• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    An apparatus (1) for electro-impedance tomography (30) comprising an electrode assembly having a plurality of electrodes (33) spaced apart therefrom, a signal feed unit (51) and a signal detection unit (50), a computing and control unit (70) is configured to detect a current elliptical peripheral shape (20) of the electrode assembly on a thorax (34) of a human subject and to provide a control signal (79) indicative of the elliptical peripheral shape (20) of the electrode assembly. The computing and control unit (70) may be configured as a central unit or as an array of distributed computing (cloud computing) to detect and provide the current elliptical perimeter shape (20).
    公开号:CH713099B1
    申请号:CH01449/17
    申请日:2017-11-28
    公开日:2018-09-28
    发明作者:Gärber Yvo (Dr )
    申请人:Draegerwerk Ag & Co Kgaa；
    IPC主号:
    专利说明:

    Description: The present invention relates to an apparatus for electro-impedance tomography with a determination of a peripheral shape of an electrode arrangement associated with the electro-impedance tomography apparatus.
    Furthermore, the present invention relates to a method for operating an apparatus for electrical impedance tomography with a determination of a circumferential shape, the electrode assembly associated with the electro-impedance tomography device.
    Devices for electro-impedance tomography (EIT) are known from the prior art. These devices are designed and intended to generate an image, a plurality of images or a continuous image sequence from signals obtained by means of electro-impedance measurements and from data and data streams obtained therefrom. These images or sequences of images show differences in the conductivity of various body tissues, bones, skin, body fluids and organs, especially the lungs, which are useful for observing the patient's situation. Thus, US Pat. No. 6,236,886 describes an electrical impedance tomograph with an arrangement of a plurality of electrodes, current supply to at least two electrodes, signal detection at the other electrodes and a method with an image reconstruction algorithm for determining the distribution of conductivities of a body such as bone , Skin and blood vessels in a basic configuration with components for signal acquisition (electrodes), signal processing (amplifier, A / D converter), power supply (generator, voltage-current converter, current limiting) and components for control.
    [0005] It is stated in US Pat. No. 5,807,251 that in the clinical application of EIT it is known to provide a set of electrodes which are placed at a certain distance from each other, for example around the thorax of a patient in electrical contact with the skin. For an electrical current or voltage input signal, alternately applied between different or all of the possible pairs of electrodes adjacent to each other. While the input signal is applied to one of the pairs of electrodes disposed adjacent to each other, the currents or voltages between each adjacent pair of the remaining electrodes are measured and the obtained measurement data is processed in a known manner to provide a representation of the resistivity distribution over a cross section of the Patient to whom the electrode ring is arranged to receive and display on a screen.
    The electrical impedance tomography (EIT) has, in contrast to other imaging radiological procedures (X-ray equipment, radiological computer tomographs), the advantage that a disadvantageous for the patient radiation exposure does not occur. In contrast to sonographic procedures, the EIT allows continuous image acquisition over a representative cross-section of the patient's entire thorax and lungs using the electrode belt. In addition, there is no need to use a contact gel, which must be applied before each examination. Electro-impedance tomography (EIT) thus offers the advantage of enabling continuous monitoring of the lungs in order to observe and document the course of therapy of a mechanically-ventilated or spontaneously-breathing patient.
    By means of an electrode assembly around the chest of a patient with an EIT device, as is known for example from US 5 807 251, an impedance measurement is performed on the chest and from the impedance an image of the patient's lungs by means of a conversion to the Chest geometry generated.
    With a total of, for example, 16 electrodes mounted around the thorax of a patient, an EIT device can image the lungs in one round of current feeds to two electrodes each and record voltage readings (EIT measurement signals) to the remaining electrodes of 32 x 32 pixels. In this case, a number of 208 impedance measured values at the electrodes is detected at the 16 electrodes. From these 208 impedance measured values, an amount of 1024 pixels then results with the EIT image reconstruction.
    The electrodes are arranged to perform the electro-impedance tomography (EIT) in a horizontal arrangement around the thorax of a living thing around and a region of the lungs of the living being comprehensively. This results in a position in the plane of the electrode assembly which may be referred to as a thoracic-axial position of the electrode assembly at the periphery of the transverse plane of the body.
    When using an electrode belt as an electrode arrangement, in or on which the electrodes are arranged and held at fixed positions with a defined distance to each other, the possibilities for deviations in the vertical position between adjacent electrodes to each other on the chest are comparatively small. Thus, in the positioning of the electrode belt on the chest a vertical shift in the image reconstruction, in which a horizontal cross-sectional view through the chest, as a so-called dorsal view, determined, plays a relatively minor role. The horizontal cross-sectional image is displayed inclined by only a few degrees. In addition, in the electrical supply to the electrodes not only electrical fields in the cutting plane itself, but also in areas above and below each about 5 to 10 centimeters of the cutting plane, which then in any case then included in the impedance measurements. Therefore, in Tidalbild the only possible slight inclination of the electrode belt as an effect is virtually imperceptible. In addition, a comparatively reproducible and representative horizontal position of the electrode belt in the application can be achieved by an orientation on the costal arches, so that possible errors in the horizontal attachment of the electrode belt to the thorax are rather rare.
    In contrast, the horizontal position of the electrodes is important in that for the generation of the dorsal view, the physiologically expected, deviating from the ideal circular circular or cylindrical shape, almost elliptical geometry of the thorax is important in that for an inclusion of the elliptical shape in the image reconstruction information is required at what position, ie front (sternum), side (ribs) or back (spine), which electrode is attached to the chest. Different types of living beings, which have in common that they exchange gases with the aid of pulmonary respiration, each have per se typical circumferential shapes in the body structure surrounding the lungs (musculature, skeleton, organs, body tissue, skin). A deviation of the shape of the rib cage from an ideal circular shape is given in principle, for example, in human beings to the effect that the typical peripheral shape is usually more elliptical than circular pronounced. In other living things such as horses, dogs, pigs, rodents or birds, depending on the species other typical forms of the peripheral forms arise. In this respect, the idea of the present invention with the device for electro-impedance tomography with a determination of a peripheral shape of a body-positioned and the electro-impedance tomography device associated electrode arrangement is not only for the application of electro-impedance tomography in human beings but also applicable to a wide biodiversity of wildlife. In human beings, in particular, the area of the electrode plane used in electro-impedance tomography (EIT), that is to say the plane in the horizontal section through the thorax, is approximately in the region of the third, fourth, fifth costal arch, as well as the fifth, sixth, seventh thoracic vertebrae, an elliptical peripheral shape (ellipsoid) in the area of the upper body and the thorax. In addition to the geometric shape with an anatomically predetermined elliptical design area, there are further characteristic features which have an effect on the impedance, impedance differences and impedance distribution measured by EIT and have a transversal view during image reconstruction for displaying the ventilation of the lungs or in mathematical terms -algorithmically applied way of image reconstruction - as well as the elliptical peripheral shape - take into account. Thus, in addition to the lungs, with areas perfused in the rhythm of the heartbeat and ventilated in the rhythm of the respiratory cycle, the heart, with essentially the same rhythm of the heartbeat, however, as in the same constant blooded areas, in this electrode plane also elements of the skeleton, in the front area of the Upper body of the sternum and arranged in the back area of the spine, whose impedances are both unaffected by blood circulation and respiratory cycle. Rather, both the sternum and, in particular, the spine have an impedance which deviates from these and other areas (heart, skin, lung, tissue) in the electrode plane and is essentially constant.
    By means of the so-called eccentricity, an ellipse can be described as a closed oval shape as a deviation from a circular shape as a dimensionless number.
