An Interstitial Fluid Transdermal Extraction Chip with Vacuum Generator and Volume Sensor for Continuous Glucose Monitoring

2013 ◽  
Vol 562-565 ◽  
pp. 571-575 ◽  
Author(s):  
Hai Xia Yu ◽  
Da Chao Li ◽  
Yong Jie Ji ◽  
Xiao Li Zhang ◽  
Ke Xin Xu
Keyword(s):  
Continuous Glucose Monitoring ◽  
Microfluidic Chip ◽  
Normal Saline ◽  
Interstitial Fluid ◽  
Glucose Sensor ◽  
Fluid Management ◽  
Glucose Monitoring ◽  
Venturi Tube ◽  
Sensor Integration ◽  
Volume Sensor

A five layer microfluidic chip which is designed and fabricated for interstitial fluid (ISF) transdermal extraction, collection, and measurement toward the application of continuous and real-time glucose monitoring is presented in this paper. The microfluidic chip consists of a Venturi tube generating vacuum for ISF extraction and fluid manipulation, a novel volume sensor of electrolytic fluid for normal saline input volume control and ISF volume measurement, pneumatic valves for fluid management, and access ports for glucose sensor integration. The output vacuum of the Venturi tube is tested, and a less than 88kPa vacuum has been achieved, when 220kPa external pressure is applied. The feasibility of using the volume sensor to control and measure the normal saline input volume is confirmed by high accuracy and low coefficient of variation (CV=0.0040, n=12). The microfluidic chip is ready for glucose sensor integration in continuous glucose monitoring.

Interstitial fluid glucose time-lag correction for real-time continuous glucose monitoring

2013 ◽  
Vol 8 (1) ◽  
pp. 81-89 ◽  
Author(s):  
D. Barry Keenan ◽  
John J. Mastrototaro ◽  
Stuart A. Weinzimer ◽  
Garry M. Steil
Keyword(s):  
Real Time ◽  
Continuous Glucose Monitoring ◽  
Interstitial Fluid ◽  
Time Lag ◽  
Glucose Monitoring

scholarly journals Accuracy of flash glucose monitoring and continuous glucose monitoring technologies: Implications for clinical practice

2018 ◽  
Vol 15 (3) ◽  
pp. 175-184 ◽  
Author(s):  
Ramzi A Ajjan ◽  
Michael H Cummings ◽  
Peter Jennings ◽  
Lalantha Leelarathna ◽  
Gerry Rayman ◽  
...  
Keyword(s):  
Continuous Glucose Monitoring ◽  
Diabetes Care ◽  
Interstitial Fluid ◽  
Glucose Monitoring ◽  
Relative Difference ◽  
Glucose Sensing ◽  
Sensor Data ◽  
Flash Glucose Monitoring ◽  
Fluid Sensor ◽  
Monitoring Technologies

Continuous glucose monitoring and flash glucose monitoring technologies measure glucose in the interstitial fluid and are increasingly used in diabetes care. Their accuracy, key to effective glycaemic management, is usually measured using the mean absolute relative difference of the interstitial fluid sensor compared to reference blood glucose readings. However, mean absolute relative difference is not standardised and has limitations. This review aims to provide a consensus opinion on assessing accuracy of interstitial fluid glucose sensing technologies. Mean absolute relative difference is influenced by glucose distribution and rate of change; hence, we express caution on the reliability of comparing mean absolute relative difference data from different study systems and conditions. We also review the pitfalls associated with mean absolute relative difference at different glucose levels and explore additional ways of assessing accuracy of interstitial fluid devices. Importantly, much data indicate that current practice of assessing accuracy of different systems based on individualised mean absolute relative difference results has limitations, which have potential clinical implications. Healthcare professionals must understand the factors that influence mean absolute relative difference as a metric for accuracy and look at additional assessments, such as consensus error grid analysis, when evaluating continuous glucose monitoring and flash glucose monitoring systems in diabetes care. This in turn will ensure that management decisions based on interstitial fluid sensor data are both effective and safe.

In Vitro Evaluation of Miniaturized Amperometric Enzyme Sensor Based on the Direct Electron Transfer Principle for Continuous Glucose Monitoring

2022 ◽  
pp. 193229682110706
Author(s):  
Yutaro Inoue ◽  
Yasuhide Kusaka ◽  
Kotaro Shinozaki ◽  
Inyoung Lee ◽  
Koji Sode
Keyword(s):  
Electron Transfer ◽  
Continuous Glucose Monitoring ◽  
Glucose Sensor ◽  
Direct Electron Transfer ◽  
Glucose Dehydrogenase ◽  
Glucose Monitoring ◽  
Reference Electrode ◽  
Enzyme Sensor

