Development of a miniaturized, single-port automated insulin delivery system utilizing a glucose sensing catheter, ultra-concentrated insulin, and an optimized control algorithm

ABSTRACT SignificanceThere are overmillion people with insulin treated diabetes in the United States who represent a disproportionately large share of the $B in direct medical costs attributable to diabetesThe use of continuous glucose monitoringCGMhas been shown to reduce HbA c levelsa proven predictor of health outcomes within this populationwith the greatest improvement achieved when CGM is coupled with continuous subcutaneous insulin infusionCSIIThe recent convergence of CGM and insulin pumps has enabled the first generation of automated insulin deliveryAIDsystemspromising even better glycemic control for insulin treated diabetesHowevercurrent AID systems are complexcumbersomeand expensive for the patient because they require multiple devices to be worn on the bodya glucose sensoran insulin pumpand an insulin delivery catheterWe have developed a glucose sensing catheter that reduces the number of subcutaneous components from two to onesignificantly reducing the size and complexity of these systemsBy integrating the sensing catheter into a patch pumpwe will further simplify the system by reducing the footprintand enabling the first fully integrated single component AID systemResulting reductions in system sizecomplexityand cost will increase adoption rates for AIDhelping improve compliancelower HbA c levelsand improve health outcomes among people with typediabetesPreliminary DataWe have demonstrated glucose sensing can be performed at the site of insulin deliveryHoweverwe have discovered that there is a glucose measurement artifact that occurs immediately after dispensing liquidinsulin or salinefrom the cannulalikely caused by dilution of the surrounding interstitial fluidPreliminary data suggest the magnitude of the artifact is related to the volume of the bolusSpecific AimsThis proposal represents the first phase of an effort to integrate the dual use cannula with a miniaturized patch pump and an AID algorithmtaking advantage of a novel concentrated insulin to reduce CGM artifact sizeIn Specific Aimwe will reduce the impact of the dilution artifact through the use of ultraconcentrated insulinWe will characterize the impact of the artifact using smaller boluses of Uinsulin in a swine studyIn Specific Aimwe will create a calibration algorithm based on a Kalman filter and a predictive model of future sensor values to further mitigate the dilution artifactIn Specific Aimwe will integrate the kinetics of the Uinsulin into a model predictive controlMPCAID algorithm developed by Oregon Health andampScience UniversityOHSUand optimize the algorithm toincorporate a model of the kinetics of the Thermalin insulin andeliminate any remaining dilution artifact that may still be presentWe will evaluate the performance of the new calibration algorithm on the data collected in Aimas well is in other human data that we have collected with the glucose sensing catheterThe MPC algorithm will be evaluated in silico using the OHSU virtual patient population in preparation for full integration into the Thermalin StampPump in phaseof this proposalIn summarythis collaborative effort between PDTOHSUand Thermalin brings together the only published amperometric glucose sensing catheter with a fault tolerant AID algorithm and the only rapidconcentrated insulinIn shortwe are the only team currently capable of providing this novel solution for a unified automated insulin delivery device NARRATIVEIn this projecta combined insulin delivering and continuous glucose monitoringCGMcannula will be integrated with a miniaturized patch pump from Thermalin and an automated insulin dosingAIDalgorithm from Oregon Health andampScience UniversityIn PhaseCGM performance will be improved through use of ultraconcentrated insulin from Thermalin to reduce bolus size and through the use of predictive algorithms that are optimized to accommodate a dilution artifact following large bolusesAn AID algorithm will be updated to work with Thermalin Uinsulin and optimized to eliminate the impact of any remaining dilution artifact