Sensor for percutaneous intravascular deployment without an indwelling cannula

Abstract

The present invention relates to a sensor for percutaneous insertion and intravascular residence without an indwelling cannula. In preferred embodiments, a glucose sensor is inserted into a blood vessel using a removable cannula. After the cannula is removed, the glucose sensor remains within the blood vessel by itself and forms a seal with the patient's tissue.

1 - 35 . (canceled) 
     
     
         36 . A method for introducing an analyte sensor into a patient, comprising:
 providing an introducer assembly comprising a piercing member associated with a removable cannula, wherein a piercing tip of the piercing member extends distally beyond the removable cannula;   inserting the introducer assembly into the patient;   retracting the piercing member from the removable cannula, while leaving the removable cannula in the patient;   providing an optical analyte sensor comprising a fluorescent indicator system disposed along a distal end region and adapted to generate an optical signal related to the patient's analyte level in response to light, an elongate optical fiber, and an optical coupling disposed along a proximal end region;   inserting the optical analyte sensor through the removable cannula and into the patient;   retracting the removable cannula from the patient, while leaving the sensor in the patient; and   removing the removable cannula from the sensor.   
     
     
         37 . The method of  claim 36 , wherein the optical analyte sensor comprises an anti-thrombogenic coating or surface treatment. 
     
     
         38 . The method of  claim 36 , wherein the optical analyte sensor has a surface comprising polytetrafluoroethylene. 
     
     
         39 . The method of  claim 36 , wherein removing the removable cannula comprises at least one of splitting the removable cannula, peeling the removable cannula, and cutting the removable cannula. 
     
     
         40 . The method of  claim 39 , wherein removing the removable cannula comprises squeezing a first wing and a second wing together, wherein the first wing and the second wing are disposed opposite each other along a longitudinal axis of the removable cannula. 
     
     
         41 . The method of  claim 36 , wherein the piercing member is inserted into a blood vessel and the introducer assembly comprises a flashback chamber, wherein the flashback chamber fills with blood when the blood vessel is cannulated. 
     
     
         42 . The method of  claim 41 , wherein the introducer assembly comprises a filter, wherein the filter contains the blood within the flashback chamber when the blood vessel is cannulated. 
     
     
         43 . The method of  claim 36 , wherein the piercing member has a diameter less than a diameter of the removable cannula. 
     
     
         44 . The method of  claim 36 , wherein the removable cannula has a proximal end and a distal end, wherein the distal end of the cannula is beveled. 
     
     
         45 . The method of  claim 36 , wherein withdrawing the removable cannula from the patient while leaving the sensor in the patient forms a seal around the sensor. 
     
     
         46 . The method of  claim 36 , wherein the chemical indicator system comprises a fluorophore configured to generate an emission signal in response to excitation light, and an analyte binding moiety operably coupled to the fluorophore, wherein the analyte binding moiety is configured to bind analyte and modulate the emission signal of the fluorophore in a manner related to the amount of analyte binding. 
     
     
         47 . The method of  claim 46 , wherein the chemical indicator system further comprises a water-insoluble polymer matrix, and wherein the fluorophore is covalently bonded to the polymer matrix. 
     
     
         48 . The method of  claim 46 , wherein the analyte binding moiety comprises an aromatic boronic acid covalently bonded to the viologen. 
     
     
         49 . The method of  claim 36 , wherein the optical analyte sensor further comprises a porous membrane disposed along the distal end region of the optical fiber. 
     
     
         50 . The method of  claim 49 , wherein the porous membrane can comprise a material selected from the group consisting of polyethylene, polycarbonate, polysulfone, and polypropylene. 
     
     
         51 . The method of  claim 49 , wherein the porous membrane is microporous and has a mean pore size that is less than two nanometers. 
     
     
         52 . The method of  claim 46 , wherein the fluorophore comprises HPTS-triCysMA and the analyte binding moiety comprises 3-3′-oBBV. 
     
     
         53 . The method of  claim 36 , wherein the piercing member is deployed in an interstitial site, interstitial fluid, or interstitial space of the patient. 
     
     
         54 . The method of  claim 36 , wherein the optical analyte sensor comprises a thermistor or thermocouple disposed along the distal end region of the optical fiber. 
     
     
         55 . The method of  claim 36 , wherein the piercing member is a hypodermic needle. 
     
     
         56 . The method of  claim 36 , wherein the piercing member is a part of the removable cannula.