Systems and methods for intravenous drug management using immittance spectroscopy

Abstract

Described herein are devices, systems, and methods for determining the composition of liquids, including the identity of one or more drugs in the liquid, the concentration of the drug, and the type of diluent using immittance spectroscopy. These devices, systems and methods are particularly useful for describing the identity and, in some variations, concentration of one or more components of a medical liquid such as intravenous fluid. In particular, described herein are devices, systems and methods that may operate in low ionic strength diluents. Also described are methods of recognizing complex immittance spectrograph patterns to determine the composition of a liquid by pattern recognition.

What is claimed is: 
     
         1 . A sensor for immittance spectroscopy configured to operate in low ionic strength liquid, the sensor comprising:
 a first electrode comprising a plurality of elongate lengths of an electrically conductive material;   a second electrode comprising a plurality of elongate lengths of an electrically conductive material;   wherein the plurality of elongate lengths of electrically conductive material of the first electrode are interdigitated with the plurality of elongate lengths of electrically conductive material of the second electrode to form an electrode pair.   
     
     
         2 . The sensor of  claim 1 , further comprising a second electrode pair comprising a plurality of elongate lengths of an electrically conductive material forming a third electrode and a plurality of elongate lengths of an electrically conductive material forming a fourth electrode, wherein the plurality of elongate lengths of electrically conductive material of the third electrode are interdigitated with the plurality of elongate lengths of electrically conductive material of the fourth electrode. 
     
     
         3 . The sensor of  claim 1 , wherein the electrically conductive material forming the first electrode is different from the electrically conductive material forming the second electrode. 
     
     
         4 . The sensor of  claim 1 , wherein the electrically conductive material forming the first electrode and the electrically conductive material forming the second electrode are selected from the group consisting of: Au, Ti, and Pd. 
     
     
         5 . The sensor of  claim 1 , wherein the elongate lengths of the first electrode are separated from the elongate lengths of the second electrode by less than 100 μm. 
     
     
         6 . The sensor of  claim 1 , wherein the elongate lengths of the first and second electrode are curved. 
     
     
         7 . The sensor of  claim 1 , further comprising a pair of electrodes configured for operation in a high ionic strength fluids. 
     
     
         8 . The sensor of  claim 1 , wherein each length of the plurality of elongate lengths of the first and second electrode has a length that is greater than 10 times its width. 
     
     
         9 . The sensor of  claim 1 , further comprising a printed circuit board substrate onto which the first and second electrodes are formed. 
     
     
         10 . The sensor of  claim 1 , further comprising a flow sensor. 
     
     
         11 . The sensor of  claim 1 , further comprising a capillary port configured to wick sample liquid onto all of the electrodes of the sensor. 
     
     
         12 . The sensor of  claim 1 , further comprising a retractable needle configured to load sample liquid onto all of the electrodes of the sensor. 
     
     
         13 . A sensor for immittance spectroscopy configured to operate in both high and low ionic strength liquids, the sensor comprising:
 at least a first pair of electrodes configured to operate in low ionic strength liquids, the first pair comprising a first electrode having a plurality parallel elongate lengths of an electrically conductive material and a second electrode comprising a plurality of parallel elongate lengths of an electrically conductive material, wherein the elongate lengths of the first electrode are interdigitated with the elongate lengths of the second electrode; and   at least a second pair of electrodes configured to operate in high ionic strength liquids.   
     
     
         14 . The sensor of  claim 13 , further comprising a flow sensor. 
     
     
         15 . The sensor of  claim 13 , further comprising a capillary port configured to wick sample liquid onto all of the electrodes of the sensor. 
     
     
         16 . The sensor of  claim 13 , further comprising a retractable needle configured to load sample liquid onto all of the electrodes of the sensor. 
     
     
         17 . A sensor for immittance spectroscopy configured to operate in both high and low ionic strength liquids, the sensor comprising:
 three pairs of electrodes configured to operate in low ionic strength liquids, wherein each first pair comprises a first electrode having a plurality parallel elongate lengths of an electrically conductive material and a second electrode comprising a plurality of parallel elongate lengths of an electrically conductive material, wherein the elongate lengths of the first electrode for a pair are interdigitated with the elongate lengths of the second electrode for that pair; and   three electrodes configured to operate in high ionic strength liquids.   
     
     
         18 . The sensor of  claim 17  further comprising a capillary port configured to wick sample liquid onto all of the electrodes of the sensor. 
     
     
         19 . The sensor of  claim 17  further comprising a retractable needle configured to load sample liquid onto all of the electrodes of the sensor.