CN104352238A - Method of collecting electrical resistance chromatographic chromatographic data of thoracic cavity of human body - Google Patents

Abstract

The invention belongs to the field of design and production of data collection systems in an electrical resistance chromatographic technology and particularly relates to a method of collecting electrical resistance chromatographic data of a thoracic cavity of a human body. A sensor employed by the method comprises a jacket covering the thoracic cavity of the human body, a plurality of electrodes, a plurality of hollow slide rods and an electromagnetic shielding case arranged outside the jacket, wherein a plurality of chutes are formed in the jacket, each electrode is fixed on one end of the corresponding hollow slide rod and the other end of each hollow slide rod slides in the corresponding chute; the method of collecting the data comprises the following steps that the position of the thoracic cavity of the checked human body is consistent to the horizontal plane of the elliptic jacket, and through moving the position of each slide rod, each electrode at the end of the corresponding slide rod is in contact with the surface of the thoracic cavity; by utilizing a gating circuit, the position of each electrode is measured, so that collection of the electrical resistance chromatographic data of the thoracic cavity of the human body is completed. The data measuring manner in the method utilizes full stimulation and full measurement, so that the position of each electrode can be quickly and accurately determined, and thus high-precision measurement of different measured crowds and different dynamic breathing processes can be implemented.

Description

Torso model resistance chromatography collecting method

Technical field

The invention belongs to medical electrical impedance tomography (electrical impedance tomography, EIT) technical field, relate to a kind of torso model resistance chromatography collecting method.

Background technology

Electrical impedance tomography (EIT) technology is that the distribution resisted with organism internal resistance or a kind of novel undamaged biomedicine being changed to imageable target are detected and imaging technique.Utilizing EIT technology, the distribution of impedance image of organism inner tissue, the impedance of bio-tissue can being shown with the impedance variation image when image of frequency change, organism organ physiological activity (as breathed, heartbeat).EIT technology is that non-intruding detects and functional imaging technology, has the features such as safe, visual, in postgraduate's object physiological function and medical diagnosis on disease, has important clinical value.As compared to traditional medical visualization detection means based on ray (x-ray, pet), it has safe, easy, noinvasive, cheap advantage, can carry out for a long time, real-time monitoring to organism.About particularly the data acquisition energy collecting of a width EIT imaging reaches 500 width per second, far away higher than the speed that just can complete piece image for the about 3-10 of medical detecting method minute of current use.Therefore develop bedside monitoring and real-time medical detection technique based on EIT, to the early prevention of disease, Diagnosis and Treat, there is very great meaning and application prospect, be subject to the extensive concern of various countries' researcher in the world.

But currently do in torso model two dimension thing field measurement at EIT, all detections and measurement electrode (being generally 16 or 32) must be fixed on certain cross section on the torso model surface of examine.These electrodes are all generally paste torso model surface skin one by one, then the position of each electrode is measured by means such as dimensional measurement or other distance measuring sensors, thus determine this measured object field (torso model) border by electrode position, make EIT imaging and visually become possibility.For torso model, this measurement existence three problems.First, in order to ensure that all electrodes are all evenly distributed on same cross section, needing repetitive measurement and repeatedly adjusting, being difficult to ensure that all electrodes are evenly distributed on same cross section.Secondly, along with torso model surface dynamic change in human body respiration process, the size and dimension of the detection thing field that thoracic cavity electrode is determined also becomes thereupon, therefore, existing measuring method cannot adapt to the dynamic change of measurement point at all, thus can not carry out the data acquisition of Real-time and Dynamic; And electrode repeatedly adjust the damage also easily causing junction point between electrode and wire, the wearing and tearing of electrode, the problem such as be pasted not strongly between electrode and skin solid.These problems bring adverse effect to the accuracy of the service life of electrode and measured signal.Finally, Current data acquisition uses adjacent actuators and adjacent metering system, causes the independence obtained to measure the pixel count (such as, 16 electrodes only have 104 independently measure number) of number far fewer than imaging process; Cause serious underdetermined problem.The problems referred to above have become the major obstacle that EIT is applied to medical visualization.

