Biomedical Microdevices

, Volume 15, Issue 1, pp 151–160 | Cite as

A miniaturized transcutaneous system for continuous glucose monitoring

  • Robert A. CroceJr
  • SanthiSagar Vaddiraju
  • Jun Kondo
  • Yan Wang
  • Liang Zuo
  • Kai Zhu
  • Syed K. Islam
  • Diane J. Burgess
  • Fotios Papadimitrakopoulos
  • Faquir C. Jain


Implantable sensors for continuous glucose monitoring hold great potential for optimal diabetes management. This is often undermined by a variety of issues associated with: (1) negative tissue response; (2) poor sensor performance; and (3) lack of device miniaturization needed to reduce implantation trauma. Herein, we report our initial results towards constructing an implantable device that simultaneously address all three aforementioned issues. In terms of device miniaturization, a highly miniaturized CMOS (complementary metal-oxide-semiconductor) potentiostat and signal processing unit was employed (with a combined area of 0.665 mm2). The signal processing unit converts the current generated by a transcutaneous, Clark-type amperometric sensor to output frequency in a linear fashion. The Clark-type amperometric sensor employs stratification of five functional layers to attain a well-balanced mass transfer which in turn yields a linear sensor response from 0 to 25 mM of glucose concentration, well beyond the physiologically observed (2 to 22 mM) range. In addition, it is coated with a thick polyvinyl alcohol (PVA) hydrogel with embedded poly(lactic-co-glycolic acid) (PLGA) microspheres intended to provide continuous, localized delivery of dexamethasone to suppress inflammation and fibrosis. In vivo evaluation in rat model has shown that the transcutaneous sensor system reproducibly tracks repeated glycemic events. Clarke’s error grid analysis on the as—obtained glycemic data has indicated that all of the measured glucose readings fell in the desired Zones A & B and none fell in the erroneous Zones C, D and E. Such reproducible operation of the transcutaneous sensor system, together with low power (140 μW) consumption and capability for current-to-frequency conversion renders this a versatile platform for continuous glucose monitoring and other biomedical sensing devices.


Implantable sensors CMOS circuits Amperometric glucose sensors Low-power microelectronics In vivo monitoring 



Financial support for this study was obtained from US Army Medical Research Grants (W81XWH-09-1-0711 and W81XWH-07-10688), NIH grants (1-R21-HL090458-01, ES013557, R43EB011886 and 9R01EB014586) and NSF/SBIR grants (1046902 and 1230148).


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Copyright information

© Springer Science+Business Media, LLC 2012

Authors and Affiliations

  • Robert A. CroceJr
    • 1
  • SanthiSagar Vaddiraju
    • 2
    • 3
  • Jun Kondo
    • 1
  • Yan Wang
    • 4
  • Liang Zuo
    • 5
  • Kai Zhu
    • 5
  • Syed K. Islam
    • 5
  • Diane J. Burgess
    • 4
  • Fotios Papadimitrakopoulos
    • 3
    • 6
  • Faquir C. Jain
    • 1
  1. 1.Electrical & Computer EngineeringUniversity of ConnecticutStorrsUSA
  2. 2.Biorasis Inc., Technology Incubation ProgramUniversity of ConnecticutStorrsUSA
  3. 3.Nanomaterials Optoelectronics Laboratory, Polymer Program, Institute of Materials ScienceUniversity of ConnecticutStorrsUSA
  4. 4.Department of Pharmaceutical SciencesUniversity of ConnecticutStorrsUSA
  5. 5.University of TennesseKnoxvilleUSA
  6. 6.Department of ChemistryUniversity of ConnecticutStorrsUSA

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