    The eccentricity describes the ratio of the two mutually perpendicular semi-axes. In the case of a circle both half-axes are of identical length, an ellipse is defined by a shorter half-axis and a - compared to the shorter half-axis - longer half-axis of different lengths. Due to the elliptical shape and depending on their eccentricity, different distances between feeding electrodes and oppositely measuring electrodes, depending on whether along the frontal plane of the human body with the feed on the front area with measurement at the rear area or feed at the rear with Measurement takes place on the front-side area, or whether along the transverse axis of the human body, the feed on the left side of the body with measurement on the right side of the body and the feed on the right side of the body with measurement on the left side of the body. The two constellations of feeds / measurements respectively opposite to left / right side of the body represent in the elliptical peripheral shape of the human body feeds / measurements on the longer half axis and the two constellations of feeds / measurements respectively opposite to body front / body back represent in the elliptical peripheral shape of the human body feeds / measurements on the shorter half-axis.
    The peripheral shape of the thorax (thorax) at the location of attachment of the electrodes is directly in the peripheral shape of the thorax positioned and - the electrodes holding - electrode assembly again, since the electrode assembly is typically formed as a largely flexible and movable, usually elastic electrode belt is such that the electrode assembly follows the peripheral shape at the location of positioning. A deviation of the circumferential shape of the chest or the electrode assembly of a typical or average elliptical shape affects in the application of electro-impedance tomography (EIT), since for the image reconstruction by means of the reconstruction algorithm, the peripheral shape with the average elliptical shape in the reconstruction algorithm with is involved. This means that the average elliptical peripheral shape of the thorax, which results from the different lengths of the two semiaxes and, as explained above, is definable by means of the eccentricity, enters the reconstruction algorithm as a predetermined variable. In the real use case, i. Depending on the patient, more or fewer deviations of the real circumferential shape from the central elliptical peripheral shape on the respective patient of the horizontal plane of the electrode arrangement as well as above and below the electrode arrangement result, depending on the patient, the attachment of the electrode arrangement around the thorax. These deviations from the average elliptical peripheral shape as well as above and below the electrode arrangement have an influence on the result of the image reconstruction, since the reconstruction algorithm without an adaptation of the reconstruction algorithm to the deviations of the real peripheral shape from the central elliptical peripheral shape is a visual representation of aeration of lung areas in determines and provides a dorsal view of the thorax, in which, for example, deviations in the shape of the area representation of the lung and thorax are given. One possibility of taking account of deviations from the average elliptical peripheral shape in the electrode plane can be effected, for example, by measuring the real lengths of the two half-axes of the ellipse and the thoracic circumference of the patient in the electrode plane by the clinical staff and by means of a manual input to the device Electro-Impedance Tomography (EIT). In the device for electro-impedance tomography (EIT) can then be determined a real elliptical peripheral shape, which then an adaptation of the reconstruction algorithm to a determination of the circumferential shape or the deviation of the peripheral shape from the average elliptical peripheral shape corrected pictorial representation of the Ventilation of lung areas allows. For clinical routine use, individual thoracic measurements, as well as subsequent manual inputs to the device, are time-consuming and error-prone (incorrect measurements, input errors) by the clinician, both of which are unfavorable in daily clinical routine and disadvantageous.
    In WO 2015/048 917 A1 a system for electrical impedance tomography is shown. The EIT system is capable of detecting electrical characteristics of a patient's lungs as impedances. For this purpose, impedance values or impedance changes of the lungs are detected by means of voltage or current supply between two or more electrodes and a signal detection on an electrode arrangement and further processed by means of data processing. The data processing includes a reconstruction algorithm with a data processor to determine and reconstruct the electrical properties from the impedances. When reconstructing the electrical properties from the acquired measurement data, an anatomical model is selected from a plurality of anatomical models based on biometric data of the patient, and the reconstruction of the EIT image data is adapted on the basis of the anatomical model or the biometric data. This adaptation requires the user to enter biometric data into the system. Biometric data include age, gender, height and circumference of the patient. This means that boundary conditions must be entered by the user before starting the measurement with the electro-impedance tomography system in order to be able to select and apply a suitable reconstruction model based on a selected anatomical model.
    For the operation of electroimpedance tomography systems, it is not necessarily advantageous in many application situations to measure or capture and input a plurality of patient data before the start of the application. In particular, the requirement of data relating to the characteristics of the body such as thoracic circumference, size and weight presupposes that the anatomical models stored in the device are also applicable to a large number of patients.
    The present invention has been made aware of the disadvantages of the known prior art described above, a suitable for imaging of the lung device for electrical impedance tomography (EIT) with one of the electro-impedance tomography Provide device associated electrode arrangement, which makes it possible to determine a deviation of a peripheral shape of a body positioned on the electrode assembly of a central peripheral shape.
    Furthermore, it is an object of the present invention to provide a device suitable for imaging of the lung device for electro-impedance tomography (EIT) with an electro-impedance tomography device associated electrode arrangement, which allows the deviation from the middle circumferential shape in a determination and imaging of a Tidalbildes the lung to be considered.
    Another object of the present invention is to provide a method of operating a pulmonary imaging apparatus for electroimpedance tomography (EIT) which includes determining a deviation of a peripheral shape of a body-positioned electrode assembly from a allows medium circumferential shape.
    These and other objects are achieved by the appended independent claims.
    According to a first aspect of the invention, the object is achieved by a device having the features of patent claim 1.
    According to a further aspect of the invention, the object is achieved by a method having the features of patent claim 10.
    Advantageous embodiments of the invention will become apparent from the dependent claims and are explained in more detail in the following description with partial reference to the figures.
    Furthermore, the method may also be provided as a computer program or computer program product, so that the scope of protection of the present application also extends to the computer program product and the computer program.
    At the beginning some of the terminology used in this patent application will be explained in more detail.
    For the purposes of the present invention, a period of observation is to be understood as a time period in a chronological sequence. The beginning and end of such a period of observation are given either by fixed or adjustable times or by events given by the characteristics of respiration or respiration. Examples of observation periods which are based on respiration or respiration are a breathing cycle, several breathing cycles, parts of breathing cycles, such as inspiration, inspiratory pause, exhalation, expiratory pause. For the purposes of the present invention, EIT measurement signals are to be understood as the following signals or data which can be detected with an EIT device by means of a group of electrodes or by means of an electrode belt. These include EIT measurement signals in different signal characteristics such as electrical voltages or voltage measurement signals, electrical currents or current measurement signals associated with electrodes or groups of electrodes or to positions of electrodes or groups of electrodes on the electrode belt, as well as voltages and currents derived electrical Resistance or impedance values.
    In the sense of the present invention, a measuring circulation means a signal feed to two feeding electrodes, a so-called feed-electrode pair, in which EIT measuring signals are taken at other electrodes, which are different from these two feeding electrodes.
    For the purposes of the present invention, a measuring cycle is understood to mean a sequence of feeds to a plurality of feed-electrode pairs, each with an associated measuring cycle at the remaining electrodes. Such a measurement cycle is typically referred to as a so-called "frame" or "time frame" when processing EIT data.
    In an EIT system with a number of 16 electrodes using an adjacent data acquisition mode, in one measurement cycle, i. E. in a "time frame", a number of 208 measurement signals.
    Accordingly, a measurement cycle as part of the measurement cycle is typically referred to as a "partial frame" in the processing of EIT data. In an EIT system with a number of 16 electrodes using an adjacent data acquisition mode, in one measurement cycle, i. E. in a "partial frame", a number of 13 measurement signals.
    The use of the adjacent data acquisition mode means that in one measuring cycle, the measuring signals of each two adjacently positioned electrodes are detected as a pair of measuring electrodes when fed to two adjacently positioned electrodes as feed-pair pair and in a measuring cycle with rotation of the feed-electrode pair then with the 16 measuring cycles for each measuring electrode pair then 16 measuring signals result.
