Systems and methods for sensing lung fluid and functionality

Abstract

An apparatus for monitoring for accumulation of lung fluid comprises a feeding tube having first electrode(s) positioned thereon for electrical contact with tissue of an esophagus of a target patient including a lower esophageal sphincter (LES) and/or tissue in proximity to the LES, second electrode(s) sized and shaped for contacting skin of the target patient, and a non-transitory memory having stored thereon code instructions for applying alternating current(s) to pair(s) of first and second electrodes, measuring a voltage over the pair(s), and computing an estimate of a change of lung fluid relative to a baseline in lung(s) of the target patient according to the applied alternating current and measured voltage, wherein the applying, the measuring, and the computing the estimate of the change in lung fluid are iteratively executed for monitoring the target patient for accumulation of lung fluid while the feeding tube is in use.

What is claimed is: 
     
         1 . A system for monitoring a subject, comprising:
 a feeding tube;   a first electrode array comprising a plurality of spaced apart electrodes disposed along a length of the feeding tube;   a second electrode array comprising a plurality of spaced apart electrodes, each electrode sized and shaped for contacting a surface of a skin of thorax of a subject;   at least one processor executing a code for: measuring a plurality of impedance values computed between the plurality of electrodes of the first electrode array and the plurality of electrodes of the second electrode array; and   computing likelihood of a medical state of the subject according to an analysis of the plurality of impedance values.   
     
     
         2 . The system of  claim 1 , further comprising code for generating a tomographical impedance map of fluid in a lung according to the plurality of impedance values. 
     
     
         3 . The system of  claim 1 , further comprising code for generating a 3D image of fluid in the lung according to the plurality of impedance values. 
     
     
         4 . The system of  claim 1 , wherein each of the first electrode array and the second electrode array includes at least 5 electrodes. 
     
     
         5 . The system of  claim 1 , wherein when the feeding tube is in use, the first electrode array and the second electrode array face each other. 
     
     
         6 . The system of  claim 1 , wherein when the feeding tube is in use, the first electrode array and the second electrode array arranged for sandwiching a lung of the subject. 
     
     
         7 . The system of  claim 1 , further comprising code for sweeping different frequencies between the first electrode array and the second electrode array for obtaining the plurality of impedance values, and aggregating the plurality of impedance values for computing the likelihood of the medical state. 
     
     
         8 . The system of  claim 1 , wherein the plurality of impedance values are obtained for each anatomical region of a plurality of different anatomical regions of a lung of the subject, the different anatomical regions corresponding to different locations of the first electrode array and the second electrode array. 
     
     
         9 . The system of  claim 8 , wherein the likelihood of the medical state is computed according to an analysis of the plurality of impedance values for the plurality of different anatomical regions of the lung of the subject. 
     
     
         10 . The system of  claim 8 , further comprising code for generating a map according to the plurality of impedance values obtained from each anatomical region of the plurality of different anatomical regions. 
     
     
         11 . The system of  claim 8 , further comprising code for differentiating between the medical state of pulmonary edema and pleural effusion according to the analysis indicating at least one of (i) impedance values that are relatively lower at electrodes at positions corresponding to at least one lobe indicative of pulmonary edema at the at least one lobe, and (ii) impedance values that are relatively lower at a base of a lung but relatively constant elsewhere are indicative of pulmonary effusion. 
     
     
         12 . The system of  claim 8 , further comprising code for sweeping different frequencies between the first electrode array and the second electrode array for obtaining the plurality of impedance values for each anatomical region of the plurality of anatomical regions. 
     
     
         13 . The system of  claim 1 , wherein the medical state comprises pleural effusion. 
     
     
         14 . The system of  claim 1 , wherein the first electrode array and the second electrode array are positioned for avoiding passing current through a heart of the subject. 
     
     
         15 . The system of  claim 1 , further comprising code for
 (1) selecting a combination including a selected frequency spectrum of an alternating current and a selected electrode pair including the a first electrode from the first electrode array and a second electrode from the second electrode array, wherein the selected electrode pair denotes a respective selected impedance sensor;   (2) compute an impedance value according to voltage over the respective selected impedance sensor and according to the alternating current applied at the selected frequency spectrum by the respective selected impedance sensor;   (3) compute a sub-impedance score according to the computed impedance value;   (4) iterate (1), (2), and (3), wherein for each iteration another combination is selected that includes an electrode pair that has not been previously selected in previous iterations, the electrode pair includes one electrode of the first electrode array and one electrode of the second electrode array, and at least another selected frequency of the alternating current applied by the respective selected impedance sensor and used to obtain the impedance value, for computing the plurality of impedance scores at a plurality of selected frequencies of the alternating current applied by the respective selected impedance sensors.   
     
     
         16 . The system of  claim 1 , wherein the second electrode array is for placement along the thorax in proximity to a first lung of the subject, and further comprising a third electrode array for placement along the thorax in proximity to a second lung of the subject, and code for analyzing the plurality of impedance values obtained between the first electrode array and the second electrode array, and between the first electrode array and the third electrode array, for differentiating between lung fluid processes that affect both lungs equally from lung fluid processes that affect only one lung. 
     
     
         17 . The system of  claim 1 , wherein the second electrode array is for placement along the thorax in proximity to a first lung of the subject, and further comprising a third electrode array for placement along the thorax in proximity to a second lung of the subject, and code for analyzing the plurality of impedance values obtained between the first electrode array and the second electrode array, and between the first electrode array and the third electrode array, for determining fluid level in the first lung and the second lung. 
     
     
         18 . A method for monitoring a subject, comprising:
 measuring a plurality of impedance values computed between a plurality of spaced apart electrodes of a first electrode array that are disposed along a length of a feeding tube and a plurality of spaced apart electrodes of a second electrode array , each electrode of the second electrode array is sized and shaped for contacting a surface of a skin of thorax of a subject, while the feeding tube is in use; and   computing likelihood of a medical state of the subject according to an analysis of the plurality of impedance values.   
     
     
         19 . A computer program product for monitoring a subject, comprising:
 a non-transitory memory having stored thereon a code which, when executed by at least one hardware processor of a computing device, while a feeding tube is in use, cause the at least one hardware processor to:
 measure a plurality of impedance values computed between a plurality of spaced apart electrodes of a first electrode array that are disposed along a length of the feeding tube and a plurality of spaced apart electrodes of a second electrode array , each electrode of the second electrode array is sized and shaped for contacting a surface of a skin of thorax of a subject; and 
 compute likelihood of a medical state of the subject according to an analysis of the plurality of impedance values.