error.
Invention content
Technical problem to be solved by the invention is to provide a kind of body complex impedance measuring system and methods, can be tied from measuring
Fruit directly learns the frequency corresponding to abnormal conditions, and convenient for investigation, and measurement data is more accurate.
To solve the above problems, the present invention proposes a kind of body complex impedance measuring system, including：Signal generator, difference
Operational amplifier, the first signal isolator, second signal isolator, measuring resistance, third signal isolator, fourth signal isolation
Device, the first phase shifter, the first signal conditioning circuit, second signal modulate circuit and signal processing circuit；
The signal generator is generating the electric signal under set frequency；
The input terminal of the differential operational amplifier connects the output end of the signal generator, and two output ends connect respectively
Connect the input terminal of first signal isolator and second signal isolator, the differential operational amplifier is receiving the electricity
Signal simultaneously will be input to the first signal isolator and second signal isolator after its differential amplification；
Two leading-out terminals of first signal isolator are separately connected the first end and measuring resistance at one position of human body
First end, two leading-out terminals of the second signal isolator are separately connected the second end and standard electric at human body one position
The second end of resistance, between first signal isolator, measuring resistance, human body one position and second signal isolator
Form closed loop；
The both ends of the measuring resistance are also connected to the input terminal of third signal isolator；The third signal isolator
Output end connects first signal conditioning circuit, to send the normal voltage of standard resistor at two terminals after signal isolation is handled
Enter the first signal conditioning circuit；First signal conditioning circuit connects the signal processing circuit, to the standard electric
It is sent into the signal processing circuit after pressure conditioning；
The both ends at one position of the human body are also connected to the input terminal of fourth signal isolator；The fourth signal isolator
Output end connect the second signal modulate circuit, to by the test voltage at the human body one position both ends after isolation processing
It is sent into the second signal modulate circuit；The second signal modulate circuit connects the signal processing circuit, to described
It is sent into the signal processing circuit after test voltage conditioning；
The phase shifter is connected between the third signal isolator and first signal conditioning circuit and/or connects
Between the fourth signal isolator and the second signal modulate circuit, to the normal voltage and/or the survey
It tries voltage and carries out phase shift, so that the signal phase difference 90 on first signal conditioning circuit and second signal modulate circuit
Degree；
The signal processing circuit is to calculate the normal voltage of reception and the phase difference of test voltage, and according to phase shifter
On phase shift phase the phase difference is compensated, according to after compensation phase difference and the normal voltage and test voltage calculate
The human body body complex impedance of one position under the frequency.
According to one embodiment of present invention, the measuring resistance includes two divider resistances, two divider resistance strings
It is associated between a leading-out terminal of first signal isolator and a leading-out terminal of the second signal isolator, and
Concatenation point connects reference ground.
According to one embodiment of present invention, the signal processing circuit calculates the normal voltage and test voltage received
Phase difference, and phase difference is removed into the phase shift phase on phase shifter, the phase difference after being compensated, according to the phase difference after compensation
And the virtual value of the normal voltage and test voltage calculates the body complex impedance R under a frequencyJ：
Wherein,I=UR/RR, RRFor the resistance value of measuring resistance, URFor the virtual value of normal voltage, I is to close
The current value of cyclization road, UEFor the virtual value of test voltage, REFor the resistance value at human body one position.
According to one embodiment of present invention, the first alternating current of conditioning is sent directly by first signal conditioning circuit
To in the signal processing circuit；
The second signal modulate circuit has the second alternating current of two-way, and the second alternating current is sent into effective value measurement electricity all the way
Road is fed through after extracting the virtual value of the test voltage in the signal processing circuit；Another way is exchanged the second of conditioning
Electricity is sent directly into the signal processing circuit.
According to one embodiment of present invention, first signal conditioning circuit and second signal modulate circuit include extremely
Few two active filters and analog switch to be filtered to different frequency signals, the analog switch is switching not
With active filter realize the filtering to normal voltage or test voltage.