    In the context of the present invention, an EIT measuring channel is understood to mean an unambiguous assignment or constellation of in each case two signal-feeding electrodes and of the two signal-feeding electrodes different from two signal-detecting electrodes from a multiplicity of electrodes. The plurality of electrodes is incorporated as part of the apparatus for electro-impedance tomography by an electrode assembly, for example, as an electrode belt attached to the thorax of a patient with a certain number of electrodes. Exemplary numbers of electrodes in the electrode belt are 16, 32 or 64 electrodes. This results in a large number of EIT measurement channels, which comprise different assignments or constellations of on the one hand feeding and on the other hand different measuring electrodes. The EIT measurement channels are preferably addressed in the form of an index-based manner, and the data recorded on the EIT measurement channels are preferably addressed in the form of indexed vectors, indexed data fields or indexed matrices, stored and processed for further processing (vector operations, matrix data). Operations). In an EIT system with a number of 16 electrodes using an adjacent data acquisition mode, there are 208 EIT measurement channels, with one measurement channel defined as a unique assignment of a feed-electrode pair and a pair of measurement electrodes. In the adjacent data acquisition mode, two adjacent electrodes of the plurality of electrodes are respectively used for feeding, and adjacent two of the remaining ones of the plurality of electrodes are used for signal detection.
    According to a first aspect of the invention, a device according to the invention is provided.
    The device for electro-impedance tomography according to the invention for determining an elliptical peripheral shape of an electrode assembly associated with the device for electro-impedance tomography and positioned on a body comprises an electrode assembly - a signal feed unit - a signal detection unit - a Calculation and control unit on.
    The electrode assembly has a plurality of electrodes, which are arranged at a distance from each other on the body circumference in the region of the thorax of a living being. The electrode assembly is arranged horizontally on or around the thorax of a patient. At least two of the electrodes of the electrode arrangement are designed to supply an alternating current or an alternating voltage, at least two of the remaining electrodes of the electrode arrangement are designed to detect measuring signals.
    The signal feed unit is designed and provided to feed in each measuring cycle of a measuring cycle, an electrical feed signal to two cyclically and in a measuring cycle varying feeding electrodes. Preferably, an alternating current is supplied to the feeding electrodes.
    The signal detection unit is configured and provided to detect a plurality of measurement signals of the plurality of electrodes in each of the measurement cycles of the measurement cycle and to provide the calculation and control unit as well as a data storage unit as EIT measurement channels for further processing. In the case of the preferred feeding of the alternating current to the feeding electrodes, voltage signals result as measuring signals in each case at electrode pairs at the multiplicity of electrodes.
    The calculation and control unit is configured and provided for performing processing of the detected plurality of measurement signals of the plurality of electrodes in each of the measurement cycles of the measurement cycle. The calculation and control unit is further designed and provided for a selection of selected measurement signals as selected EIT measurement channels from the detected plurality of measurement signals (EIT measurement channels) and for carrying out a processing of the selected measurement signals. The computing and control unit is associated with the data storage unit which is designed and provided for storing EIT measurement channels, measurement signals, measurement signals and waveforms selected from the measurement signals, and comparison data such as comparison waveforms, pattern waveforms, comparison thresholds, and preferably organized for further processing, addressing in vectors, data fields (matrices).
    The calculation and control unit is further configured to coordinate the data storage unit, the signal feeding unit and the signal detection unit. This coordination takes place in such a way that, via the multiplicity n of electrodes (ΕΊ... Εη) within each measuring cycle, the pair of signal-detecting electrodes is rotated by the calculating and control unit and in each measuring cycle the pair of signal-feeding electrodes are rotated by the Thorax is rotated, so that for a number of n electrodes in a measurement (partial frame) for each feed pair a number of n-3 measurement signals results and total in a measurement cycle (time frame) a number of n * (n-) 3) results in measurement signals. The calculation and control unit is preferably designed, for example, as a central processing unit (CPU, μΡ) or arrangement of individual or several microcontrollers (pC).
    According to the invention, the calculation and control unit is designed to determine a current elliptical peripheral shape of the electrode arrangement on the thorax with the aid of selected measurement signals, which are obtained from a selection of electrodes opposite the two feeding electrodes, and a control signal indicating the elliptical peripheral shape of the Electrode array indicated to identify and provide.
    These selected measuring signals obtained from the respective two feeding electrodes opposite electrodes thus represent so-called opposing EIT measuring channels on which the determination of the current elliptical peripheral shape of the electrode assembly based on the thorax.
    The determination of the elliptical peripheral shape of the electrode arrangement on the thorax is carried out in that - of the calculation and control unit in cooperation with the data storage unit in each measurement cycle respectively averages the respective selected measurement signals of each of the two feeding electrodes opposite the thorax arranged electrode pairs of each determined and stored by the calculation and control unit in cooperation with the data storage unit in each measurement cycle average values of the respectively selected measurement signals of each of the two feeding electrodes opposite to the thorax arranged electrode pairs of the respectively selected electrodes in each measurement cycle and stored by the computing and control unit in cooperation with the data storage unit for each electrode pair of the selected electrodes, respectively ls ratio mass (W) from the selected measurement signals and the average values determined for these selected electrodes are determined as a current signal course (W1... W16), by the calculation and control unit in cooperation with the data storage unit, a comparison of the currently determined signal course (FIG. W1 ... W16) is performed with at least one pattern waveform (W_0) from a set of pattern waveforms, wherein the pattern waveforms represent typical waveforms for various elliptical peripheral shapes of the electrode array at the thorax, from the calculation and control unit based on the comparison the current elliptical Peripheral shape of the electrode assembly is determined at the thorax, -von the calculation and control unit, a control signal is generated and provided, which indicates the currently determined elliptical peripheral shape of the electrode assembly.
    The determination of the average values on the basis of the number of selected measuring signals of the electrodes opposite the feeding electrodes in one or more measuring cycles can be effected as arithmetic, geometric or quadratic averaging, as well as a non-linear averaging, for example as a median Filtering in the form of a "1 out of 3 filters" or "1 out of 5 filters" done.
    The at least one sample waveform (W_0), as well as the set of pattern waveforms which represent various typical elliptical peripheral shapes of the electrode array on the thorax, can be based on measurement experiments on subjects with different thorax circumferences in the elliptical shape as well as on basis of theoretical considerations and / or simulation calculations for the propagation of injected signals in different elliptical thorax forms based on the previously explained relationships with arrangement and distribution of skeleton, organs and tissues in the thorax space are obtained.
    In a preferred embodiment of the device for electro-impedance tomography, besides the coordination of the signal feed unit, the signal acquisition unit, the data storage unit, the calculation and control unit is in coordination with one in or on the electro-impedance device Formed tomography or the device for electro-impedance tomography associated output unit.
    This output unit is for a graphical, pictorial, visual or numerical output of data and / or information of the calculation and control unit, as determined by the detected measurement signals from the calculation and control unit impedances, impedance changes or impedance distributions in the region of the thorax means configured and provided the generated by the calculation and control unit provided control signal. The output unit can be configured, for example, as a display device (screen, monitor, data display device) or else as a graphics interface (HDMI, VGA, PAL) in order to locate other types of data display devices (smartphones, tablet PCs, laptop PCs) locally (LON , LAN, WLAN, fieldbus, professional BUS, CAN, POWERLINK) or remote (Profi-NET, LAN), direct (USB, RS232) or indirect (network, ETHERNET, Intranet, Internet), wireless (WLAN, Bluetooth) or be formed wired (LAN).
