A kind of portable body analytical instrumentTechnical field
The present invention relates to a kind of equipment for analyzing human body component content, belonging to human body component examination and analysb technical field.
Background technology
Bioelectrical impedance analysis (BIA) is the technology of the human body composition grown up in nearly 20 years, because it has that noinvasive can't harm, the repeatability measured is high and the advantage such as the high sensitive of dynamic change, become the hot topic of research always.
Bioelectrical impedance analysis is a kind of by electrochemical method determining body water and fatty technology, faint (being less than 500 μ A) harmless ac signal is imported human body, and electric current can flow by little along with resistance, that conductive performance is good body fluid.And the cell of a large amount of various shape is contained in the biological tissue in human body, the liquid between these cells can be considered as electrolyte, has good electric conductivity.Because we can be considered as electric capacity cell membrane, when direct current or low-frequency current put on biological tissue, cell can be considered as insulation, and electric current will walk around cell, mainly flow through extracellular fluid.When power frequency increases, the capacitive reactance of cell membrane reduces, and one part of current will flow through intracellular fluid through cell membrane.Research shows, when the frequency of electric current is less than 50KHz, electric current does not flow through intracellular fluid substantially, and test is main measures extracellular resistance; And when the frequency of electric current increases gradually, the ratio that electric current flows through intracellular fluid increases gradually, thus the resistance of intracellular fluid and extracellular liquid can be measured simultaneously.In addition, non-fat tissue contains a large amount of water and eletrolytes, conducts electricity very well, and electrical impedance is less, and fat is anhydrous substances, and electrical impedance is larger.Therefore, when applying the alternating current of the different constant magnitude of frequency to human body, in human body, non-fat is more, and electrical impedance is lower; Body fat mass in human body is more, and electrical impedance is higher.In addition, form according to anatomy and human body and learn, between the compositions such as total body water content (TBW) and fat free body weight (FFM), whole body potassium content (TBK) and fat free body weight, whole body potassium content and BCM (BCM), all there is fixing ratio.According to above principle, use multiple linear regression method statistically, the regression equation of impedance, height, body weight, sex, age and human body component content can be set up, can accurately for the measurement of human body component content.
Present stage, the bioelectrical impedance analysis instrument of main flow presented the trend of polarization: a kind of structure is simple, only have four electrodes even two electrodes, the precision of measurement is low, measures content few, generally can only be applied to the simple machines such as fat scale, the more requirement of people can not be met; Another kind of complex structure volume is large, and be inconvenient to move, must be operated by professional, expensive, be substantially applied to the professional institutions such as hospital, general public use cost is too high." a kind of bioelectrical impedance analysis device " and CN202141974U disclosed " there is the notebook computer of human body component analysis function " disclosed in Chinese patent literature CN203953657U.
Summary of the invention
The present invention is directed to the deficiency that existing bioelectrical impedance analysis technology exists, provide one to have and measure multiformity and accuracy, volume is little, simple and quick, be convenient to the portable body analytical instrument measured.
Portable body analytical instrument of the present invention, adopts following technical scheme:
This analyser, comprises Master control chip, measured body weight circuit, reference impedance circuit, human body impedance measuring circuit, measurement electrode, communication module and host computer; Master control chip is connected with host computer by communication module; Human body impedance measuring circuit comprises pre-filtering amplifying circuit and operating die, operating die is directly connected with Master control chip, operating die has included constant current source generating circuit, analog to digital conversion circuit and electrode gating circuit, and pre-filtering amplifying circuit is connected with analog to digital conversion circuit; Measured body weight circuit is directly connected with described operating die; Reference impedance circuit is connected by measurement electrode with human body impedance measuring circuit.
Host computer comprises computer or embedded platform, and these two modules (computer and embedded platform) are separate, but operationally can only have a module work.Host computer is used for man-machine interaction, system initialization, portable collection and receives and process data, display and management measurement result, for portable acquisition and processing data, and display measurement result.