According to one embodiment of present invention, further include third signal conditioning circuit and fourth signal modulate circuit,
The third signal conditioning circuit is connected between the measuring resistance and the third signal isolator, to incite somebody to action
The normal voltage of the standard resistor at two terminals is sent into third signal isolator after carrying out signal condition；
The fourth signal modulate circuit is connected between human body one position and the fourth signal isolator, to incite somebody to action
The normal voltage at the both ends is sent into fourth signal isolator after carrying out signal condition.
According to one embodiment of present invention, third signal conditioning circuit and fourth signal modulate circuit are put including operation
Big circuit, the test voltage at the normal voltage of standard resistor at two terminals or the human body one position both ends to be amplified.
The present invention also provides a kind of body complex impedance measurement methods, include the following steps：
S1：Signal generator generates the electric signal under set frequency；
S2：Differential operational amplifier receive the electric signal and will be input to after its differential amplification the first signal isolator and
Second signal isolator, and first signal isolator, measuring resistance, human body one position and second signal isolator it
Between respond on the closed loop that is formed and be powered；
S3：The normal voltage of standard resistor at two terminals is sent to after the processing of third signal isolator in phase shifter, phase shifter
It is sent into the first signal conditioning circuit after normal voltage phase shift is handled, first signal conditioning circuit is to the normal voltage tune
Signal processing circuit is sent into after reason；The test voltage at the both ends at human body one position is sent to after the processing of fourth signal isolator
Second signal modulate circuit, the second signal modulate circuit are sent into the signal processing electricity after improving the test voltage
Road；Wherein, the phase shift of the phase shifter makes the signal phase on first signal conditioning circuit and second signal modulate circuit
90 degree of position difference；
S4：The signal processing circuit：The phase difference of the normal voltage and test voltage that receive is calculated, and according to phase shifter
On phase shift phase the phase difference is compensated, according to after compensation phase difference and the normal voltage and test voltage calculate
Body complex impedance of human body one position under a frequency.
According to one embodiment of present invention, further include step S5：Different frequency is set and recycles execution step S1-S4, directly
The frequency of extremely required measurement, which measures, to be finished.
According to one embodiment of present invention, further include step S6：The different parts cycle of switching connection human body executes step
Rapid S1-S5, until the position of required measurement measures and finishes.
After adopting the above technical scheme, the present invention has the advantages that compared with prior art：
The cooperation cooperation of system integrated connection relationship and each circuit module in through the embodiment of the present invention so that human body
The measurement of complex impedance carries out under single-frequency, and in calibration, result under which frequency can be directly learnt from measurement result
It is abnormal, it is debugged without the electric signal for each frequency, operation is more simple and efficient；By the way that phase shifter is arranged, make
The phase difference that 90 degree are finally kept between the standard signal that must be obtained and measuring signal is obtaining two paths of signals and is calculating the two
Phase difference after carry out phase compensation again so that measurement data is more accurate；And calculate body complex impedance be it is real-time, it is more smart
Really.
Description of the drawings
Fig. 1 is the structure diagram of the body complex impedance measuring system of one embodiment of the invention；
Fig. 2 is the structure diagram of part connection relation in Fig. 1；
Fig. 3 is the structure diagram of part connection relation in Fig. 1；
Fig. 4 is the flow diagram of the body complex impedance measurement method of one embodiment of the invention.
Description of symbols in figure：
1- signal generators, 2- differential operational amplifiers, the first signal isolators of 31-, 32- second signal isolators, 33-
Third signal isolator, 34- fourth signal isolators, 4- measuring resistances, the first signal conditioning circuits of 51-, 52- second signal tune
Manage circuit, 53- third signal conditioning circuits, 54- fourth signal modulate circuits, 6- phase shifters, 7- signal processing circuits.
Specific implementation mode
In order to make the foregoing objectives, features and advantages of the present invention clearer and more comprehensible, below in conjunction with the accompanying drawings to the present invention
Specific implementation mode be described in detail.
Many details are elaborated in the following description in order to fully understand the present invention.But the present invention can be with
Much implement different from other manner described here, those skilled in the art can be without prejudice to intension of the present invention the case where
Under do similar popularization, therefore the present invention is not limited to the specific embodiments disclosed below.