    In a preferred embodiment of the device for electro-impedance tomography of the calculation and control unit in cooperation with the signal feed unit in each measuring cycle of the measuring cycle of the two feeding electrodes opposite two directly adjacent electrodes as respective pairs of electrodes for detecting the Selected measurement signals selected. Such a way of performing the electro-impedance tomography is referred to as a so-called "adjacent data acquisition mode". In this case, an overall image of the impedance distribution is obtained on the entire thorax in a regular manner, since measuring signals of all electrodes successively in the measuring cycle of all measuring cycles contribute the respective proportion of information to the overall image. Jumping with skipping or omitting individual electrodes in the signal feed or in the signal detection takes place in the so-called "adjacent data acquisition mode" only in situations in which individual electrodes have been identified as faulty (Fault-Electrode). Further, in such a so-called "adjacent data acquisition mode", the signal feed variation occurs such that in one measurement cycle, each of the two feed electrodes participates at most twice in the feed in the measurement cycle, and in a sample cycle each of the selected electrodes participates at most twice in the detection the selected measurement signals is taken into account.
    In a preferred embodiment of the device for electro-impedance tomography, the calculation and control unit uses a scaling in determining the ratio mass (W) from the selected measurement signals and the average values determined for these selected electrodes. The scaling used enhances or emphasizes a signal difference between the selected measurement signals and the averaged values.
    A practical possibility in the processing of the measurement signals by the calculation and control unit to the signal difference in the determination of the ratio mass (W), i. E. of the quotient to emphasize or amplify by means of scaling from the selected measurement signals and the average values determined for these selected electrodes is the inclusion of a mathematical function on the ratio (W), such as the logarithm (Ig, In, log2).
    In a preferred embodiment of the device for electro-impedance tomography, the calculation and control unit uses a logarithmic scaling in the determination of the ratio mass (W), preferably in a signal-differentiating manner, preferably in logarithmic scaling to the base 10 W = Ig (j ^ ·). in logarithmic scaling to base e W = In or in logarithmic scaling to base 2 W - log2 (^).
    In this way, in the waveforms (W1 ... W16) a succinct form of the waveform is highlighted, this results in succinct forms of the waveforms (W1 ... W16) of the proportional mass (W) associated with the plurality of electrodes. The result is a so-called "W-shape", which illustrates the difference in the propagation of the injected signals at the thorax, at which location of the elliptical peripheral shape (longer Halbach-se / shorter half-axis of the ellipse) the signal input to the shorter half-axis of the elliptical Peripheral shape at the thorax, so the so-called frontal axis (sternum (spine), the level of arrangement of the plurality of electrodes or on the longer half-axis of the elliptical peripheral shape at the thorax, so the so-called transverse axis (left side of the body / right side of the body), the plane of the arrangement Variety of electrodes has taken place.
    In a preferred embodiment of the device for electro-impedance tomography, a number of three, four, five or more than six electrodes of the electrodes opposite the two feeding electrodes are selected by the calculation and control unit as selected electrodes for detecting the selected measurement signals , The number of electrodes selected by the calculating and controlling unit and the feeding electrodes for detecting the selected measuring signals is to be selected differently for a different number (8, 12, 16, 32, 64) of the thorax-arranged plurality of electrodes. For example, with a number of sixteen electrodes, a choice of four, five or six opposing electrodes is advantageous in effectively forming the ratio mass (W), highlighting the succinct "W shape". For a number of eight electrodes, a selection of two to four, for example three, opposing electrodes may be advantageous in forming the ratio mass (W), for a number of 32 electrodes a selection of more than six, for example eight to twelve, may be opposed Electrodes to form the ratio mass (W) be advantageous.
    In a preferred embodiment of the device for electro-impedance tomography, measurement signals selected by the calculation and control unit are respectively determined from average values of the selected measurement signals of a plurality of measurement cycles. The inclusion of multiple measurement cycles to form the average provides advantages in terms of reducing the effects of interferences superimposed by measurement signals. This can be achieved, for example, that the determined succinct "W-shape" of the waveforms (W1 ... W16) pronounced and largely free of distortions of the "W-shape" and thus the comparison with the pattern waveform (W_0) with great clarity the comparison result is possible. The averaging of the selected measurement signals of the electrodes facing the feeding electrodes over several measuring cycles can be carried out as arithmetic, geometric or quadratic averaging, as well as nonlinear averaging, for example as median filtering in the form of a "1 out of 3 filter" or "1 out of 5 filters".
    In a preferred embodiment of the device for electroimpedance tomography, the calculation and control unit is designed, by means of an algorithm for image reconstruction, impedance values or impedance distributions in the thorax in the plane of the electrodes at the thorax on the basis of that from the signal detection unit to calculate a multiplicity of measured values and to determine a tidal image on the basis of the calculated impedance values and / or impedance changes and / or impedance distributions in the thorax in the plane of the electrodes at the thorax and on the basis of the currently determined elliptical peripheral shape of the electrode arrangement and to include this in the control signal To provide control signal for the output unit. This makes it possible to consider the currently determined elliptical peripheral shape of the electrode assembly by applying scaling operations on indexed vectors or indexed matrices with impedance values in image reconstruction from the EIT measurement channels in the Tidal image. On the one hand, the currently determined elliptical peripheral shape of the electrode arrangement on the thorax of an individual individual patient can be taken into account directly during the correction for the Tidal image, but alternatively, and / or additionally a deviation of the currently determined or actual individual elliptical peripheral shape of the electrode arrangement at the thorax of the individual individual patient from a typical elliptical peripheral shape. This results in the determined elliptical peripheral shape of the electrode assembly corrected and improved Tidalbilder with the application of the electro-impedance tomography, which are based in almost every application on a real arrangement and shape of an elliptical peripheral shape of the electrode assembly on the thorax, without the user of the device For electro-impedance tomography further information, such as, thoracic circumference, size, weight, gender or other individual data of the patient to be examined must provide, from which the peripheral shape of the patient can be approximately determined.
    In a further preferred embodiment, the output unit is designed to output and / or provide the currently determined elliptical peripheral shape on the basis of the provided control signal. The output and / or provision is preferably in a numerical manner, for example, as a scalar value representing an eccentricity of the elliptical peripheral shape of the electrode assembly or the circumferential shape of the thorax, or as a pair of values having respective values of dimensions of the shorter and longer semiaxes currently determined elliptical peripheral shape.
    The calculation and control unit may be configured as a central unit in the device for electro-impedance tomography, which coordinates or performs both the detection and analysis of the measurement signals and the detection and provision of the control signal as well as the consideration of the control signal at the output of the corrected Tidalbildes initiated. However, it can also be an embodiment of the calculation and control unit be advantageous in which instead of a central unit a plurality of distributed units for detection, analysis and determination and provision of the control signal, for example, in a kind of so-called cloud computing. One possible advantage of this can be achieved by the fact that the correction of the Tidalbildes and its provision can be done at a different location than the place where the measurement signals are detected.
    All of the advantages that can be achieved with respect to the device described can be achieved in the same or similar manner with the method for operating an arrangement for electrical impedance tomography described as a further aspect of the invention.
    According to the further aspect of the invention, in a method according to the invention for operating an arrangement for electro-impedance tomography, a determination of an elliptical peripheral shape of an electrode arrangement arranged on the thorax of a patient is carried out with a multiplicity of electrodes.
    This method of operating the device for electro-impedance tomography is subdivided into a sequence of steps with the following steps: In a first step, in each measuring cycle of a measuring cycle, an electrical feed-in signal is sent to each two cyclically and in one measuring cycle fed varying feeding electrodes.
    In a second step, selected measuring signals are detected in each selected measuring electrode of a measuring cycle, in each case at the respectively selected electrodes opposite to the selected electrodes.
    In a third step, mean values (t7S6) of the respectively selected measuring signals of the respective electrode pairs of the respectively selected electrodes in each measuring circuit arranged opposite the two feeding electrodes at the thorax are determined.
    In a fourth step, a ratio as a logarithmic ratio of the selected measurement signals and the mean values (Ì7S6) determined for these selected electrodes is determined as a current waveform (W1 ... W16).
    In a fifth step, a comparison of the determined current signal waveform (W1... W16) with at least one sample waveform (W_0) is performed from a set of sample waveforms, the pattern waveforms representing different waveforms for various typical elliptical peripheral shapes of the electrode array at the thorax and a current elliptical peripheral shape determined based on the comparison.
