Development of a pH-Insensitive Glucose Indicator for Continuous Glucose Monitoring

Glicosímetro de pulso

“…Table II presents the accuracy (Arms), the average deviation (B), the standard deviation (SDR) and the precision (Ps) of the measurement pairs collected from all volunteers with the proposed pulse glucometer as a function of the measurements taken with the commercial blood glucose level monitor. Calculations were performed according to the equations (12) to (15). Afterwards the data from the tested glucometer were compared to the data from the commercial glucometer in order to verify the possibility of obtaining a linear curve with an angular coefficient near one unit (identity curve).…”

“…Accuracy (Arms), average deviation (B), standard deviation (SDR) and precision (Ps), as suggested by Severinghaus [21], were calculated for several conditions with the use of the following mathematical expressions: (15) where n is the number of measurement pairs used, G i is the i th blood glucose level value estimated by the pulse glucometer hereby proposed, Gr i is the i th reference value presented by the commercial personal blood glucose level monitor of the "fingertip" type and Gfit i is the i th blood glucose level value, adjusted with the polynomial curve.…”

“…For each measurement taken with the commercial personal blood glucose level monitor it was necessary to puncture the finger to collect a small blood sample using a disposable lancet. Samples were collected after fasting and 15,30,45,60,90,120,150 and 180 minutes after the ingestion of 75 grams of glucose.…”

“…As medições da concentração de glicose no sangue arterial utilizam dois diferentes comprimentos de ondas, como explicado anteriormente. 15 Dois diodos emissores de luz ou LEDs (2) -um com comprimento de onda de 805 nm e outro com comprimento de onda de 1350 nm, por exemplo -emitem luz através dos tecidos do dedo (D) de um paciente até encontrar seu respectivo fotodetector (3). Cada fotodetector (3) Para os circuitos de isolação foi utilizado um módulo já disponível, denominado S.FNT.0002-4, que tem uma fonte isolada dentro das 5 prescrições da série de Normas Técnicas NBR IEC 60601.…”

“…Liu et al [8] proposed a subcutaneous sensor using reverse iontophoresis. Jacobs et al [9] studied otoacoustic emission with blood glucose levels, Lumbroso et al [10] developed a bioimpedance sensor for glucose recognition, whereas Maruo et al [11] have published an article describing a system using near-infrared, Chaudhary et al [12] used dissolved core alginate microspheres as "smarttatto" for glucose measurements, Park et al [13] used a nonenzymatic glucose sensor, Lee and Cui [14] built layer-bylayer self-assembled single-walled carbon nanotubes and Garret et al [15] developed PH-insensitive glucose indicator, among many others. The measuring methods adopted in those studies differ in their proposed instrumentation methods because they do not use optics as a measurement principle, or because they do not use the pulsing characteristic of arterial blood in the described methods.…”