It is to be removed from main block diagram 1 to more clearly illustrate the connection relation of system referring to Fig. 1-3, Fig. 2 and Fig. 3
Out.In one embodiment, body complex impedance measuring system includes：Signal generator 1, differential operational amplifier 2, first
Signal isolator 31, second signal isolator 32, measuring resistance 4, third signal isolator 33, fourth signal isolator 34, the
One phase shifter 6, the first signal conditioning circuit 51, second signal modulate circuit 52 and signal processing circuit 7.It is of course also possible to root
Enter according to needing other circuit modules are arranged again.
The connection relation of the embodiment of the present invention focused between these circuit modules and the principle of cooperation cooperation, not
It is the details of physical circuit module, thus very detailed elaboration is not done to each circuit module herein.
The signal generator 1 is generating the electric signal under set frequency.Signal generator 1 can also be at connection signal
Manage circuit 7, by signal processing circuit 7 come be arranged its generation electric signal frequency, it is of course also possible to connect other controllers or
Person's setting corresponding configuration interface realizes the operation, specifically unlimited.
The electric signal is preferably ultra-weak electronic signal, that is, the small signal that amplitude is little, avoids bringing injury to human body.Letter
Number generator 1 for example may include the amplifying circuit of Direct Digital Synthesizer (DDS) and operational amplifier composition.DDS
It is signal generator, the electric signal of different frequency can be generated.DDS is input to operational amplifier by capacitance, by AC signal,
Low level signal amplification is exported.
In the present embodiment, signal isolation circuit includes the first signal isolator 31, second signal isolator 32, third signal
Isolator 33, fourth signal isolator 34.These signal isolators can be transformer, and primary side side is as input terminal, secondary side
Side is as leading-out terminal.Signal isolator can be such that signal generator or other circuit modules keeps apart with human body, due to transformation
Device has the function that energy is isolated, and electrical signal energy is made to weaken, and will not generate injury to human body, can protect tissue.
The input terminal of the differential operational amplifier 2 connects the output end of the signal generator 1, two output end difference
Connect the input terminal of first signal isolator 31 and second signal isolator 32.The differential operational amplifier 2 is connecing
The electric signal is received, and by after the single-ended electrical signal differential amplification, the signal for forming positive and negative two-pass DINSAR is separately input into first
Signal isolator 31 and second signal isolator 32.
Two leading-out terminals of first signal isolator 31 are separately connected the first end and standard electric at one position of human body
The first end of resistance 4, two leading-out terminals of the second signal isolator 32 be separately connected human body one position second end and
The second end of measuring resistance 4, in first signal isolator 31, measuring resistance 4, human body one position and second signal
Closed loop is formed between isolator 32.
In Fig. 1 and Fig. 2, the difference output end of differential operational amplifier 2, an original for being connected to the first signal isolator 31
Avris positive terminal, another is connected to the primary side side negative pole end of second signal isolator 32, the primary side of the first signal isolator 31
The primary side side positive terminal of side negative pole end and second signal isolator 32 is grounded；The first end of measuring resistance 4 connects the first signal
The secondary avris positive terminal of isolator 31, the secondary avris negative pole end of the second end connection second signal isolator 32 of measuring resistance 4；People
The first end at body one position connects the secondary avris negative pole end of the first signal isolator 31, the second end connection at human body one position
The positive terminal of the secondary avris of second signal isolator 32.Certainly, each terminal can also with the connection terminal of each signal isolator
It is all positive and negative to exchange.In the closed loop of formation, the electric signal of generation is responded from the secondary avris stream of the first signal isolator 31
Go out, after human body, the secondary avris of second signal isolator 32, measuring resistance 4, and it is secondary back to the first signal isolator 31
Avris.
