Glucose sensors modelling

Gilligan BJ, Shults MC, Rhodes RK, Updike SJ. Evaluation of a subcutaneous glucose sensor out to 3 months in a dog model. Diabetes Care 1994, 17, 882-887. 

So far decades of effort and large expenditures directed toward the development of a long-term implantable glucose sensor have failed to meet the expectations of medical researchers and the lay public. What should be apparent from this experience is that the complex foreign body reaction by the host dominates, and thus methodical, stepwise research using relevant and powerful in vivo model systems cannot be bypassed. This approach is virtually requisite if we are to ever have a clinically useful, subcutaneously implantable glucose sensor. 

Figure 11.1 Top Modeled response of a flux-based glucose sensor subject to a moderate biofouling rate. The sensor signal decreases immediately and is rendered useless after 3.7 days. Bottom Modeled response of an optical glucose sensor subjected to the same fouling rate. The measured signal is not affected until a period of 76 days. Adapted with permission from Ref. 17.

The next stage was achieved in 1967 by Updike and Hicks, who entrapped GOD in a gel of polyacrylamide, thus increasing the operational stability of the enzyme and simplifying the sensor preparation. Further investigations by Reitnauer (1972) enabled the successful application of an enzyme electrode in a prototype blood glucose analyzer. In 1975 Yellow Springs Instrument Co. (USA) commercialized a glucose analyzer (model 23 A) which was based on a patent by Clark (1970). The Lactate Analyzer LA 640 by La Roche (Switzerland) followed one year later. In this instrument the enzyme is dissolved in a buffer in a reaction chamber placed in front of the electrode. 

Muehlbauer et al. (1989) attached a Bi/Sb thermopile directly to a membrane containing immobilized GOD and catalase. The basic sensor was assembled by vacuum deposition of the metals. The dynamic behavior of the thermoelectric glucose sensor was modeled. The results properly reflected the sensor response. 

Amperometric responses of GOD-PBT electrode to glucose were made in a three-electrode flow cell with 0.1 mol dm 3 phosphate buffer, pH 7.0 solution as supporting electrolyte. The schematic description of the amperometric glucose sensor is depicted in Figure 1. The flow rate was controlled at 1 ml min l by a Atto Coporation model SH-121IH perista pump. All supporting electrolyte solutions and glucose solutions were air-saturated prior to experiment. 

Novak MT, Ynan F, Reichert WM. Modeling the relative effects of biofouling, fibrous encapsulation and microvessel density on implanted glucose sensor performance. Biophysical Jonmal 2010 98(3) 407A-A. 

Facchinetti A, Del Favero S, Sparacino G, Castle JR, Ward WK, Cobelli C (2014) Modeling the glucose sensor error. IEEE Trans Biomed Eng 61(3) 620-629... 

Glucose sensor described above (see Sect. 7.1) was designed even for in vivo transcutaneous glucose sensing on rat models (Stuart et al. 2006). The principle of the sensor is illustrated in Fig. 7.16. Ag FON with mixed SAMs of DT/MH was... 

Muchlbauer M.J., Guilbeau E.J. and Towe B.C. (1989) Model for a thermoelectric enzyme glucose sensor. Anal. Chem., 61, 77-83. 

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