Summary of the invention

The object of the invention is the above-mentioned deficiency overcoming prior art, a kind of torso model resistance chromatography collecting method is provided, for the thoracic cavity profile that any tested crowd is different, and the thoracic cavity shape of dynamically respiratory change, only need electrode be pasted at skin surface during measurement, and do not need to do any other and repeat adjustment, this collecting method can determine the locus of electrode in real time, accurately, thus accurately determine the thing field of torso model imaging, provide indispensable and effective condition for EIT detects.Simultaneously, based on the absolute advantages of EIT acquisition speed relative to human viewableization transient response, take the DATA REASONING mode that arbitrary interval encourages and arbitrary interval measures, make independently to measure number and improve a more than order of magnitude than current existing metering system, overcome the underdetermined problem in EIT imaging process.Technical scheme of the present invention is as follows:

A kind of torso model resistance chromatography collecting method, the sensor adopted comprises the overcoat for being enclosed within outside torso model, multiple electrode, multiple hollow slide bar and the electro-magnetic shielding cover be arranged on outside overcoat, wherein, offer multiple chute on the coat, one end of hollow slide bar is fixed with electrode, the size of the other end matches with chute, can slide in chute; The main body of overcoat is made up of insulant, and runner wall is conduction, and hollow slide bar is made up of uniform conductor material, and the wire of connection electrode passes in the middle part of hollow slide bar, respectively draws a wire from each runner wall; The connection of the connection between each wire or each wire and power supply utilizes gating circuit to realize; Described collecting method comprises step below:

(1) make examined torso model position consistent with the horizontal plane at oval overcoat place, made by mobile slide bar position the electrode being positioned at slide bar end contact with surface, thoracic cavity;

(2) gating circuit is utilized, according to following electrode position measuring method, realize the position measurement of each electrode: by the wire be connected to electrode and the two ends being connected on power supply from the wire that the runner wall that electrode is therewith corresponding is drawn, because slide bar is that uniform conductor is made, according to measured resistance sizes, try to achieve the length that slide bar stretches into jacket internal, then obtain the position of this electrode;

(3) utilize gating circuit, choose after different electrode pairs is in series as exciting electrode at every turn and be connected with power supply again, choose other two electrode pairs as measurement electrode, measure the potential change that detected object causes; After the compound mode traveling through various exciting electrode and measurement electrode, data are transferred to host computer, complete the collection of a width torso model resistance chromatographic data.

Feature of the present invention is, on the basis not changing traditional E IT imaging data measuring principle, for different tested crowds and the dynamic respiratory of torso model, the position (coordinate) of electrode can be determined adaptively, solve the difficult problem that current EIT sensor can not determine border in real time.On the other hand, current based on EIT acquisition speed minimum level also higher than 200 width per second, and the speed of the transient response of human viewableization process is approximately 0.2 second (being approximately 5 width per second); Therefore, EIT acquisition speed has absolute advantages relative to human viewableization transient response.This is that the full metering system of full excitation that can adopt of the present invention carries out the basic foundation measured.

Accompanying drawing explanation

Fig. 1 sensor side view

Fig. 2 sensor top view

Fig. 3 sensor construction schematic diagram

Fig. 4 is used for the current loop probeing into depth survey of slide bar

Fig. 5 thing field object measuring circuit.

Detailed description of the invention

First 1 ~ 3 configuration and techniques principle of the present invention is explained by reference to the accompanying drawings below.

Sensor of the present invention is made up of following assembly: circular electrode (1); Hollow slide bar (2); Oval overcoat (3); Chute (4); Electrode connecting line (5); Chute connecting line (6); The support triangle frame (7) of height can be regulated; Electromagnetic shielding outer housing (8).Be described as follows:

1. 32 circular electrodes form an electrod-array, according to waiting distribution of central angle principle between each electrode, each electrode reverse side has and stretches out circular screw-socket annulus, circle ring center fixes and draws a wire and is connected with power supply through hollow slide bar, and electrode to be contacted with corresponding screw-socket by the slide bar of screw-socket annulus and tightens compact siro spinning technology, the two forms a connecting overall.32 slide bars and chute according to etc. central angle be uniformly distributed, and then ensure that 32 electrodes are evenly distributed on same cross section.Chute is made up of conductive material and is fixed on oval outer to put and perpendicular to its surfaces externally and internally.Slide bar can make the moving of surfaces externally and internally of direction perpendicular to oval overcoat along chute.The material that can conduct electricity and can lubricate is scribbled, to reduce contact resistance between the two and resistance to sliding between slide bar and chute.

2. oval overcoat had both served as the supporting adn fixing device of all electrodes of sensor, served as again the fixed reference border (thoracic cavity outer surface) of detected material field (thoracic cavity).Selected coordinate system arbitrarily, the center (coordinate) putting fixing chute outside each ellipse is known.The making of electrode and traditional fixed electrode make as broad as long, are all to select to be applicable to the conductor material pasted at human body surface to be made, and electrode shape is circular conducting strip; For different torso model profiles and dynamic respiratory, paste, at the electrode of thoracic cavity skin surface, band moving slide-bar will be had different mobile (probeing into) length relative to oval overcoat.By calculate this and move (probeing into) length and with the location comparison of corresponding chute, just can calculate the position (coordinate) of each electrode.

