Device for processing and visualizing data of an electric impedance tomography apparatus for determining and visualizing regional ventilation delays in the lungs

Abstract

A device ( 10 ) processes and visualizes EIT data ( 3 ) of at least one region of the lungs to determine and visualize ventilation delays in the lungs of a living being. The EIT data ( 3 ) are obtained from an electrical impedance tomography apparatus ( 30 ). The device makes it possible to visualize regional ventilation delays of the lungs or of regions of the lungs in which the delay exceeds a predefined duration ( 76 ) in a joint image ( 900 ).

What is claimed is: 
     
         1 . A device for processing and visualizing electrical impedance tomography (EIT) data of at least one region of lungs to determine and visualize ventilation delays in the lungs, wherein the EIT data are obtained from an electrical impedance tomography apparatus, the device comprising:
 a data input unit configured to receive and provide the EIT data of at least one region of the lungs;   a calculation and control unit, wherein:   the calculation and control unit is configured to determine local impedance values and impedance changes of at least one region of the lungs from the EIT data;   the calculation and control unit is configured to determine a tidal image with a local distribution of the impedance values and impedance changes in the lungs from the local impedances and local impedance changes and to generate and provide a first control signal of the lungs, which is representative of the determined tidal image of the lungs;   the calculation and control unit is configured to determine regional ventilation delays in the lungs in relation to a comparison variable related to an observation period from the local impedances and local impedance changes, the regional ventilation delays are also determined using a volume/impedance criterion of both the local impedances and the comparison variable in the observation period, the volume/impedance criterion being a ratio of a defined duration of a local range t x  to a defined duration of the global impedance curve T x , the defined duration being determined as a same percentage of local and global maximum impedances respectively;   the calculation and control unit is configured to analyze the determined regional ventilation delays in the lungs to determine whether the determined regional ventilation delays exceed a predefined duration; and   the calculation and control unit is configured to generate and provide a second control signal, which represents local regions of the lungs having regional ventilation delays that exceed the predefined duration; and   an image processing and output unit, wherein:   the image processing and output unit is configured to generate, provide or output an output signal using the first control signal and the second control signal; and   the output signal represents a superimposition of the tidal image with an image of the local regions of the lungs having regional ventilation delays that exceed the predefined duration, the output signal not representing regional ventilation delays below the predefined duration, and local impedances which lead the global impedance.   
     
     
         2 . A device in accordance with  claim 1 , further comprising a data output unit with a component for graphic visualization configured to visualize a joint image based on the output signal, the data output unit being arranged or connected in or at the device for processing and visualizing EIT data, wherein the image that represents the local regions of the lungs having regional ventilation delays exceed the predefined duration is superimposed to the tidal image in the joint image. 
     
     
         3 . A device in accordance with  claim 1 , wherein the duration of a phase of exhalation is selected as the observation period and the volume/impedance criterion is derived from shapes of global impedance curves of one or more phases of exhalation in combination with the tidal volume. 
     
     
         4 . A device in accordance with  claim 1 , wherein the duration of inhalation is determined from a shape of a global impedance curve. 
     
     
         5 . A device in accordance with  claim 1 , wherein the calculation and control unit is configured to perform a numerical stabilization of the EIT data, of the local impedances or impedance changes and to generate and provide a numerically stabilized second control signal and to use the numerically stabilized second control signal with the first control signal to generate, provide or output the output signal. 
     
     
         6 . A device for processing and visualizing electrical impedance tomography (EIT) data of lungs of a patient to determine and visualize ventilation delays in the lungs, wherein the EIT data are obtained from an electrical impedance tomography apparatus, the device comprising:
 a data input unit configured to receive the electrical impedance tomography (EIT) data representing impedances over time of the lungs;   a calculation and control unit configured to:   determine local impedances over time for a plurality of regions of the lungs, each of the plurality of regions being a portion of the lungs;   generate a tidal image showing the plurality of regions of the lungs, and the local impedance for said each of the plurality of regions;   determining a global impedance over time of the lungs;   comparing each of the local impedances of each of the plurality of regions with the global impedances to determine a regional ventilation delay for each of the plurality of regions, the comparing step being performed as a function of a defined amount of the volume flowing into or out of the lungs, said comparing step includes determining a difference between a local time point (t x ) of the local impedances of one the regions and a global time point (T x ) of the global impedances to determine the regional ventilation delay, the local time point and global time point being determined as functions of local and global maximum impedances;   a graphic visualization unit receiving the local tidal image, and the regional ventilation delays for each of the plurality of regions from the calculation and control unit, said graphic visualization unit displaying the regional ventilation delay of each of the plurality of regions superimposed on corresponding regions of the tidal image, said graphic visualization unit not displaying regional ventilation delays below the predefined duration, and local impedances which lead the global impedance.   
     
     
         7 . A device in accordance with  claim 6 , wherein:
 said calculation and control unit is configured to determine the local time point (t x ) as a function based on the local maximum impedance of the one region;   said calculation and control unit is configured to determined the global time point (T x ) by the same function used by the local time point, but based on the global maximum impedance.   
     
     
         8 . A method for detecting anomalies in the lungs of a patient, the method comprising the steps of:
 receiving electrical impedance tomography (EIT) data representing impedances over time of a plurality of regions of the lungs;   determining local impedances over time for each of the plurality of regions;   generating a tidal image showing the plurality of regions of the lungs, and the local impedance for each of the plurality of regions;   determining global impedances over time of the lungs;   determining a regional ventilation delay for each of the plurality of regions, the regional ventilation delay of each of the plurality of regions being a difference between the respective local impedance and the global impedance;   determining regional ventilation delays which exceed a predefined duration;   displaying the regional ventilation delay exceeding the predefined duration of each of the plurality of regions superimposed on corresponding regions of the tidal image;   not displaying regional ventilation delays below the predefined duration, and local impedances which lead the global impedance.   
     
     
         9 . A method in accordance with  claim 8 , wherein:
 said determining of the regional ventilation delay includes determining a difference between a local time point (t x ) of the local impedances of one the regions and a global time point (T x ) of the global impedances.   
     
     
         10 . A method in accordance with  claim 9 , wherein:
 the local time point (t x ) and global time point (T x ) are determined as a same percentage of local and global maximum impedances respectively.   
     
     
         11 . A method in accordance with  claim 9 , wherein:
 the local time point (t x ) and global time point (T x ) are determined as a time when the local impedance and the global impedance are a same percentage of local and global maximum impedances respectively.   
     
     
         12 . A method for detecting anomalies in the lungs of a patient, the method comprising the steps of:
 receiving electrical impedance tomography data representing impedances over time of a plurality of regions of the lungs;   determining local impedances over time for each of the plurality of regions;   generating a tidal image showing the plurality of regions of the lungs, and the local impedance for each of the plurality of regions;   determining global impedances over time of the lungs;   determining a regional ventilation delay for each of the plurality of regions, the regional ventilation delay of each of the plurality of regions being a difference between the respective local impedance and the global impedance;   determining regional ventilation delays which exceed a predefined duration;   superimposing indications for each of the plurality of regions exceeding the predefined duration on corresponding regions of the tidal image to provide a superimposed image;   not superimposing indications on the superimposed image for regions which are less than the predefined duration;   not superimposing indications on the superimposed image for regions which lead the global impedance;   providing the superimposed image to an operator.   
     
     
         13 . A method in accordance with  claim 12 , further comprising:
 providing a calculation and control unit configured to perform the method steps previously set forth.