Communication module comprises serial communication modular or bluetooth communication, and these two modules are separate, but operationally can only have a module work; Serial communication modular is connected with computer, carries out data transmission simultaneously and communicates with control; Bluetooth communication is connected with embedded platform, carries out data transmission simultaneously and communicates with control.
Measurement electrode comprises six road galvanic electrodes and six road voltage electrodes, and wherein two-way voltage electrode is connected with reference impedance circuit with two-way galvanic electrode, and all the other voltage electrodes are all directly connected with human body with galvanic electrode.
The voltage electrode be directly connected with human body and galvanic electrode adopt combined electrode structure, comprise two and hold handle and two foot pedals, each handle of holding comprises a pin interfaces, be provided with a symmetrical two panels galvanic electrode in road by pin interfaces holding handle front end, rear end is provided with symmetrical two plate electrodes in a road; Foot pedal is divided into independently two pieces, left and right, every block foot pedal is arranged a pin interfaces, this pin interfaces connects road a slice galvanic electrode and road a slice voltage electrode, and pedal front end is provided with the conducting block being communicated with galvanic electrode, and rear end is provided with the conducting block being communicated with voltage electrode.
Measured body weight circuit is connected with operating die, adopts quadrupole bridge pressure sensor, directly measures body weight data and is transferred to host computer via Master control chip.
Reference impedance circuit is in parallel with extracellular fluid equivalent resistance Re in the lump again after intracellular fluid equivalent resistance Ri connects with cell membrane equivalent capacity C.Reference impedance circuit, under Master control chip controls, provides fixing reference value when each measurement, reduces measurement error, ensure certainty of measurement.
Human body impedance measuring circuit controls by Master control chip, and primary responsibility gathers human limb impedance information and trunk impedance information and the data collected are transferred to host computer via Master control chip.It is 375uA that the Master control chip constant-current source circuit controlled in operating die produces constant magnitude, frequency is the adjustable electric current putting on reference impedance circuit and human body of 1KHz-250KHz, then galvanic electrode opened by Master control chip control electrode gating circuit, the electric current of assigned frequency is applied to reference impedance circuit or human body, open corresponding voltage electrode simultaneously, the voltage signal detected is sent into operating die after preposition filter amplification circuit, and warp after date processing is transferred to host computer by Master control chip by operating die.Computer or embedded platform be possessor's machine interactive interface all, tester can input its data, the beginning of control survey and end, and according to the mode control survey circuit working set, control gating and the closedown of corresponding galvanic electrode and voltage electrode, and by human-computer interaction interface viewing, storage or deletion measurement result.
The present invention is by reasonably combined, the reference impedance circuit of each road measurement electrode and the abundant use of human body impedance measuring measuring circuit and host computer disposal ability, not only ensure that multiformity and the accuracy of measurement, also reduce the volume of equipment fully, achieve the portable type measuring of simple and fast.
Accompanying drawing explanation
Fig. 1 is the structured flowchart of analyser of the present invention.
Fig. 2 is the workflow diagram of analyser of the present invention.
Fig. 3 is the reference impedance circuit theory diagrams of analyser of the present invention, and Re is extracellular fluid equivalent resistance, and Ri is intracellular fluid equivalent resistance, and C is cell membrane equivalent capacity.
Detailed description of the invention
As shown in Figure 1, portable body analytical instrument of the present invention comprises Master control chip, measured body weight circuit, reference impedance circuit, human body impedance measuring circuit, measurement electrode, communication module and host computer.Master control chip can adopt single-chip microcomputer.
Master control chip is connected with host computer by communication module.Master control chip is responsible for the collection controlling body weight information and impedance information, and communicates with host computer.Host computer comprises computer or embedded platform.Its Computer is mainly used in man-machine interaction, the initialization of control system, receives and process data, and display and management measurement result, lay particular emphasis on the use of stiff end.Embedded platform is mainly used in portable acquisition and processing data, and display measurement result mainly lays particular emphasis on the use of mobile terminal.Communication module comprises serial communication circuit or bluetooth communication circuit.Wherein serial communication circuit is connected with computer, carries out data transmission simultaneously and communicates with control; Bluetooth communication circuit is connected with embedded platform, carries out data transmission simultaneously and communicates with control.
