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The Pursuit of Noninvasive Glucose: Hunting the Deceitful Turkey
... A large majority of the literature on non-invasive blood glucose monitoring uses spectroscopic approaches, more specifically utilizing near-infrared (NIR) spectrum (Gayathri, Sruthi, & Menon, 2017;Menon, Hemachandran, & Abhishek, 2013;Menon, Hemachandran, & Kunnath, 2013;Smith, 2015;Villena Gonzales, Mobashsher, & Abbosh, 2019;Yadav, Rani, Singh, & Murari, 2015). These works utilize both NIR plethysmography signals (obtained from a patient's wrist or fingertip) as well as patient demography, which is given as input to machine learning techniques to compute blood glucose (Gupta, Kwon, Hossain, & Kim, 2021;Habbu, Dale, & Ghongade, 2019;Hossain et al., 2019;Islam, Ahmed, Hassanuzzaman, Bin Amir, & Rahman, 2021;Monte-Moreno, 2011). ...
... The main three 'C' associated with glucose monitoring are Cost, Comfort, and Convenience and these are the driving factors for developing a non-invasive blood glucose monitoring device. Smith (2015) presents an extensive analysis of non-invasive glucose monitoring. This book reviews the past, present, and future of non-invasive glucose monitoring, its limitations, and the challenges associated with various techniques. ...
... Among the technologies discussed, NIR is the most common technology that has been widely studied for non-invasive blood glucose monitoring (Gayathri et al., 2017;Menon, Hemachandran, & Abhishek, 2013;Menon, Hemachandran, & Kunnath, 2013;Smith, 2015;Yadav et al., 2015) due to its properties such as sensitivity, selectivity, reduced complexity, and better signal-tonoise ratio (SNR). Also, it has a spectrum range with the ability to penetrate the light from 1-100 mm deep into the tissue where blood vessels can be seen. ...
... Reproduced from ref [24] with permission from Elsevier, Copyrights 2014. (Figure 4Ai), which uses an electric current to extract glucose molecules out of the body tissues across the skin [44]. This technology was developed by the University of California (San Francisco) and Cygnus Therapeutic Corporation (Redwood City, CA) and was approved by FDA [44]. Figure 4Aii presents the photograph of the GlucoWatch CGM system. ...
... (Figure 4Ai), which uses an electric current to extract glucose molecules out of the body tissues across the skin [44]. This technology was developed by the University of California (San Francisco) and Cygnus Therapeutic Corporation (Redwood City, CA) and was approved by FDA [44]. Figure 4Aii presents the photograph of the GlucoWatch CGM system. ...
... Moreover, the current generated by the device could result in severe skin irritation, such as reddening, burning, and even blisters [44]. Another CGM system is Pendra, initially introduced by Pendragon Medical and approved by CE in 2003 [45]. ...
Diabetes has recently become the leading cause of death worldwide. So far, there is no effective treatment to cure or prevent diabetes. Still, reasonable blood control through glucose monitoring can improve treatment efficiency, relieve symptoms, and reduce the complications of the disease. However, conventional glucose detection is based on the finger-prick measurement, which may bring discomfort and pain to patients. Electrochemical-based continuous glucose monitoring (CGM) devices have been commercialized and appreciated by patients. However, those sensors still have high costs, short lifetime, and frequent calibration via finger-prick measurement. In recent studies, as a promising method for glucose quantification, optical glucose sensing technology has been considered a potential alternative to electrochemical CGM sensors. A commercial CGM sensor based on fluorescence sensing has been developed and can be worn for a longer period before a replacement. This paper aims to review optical methods for CGM, including near-infrared (NIR) spectroscopy, mid-infrared (MIR) spectroscopy, Raman spectroscopy, photoacoustic (PA) spectroscopy, fluorescence technology, optical coherence tomography (OCT), holographic technology, and hydrogel sensing technology in aspects of principles, current research, and limitations. Discussions and comparisons in these different optical glucose sensing technologies are also conducted. Moreover, the review discusses the future prospects for optical glucose sensing methods and concludes that further optical CGM research should focus on the improvement of data processing methods.
... A non-invasive method has a painless operation, does not cause discomfort or tissue damage, without biological samples, without chemical reagents, without the production of waste of any kind, reducing costs for the health system (SILVA, 2017;SMITH, 2015). ...
Diabetes is a worldwide health problem, a metabolic disorder that can lead to serious complications and damage to all vital organs. The resulting complications can be prevented with regular monitoring and maintenance of blood glucose level. The present review study aims to gather information on current methods for monitoring capillary blood glucose. Scientific articles were consulted in national and international journals, in addition to the Guidelines of the Brazilian Society of Diabetes and 9th Edition of the Diabetes Atlas of the International Diabetes Federation, American Diabetes Association, Ministry of Health and Brazilian Institute of Geography and Statistics (IBGE) data. Non-invasive methods include impedance spectroscopy, optical coherence tomography, photoacoustic spectroscopy, mid and near infrared spectroscopy, photoplethysmography. The advantages, in general, of non-invasive methods, seek ease of implementation and use, cost, accuracy in blood glucose measurement. The main disadvantages are physical parameters that can interfere with glucose measurement, as well as environmental variations. Interferences due to physiological factors can be eliminated using filtering processes, which suppress noise and increase effective information. With the present study, it is possible to conclude that there is a need to develop a non-invasive, painless, easily accessible method, without tissue damage, providing cost savings for the health system, considering quality of life, functional limitations, social and financial stress, emotional discomfort and depression in individuals with diabetes mellitus.