    In a sixth step, a control signal is generated and provided which indicates the particular current elliptical peripheral shape of the electrode arrangement on the thorax.
    The described embodiments constitute, individually and in combination with one another, particular embodiments of the device according to the invention and of the method according to the invention for operating the device for electro-impedance tomography with the electrode arrangement arranged on the thorax of a patient with a large number of electrodes However, advantages and other embodiments resulting from combinations or combinations of several embodiments are nevertheless included in the concept of the invention, even though not all possible combinations of embodiments are described in detail in each case.
    The above-described inventive embodiments of the method can also be in the form of a computer-implemented method as a computer program product with a computer, wherein the computer for performing the method described above, the inventive method is caused when the computer program on the computer or on a Processor of the computer or a so-called "embedded system" as part of a medical device, in particular the EIT device is executed. In this case, the computer program can also be stored on a machine-readable storage medium. In an alternative embodiment, a storage medium may be provided which is intended to store the above-described computer-implemented method and is readable by a computer.
    It is within the scope of the present invention that not all steps of the method inevitably have to be performed on the same computer instance, but they can also on different computer instances, for example in a form and with means of so-called cloud computing, in one Data network system to be executed.
    The sequence of the method steps can also be varied if necessary. It is also possible that individual sections of the method described above in a separate, self-sellable unit (such as on a preferably located in the vicinity of the patient data analysis system) other parts on another salable unit (such as on a display - And visualization unit, which is arranged for example as part of a hospital information system preferably in a set up for monitoring several patient rooms space), so to speak as a distributed system, can be executed.
    The advantages described for the method according to the invention can be achieved in the same or a similar manner with the device according to the invention and the described embodiments of the device. Furthermore, the described embodiments and their features and advantages of the method are transferable to the device, as well as the described embodiments of the device are transferable to the method.
    The corresponding functional features of the method are thereby formed by corresponding physical modules of a device, in particular by hardware components (CPU, PC, DSP, MP, FPGA, ASIC, GAL), for example in the form of a processor, multiple processors (pC, pP, DSP) or in the form of instructions in a memory area which are processed by the processor.
    The present invention will now be explained in more detail with the aid of the following figures and the associated description of the figures without any limitations on the general concept of the invention.
    It shows: [0074]
    1 is a schematic representation of functional elements of an electro-impedance tomography device,
    2 two representations of different constellations of electrode arrangements positioned at different elliptical peripheral shapes,
    3 signal waveforms at different elliptical peripheral shapes of electrode assemblies,
    4 shows a flow chart for determining an elliptical peripheral shape of an electrode arrangement on the thorax.
    FIG. 1 shows an arrangement for impedance tomography 1. In the impedance tomography arrangement, a number of electrodes 33 are arranged on the thorax 34 of a patient 35. Of the electrodes 33, EIT data 3 are transmitted to a calculation and control unit 70 by means of a data acquisition unit 50. The transmission of the EIT data 3 from the electrodes 33 takes place by means of line connections 32. A processor unit 78 and a data memory 71 are arranged in the calculation and control unit 70. The processing unit 78 processes the EIT data 3 provided by the signal detection unit 50. In this FIG. 1 it is shown that the EIT data 3 arrive as measuring signals 55 to the calculation and control unit 70 with the processor unit 78. The processor unit 78 determines by means of suitable calculation methods and algorithms from the measurement signals 55 selected measurement signals 56 and a current waveform (W1 ... W16) 76. Selected measurement signals 56 are the measurement signals which are obtained opposite from signal-feeding electrodes 37 of selected electrodes 36. This can be seen in detail in the schematic representation 4 of signal input and signal detection. At least one sample waveform (W_0) 73 is used in the calculation and control unit 70 for selecting selected measurement signals 56, or a current waveform 76 (W1... W16) (FIG. 3, FIG. 4) determined from the measurement signals 56 (FIG. 3, FIG. 4) to evaluate a comparison. As a result of the evaluation of the comparison, a control signal 79 results, which indicates a current elliptical peripheral shape 20 '(FIG. 2) of the electrodes 33 combined to form an electrode arrangement. The control signal 79 is provided in this FIG. 1 to an EIT device 30 with an output unit 80. The output unit 80 makes it possible to visualize 82 the impedances or the impedance changes in the horizontal plane of the thorax 34 determined by the calculation and control unit 70 from the measurement signals 55 in a so-called dorsal view.
    In FIG. 1, above the arrangement for impedance tomography 1, a representation 2 of an arrangement of electrodes 33 on the thorax 34 is shown schematically. A space coordinate system 5 with an X-axis 6 and a Y-axis 7 is shown. The electrodes 33 are arranged approximately uniformly distributed around the thorax 34. This representation 2 represents a horizontal section through the thorax 34 in the plane of the arrangement of the electrodes 33, that is to say the plane of representation of the dorsal view for the visualization 82. The schematic illustration 2 shows a typical elliptical peripheral shape 20 which is typical for the plurality of human beings in the field of the arrangement of the electrodes 33 around the thorax 34 is. The schematic representation 2 of electrodes 33 on the thorax 34 has a number of sixteen electrodes. In the schematic illustration 4 of signal feed and signal detection, a current is fed to two electrodes, namely to the electrode E1 57 and to the electrode E16 58 by means of a signal feed unit 51. Opposite the two feed electrodes E1 57, E16 58 are detected in one round of signal detection on a selection of at least two electrodes 36 by means of the signal detection unit 50 as a current waveform 76 of selected measurement signals 56.
    In this FIG. 1, the at least two electrodes E6-E11 are shown by way of example as a selection of six electrodes 36. For the purposes of the present invention, however, it is also encompassed that a number other than the six selected electrodes 36 shown, for example five, four, three electrodes, which are arranged opposite the feeding electrodes 37, are used for the evaluation for determining elliptical peripheral shapes 20 , 21, 22 (FIG. 2) of the thorax 34 of the patient 35. After being fed to the electrodes E1, E16, 57, 58 by the signal feed unit 51, in this FIG. 1 shown as a counterclockwise rotation 52, the feed is made at the next feed pair, ie the electrodes E16 and E15. The signal detection is then also carried out by means of a counterclockwise rotation 53 (shown in this FIG. 1) on the electrodes E5-E10 then opposite the electrodes E15 and E16. Infeed and signal acquisition rotations 52, 53 are performed in one measurement cycle for all pairs of adjacent electrodes of the 16 electrodes E1-E16. In this way, a set of selected measurement signals 56 results. Thus, a measurement signal W1, W2... W16 is assigned to each electrode pair of sensing electrodes 36. These selected measurement signals 56 obtained in the measurement cycle, each obtained from the electrodes 36 respectively facing the feeding electrodes 37, are further processed by the calculation and control unit 70 as a current waveform (W1... W16) 76 and as such with at least one Pattern waveform (W_0) 73 is compared from a set of pattern waveforms 74, 74 ', 74 "(Figure 3). Pattern patterns 74, 74', 74" (Figure 3) represent waveforms for different typical elliptical peripheral shapes of electrode assembly 33a Thorax 34. From the result of the comparison, the control signal 79 is determined. The details of a generation of the control signal 79 and the further processing and utilization or use of the control signal 79 are shown in the illustrations in FIGS. 2, 3, 4 and the associated descriptions. As a result, a current elliptical peripheral shape 20 '(FIG. 4) is determined; alternatively and / or additionally, a deviation of the currently determined or actual individual elliptical peripheral shape 21, 22 (FIG. 2) of the thorax 34 of a single patient 35 are determined from a typical elliptical peripheral shape 20. This result, i. the determined actual circumferential shape 20 '(FIG. 4) or the determined deviation from the typical peripheral shape 20 is used by the control signal 79 to adjust the visualization 82 in the output unit 80 by means of a correction to the currently determined or actual individual elliptical peripheral shape 20 '(Figure 4). This enables a high-quality measurement for electroimpedance tomography to be performed with the EIT device 30 even for elliptical peripheral shapes deviating from typical peripheral shapes. It is thus provided, as it were, before carrying out further examinations or measurements with the EIT device 30, a possibility for calibration to the actual individual elliptical peripheral shape on the thorax 34 of a patient 35 to be examined.