Measured body weight circuit is connected with operating die, adopts quadrupole bridge pressure sensor, directly measures body weight data and is transferred to host computer via Master control chip.
Human body impedance measuring circuit comprises pre-filtering amplifying circuit and operating die, and operating die has included constant current source generating circuit, analog to digital conversion circuit and electrode gating circuit, and pre-filtering amplifying circuit is connected with analog to digital conversion circuit.Filter amplification circuit, constant current source generating circuit, analog to digital conversion circuit and electrode gating circuit adopt existing custom circuit.
As shown in Figure 3, the circuit structure that reference impedance circuit is in parallel with extracellular fluid equivalent resistance Re in the lump again after adopting intracellular fluid equivalent resistance Ri to connect with cell membrane equivalent capacity C.Reference impedance circuit is connected with operating die by measurement electrode, under Master control chip controls, provides fixing reference value, reduce measurement error, ensure certainty of measurement when each measurement.Give the schematic diagram of reference impedance circuit.
Human body impedance measuring circuit is controlled by Master control chip by operating die, and primary responsibility gathers human limb impedance information and trunk impedance information and the data collected are transferred to host computer via Master control chip.It is 375 μ A that the Master control chip constant-current source circuit controlled in operating die produces constant magnitude, frequency is the adjustable electric current putting on reference impedance circuit and human body of 1KHz-250KHz, then galvanic electrode opened by Master control chip control electrode gating circuit, the electric current of assigned frequency is applied to reference impedance circuit or human body, open corresponding voltage electrode simultaneously, the voltage signal detected is sent into operating die after preposition filter and amplification, and warp after date processing is transferred to host computer by Master control chip by operating die.
Measurement electrode is connected with human body impedance measuring circuit, is connected respectively with the constant current source generating circuit in pre-filtering amplifying circuit and operating die and electrode gating circuit.Measurement electrode comprises galvanic electrode and voltage electrode, and galvanic electrode and voltage electrode respectively have 6 tunnels, comprises altogether 12 path electrodes.Wherein 4 tunnels (two-way voltage electrode and two-way galvanic electrode) is connected with reference impedance circuit, and this 4 path electrode adopts plate to carry fixed form, and its position and connected mode can not be changed again.Remain 8 tunnels to be directly connected with human body, this 8 path electrode have employed combined electrode structure, comprise two and hold handle and two panels foot pedal two parts, each handle of holding comprises a pin interfaces, a symmetrical two panels galvanic electrode in road is provided with holding handle front end by pin interfaces, rear end is provided with symmetrical two plate electrodes in a road, and the insulation distance between galvanic electrode and voltage electrode is 2.5cm.Foot pedal adopts insulant separation design, be divided into independently two pieces, left and right, every block pedal comprises a pin interfaces, each pin interfaces connects a road electric current and a road voltage electrode, pedal front end is the conductive metal material that one piece of 4cm*5cm is communicated with galvanic electrode, be the conductive metal material that one piece of 4cm*4cm is communicated with voltage electrode below, the insulation distance of the two pieces of conductive metal material in front and back is 9cm.
The workflow of above-mentioned analyser as shown in Figure 2.
To be initiatedly to complete after start etc., now personnel to be measured can consult and manage former measurement result, if carry out new measurement, then need to input the various data of person to be measured, comprise age, height, sex, by selecting metering system, body weight also can input, and need not carry out slave computer measurement again.After various setting completes, the measurement carrying out impedance can be started, first the resistance value of witness mark resistance, the data recorded are transmitted back host computer; Then measure the segmentation frequency division impedance of human body, the result measured is transmitted back host computer.After slave computer is all measured and is transmitted, the data analysis that host computer will record, and demonstrate result, after person to be measured finishes watching measurement result, host computer can store this measurement result.