CN203354542U - Device for evaluating edema of human limbs based on bioimpedance - Google Patents

Abstract

The utility model discloses a device for evaluating the edema of human limbs based on bioimpedance. The device comprises a microprocessor which is mounted on a protecting device, a stimulating current generating module, an impedance measuring module and a display and control module, wherein the stimulating current generating module, the impedance measuring module and the display and control module are respectively connected with the microprocessor. According to the device, by the aid of an electrode on the surface of a detected position, through control of the microprocessor, stimulating currents of different frequencies are generated to act on the detected position, and the index of the edema is calculated and evaluated in real time combined with the height h, the weight w and the perimeter l of the detected position of a detected person according to the detected impedance value of the detected position. The bioimpedance measured through the comprehensive same frequency can avoid misdiagnosis caused by single frequency measuring.

Description

A kind of device based on bio-impedance assessment human body edema of the limbs

Technical field

This utility model relates to the armarium technical field, is specifically related to assess the device of human body edema of the limbs.

Background technology

Edema refers in EV interstice has too much body fluid to gather, and is a kind of common pathological process.Edema can indicate the disease that some are inner usually, and as diseases such as hypertension, diabetes, congestive heart disease, so the detection of edema has great significance in clinical.

The detection of edema still stretches and the gloss situation by observing edema area clinically at present, and the compressing edema area observes whether depression is arranged.Yet such Clinical detection method can not detect relevant disease as early as possible, but etc. the edema symptom testing result is comparatively obviously just arranged.And the method for bio-impedance carry out edema monitoring be exactly utilize organize and the functional pathological changes of organ often prior to the characteristics of organic disease and clinical symptoms, prevent timely and guard.

Biological tissue is at the electrical properties of low frequency region (lower than 1MHz) extracellular fluid, intracellular fluid close to resistance, and cell membrane can equivalent capacity.At present most widely used three assembly equivalent-circuit models as shown in Figure 1, R wherein _i, R _e, C _mbe respectively intracellular fluid equivalent resistance, extracellular fluid equivalent resistance and cell membrane equivalent capacity.

The track of bio-impedance three element equivalent-circuit model on complex plane is a semicircle of fourth quadrant, is called impedance circle diagram, and as shown in Figure 2, its electrical impedance characteristic equation is

$Z=R_{\∞}+\frac{R_0-R_{\∞}}{1+\mathrm{j\ω}{\mathrm{\τ}}^{\mathrm{\α}}}$

R wherein ₀, R _∞, τ represents respectively the resistance value that frequency is 0, resistance value, the time constant that frequency is infinite general goal.

Summary of the invention

Goal of the invention: for above-mentioned prior art, provide a kind of device based on bio-impedance assessment human body edema of the limbs, solve subjectivity and hysteresis quality that traditional clinical edema detects.

Technical scheme: a kind of device based on bio-impedance assessment human body edema of the limbs, comprise the microprocessor be arranged on protector, and the stimulating current generation module, impedance bioelectrical measurement module, demonstration and the control module that with microprocessor, are connected respectively; Wherein:

Described stimulating current generation module comprises: the DDS module, VCCS module, the stimulating electrode that connect successively; Described microprocessor is controlled the DDS module and is produced the sine voltage signal, and is transferred to described VCCS module; Described VCCS module is converted to current signal by the sine voltage signal received, and is transferred to described stimulating electrode; Described stimulating electrode comprises the first stimulating electrode, the second stimulating electrode, for injecting stimulating current to tested position;

Described impedance bioelectrical measurement module comprises: the measurement electrode, signal condition module, the width phase detection module that connect successively, and described width phase detection module is connected with described microprocessor; Described measurement electrode comprises the first measurement electrode, the second measurement electrode, inject potential difference between 2 of stimulating currents for gathering on tested position, and the transmission potential difference signal is to described signal condition module; Described signal condition module sends to described width phase detection module after the potential difference signal amplification filtering is processed; Described width phase detection module, for after extracting the amplitude and phase place that receives signal, is sent to described microprocessor;

Described demonstration comprises with control module LCD, the keyboard that is connected respectively described microprocessor, and bluetooth communication module; Described microprocessor is used for carrying out the edema evaluation according to the amplitude and the phase information that receive, and appreciation information is sent to described LCD, and described microprocessor is controlled described bluetooth communication module and sent appreciation information to computer simultaneously.