The both ends of the measuring resistance 4 are also connected to the input terminal of third signal isolator 33, the spy as measuring resistance 4
Survey time road.The output end of the third signal isolator 33 connects first signal conditioning circuit 51, by the standard electric of reception
The normal voltage at 4 both ends is hindered after signal carries out isolation processing, is sent to the first signal conditioning circuit 51.The first signal tune
Reason circuit 51 connects the signal processing circuit 7, to reception after the normal voltage of isolation processing carries out signal condition, is sent into
The signal processing circuit 7.Measuring resistance 4 is that the higher resistance of precision is better.
The both ends at one position of the human body are also connected to the input terminal of fourth signal isolator 34, as human body one position
Detection circuit.The output end of the fourth signal isolator 34 connects the second signal modulate circuit 52, by the people of reception
After the test voltage at the body one position both ends carries out isolation processing, it is sent in the second signal modulate circuit 52.Described
Binary signal modulate circuit 52 connects the signal processing circuit 7, and signal tune is carried out to the test voltage through isolation processing of reception
After reason, it is sent into the signal processing circuit 7.
Normal voltage and test voltage are AC signals, and the first signal conditioning circuit 51 and second signal modulate circuit 52 divide
Yong Lai signal condition not carried out to normal voltage and test voltage, for example, can be filtered, waveform shaping etc. it is unlimited.
In Fig. 1-3, it is to belong to signal circuit and detection circuit to distinguish human body and the connection of measuring resistance 4, will detects
Loop feature is represented by dotted lines, but in practical work process, these dotted lines are the electrical connections of entity.
The phase shifter 6 be connected between the third signal isolator 33 and first signal conditioning circuit 51 and/
Or be connected between the fourth signal isolator 34 and the second signal modulate circuit 52, to the normal voltage
And/or the test voltage carries out phase shift, so that on first signal conditioning circuit 51 and second signal modulate circuit 52
Signal phase differs 90 degree.
In Fig. 1 and Fig. 3, phase shifter 6 is to be connected to the third signal isolator 33 and first signal condition electricity
Between road 51, and phase shifter is not connected between fourth signal isolator 34 and the second signal modulate circuit 52, also
It is to say, phase shift processing only is carried out to normal voltage, and do not do phase shift processing to test voltage, phase shift makes the phase of two paths of signals
90 degree of difference.Such setting can be handled in order to phase compensation.
Phase shifter 6 may include the lag filter circuit of operational amplifier and resistance capacitance composition, will pass through standard electric
The signal of resistance carries out phase shift, the convenient calculating for more accurately carrying out phase.Certainly, phase shifter, which can also be other, can realize shifting
The circuit module of phase ensures that institute's jayrator is being able to detect that or known.
The purpose of phase shift is that have one in the signal of detection circuit because the signal of detection circuit is not ideal sinusoidal signal
The noise contribution of certainty ratio.
In power analysis theory, the average mode of energy integral may be used to calculate in the active power of load：
And in metastability exchange circuit analysis, the active power of the linear load of sinusoidal excitation is as follows：
Wherein U and I is the virtual value of voltage and current, i.e. root-mean-square value：
Wherein, T is the period, and U (t) is the voltage in time t, and I (t) is the electric current in time t.
Phase angle can be obtained by simple arccos operations, only be the absence of symbolic information.In the actual field of application
Jing Zhong, human body is capacitive load forever and the phase shift that brings is no more than 10 °, therefore does not need symbolic information.Due to signal
Grass come consequence be power-factor angle ≠ phase angle difference, that is to say, that phase angle cannot be obtained simply by arccos operations
It arrives.Fortunately, when mixing white noise in sinusoidal signal, it still can guarantee the total work when two sinusoidal signals itself are orthogonal
Rate factor is zero.This conclusion will be explained from the orthogonality of sinusoidal base and the angle of probability theory, briefly, due to white noise
It is random distribution, therefore the pertinency factor between two white noise signals is zero, it is related between white noise and sinusoidal signal
Factor is also zero, will not generate projection mutually, that is the white noise of standard will not be tested from the perspective of circuit analysis
Unit contributes active power.