Background: The bacterial derived flavin adenine dinucleotide (FAD)-dependent glucose dehydrogenase (FADGDH) is the most promising enzyme for the third-generation principle-based enzyme sensor for continuous glucose monitoring (CGM). Due to the ability of the enzyme to transfer electrons directly to the electrode, recognized as direct electron transfer (DET)-type FADGDH, although no investigation has been reported about DET-type FADGDH employed on a miniaturized integrated electrode. Methods: The miniaturized integrated electrode was formed by sputtering gold (Au) onto a flexible film with 0.1 mm in thickness and divided into 3 parts. After an insulation layer was laminated, 3 openings for a working electrode, a counter electrode and a reference electrode were formed by dry etching. A reagent mix containing 1.2 × 10−4 Unit of DET-type FADGDH and carbon particles was deposited. The long-term stability of sensor was evaluated by continuous operation, and its performance was also evaluated in the presence of acetaminophen and the change in oxygen partial pressure (pO2) level. Results: The amperometric response of the sensor showed a linear response to glucose concentration up to 500 mg/dL without significant change of the response over an 11-day continuous measurement. Moreover, the effect of acetaminophen and pO2 on the response were negligible. Conclusions: These results indicate the superb potential of the DET-type FADGDH-based sensor with the combination of a miniaturized integrated electrode. Thus, the described miniaturized DET-type glucose sensor for CGM will be a promising tool for effective glycemic control. This will be further investigated using an in vivo study.

scholarly journals Electrochemically Activated Conductive Ni-Based MOFs for Non-enzymatic Sensors Toward Long-Term Glucose Monitoring

2020 ◽  
Vol 8 ◽  
Author(s):  
Yating Chen ◽  
Yulan Tian ◽  
Ping Zhu ◽  
Liping Du ◽  
Wei Chen ◽  
...  
Keyword(s):  
Continuous Glucose Monitoring ◽  
Glucose Sensor ◽  
Glucose Monitoring ◽  
Glucose Sensors ◽  
Blood Glucose Monitoring ◽  
Diabetic Patients ◽  
Potential Range ◽  
Potential Applications ◽  
Naoh Solution

Continuous intensive monitoring of glucose is one of the most important approaches in recovering the quality of life of diabetic patients. One challenge for electrochemical enzymatic glucose sensors is their short lifespan for continuous glucose monitoring. Therefore, it is of great significance to develop non-enzymatic glucose sensors as an alternative approach for long-term glucose monitoring. This study presented a highly sensitive and selective electrochemical non-enzymatic glucose sensor using the electrochemically activated conductive Ni3(2,3,6,7,10,11-hexaiminotriphenylene)2 MOFs as sensing materials. The morphology and structure of the MOFs were investigated by scanning SEM and FTIR, respectively. The performance of the activated electrode toward the electrooxidation of glucose in alkaline solution was evaluated with cyclic voltammetry technology in the potential range from 0.2 V to 0.6 V. The electrochemical activated Ni-MOFs exhibited obvious anodic (0.46 V) and cathodic peaks (0.37 V) in the 0.1 M NaOH solution due to the Ni(II)/Ni(III) transfer. A linear relationship between the glucose concentrations (ranging from 0 to 10 mM) and anodic peak currents with R2 = 0.954 was obtained. It was found that the diffusion of glucose was the limiting step in the electrochemical reaction. The sensor exhibited good selectivity toward glucose in the presence of 10-folds uric acid and ascorbic acid. Moreover, this sensor showed good long-term stability for continuous glucose monitoring. The good selectivity, stability, and rapid response of this sensor suggests that it could have potential applications in long-term non-enzymatic blood glucose monitoring.

scholarly journals Further Evidence of Severe Allergic Contact Dermatitis From Isobornyl Acrylate While Using a Continuous Glucose Monitoring System

2018 ◽  
Vol 12 (3) ◽  
pp. 630-633 ◽  
Author(s):  
Stefanie Kamann ◽  
Olivier Aerts ◽  
Lutz Heinemann
Keyword(s):  
Contact Dermatitis ◽  
Allergic Contact Dermatitis ◽  
Monitoring System ◽  
Continuous Glucose Monitoring ◽  
Glucose Sensor ◽  
Skin Irritation ◽  
Glucose Monitoring ◽  
Gas Chromatography Mass Spectrometry ◽  
Skin Reactions ◽  
Allergic Contact

In the past decade, new diabetes technologies, including continuous glucose monitoring (CGM) systems, support patients with diabetes in their daily struggle with achieving a good glucose control. However, shortly after the first CGM systems appeared on the market, also the first concerns about adverse skin reactions were raised. Most patients claimed to suffer from (sometimes severe) skin irritation, or even allergy, which they related to the (acrylate-based) adhesive part of the device. For a long time the actual substance that caused these skin reactions with, for example, the Flash Glucose Monitoring system (iscCGM; Freestyle® Libre) could not be identified; however, recently Belgian and Swedish dermatologists reported that the majority of their patients that have developed a contact-allergic while using iscCGM react sensitively to a specific acrylate, that is, isobornyl acrylate (IBOA). Subsequently they showed by means of gas chromatography-mass spectrometry that this substance is present in the case of the glucose sensor attached by an adhesive to the skin. We report three additional cases from Germany, including a 10-year-old boy, suffering from severe allergic contact dermatitis to IBOA.

scholarly journals First Clinical Evaluation of a New Percutaneous Optical Fiber Glucose Sensor for Continuous Glucose Monitoring in Diabetes

2013 ◽  
Vol 7 (1) ◽  
pp. 13-23 ◽  
Author(s):  
Achim Josef Müller ◽  
Monika Knuth ◽  
Katharina Sibylle Nikolaus ◽  
Roland Krivánek ◽  
Frank Küster ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Clinical Evaluation ◽  
Continuous Glucose Monitoring ◽  
Glucose Sensor ◽  
Glucose Monitoring
Sign in / Sign up

Export Citation Format

Share Document