    FIG. 2 shows an electrode arrangement with a plurality of electrodes 33 on a first elliptical peripheral shape 11 and an electrode arrangement on a second elliptical peripheral shape 13 of a thorax 34 of a patient 35 (FIG. 1). Like elements in Figs. 1 and 2 are designated in Figs. 1 and 2 with the same reference numerals. In the two elliptical peripheral forms 11, 13 of the thorax 34, a space coordinate system 5 with an X-axis 6 and a Y-axis 7 is shown. In the illustration of the first elliptical peripheral shape 11, an elliptical peripheral shape 20 (shown as a continuous line shape) and two further elliptical peripheral shapes 21, 22 (shown in dashed or dotted-dashed line shape) are shown. The two other elliptical peripheral shapes 21, 22 have a difference from the elliptical peripheral shape 20 in that these three peripheral shapes 20, 21, 22 are elliptically different from each other. These three different elliptical peripheral shapes 20, 21, 22 each have different extensions in the two horizontal axes (body front / body back, left / right body side). The elliptical peripheral shape 20 is in this Fig. 2 by way of example coincident with a typical elliptical peripheral shape.
    In the electrode arrangement of the first elliptical peripheral shape 11, as described in FIG. 1, an electric current is fed to the electrodes E1 57 and E16 58 as feed electrodes 37. The signals fed in by the feed electrodes 37 pass as propagation of the feed 39 in the thorax 34 to the opposite electrodes 36 (E6 ... E11). The opposing electrodes 36 in this FIG. 2 are the electrodes E6-E11. In the electrode assembly on the second elliptical peripheral shape 13, the ellipsoidal peripheral shape 22 drawn in the electrode assembly of the first elliptical peripheral shape is shown again in detail with an arrangement of the feeding electrodes 37 and opposing signal sensing electrodes 36 '(E6 ... E11). The result is a different propagation 39 'of the feed signals into and through the thorax 34 relative to the electrode arrangement on the first elliptical peripheral shape 11 to the opposite electrodes 36'. In this Fig. 2 is selected as a selection of electrodes 36, 36 'of electrodes 33, which are arranged opposite the feed electrodes 37, a number of six electrodes. However, it is also included in the sense of the present invention that also other numbers of selected electrodes, for example three, four, five or more than six electrodes can function as selected electrodes 36, 36 '. The differences in the propagations 39, 39 'are reflected in the pattern waveforms 74, 74', 74 "(FIG. 3) and / or in the current waveform 76 (FIG. 3), as more fully described in the description of FIG is explained and described.
    3, in a signal representation 60 three-for reasons of simplified drawing-different pattern signal curves 74, 74 ', 74 ", which are characteristic of three typical elliptical peripheral shapes of electrode arrangements on the thorax 34 (FIG. 2), are shown in FIG. The pattern signal curves 74, 74 ', 74 "are shown in dotted line form in this FIG. The same elements in FIGS. 1, 2, 3 are designated by the same reference numbers in FIGS. 1, 2, 3. Furthermore, a current signal curve 76 based on selected measured values 56 is shown, wherein the measured values 56 belong to the electrodes 33 E1 57 to E16 58. The measured values 56 are connected to one another in this FIG. 3 by means of a solid line. The current signal profile 76 is also evaluated in a sequence 100 shown in FIG. 4.
    The pattern signal curves 74, 74 ', 74 "and the current signal curve 76 represent signal ratios (W) 72 of a weighted logarithmic ratio W = log-ι0 (¾) of the individual measurement signals 56 from selected electrodes 36 to mean values (üS6) The current signal curve 76 is shown on the basis of selected measurement voltages 56 from electrodes 36 (FIG. , 74 "figuratively have a" w-shaped "course. Depending on the elliptical shape of the electrode arrangement on the circumference of the thorax and thus also dependent on the elliptical shape of the circumference of the thorax itself, this results in a differently significant expression of this "W shape". The described "W-shape" is all the more pronounced with its minima and maxima, the greater the extent of the ellipse in the direction of the horizontal axis 6 (FIG. 1) in the spatial coordinate system 5 (FIG. 1). 3, the signal course 74 is the pattern signal course which has the greatest possible match with the current signal course 74, 74 ', 74', 74. Therefore, in this FIG. 3, this pattern signal curve 74 results, by way of example, as the at least one pattern signal course (W_0) 73, as is also used in Fig. 1 and Fig. 4. The typical elliptical peripheral shape deposited for this at least one pattern signal profile (W_0) 73 describes an associated typical ratio of the lengths of the shorter semiaxis 7 (Fig. 1) to the longer half-axis 6 (FIG. 1) for a peripheral shape which approximately matches, for example, the peripheral shape 20 shown in FIGURE 2 (FIGURE 1,2) .The result of this comparison is provided by the computing and control unit 70 (FIG. 1) to a control signal 79 (FIG. 1).
    The control signal 79 (FIG. 1) can on the one hand directly indicate a typical elliptical peripheral shape 20 '(FIG. 4). On the other hand, the control signal 79 (FIG. 1) can also indicate with which at least one sample waveform (W_0) 73 from the set of pattern waveforms 74, 74 ', 74 "the current waveform 76 has the greatest possible match and, in an advantageous embodiment, additionally Information on how well the correspondence between the current waveform 76 and the at least one pattern waveform (W_0) is given 73. In this example of Fig. 3, the pattern waveform 74 has the best possible match with the current waveform 76. The determination of the largest possible Agreement can be made by means of mathematical compensation calculation (fit, regression analysis), for example with the aid of the "least squares method".
    The control signal 79 (Figure 1) may be used for further data processing of the EIT data 3 (Figure 1) in the application of electro-impedance tomography by the EIT device, for example 30 (Figure 1) for visualization 82 (Figure 1) on the output unit 80 (Figure 1). One such use is, for example, the inclusion of the determined elliptical circumferential shape or the deviation from a given typical circumferential shape of the thorax 34 (FIG. 1, FIG. 2) in the image reconstruction algorithm for obtaining the image data for the visualization 82 (FIG. 1) of the impedance distribution in FIG the dorsal view (Figure 1) based on the measurement signals 55 (Figure 1).
    FIG. 4 shows a sequence 100 for operating an electro-impedance tomography device 30 (FIG. 1) with a sequence of steps 101 to 106 for determining an elliptical peripheral shape (20 ') of a thorax 34 of a patient 35 (Figure 1) arranged electrode assembly having a plurality of electrodes 33. The same elements in Figs. 1,2, 3 and 4 are designated in Figs. 1,2, 3, 4 with the same reference numerals.
    The sequence of steps 101 to 106 starts from an ongoing measurement operation or after a startup of the arrangement for the electro-impedance tomography 30 (FIG. 1), so that in a first step in each measurement cycle of a measurement cycle by means of a unit for signal feed 51 an electrical feed signal to two cyclically and in a measuring cycle varying feeding electrodes 37 is fed.
    In a second step 102, measurement signals 56 selected in each measuring cycle of the measuring cycle are detected, the respective electrodes 36, which are arranged opposite each other at the thorax 34, are supplied with selected measuring electrodes 56.
    In a third step 103, mean values (56) of the respectively selected measuring signals 56 of the electrode pairs of the respectively selected electrodes 36 of the respectively selected electrodes 36 opposite the two feeding electrodes 37 on the thorax 34 are determined in each measuring cycle.