Using this characteristic, a conclusion can be obtained：Phase difference between two groups of sinusoidal signals has closer to 90 °
The white noise that the measurement accuracy of work(power mixes in by signal is influenced smaller.The work of " phase shifter " on signal conditioning circuit
Be exactly by fine tuning ensure two paths of signals can with close to 90 ° of relative phase be measured, to reduce white noise pair to the greatest extent
The influence of measurement accuracy keeps measurement result more acurrate.
The signal processing circuit 7 is to calculate the normal voltage of reception and the phase difference of test voltage, and according to phase shift
Phase shift phase on device 6 compensates the phase difference, according to the phase difference and the normal voltage and test voltage after compensation
The calculating human body body complex impedance of one position under the frequency.Due to having carried out phase shift previously by phase shifter 6, thus counting
It needs to return phase shift when calculating body complex impedance.
Preferably, the measuring resistance 4 includes two divider resistances, which is connected on first signal
Between one leading-out terminal of isolator 31 and a leading-out terminal of the second signal isolator 32, and concatenates point and connect reference
Ground.That is, the concatenation point ground connection of two divider resistances, the point without concatenation are separately connected the one of the first signal isolator 31
One leading-out terminal of a leading-out terminal and the second signal isolator 32.It is appreciated that each divider resistance can be one
A list resistance can also be a serial or parallel connection or the resistor network of connection in series-parallel mixing.Can be by the ground connection of measuring resistance 4
Signal in closed loop provides one and refers to earth signal, and it is that best reference point connects that reference ground, which is connected in measuring resistance 4,
Position is connect, reference signal makes the calculating of each signal all more simple, without carrying out complicated conversion.
In one embodiment, the signal processing circuit 7 calculates the phase difference of the normal voltage and test voltage that receive,
And phase difference is removed into the phase shift phase on phase shifter 6, the phase difference after being compensated.Phase be tool it is directive, thus
Phase difference need to be considered positive and negative when subtracting phase shift phase, carry out corresponding compensation so that the phase that phase shifter 6 is moved can be moved back to
Come.
According to after compensation phase difference and the virtual value of the normal voltage and test voltage calculate the people under a frequency
Body complex impedance RJ：
Wherein,I=UR/RR, RRFor the resistance value of measuring resistance, URFor the virtual value of normal voltage, I is
Current value on closed loop, UEFor the virtual value of test voltage, REFor the resistance value at human body one position.
Preferably, there is the first alternating current in first signal conditioning circuit 51, carried by the first selective frequency filter circuit
It is sent directly into the signal processing circuit after taking the first alternating current of signal in the measuring resistance conditioned；Second signal
Modulate circuit 52 has the second alternating current of two-way, after the second selective frequency filter circuit is extracted from by one position signal of human body, one
The second alternating current of road is sent into effective value measurement circuit, and the signal processing electricity is fed through after extracting the virtual value of the test voltage
Lu Zhong is sent directly into after the second alternating current of another way is conditioned into the signal processing circuit.
That is, the calculating of effective value of alternating current is placed in signal conditioning circuit, only need to in signal processing circuit
It carries out phase difference calculating and compensation and calculates final body complex impedance using virtual value.Certainly, the first signal condition
The circuit part that can also include other signal conditions in circuit 51 and second signal modulate circuit 52, in the same of output virtual value
When, the signal of phase can be at least characterized in output end output.
The virtual value counting circuit that effective value measurement circuit can be made of operational amplifier, diode, resistance capacitance, can
To use existing virtual value counting circuit, the related circuit module etc. e.g. in current effective value measuring circuit.
Preferably, first signal conditioning circuit 51 and second signal modulate circuit 52 include at least two to right
The active filter and analog switch that different frequency signals are filtered, the analog switch is switching different active power filterings
Device realizes the filtering to normal voltage or test voltage.Active filter can pass through operational amplifier, resistance and capacitance etc.
Composition, can be existing active filter, and the corresponding different active filter of measurement of different frequency is measured in different frequency
When, it is switched to by analog switch on corresponding active filter, to export after being filtered to the signal received.
Virtual value counting circuit above-mentioned can be connected to analog switch, receive the signal of active filter filtering output into
Row effective value measurement, certainly, the signal of active filter output are also outputted to the calculating that phase difference is carried out in signal processing circuit
And compensation.