3. the degree of depth that probes into of slide bar is measured according to a current loop.Slide bar is made up of the uniform conductor material that electric conductivity is good, and its length is decided according to the actual requirements, and section girth will match with the slideway aperture on round jacket; Scribble between slide bar and chute liquid matter conductive material with ensure enough little contact resistance and enough little smoothness; Each electrode is connected by the positive pole of the wire with power supply that are placed in slide bar hollow core; And the negative pole of power supply is connected with runner wall by wire, runner wall is connected with electrode by the slide bar of conduction again, forms a current loop as shown in Figure 4.

4. much less than the resistance of sliding bar own of the resistance of wire and chute are connected; Therefore the resistance sizes of above-mentioned current loop is determined by the slide bar length probeing into oval coat part.For each slide bar, electricalresistivityρ and cross-sectional area S are constant, and therefore, the length L that the resistance R in loop probes into part by slide bar completely determines; Namely, after measuring R value, the size of length L calculates according to following Ohm's law:

L＝SRρ ^-1

The position (coordinate) of electrode can be obtained by measuring the sliding bar resistance R change be positioned at outside oval overcoat.

5. after electrode position measurement completes, all power cathodes and chute open circuit; And each power cathode go between with the extraction of another electrode according to a graded and arrangement and is connected, formation thing field object measuring circuit as shown in Figure 5.

Thus obtain the measurement data detecting detected object in thing field.The measurement data of above measured object field plate position (coordinate) measurement and detection thing field detected object obtains and hockets, and because this process can complete at the millisecond order of magnitude, therefore can be applicable to thoracic cavity boundary dynamics real-time change completely.

6. oval electromagnetic shielding overcoat is positioned at the outermost layer of sensor, be made up of common multilamellar stalloy, the longitudinal length of outer housing should be greater than 5 times of electrode diameter, effectively can shield extraneous electromagnetic interference, ensure the stability of measuring-signal, and then improve the signal to noise ratio of data collecting system.The measurement device comprising oval overcoat and electrode is fixed in a height-adjustable triangular supports, and what difference Height Adjustable spider and normally used spider do not have; But the size principle of oval overcoat is wanted can hold proprietary thoracic cavity.Therefore the major and minor axis of oval overcoat goes out greatly 20% with applicable all groups than the greatest length of normal person's thoracic contours and thickness, and material selection is easy to processing and lightweight inorganic material.

7. the full measurement pattern of full excitation.Different according to the electrodeplate at interval for N number of electrode, all electrode pairs have N kind energisation mode and N kind metering system respectively, according to reciprocity principle, total total (N/2) × (N/2) comprising present adjacent actuators and adjacent measurement plants different metering systems.The full measurement pattern of full excitation that this sensor utilizes all these different encourages detected material field and measures, thus the measurement data making detected object corresponding increases a more than order of magnitude, with the spatial resolution of the underdetermined problem thus raising EIT imaging that at utmost overcome EIT imaging.

Below in conjunction with embodiment, collecting method of the present invention is described.

The height of adjusting triangle support, makes examined torso model position consistent with the horizontal plane at oval overcoat place, manually moves slide bar position and is connected with surface, thoracic cavity.Closed power supply realizes by gating switch the adaptive model that sensing station is measured and detected object measurement data two processes hocket.

One, position measurement.Adopt serial mode to implement for the sensor comprising N number of electrode, first by power supply, current excitation is applied to No. 1 electrode, the current intensity of measuring circuit can be obtained, thus calculate the size of resistance R, and then be calculated the length probeing into slide bar by Ohm's law; By all probe into sliding bar and all when outside the resistance value of two extreme case priori compare, just can draw the input length of slide bar, then compared with the known location coordinate of chute, just can calculate the position coordinates of No. 1 electrode; Repeat this process to apply respectively to be activated to No. 2, No. 3 ..., N electrode, then finally obtain the position coordinates of all N number of electrodes.

