On line continuous monitoring of subcutaneous tissue glucose in men by combining portable glucosensor with microdialysis

Meyerhoff, C; Bischof, F; Sternberg, F; Zier, H; Pfeiffer, E. F.

doi:10.1007/bf02221686

Cited by 115 publications

(45 citation statements)

References 18 publications

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“…A microdialysis fiber assembled by Medica (Medulla, Italy), using 2 cm of hollow fiber (regenerated cellulose with an internal diameter of 0.17 mm and a molecular weight cutoff of 18.000 Dalton), was glued to a nylon tube and sterilized for in vivo use with ethylene oxide gas; it was then inserted subcutaneously in the periumbelical region, without local anesthesia, using a 18-gauge Teflon catheter as a guide, as previously described (4). For the 24-h monitoring, the fiber was then connected to a portable apparatus that weighs 245 g and is powered by a 9-V battery; the apparatus uses a wall-jet flow cell composed of a platinum electrode (diameter 0.4 mm) covered by three membranes (cellulose acetate, enzyme membrane, and polycarbonate membrane) housed in a Teflon tube.…”

Section: Study Protocolmentioning

confidence: 99%

Continuous Subcutaneous Glucose Monitoring in Diabetic Patients

et al. 2002

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RESEARCH DESIGN -A multicenter study was performed in 70 diabetic patients. A microdialysis fiber was inserted subcutaneously into the periumbelical region and perfused with a buffer solution. Glucose concentrations in the dialysate were then measured every 3 min by the glucose sensor over a 24-h period, during which nine venous blood samples were also collected throughout the day.RESULTS -Both the insertion of the fiber and the wearing of the device were well tolerated by the patients. Subcutaneous glucose levels were well correlated with venous glucose measurements (r ϭ 0.9, P Ͻ 0.001) over a wide range (40 -400 mg/dl) for up to 24 h, with a single-point calibration. An analysis of 381 data pairs showed a linear relationship between the GlucoDay and serial venous blood glucose levels, and 97% of the data fell in the A and B regions of the error grid analysis. Percentage bias between the GlucoDay and the blood venous levels was Ϫ2.0% in the hypoglycemic range (Ͻ70 mg/dl), 6.9% in the euglycemic range (70 -180 mg/dl), and 11.2% in the hyperglycemic range (Ͼ180 mg/dl).CONCLUSIONS -The GlucoDay system demonstrated high reliability and reported values that closely agreed with venous blood glucose measurements. The system was well tolerated and thus constitutes a relatively easy method to monitor glucose excursions in diabetic patients. Diabetes Care 25:347-352, 2002T he benefits of strict metabolic control on microvascular complications of both type 1 and type 2 diabetes have been well established (1,2). In the last decade, self-monitoring of blood glucose levels has been the only available measure for diabetic patients to achieve a good metabolic control; however, glucose fluctuations during the day are often missed with this technique (3), and only continuous glucose measurements over prolonged periods can ensure optimal blood glucose management. Recently, minimally invasive techniques have been proposed for continuous monitoring of subcutaneous glucose in both normal and diabetic patients. Microdialysis of subcutaneous adipose tissue has been shown to identify glucose variations in vivo that closely mimic blood glucose patterns observed in patients on intensified insulin therapy. A monitoring system that provides automatic and frequent determinations would therefore identify the glycemic excursions and typical glucose trends in diabetic patients in a manner that is not possible even with frequent blood glucose meter readings. The ability to detect such fluctuations during the day, and particularly during the night, would enable appropriate changes in diabetes management in order to achieve the goal of optimal metabolic control in diabetic patients.We documented the efficacy of a new glucose sensor and its accuracy in monitoring glucose levels in type 1 and type 2 diabetic patients recruited in a multicenter study. The GlucoDay is composed of a subcutaneous microdialysis probe connected to a portable unit. The system takes a glucose measurement every second and stores an average value every 3 min, for a total of ...

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Section: Study Protocolmentioning

confidence: 99%

Continuous Subcutaneous Glucose Monitoring in Diabetic Patients

et al. 2002

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“…Blood glucose concentrations are well correlated with subcutaneous glucose concentrations at steady-state (1)(2)(3)(4)(5). When the blood glucose concentration increases rapidly (3,4,(6)(7)(8)(9) or decreases (7,9,10) there is, however, a time lag, resulting in a transient difference between the blood and subcutaneous glucose concentrations. With recently developed 5 ϫ 10 Ϫ4 cm 2 active area, Ͻ150-sec response time flexible glucose electrodes, small enough to be implanted not only subcutaneously but also in the jugular vein of rats, it became possible to continuously and simultaneously track the two concentrations and to better time resolve them (11,12).…”

mentioning

confidence: 99%

Measurement and modeling of the transient difference between blood and subcutaneous glucose concentrations in the rat after injection of insulin

Schmidtke

Freeland

Heller

et al. 1998

Proc. Natl. Acad. Sci. U.S.A.