In one embodiment, body complex impedance measuring system can also include that third signal conditioning circuit 53 and the 4th is believed
Number modulate circuit 54.The third signal conditioning circuit 53 is connected to the measuring resistance 4 and the third signal isolator 33
Between, third signal isolator 33 will be sent into after the normal voltage at 4 both ends of measuring resistance progress signal condition；It is described
Fourth signal modulate circuit 54 is connected between human body one position and the fourth signal isolator 34, to by human body this one
The test voltage at the both ends at position is sent into fourth signal isolator 34 after carrying out signal condition.
Preferably, third signal conditioning circuit 53 and fourth signal modulate circuit 54 include operational amplification circuit, to
The test voltage at the normal voltage of standard resistor at two terminals or the human body one position both ends is amplified.Operational amplification circuit can be with
It is made of operational amplifier, resistance and capacitance etc., can be existing operational amplification circuit.
Referring to Fig. 4, the present invention also provides a kind of body complex impedance measurement methods, and the human body of previous embodiment can be used multiple
Impedance measurement system realizes that this approach includes the following steps：
S1：Signal generator generates the electric signal under set frequency；
S2：Differential operational amplifier receive the electric signal and will be input to after its differential amplification the first signal isolator and
Second signal isolator, and first signal isolator, measuring resistance, human body one position and second signal isolator it
Between respond on the closed loop that is formed and be powered；
S3：The normal voltage of standard resistor at two terminals is sent to after the processing of third signal isolator in phase shifter, phase shifter
It is sent into the first signal conditioning circuit after normal voltage phase shift is handled, first signal conditioning circuit is to the normal voltage tune
Signal processing circuit is sent into after reason；The test voltage at the both ends at human body one position is sent to after the processing of fourth signal isolator
Second signal modulate circuit, the second signal modulate circuit are sent into the signal processing electricity after improving the test voltage
Road；Wherein, the phase shift of the phase shifter makes the signal phase on first signal conditioning circuit and second signal modulate circuit
90 degree of position difference；
S4：The signal processing circuit：The phase difference of the normal voltage and test voltage that receive is calculated, and according to phase shifter
On phase shift phase the phase difference is compensated, according to after compensation phase difference and the normal voltage and test voltage calculate
Body complex impedance of human body one position under a frequency.
Above-mentioned steps, the body complex impedance completed under the unifrequency for one position of human body measure.
According to one embodiment of present invention, further include step S5：Different frequency is set and recycles execution step S1-S4, directly
The frequency of extremely required measurement, which measures, to be finished.
By step S5, realize that the corresponding body complex impedance of the multi-frequency at human body one position measures, and under each frequency
Measurement all independently carry out, be also known with the body complex impedance result one-to-one relationship measured, if thus wherein
Result mistake at one can rapidly know it is the measurement generation mistake under which frequency, and operation is more simple and efficient, does not need one
A pair of each frequency carries out debugging investigation.
According to one embodiment of present invention, further include step S6：The different parts cycle of switching connection human body executes step
Rapid S1-S5, until the position of required measurement measures and finishes.
By step S6, realize that the corresponding body complex impedance of the multi-frequency at the multiple positions of human body measures.It is appreciated that step
S5 and S6 can certainly be exchanged, and be exactly often to survey a frequency position measured just will all be needed to measure one time, so
After replace next frequency again to whole positions carry out one-shot measurement.
More particular contents of body complex impedance measurement method about the embodiment of the present invention may refer to previous embodiment
Body complex impedance measuring system part description content, details are not described herein.
Although the present invention is disclosed as above with preferred embodiment, it is not for limiting claim, any this field
Technical staff without departing from the spirit and scope of the present invention, can make possible variation and modification, therefore the present invention
Protection domain should be subject to the range that the claims in the present invention are defined.