Beneficial effect: device of the present utility model is by the electrode that is placed in surface, tested position, by microprocessor, control, the stimulating current that produces different frequency acts on tested position, and, according to the tested position resistance value recorded, calculate in real time the index of assessment edema in conjunction with measured's height h, body weight w, tested position girth l.The bio-impedance of measuring by comprehensive same frequency, the mistaken diagnosis that can avoid the single-frequency measurement to cause.Simultaneously, the formation of edema exists time integral, and this utility model can be to be combined with the equipments such as edema apparatus for evaluating and human limb protector.Thereby can carry out to tested position the monitoring of long-term edema, and according to the variation of impedance, aggregative indicator is carried out the edema judgement, and appreciation information is presented at timely to LCD and sends to the host computer system by bluetooth communication, obtain in time the accurate information of the state of an illness to facilitate patient and doctor.Edema apparatus for evaluating of the present utility model also has noinvasive, cheapness, safe, nontoxic and informative characteristics.

The accompanying drawing explanation

Fig. 1 is bio-impedance equivalent-circuit model figure;

Fig. 2 is traditional biological impedance circle diagram or Cole-Plot;

Fig. 3 is the impedance measurement edema apparatus for evaluating in legging;

Fig. 4 is the bio-impedance testing system structure chart;

Fig. 5 is the bio-impedance value matching Cole impedance circle diagram of measuring;

Fig. 6 is that intermittent is measured bio-impedance amplitude under experimenter's different stimulated frequency and the graph of a relation of time.

The specific embodiment

Below in conjunction with accompanying drawing, this utility model is done further and explained.

As shown in Figure 3, Figure 4, a kind of device based on bio-impedance assessment human body edema of the limbs, comprise the legging 7 be enclosed within on shank 6, be arranged on the microprocessor 11 on legging 7, and the stimulating current generation module, impedance bioelectrical measurement module, demonstration and the control module that with microprocessor 11, are connected respectively.Wherein:

Stimulating current generation module comprises: the DDS module 14, VCCS module 15, the stimulating electrode 4 that connect successively.Described microprocessor 11 is controlled DDS module 14 and is produced the sine voltage signal according to the human-body safety electric current, and is transferred to described VCCS module 15.VCCS module 15 is converted to current signal by the sine voltage signal received, and is transferred to stimulating electrode 4, and the stimulating current frequency is 10-50KHz here, and size of current is 0.2-2mA.Stimulating electrode 4 comprises the first stimulating electrode 4a, the second stimulating electrode 4b, for injecting stimulating current to tested position; Two 5 centimetres of electrode gap left and right.Stimulating electrode can adopt the karaya electrode that band electrode that width is 0.8 centimetre or diameter are 3 centimetres, or disposable electrocardiogram Ag/AgCI adhesive electrode.

The impedance bioelectrical measurement module comprises: the measurement electrode 5, signal condition module 9, the width phase detection module 10 that connect successively, width phase detection module 10 also is connected with microprocessor 11.Measurement electrode 5 comprises the first measurement electrode 5a, the second measurement electrode 5b; Two measurement electrode, between two stimulating electrodes, inject potential difference between 2 of stimulating currents for gathering on tested position, and the transmission potential difference signal are to described signal condition module 9.Signal condition module 9 sends to width phase detection module after the potential difference signal amplification filtering is processed.Width phase detection module 10, for after extracting the amplitude and phase place that receives signal, is sent to microprocessor 11.Voltage electrode can adopt diameter to be about 1 centimetre and scribble the karaya electrode of conductive paste.

Show and comprise with control module LCD13, the keyboard 12 that is connected respectively microprocessor 11, and bluetooth communication module 14.Microprocessor 11 is used for carrying out the edema evaluation according to the amplitude and the phase information that receive, and appreciation information is sent to LCD13, and microprocessor 11 is controlled bluetooth communication module 14 and sent appreciation information to computer simultaneously.

The using method of the device based on above-mentioned assessment human body edema of the limbs, comprise the steps:

Step 1): it is 10-50KHz that microprocessor is controlled stimulating current generation module generation frequency, and size is the stimulating current of 0.2-2mA, and injects tested position by the first stimulating electrode, the second stimulating electrode;

Step 2): measure the potential difference of tested position between two stimulating electrodes by the first measurement electrode in the impedance bioelectrical measurement module and the second measurement electrode, and amplitude and the phase value of the potential difference that records under different frequency are sent to microprocessor;

Step 3): amplitude and phase value according to the stimulating current value of different frequency and the corresponding potential difference recorded calculate tested position resistance value, and draw the Cole impedance diagram according to the resistance value matching; In conjunction with the Cole impedance diagram, and measured's height h, body weight w, tested position girth l, according to index, E assesses edema.

