Devices, systems, and methods to obtain conductance and temperature data

Abstract

Devices, systems, and methods to measure parallel tissue conductance, luminal cross-sectional areas, fluid velocity, and/or determine plaque vulnerability using temperature. In at least one embodiment of a method to obtain parallel tissue conductance, the method comprises the steps of inserting at least part of a detection device into a luminal organ, applying current thereto, obtaining a native temperature measurement, injecting a solution of a known conductivity into the luminal organ, detecting a temperature change indicative of the fluid within the luminal organ, measuring an output conductance, and calculating a parallel tissue conductance based upon the output conductance and the conductivity of the injected solution.

1 . A method to obtain conductance data within a luminal organ, the method comprising the steps of:
 operating a detection device having an electrode and a thermistor, the detection device at least partially positioned within a luminal organ to detect a temperature change from a first temperature to a temperature indicative of an injection of a bolus of a solution having a known conductivity; and   obtaining multiple conductance measurements using the electrode of detection device prior to dilution of the bolus at least until a threshold temperature is reached.   
     
     
         2 . The method of  claim 1 , further comprising the step of:
 calculating a parallel tissue conductance at the first location based in part upon the temperature change, at least one conductance measurement of the multiple conductance measurements, and the conductivity of the injected solution.   
     
     
         3 . The method of  claim 1 , further comprising the step of:
 calculating a dimension of the luminal organ based in part upon at least one conductance measurement of the multiple conductance measurements.   
     
     
         4 . The method of  claim 3 , further comprising the steps of:
 selecting an appropriately-sized stent based upon the calculated dimension; and   implanting the stent into the luminal organ.   
     
     
         5 . The method of  claim 1 , wherein the first temperature is a measurement of blood obtained using the thermistor of the detection device. 
     
     
         6 . The method of  claim 1 , wherein the temperature change is based upon a temperature measurement at least 5° C. lower than the first temperature. 
     
     
         7 . The method of  claim 1 , wherein the threshold temperature is within 2° C. of the first temperature. 
     
     
         8 . The method of  claim 1 , further comprising the step of:
 calibrating the detection device using at least one phantom immersed in a solution bath of the same solution injected into the luminal organ, wherein the solution within the solution bath is at a known temperature.   
     
     
         9 . The method of  claim 1 , wherein the detection device further comprises an inflatable balloon along a longitudinal axis of the detection device. 
     
     
         10 . The method of  claim 9 , further comprising the step of:
 inflating the balloon to breakup materials causing a stenosis within the luminal organ.   
     
     
         11 . The method of  claim 9 , wherein the detection device further comprises a stent located over the balloon, the stent capable of being distended to a desired lumen size and implanted into the luminal organ. 
     
     
         12 . A detection device configured to obtain conductance data within a luminal organ, comprising:
 an elongated body having a thermistor located thereon, the thermistor configured to detect a temperature change within the luminal organ from a first temperature to a temperature indicative of an injection of a bolus of a solution having a known conductivity; and   at least two electrodes along the elongated body wherein at least one of the at least two electrodes is/are located distal to the thermistor, the at least two electrodes configured to obtain multiple conductance measurements within the luminal organ in connection with the injected solution and based upon the detected temperature change prior to dilution of the bolus and at least until a threshold temperature is reached.   
     
     
         13 . The device of  claim 12 , configured so that a parallel conductance can be calculated based in part upon the temperature change obtained by the thermistor, at least one conductance measurement of the multiple conductance measurements obtained by the at least two electrodes, and the conductivity of the injected solution. 
     
     
         14 . The device of  claim 12 , wherein the at least two electrodes comprises at least two detection electrodes, and wherein the device further comprises at least two excitation electrodes, wherein two of the at least two detection electrodes are positioned in between two of the at least two excitation electrodes. 
     
     
         15 . The device of  claim 14 , wherein at least one excitation electrode is/are in communication with a current source capable of supplying electrical current to the at least one excitation electrode. 
     
     
         16 . The device of  claim 12 , wherein the elongated body is selected from the group consisting of a wire and a catheter. 
     
     
         17 . The device of  claim 12 , wherein the device defines a lumen therethrough and further comprises a suction/infusion port located proximal to the at least one electrode, wherein the suction/infusion port is in communication with the lumen, thereby enabling injection of a solution into a luminal organ through the suction/infusion port. 
     
     
         18 . The device of  claim 12 , wherein at least one of the at least two electrodes and the thermistor share an electrical wire connection capable of providing current to the at least one of the at least one electrodes and the thermistor. 
     
     
         19 . A system configured to obtain conductance data within a luminal organ, comprising:
 a detection device, comprising:
 an elongated body having a thermistor located thereon, the thermistor configured to detect temperature data including a temperature change within the luminal organ from a first temperature to a temperature indicative of an injection of a bolus of a solution having a known conductivity; and 
 at least two electrodes along the elongated body wherein at least one of the at least two electrodes is/are located distal to the thermistor, the at least two electrodes configured to obtain multiple conductance measurements within the luminal organ in connection with the injected solution and based upon the detected temperature change prior to dilution of the bolus and at least until a threshold temperature is reached; and 
   a data acquisition and processing system operably coupled to the device and capable of (a) receiving the temperature data from the thermistor in connection with the injection of the bolus, and (b) obtaining the multiple conductance measurements from the at least two electrodes while receiving the temperature data.   
     
     
         20 . The system of  claim 19 , wherein the elongated body is selected from the group consisting of a wire and a catheter, and wherein the data acquisition and processing system is further operable to calculate a parallel tissue conductance based in part upon at least one conductance measurement of the multiple conductance measurements and the known conductivity of the solution.