Claims (10)
1. a kind of body complex impedance measuring system, which is characterized in that including：Signal generator, differential operational amplifier, the first letter
Number isolator, second signal isolator, measuring resistance, third signal isolator, fourth signal isolator, the first phase shifter,
One signal conditioning circuit, second signal modulate circuit and signal processing circuit；
The signal generator is generating the electric signal under set frequency；
The input terminal of the differential operational amplifier connects the output end of the signal generator, and two output ends are separately connected institute
State the input terminal of the first signal isolator and second signal isolator, the differential operational amplifier is receiving the electric signal
And the first signal isolator and second signal isolator will be input to after its differential amplification；
Two leading-out terminals of first signal isolator be separately connected one position of human body first end and measuring resistance
One end, two leading-out terminals of the second signal isolator are separately connected the second end and measuring resistance at human body one position
Second end, to be formed between first signal isolator, measuring resistance, human body one position and second signal isolator
Closed loop；
The both ends of the measuring resistance are also connected to the input terminal of third signal isolator；The output of the third signal isolator
End connects first signal conditioning circuit, the normal voltage of standard resistor at two terminals to be sent into the after signal isolation is handled
One signal conditioning circuit；First signal conditioning circuit connects the signal processing circuit, to the normal voltage tune
The signal processing circuit is sent into after reason；
The both ends at one position of the human body are also connected to the input terminal of fourth signal isolator；The fourth signal isolator it is defeated
Outlet connects the second signal modulate circuit, the test voltage at the human body one position both ends to be sent into after isolation processing
The second signal modulate circuit；The second signal modulate circuit connects the signal processing circuit, to the test
It is sent into the signal processing circuit after voltage conditioning；
The phase shifter is connected between the third signal isolator and first signal conditioning circuit and/or is connected to institute
It states between fourth signal isolator and the second signal modulate circuit, to the normal voltage and/or test electricity
Pressure carries out phase shift, so that the signal phase on first signal conditioning circuit and second signal modulate circuit differs 90 degree；
The signal processing circuit is to calculate the normal voltage of reception and the phase difference of test voltage, and according on phase shifter
Phase shift phase compensates the phase difference, according to after compensation phase difference and the normal voltage and test voltage calculate human body
The body complex impedance of one position under the frequency.
2. body complex impedance measuring system as described in claim 1, which is characterized in that the measuring resistance includes two partial pressures
Resistance, two divider resistances are connected on a leading-out terminal of first signal isolator and the second signal isolator
A leading-out terminal between, and concatenate point connect reference ground.
3. body complex impedance measuring system as described in claim 1, which is characterized in that the signal processing circuit, which calculates, to be received
Normal voltage and test voltage phase difference, and by phase difference remove phase shifter on phase shift phase, the phase after being compensated
Potential difference, according to after compensation phase difference and the virtual value of the normal voltage and test voltage to calculate the human body under a frequency multiple
Impedance RJ：
Wherein,I=UR/RR, RRFor the resistance value of measuring resistance, URFor the virtual value of normal voltage, I is to be closed
Current value on loop, UEFor the virtual value of test voltage, REFor the resistance value at human body one position.
4. body complex impedance measuring system as claimed in claim 3, which is characterized in that first signal conditioning circuit will be adjusted
First alternating current of reason is sent directly into the signal processing circuit；
The second signal modulate circuit has the second alternating current of two-way, and the second alternating current is sent into effective value measurement circuit all the way,
It is fed through in the signal processing circuit after extracting the virtual value of the test voltage；Another way is by the second alternating current direct of conditioning
It connects and is fed through in the signal processing circuit.
5. the body complex impedance measuring system as described in claim 1 or 3, which is characterized in that first signal conditioning circuit
With second signal modulate circuit including at least two to the active filter being filtered to different frequency signals and simulation
Switch, the analog switch realize the filtering to normal voltage or test voltage to switch different active filters.
6. body complex impedance measuring system as described in claim 1, which is characterized in that further include third signal conditioning circuit and
Fourth signal modulate circuit,
The third signal conditioning circuit is connected between the measuring resistance and the third signal isolator, to will be described
The normal voltage of standard resistor at two terminals is sent into third signal isolator after carrying out signal condition；
The fourth signal modulate circuit is connected between human body one position and the fourth signal isolator, to will be described
The normal voltage at both ends is sent into fourth signal isolator after carrying out signal condition.