Wherein, under the tested position different frequency calculated step 3), resistance value comprises extracellular fluid equivalent resistance R _e, the intracellular fluid equivalent resistance refers to R _i, cell membrane shunt capacitance value C _m; According to assess over time edema.

Over time, can find the increase along with the edema degree by observing bio-impedance under different frequency, the more low-impedance sensitivity to edema of frequency is higher.

The formation of edema exists the accumulation of time, and the judgement of absolute index can not judge the edema state accurately, therefore by native system and the daily life tools effect that combination is guarded for a long time to reach edema as equipments such as leggings.According to desired value E property over time, the edema state is assessed.Long-term monitor system adopts MSP430 microprocessor 11 and buetooth4.0 equipment 14 to carry out transmission as a result, outstanding low-power consumption and mobility.When desired value, E is too high, and system can send a warning to PC by buetooth4.0.

During concrete enforcement, after settling stimulating electrode and measurement electrode device, keep two measurement electrode distances constant during measuring, and carry out the biological impedance that the experimenter sits quietly for a long time.As shown in Figure 6, this figure is that intermittent is measured bio-impedance amplitude under experimenter's different stimulated frequency and the graph of a relation of time.

The situation that compares local bio-impedance amplitude change rate Δ Z% under 20KHz, 30KHz, 50KHz, 200KHz stimulus frequency: wherein, Δ Z%=100* (Z ₀-Z _i)/Z ₀.

Wherein, Z ₀for initial impedance value, Z _iimpedance while being i*10 minute, 0≤i≤6.The bio-impedance rate of change that compares different frequency, as can be seen from the figure, stimulus frequency is lower, the rate of change of its impedance is more greatly that edema is more easily monitored, the frequency that so the most obvious impedance variation occurs in stimulus signal is 0 o'clock, yet can cause larger potential difference while due to the existence of Skin Resistance, injecting DC current, safety is difficult to ensure like this.Along with the postponement of time, experimenter's local bio-impedance is constantly reducing, and the basic linearity that keeps reduces.

The above is only preferred implementation of the present utility model; it should be pointed out that for those skilled in the art, under the prerequisite that does not break away from this utility model principle; can also make some improvements and modifications, these improvements and modifications also should be considered as protection domain of the present utility model.

Claims (1)

1. the device based on bio-impedance assessment human body edema of the limbs, it is characterized in that: comprise the microprocessor (11) be arranged on protector, and the stimulating current generation module, impedance bioelectrical measurement module, demonstration and the control module that with microprocessor (11), are connected respectively; Wherein:

Described stimulating current generation module comprises: the DDS module (14), VCCS module (15), the stimulating electrode (4) that connect successively; Described microprocessor (11) is controlled DDS module (14) and is produced the sine voltage signal, and is transferred to described VCCS module (15); Described VCCS module (15) is converted to current signal by the sine voltage signal received, and is transferred to described stimulating electrode (4); Described stimulating electrode (4) comprises the first stimulating electrode (4a), the second stimulating electrode (4b), for injecting stimulating current to tested position;

Described impedance bioelectrical measurement module comprises: the measurement electrode (5), signal condition module (9), the width phase detection module (10) that connect successively, and described width phase detection module (10) is connected with described microprocessor (11); Described measurement electrode (5) comprises the first measurement electrode (5a), the second measurement electrode (5b), inject potential difference between 2 of stimulating currents for gathering on tested position, and the transmission potential difference signal is to described signal condition module (9); Described signal condition module (9) sends to described width phase detection module (10) after the potential difference signal amplification filtering is processed; Described width phase detection module (10), for after extracting the amplitude and phase place that receives signal, is sent to described microprocessor (11);

Described demonstration comprises with control module LCD (13), the keyboard (12) that is connected respectively described microprocessor (11), and bluetooth communication module (14); Described microprocessor (11) is used for carrying out the edema evaluation according to the amplitude and the phase information that receive, and appreciation information is sent to described LCD (13), described microprocessor (11) is controlled described bluetooth communication module (14) and is sent appreciation information to computer simultaneously.

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