    In a fourth step 104, a logarithmic ratio (W) 72, for example w = ln (¾) or w = l0 ^ (¾), is calculated from the selected measurement signals 56 and the mean values (i / S6 ) 560 is determined to be a current waveform 76.
    In a fifth step 105, a comparison of the current signal profile 76 with at least one sample signal waveform (W_0) 73 is performed. The at least one sample waveform (W_0) 73 in this FIG. 4 represents a sample waveform from a set of sample waveforms for typical elliptical peripheral shapes of the electrode assembly at the thorax 34 (FIG. 1). By means of this comparison, a current elliptical peripheral shape 20 'of the electrode arrangement at the thorax 34 (FIG. 1) is determined.
    In a sixth step 106, a control signal 79 is generated and provided which indicates the particular current elliptical peripheral shape 20 'of the electrodes 33 (FIG. 1) on the thorax 34 (FIG. 1).
    LIST OF REFERENCES 1 Arrangement for electro-impedance tomography 2 Schematic representation of an arrangement of electrodes on the thorax 3 EIT signals, EIT data 4 Schematic representation of signal feed and signal acquisition 5 Spatial coordinate system 6 X-axis 7 Y-axis 11 Electrode arrangement on one first elliptical peripheral shape 13 electrode arrangement on a second elliptical peripheral shape 20 'current elliptical peripheral shape of the thorax 20, 21,22 elliptical peripheral shapes of the thorax 30 EIT device 32 cable connections, leads of the electrodes 33 electrodes E1 ... E16, electrode arrangement 34 thorax, thorax, Throat circumference 35 Patient 36, 36 'Selection of electrodes, opposite to feed electrodes 37 Infeed electrodes 39, 39' Infeed in thorax 50 Signal acquisition unit (DAQ) 51 Signal input unit 52 Circulation of signal feeds (measurement cycle, frame) 53 Circulation of signal acquisitions ( Measuring cycle, partial frame) 55 measuring signals U- | Un 56 selected measurement signals W1 ... W16 57 electrode E1 58 electrode E16 60 signal representation 70 calculation and control unit 71 data memory 72 signal ratio, weighted amplitude ratio, ratio (W) 73 sample waveform (W_0) 74, 74 ', 74 "pattern signal curves 76 current signal curve 78 processor unit (μΡ, μθ, CPU) 79 control signal 80 output unit, screen 82 visualization 100 sequence 101-106 step sequence 560 average values (ÜS6)
    权利要求:
    Claims (12)
    [1]
    1. An apparatus for electro-impedance tomography (1) for determining an elliptical peripheral shape (20 ') with one of the device for electro-impedance tomography (1) and the thorax (34) of a patient (35) horizontally arranged electrode assembly comprising: - an electrode assembly having a plurality of electrodes (33) adapted to be spaced apart from one another on the circumference of the body in the region of the thorax (34) of the patient (35), - a signal feed unit (51) , which is designed and intended to feed in each measuring cycle of a measuring cycle, an electrical feed signal to two cyclically and in a measuring cycle varying feeding electrodes (37), - a signal detection unit (50), which is designed and intended, a To detect and provide a plurality of measurement signals (55) of the plurality of electrodes (33) in each of the measurement cycles of the measurement cycle, - a calculation u and control unit (70) configured and arranged to perform processing of the detected plurality of measurement signals (55) of the plurality of electrodes (33) and select selected measurement signals (56) from the detected plurality of measurement signals (55) and processing perform the selected measurement signals (56), - one, the computing and control unit (70) associated data storage unit (71) which is designed and provided from the measurement signals (55) selected measurement signals (56) and waveforms (76) and comparison data (73), the apparatus being adapted to determine the elliptical peripheral shape (20) of the computing and control unit (70) in cooperation with the data storage unit (71) from the measurement signals (55) of each Measuring cycle of the measuring cycle those of the measuring signals (55) as selected measuring signals (56) selected and stored who those detected at the pair of electrodes arranged opposite the two feeding electrodes (37) on the thorax (34), by the calculation and control unit (70) in cooperation with the data storage unit (71) in each measuring cycle averages (560) the respectively selected measuring signals (56) of the respective electrode pairs of the respectively selected electrodes (36, 36 ') arranged opposite the two feeding electrodes (37) on the thorax (34) are determined and stored in each measuring cycle, - by the calculating and control unit ( 70) in cooperation with the data storage unit (71), for each pair of electrodes of the selected electrodes (36, 36 '), respective mass (72) of the selected measurement signals (56) and averaged and stored values for these selected electrodes (36, 36') ( 560) are determined as a current waveform (76), - from the calculation and control unit (70) in Z a comparison of the current waveform (76) with at least one pattern waveform (73) from a set of pattern waveforms (74, 74 '74 ") is performed, the pattern waveforms (74, 74' 74") typical Represent waveforms for various elliptical peripheral shapes of the electrode assembly on the thorax (34), determined by the calculation and control unit (70) based on the comparison of a current elliptical peripheral shape (20 ') of the electrode assembly on the thorax (34), - of the calculation and control unit (70) generates and provides a control signal (79) which indicates the currently determined elliptical peripheral shape (20 ') of the electrode arrangement.
    [2]
    2. Device (1) according to claim 1, wherein the calculation and control unit (70) is adapted to coordinate an output unit (80), wherein the output unit (80) in or on the device for electro-impedance tomography (1). is arranged or assigned to the device for electro-impedance tomography (1).
    [3]
    3. The device (1) according to claim 1, wherein the calculation and control unit (70) is designed such that in cooperation with the signal feed unit (51) in each measurement cycle of the measurement cycle of the two feeding electrodes (37) opposite two directly adjacent electrodes are selected as respective electrode pairs for detecting the selected measurement signals (56) and the variation of the two feed electrodes (37) is performed so that in a measurement cycle each of the two feed electrodes (37) is involved at most twice in the feed in the measurement cycle and in each measuring cycle, each of the selected electrodes (36, 36 ') is considered at most twice during the detection of the selected measuring signals (56).
    [4]
    4. Device (1) according to claim 1, wherein the calculation and control unit (70) is designed such that in determining the ratio mass (72) from the selected measurement signals (56) and the electrodes (36, 36 ') selected therefor. ) means (560) a scaling is applied in a signal difference between the selected measurement signals (56) and the determined mean values (560) in a signal differentiation emphasizing or amplifying manner.
    [5]
    The apparatus (1) of claim 4, wherein the computing and control unit (70) is configured such that in determining the mass of mass (72) logarithmic scaling, as a signal emphasizing or amplifying manner, preferably in logarithmic scaling to base 10 W = Ig (¾) in logarithmic scaling to the base eW = In (ÿ) or in logarithmic scaling to base 2 W = log2 (¾) is applied, where U56x, the individual measurement signals (56) from the selected electrodes ( 36) and (üS6) corresponds to the mean values of the respectively selected measuring signals (56) of the respectively selected electrodes (36).
    [6]
    6. Device (1) according to one of the preceding claims, wherein the calculation and control unit (70) is designed such that as a selected electrode (36, 36 ') for detecting the selected measurement signals (56) a number of three, four, five or more than six electrodes (33, 36, 36 ') of the electrodes (33, 36, 36') opposite the two feeding electrodes (37) are selected.
    [7]
    7. Device according to one of the preceding claims, wherein the calculation and control unit (70) is designed such that the selected measurement signals (56) are each determined from average values of a plurality of measurement cycles.
    [8]
    8. Device (1) according to one of the preceding claims, wherein the calculation and control unit (70) is formed, by means of an algorithm for image reconstruction impedance values and / or impedance changes and / or impedance distributions in the thorax (34) in the plane of the electrodes at the thorax (34) based on the plurality of measurements (55) provided by the signal acquisition unit (50), and a tidal image (82) based on the calculated in-plane impedance and / or impedance changes and / or impedance distributions in the thorax (34) the electrodes at the thorax and based on the currently determined elliptical peripheral shape (20 ') of the electrode assembly to determine and include in the control signal (79) and the control signal (79) for the output unit (80) provide.