7. body complex impedance measuring system as claimed in claim 6, which is characterized in that third signal conditioning circuit and the 4th letter
Number modulate circuit includes operational amplification circuit, to by the normal voltage of standard resistor at two terminals or the human body one position both ends
Test voltage is amplified.
8. a kind of body complex impedance measurement method, which is characterized in that include the following steps：
S1：Signal generator generates the electric signal under set frequency；
S2：Differential operational amplifier receives the electric signal and will be input to the first signal isolator and second after its differential amplification
Signal isolator, and the shape between first signal isolator, measuring resistance, human body one position and second signal isolator
At closed loop on respond be powered；
S3：The normal voltage of standard resistor at two terminals is sent to after the processing of third signal isolator in phase shifter, and phase shifter will be marked
The first signal conditioning circuit is sent into after quasi- voltage shift phase processor, after first signal conditioning circuit improves the normal voltage
It is sent into signal processing circuit；The test voltage at the both ends at human body one position is sent to second after the processing of fourth signal isolator
Signal conditioning circuit, the second signal modulate circuit are sent into the signal processing circuit after improving the test voltage；Its
In, the phase shift of the phase shifter makes the signal phase on first signal conditioning circuit and second signal modulate circuit differ
90 degree；
S4：The signal processing circuit：The phase difference of the normal voltage and test voltage that receive is calculated, and according on phase shifter
Phase shift phase compensates the phase difference, according to after compensation phase difference and the normal voltage and test voltage calculate human body
Body complex impedance of one position under a frequency.
9. body complex impedance measurement method as claimed in claim 8, which is characterized in that further include step S5：Different frequencies are set
Rate cycle executes step S1-S4, until the frequency of required measurement is measured and finished.
10. body complex impedance measurement method as claimed in claim 9, which is characterized in that further include step S6：Switching connection people
The different parts cycle of body executes step S1-S5, until the position of required measurement measures and finishes.
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| CN201711452173 | 2017-12-27 | ||
| CN2017114521737 | 2017-12-27 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201810154762.5A Pending CN108378850A (en) | 2017-12-27 | 2018-02-22 | Body complex impedance measuring system and method |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110738820A (en) * | 2019-10-31 | 2020-01-31 | 国网河南省电力公司信息通信公司 | distribution operation field safety early warning circuit |
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| CN2669791Y (en) * | 2003-08-05 | 2005-01-12 | 彭飞 | Human body impedance measuring devices |
| US20050054944A1 (en) * | 2003-09-05 | 2005-03-10 | Tanita Corporation | Bioelectrical impedance measuring apparatus |
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| CN203988052U (en) * | 2014-07-10 | 2014-12-10 | 北京东华原医疗设备有限责任公司 | For measuring the device of bio-electrical impedance |
| CN205831788U (en) * | 2016-05-06 | 2016-12-28 | 武汉大学 | A kind of bio-impedance measurement system |
| CN206603770U (en) * | 2016-09-27 | 2017-11-03 | 常熟理工学院 | A kind of SCM Based physiology impedance instrument |
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|---|---|---|---|---|
| CN2669791Y (en) * | 2003-08-05 | 2005-01-12 | 彭飞 | Human body impedance measuring devices |
| US20050054944A1 (en) * | 2003-09-05 | 2005-03-10 | Tanita Corporation | Bioelectrical impedance measuring apparatus |
| CN101579236A (en) * | 2009-06-05 | 2009-11-18 | 大连大学 | Multi-frequency and multi-segment measuring device and measuring method of human body impedance |
| CN203988052U (en) * | 2014-07-10 | 2014-12-10 | 北京东华原医疗设备有限责任公司 | For measuring the device of bio-electrical impedance |
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| CN110738820A (en) * | 2019-10-31 | 2020-01-31 | 国网河南省电力公司信息通信公司 | distribution operation field safety early warning circuit |
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