Two, object is measured.Full excitation and full measurement pattern are adopted for the sensor comprising N number of electrode.It is following adjacent actuators, 1, interval electrode excitation, 2, interval electrode excitation ...., interval (N/2-1) individual electrode excitation is designated as successively: excitation 1, excitation 2, excitation 3 ..., excitation (N/2-1); Correspondingly, adjacent measurement, 1, interval electrode measurement, 2, interval electrode measurement ...., interval (N/2-1) individual electrode measurement is designated as successively: measure 1, measures 2, measures 3 ..., measure (N/2-1); Therefore, the individual full excitation of (N/2) × (N/2) and full measurement pattern work as follows:

(1) 1 and 1 pattern of measurement is encouraged.1-2 electrode composition electrode pair carries out current excitation, then at No. 3-4, and No. 5-6 ..., the potential change that detected object causes measured by (N-1)-N electrode pair; Repeat this process, use No. 3-4 successively, No. 5-6 ..., (N-1)-N electrode is as exciting electrode pair, and other electrode, as measurement electrode pair, measures the potential change that detected object causes.

(2) 1 and 2 patterns of measurement are encouraged.1-2 electrode composition electrode pair carries out current excitation, then at No. 3-5, and No. 4-6 ..., the potential change that detected object causes measured by ((N-2)-N) number electrode pair; Repeat this process, use No. 3-4 successively, No. 5-6 ..., ((N-1)-N) number electrode is as exciting electrode pair, and two electrodes at one, other interval, as measurement electrode pair, measure the potential change that detected object causes.

(3) 1 and 3 patterns of measurement are encouraged.Current excitation implemented by 1-2 electrode composition electrode pair, then at No. 3-6, and No. 4-7 ..., the potential change that detected object causes measured by ((N-3)-N) number electrode pair; Repeat this process, use No. 3-4 successively, No. 5-6 ..., (N-1)-N electrode is as exciting electrode pair, and the electrode at two, other interval, as measurement electrode pair, measures the potential change that detected object causes.

…………………………………………………..

(4) (N/2-1) and (N/2-1) pattern of measurement is encouraged.1-(N/2-1), 2-(N/2) number, 3-(N/2+1), (N/2-1)-(N) current excitation implemented by electrode composition electrode pair, then at 3-(2+N/2) number, and No. 6,4-(3+N/2),, the potential change that detected object causes measured by ((N+N/2)) number electrode pair; Repeat this process, use 2-(N/2) number successively, 3-(N/2+1), (N/2-1)-(N) number electrode is as exciting electrode pair, and two electrodes at one, other interval, as measurement electrode pair, measure the potential change that detected object causes.After above process completes, altogether obtain 2345 and independently measure number.

Three, pattern switches and controls.By a gating circuit, realize respectively position measurement and object measure between switching, and the switching between different measuring pattern.When gating circuit makes power supply be connected to same electrode formation current loop, realize the position measurement of sensor; When power cathode and chute open circuit, and when any one other electrode is connected with other, just can realize entirely encouraging full measurement pattern.By clock switch, when the individual full excitation of all (N/2) × (N/2) with after entirely having measured, data are transferred to data and store and analytical system, complete the DATA REASONING of a width EIT imaging.

Claims (1)

1. a torso model resistance chromatography collecting method, the sensor adopted comprises the overcoat for being enclosed within outside torso model, multiple electrode, multiple hollow slide bar and the electro-magnetic shielding cover be arranged on outside overcoat, wherein, offer multiple chute on the coat, one end of hollow slide bar is fixed with electrode, the size of the other end matches with chute, can slide in chute; The main body of overcoat is made up of insulant, and runner wall is conduction, and hollow slide bar is made up of uniform conductor material, and the wire of connection electrode passes in the middle part of hollow slide bar, respectively draws a wire from each runner wall; The connection of the connection between each wire or each wire and power supply utilizes gating circuit to realize.Described collecting method comprises step below:

(1) make examined torso model position consistent with the horizontal plane at oval overcoat place, made by mobile slide bar position the electrode being positioned at slide bar end contact with surface, thoracic cavity;

(2) gating circuit is utilized, according to following electrode position measuring method, realize the position measurement of each electrode: by the wire be connected to electrode and the two ends being connected on power supply from the wire that the runner wall that electrode is therewith corresponding is drawn, because slide bar is that uniform conductor is made, according to measured resistance sizes, try to achieve the length that slide bar stretches into jacket internal, then obtain the position of this electrode;

(3) utilize gating circuit, choose after different electrode pairs is in series as exciting electrode at every turn and be connected with power supply again, choose other two electrode pairs as measurement electrode, measure the potential change that detected object causes; After the compound mode traveling through various exciting electrode and measurement electrode, data are transferred to host computer, complete the collection of a width torso model resistance chromatographic data.