    [9]
    9. Device (1) according to one of the preceding claims, wherein an output unit (80) for outputting and / or providing the currently determined elliptical peripheral shape (20 ') on the basis of the provided control signal (79) is formed.
    [10]
    10. A method for operating (100) an apparatus for electro-impedance tomography (30) for determining an elliptical peripheral shape (20 ') of an thorax (34) of a patient (35) arranged electrode arrangement having a plurality of electrodes (33). in which in a first step (101) in each measuring cycle of a measuring cycle, an electrical feed signal is fed to two cyclically and in a measuring cycle varying feeding electrodes (37), - wherein in a second step (102) in each measuring cycle of a Measuring cycle (56) are respectively detected at the respective feeding electrodes (37) on the thorax (34) opposite selected electrodes (36, 36), wherein in a third step (103) average values ((756) (560) of FIG respectively selected measuring signals (56) of the respectively the two feeding electrodes (37) on the thorax (34) arranged opposite electrode pairs of the respectively selected electrodes (36, 36 ') in in a fourth step (104), a logarithmic ratio (72) w = ln (¾) or w = l0 ^ (¾) from the selected measurement signals (56) and the electrodes (36, 36 ') is determined to be a current waveform (76), wherein in a fifth step (105) a comparison of the determined current waveform 76 with at least one pattern waveform (73) from a set of pattern waveforms (74, 74 ', 74 "), the pattern waveforms (74, 74', 74") representing different waveforms for various typical elliptical peripheral shapes of the electrode assembly on the thorax (34) and a current elliptical peripheral shape (20 ') based on the comparison is determined, wherein in a sixth step (106), a control signal (79) is generated and provided which the particular current elliptical peripheral shape (20 ') of the electrode assembly a m thorax (34), where U56x corresponds to the individual measurement signals (56) from the selected electrodes (36) and (ÿ56) to the mean values of the respectively selected measurement signals (56) of the respectively selected electrodes (36).
    [11]
    11. The method of claim 10, wherein as selected electrodes (36, 36 ') for detecting the selected measuring signals (56) a number of three, four, five or more than six electrodes (33, 36, 36') of the two feeding electrodes (37) opposite electrodes (33, 36, 36 ') is selected.
    [12]
    12. The method according to any one of claims 10 to 11, wherein the selected measurement signals (56) are each determined from average values of a plurality of measurement cycles.
    类似技术:
    公开号 | 公开日 | 专利标题
    DE102014009439B4|2018-05-30|Apparatus and method for processing tomographic data
    DE60124541T3|2011-05-12|METHOD AND DEVICE FOR PRESENTING INFORMATION OBTAINED BY ELECTRICAL IMPEDANCE TOMOGRAPHY
    DE102014018107B4|2022-03-10|Device for processing tomographic data to display a course of therapy
    EP2961315B1|2019-11-27|System for automated adjustment of a pressure specified by a breathing device
    DE102018008545A1|2020-05-07|Device and method for electro-impedance tomography | with determination of a heart region
    DE102005017492A1|2006-10-19|Method for computationally compensating a periodic movement of an organ
    DE102015006902B3|2016-06-30|Device for processing and visualizing data from an electro-impedance tomography device for the detection and visualization of regional delays in ventilation in the lungs
    DE102011076885A1|2012-12-06|Method for controlling a medical device, device with a medical device and data carrier
    DE102011076880A1|2012-12-06|Method for controlling a medical device, device with a medical device and data carrier
    DE102012205351A1|2013-10-02|Representation of blood vessels and tissue in the heart
    DE102012101791A1|2012-09-06|A method of reducing a radiation dose delivered by an imaging system
    CH713098A2|2018-05-31|Apparatus and method for determining an axial position of an electrode assembly for electro-impedance tomography.
    WO2019001849A1|2019-01-03|Device and method for processing and visualizing data relating to cardiac and pulmonary circulation, obtained by means of an electrical impedance tomography device |
    EP2762062A1|2014-08-06|Electro-impedance tomography device and method
    DE202017106016U1|2017-12-07|A medical information processing apparatus, X-ray CT apparatus and computer-readable storage medium having a program for a medical information processing method
    DE102017007224A1|2019-02-07|Apparatus and method for determining difference ratios based on EIT data
    DE102004006548B4|2006-10-19|Method for planning the radiotherapy of a patient and CT system for this and for the production of CT images
    CH713099B1|2018-09-28|Apparatus and method for determining a peripheral shape of an electrode assembly for electro-impedance tomography.
    EP2799110A1|2014-11-05|Method for operating a bioresonance device
    DE102016011161A1|2018-03-22|Device for processing and visualizing data of an electro-impedance tomography device for the determination and visualization of regional characteristics of the ventilation of the lungs
    EP3412208A1|2018-12-12|Provision of a medical image
    DE102015011390A1|2017-03-09|Apparatus, method and computer program for ventilating a patient
    EP3363363B1|2021-11-17|Method for performing an imaging examination
    DE102007013367A1|2008-09-18|Thoracic electrical impedance acquiring device for use during e.g. treatment of critically sick people, has measuring amplifier with inlet connected to measuring electrode, where impedance of control unit controls circuit and alternator
    DE102014018490A1|2015-11-05|Apparatus and method for removing pulse-like noise signals from mis-signals of an electro-impedance tomography apparatus suitable for lung imaging
    同族专利:
    公开号 | 公开日
    US20180146882A1|2018-05-31|
    CN108113675A|2018-06-05|
    CN108113675B|2021-03-12|
    DE102016014252A1|2018-05-30|
    US10765339B2|2020-09-08|
    CH713099A2|2018-05-31|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US5184624A|1988-04-15|1993-02-09|The University Of Sheffield|Electrical impedance tomography|
    AU699170B2|1994-03-11|1998-11-26|British Technology Group Limited|Electrical impedance tomography|
    RU2127075C1|1996-12-11|1999-03-10|Корженевский Александр Владимирович|Method for producing tomographic image of body and electrical-impedance tomographic scanner|
    US20060084855A1|2004-10-20|2006-04-20|Drager Medical Ag & Co. Kgaa|Electrode belt for carrying out electrodiagnostic procedures on the human body|
    JP2009225854A|2008-03-19|2009-10-08|Omron Healthcare Co Ltd|Body composition information measuring device|
    DE102011106405B4|2011-07-02|2021-08-12|Drägerwerk AG & Co. KGaA|Electro-impedance tomography device|
    US20130096425A1|2011-10-14|2013-04-18|General Electric Company|System and method for data reconstruction in soft-field tomography|
    CN102894976B|2012-10-30|2015-03-18|中国人民解放军第四军医大学|Circular array electrode for brain electrical impedance tomography|
    US10285618B2|2013-07-02|2019-05-14|School Juridical Person Kitasato Institute|EIT measurement device, EIT measurement method and program|
    WO2015025113A1|2013-08-20|2015-02-26|Khor Joo Moy|Apparatus and method for estimating shape|
    WO2015048917A1|2013-10-04|2015-04-09|Swisstom Ag|An electrical impedance tomography system|
    CN103876738B|2014-04-03|2016-03-09|思澜科技（成都）有限公司|Based on the biological impedance probe of spectral characteristic, measuring system and method|
    DE102016014251A1|2016-11-30|2018-05-30|Drägerwerk AG & Co. KGaA|Apparatus and method for determining an axial position of an electrode assembly for electro-impedance tomography|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    DE102016014252.9A|DE102016014252A1|2016-11-30|2016-11-30|Apparatus and method for determining a peripheral shape of an electrode assembly for electro-impedance tomography|
    [返回顶部]