113

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The kinetics of the fall in subcutaneous f luid glucose concentration in anesthetized rats (n ‫؍‬ 7) after intravenous injection of insulin (0.5 units͞kg) was studied by using 5 ؋ 10 ؊4 cm 2 active area, <150-sec 10-90% response time, amperometric glucose sensors. The onset of the decline in the subcutaneous glucose concentration was delayed and statistically different (P < 0.001) from that in blood (8.9 ؎ 2.1 min vs. 3.3 ؎ 0.5 min). Similarly, the rate of drop in glucose concentration between 6 and 20 min after the insulin injection was different for subcutaneous tissue (3.9 ؎ 1.3 mg⅐dl ؊1 ⅐ min ؊1 ) and blood (6.8 ؎ 2.0 mg⅐dl ؊1 ⅐min ؊1 ) (P ‫؍‬ 0.003). The hypoglycemic nadir in subcutaneous f luid occurred 24.5 ؎ 6.8 min after that in the blood (P < 0.001). A ''forward'' masstransfer model, predicting the subcutaneous glucose concentration from the blood glucose concentrations and an ''inverse'' model, predicting the blood glucose concentration from the subcutaneous glucose concentration were derived. By using an algorithm based on the latter, the average discrepancy between the measured blood glucose concentration and that estimated from the subcutaneous measurement through the entire 4-hr experiment was reduced from 22.9% to 11.1% (P ‫؍‬ 0.025). The maximum discrepancy during the 40-min period after the injection of insulin was reduced from 84.1% to 29.3% (P ‫؍‬ 0.006).We address the avoidance of clinical error in the treatment of diabetes when the glucose concentration is monitored not in the blood but in the subcutaneous interstitial fluid, where amperometric sensors, operating continuously, can be placed. Blood glucose concentrations are well correlated with subcutaneous glucose concentrations at steady-state (1-5). When the blood glucose concentration increases rapidly (3, 4, 6-9) or decreases (7, 9, 10) there is, however, a time lag, resulting in a transient difference between the blood and subcutaneous glucose concentrations. With recently developed 5 ϫ 10 Ϫ4 cm 2 active area, Ͻ150-sec response time flexible glucose electrodes, small enough to be implanted not only subcutaneously but also in the jugular vein of rats, it became possible to continuously and simultaneously track the two concentrations and to better time resolve them (11, 12). Here we report substantial transient differences between the two, large enough to lead to clinical error, after injection of regular insulin. We also show that this transient difference can be modeled and derive an algorithm that corrects for most of the transient difference. MATERIALS AND METHODSGlucose Electrodes. The electrodes were structurally similar to the earlier reported ones (12). Their 5 ϫ 10 Ϫ4 cm 2 active area had three layers. Of these layers, the ''wired'' glucose oxidase transduction layer and the biocompatible layer were identical with those described in ref. 12. The glucose flux restricting layer however was modified by sequentially filling the 90-m deep, 250-m diameter recess and curing (at room temperature for 20 min) twice with a 1% solu...

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“…Here, the analyte matrix is interstitial fluid, which is gained by different methods. Most common are the microdialysis [44,45,46], microperfusion [47,48], and iontophoresis [49,50] methods. The sensor systems are envisioned to be exchanged at the latest after 3 days to prevent inflammation processes, so that the demand for long-term stability is reduced to this period.…”

Section: Glucose Sensor For Continuous Monitoring In Interstitial Fluidmentioning

confidence: 99%

Electrical biochip technology?a tool for microarrays and continuous monitoring

Albers

Grünwald²,

Nebling

et al. 2003

Analytical and Bioanalytical Chemistry

106

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Based on electrical biochips made in Si-technology cost effective portable devices have been constructed for field applications and point of care diagnosis. These miniaturized amperometric biosensor devices enable the evaluation of biomolecular interactions by measuring the redox recycling of ELISA products, as well as the electrical monitoring of metabolites. The highly sensitive redox recycling is facilitated by interdigitated ultramicroelectrodes of high spatial resolution. The application of these electrical biochips as DNA microarrays for the molecular diagnosis of viral infections demonstrates the measurement procedure. Self-assembling of capture oligonucleotides via thiol-gold coupling has been used to construct the DNA interface on-chip. Another application for this electrical detection principle is continuous measuring with bead-based biosensors. Here, paramagnetic nanoparticles are used as carriers of the bioanalytical interface in ELISA format. A Si-micromachined glucose sensor for continuous monitoring in interstitial fluid ex vivo shows the flexibility of the electrical platform. Here the novel approach is a pore membrane in micrometer-dimensions acting as a diffusion barrier. The electrochemical detection takes place in a cavity containing glucose oxidase and a Pt-electrode surface. The common hydrogen peroxide detection, together with Si technology, enable precise differential measurements using a second cavity.

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On line continuous monitoring of subcutaneous tissue glucose in men by combining portable glucosensor with microdialysis

Cited by 115 publications

References 18 publications

Continuous Subcutaneous Glucose Monitoring in Diabetic Patients

Continuous Subcutaneous Glucose Monitoring in Diabetic Patients

Measurement and modeling of the transient difference between blood and subcutaneous glucose concentrations in the rat after injection of insulin

Electrical biochip technology?a tool for microarrays and continuous monitoring

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