... However, it needs periodic calibration with standard measurements and has long-term reliability and stability difficulties, making the devices costlier and unreliable for routine blood glucose monitoring. As a result, researchers have explored various NI methods for measuring blood glucose that are painless, reliable, and cost-effective [9]. This advancement has the potential to make regular blood glucose monitoring more comfortable and accessible to millions of people. ...
In this paper, a dual wavelength short near-infrared system is described for the detection of glucose levels. The system aims to improve the accuracy of blood glucose detection in a cost-effective and non-invasive way. The accuracy of the method is evaluated using real-time samples collected with the reference finger prick glucose device. A feed forward neural network (FFNN) regression method is employed to predict glucose levels based on the input data obtained from NIR technology. The system calculates glucose evaluation metrics and performs Surveillance error grid (SEG) analysis. The coefficient of determination R2 and mean absolute error are observed 0.99 and 2.49 mg/dl, respectively. Additionally, the system determines the root mean square error (RMSE) as 3.02 mg/dl. It also shows that the mean absolute percentage error (MAPE) is 1.94% and mean squared error (MSE) is 9.16 (mg/dl)2 for FFNN. The SEG analysis shows that the glucose values measured by the system fall within the clinically acceptable range when compared to the reference method. Finally, the system uses the multi-class classification method of the multilayer perceptron (MLP) and K-nearest neighbors (KNN) classifier to classify glucose levels with an accuracy of 99%.
... The instrument, later known as Glucoscan, was a battery-driven, digital reflectance meter manufactured by Medistron in England, with the reagent strip produced in Japan by Eiken. [22] During the 1980s, meters and strips requiring less amount of blood sample became available, all at a cheaper price. SMBG became the standard of care, especially for patients with T1D. ...
Monitoring of blood glucose levels is an inevitable part of diabetes management. The last decade was marked by path-breaking and transformational changes in diabetes technologies that ushered in the introduction of a wide spectrum of glucose monitoring devices that are more reliable and user-friendly. This review describes the evolution of capillary glucose monitoring from simple urine sugar screening tests to reagent strip systems and to sophisticated glucose monitors over the past four decades since the introduction of the first glucose meter in 1970.
... They usually incorporate microneedles to be implanted subcutaneously to measure the glucose level in body fluids, i.e. interstitial fluid (ISF), like Abbott FreeStyle Libre. Nevertheless, the sensitivity of sensors may gradually degrade as the protein accumulates on the needle surface, requiring regular replacement to maintain measurement accuracy [115,116] . Finger-prick blood test is still needed during rapid changes in glucose levels. ...
... There are, however, conflicting reports on how fast the glucose concentrations in aqueous rise following an increase in blood glucose. 26,27 In a study by Cameron et al., 26 aqueous was sampled from rabbits' anterior chamber every 2 weeks at varying time points after using xylazine to elevate blood glucose levels. Their results showed a delay of 3.4 minutes for aqueous glucose levels to rise as compared to blood glucose levels. ...
Purpose:
The purpose of the study was to determine if aqueous glucose levels rise in a comparable time frame to interstitial fluid and could therefore be suitable for a continuous glucose monitoring (CGM) site.
Methods:
An intravenous glucose tolerance test was performed on five New Zealand white rabbits. Aqueous humor from the posterior and anterior chamber of the eye and venous blood were sampled for glucose concentration measurement. Glucose concentrations in the interstitial fluids were monitored using a CGM system. A compartment model was created to map the glucose response curves in each compartment. The delay in rising glucose concentrations between blood and interstitial fluid and aqueous humor in the posterior chamber and anterior chamber of the eye were analyzed.
Results:
The results showed a statistically similar time lag and rate of change in glucose concentrations between blood and interstitial fluids or aqueous humor in either the posterior or anterior chamber.
Conclusions:
The results of this study add further support to the aqueous humor being used as an alternative CGM site.
Translational relevance:
The study provides the basis for developing an intraocular continuous glucose sensor that can overcome limitations of current CGM systems.
PurposeDiabetes is one of the most common diseases in the world. A finger prick is typically required to obtain blood samples for diabetes testing. It is uncomfortable and prone to infection to undergo these treatments. To address this issue, a non-invasive short wave near-infrared-based optical detection system with a 950 nm wavelength sensor operating in a reflective mode is proposed. This research seeks to improve the accuracy of blood glucose detection non-invasively with low cost.Methods
To estimate glucose, a 950 nm reflective sensor is used, and the measured signal is converted to voltages and passed through a precision analog-to-digital converter. The relationship between voltage and predicted glucose is evaluated using absorbance and transmittance measurements. The proposed method employs a third-order polynomial expression to improve accuracy through the use of an algorithm. In total, 184 real-time samples were collected using the reference finger prick glucose device, of which 25 were collected while fasting and the remaining during non-fasting periods. The glucose evaluation metrics are computed and surveillance error grid (SEG) analysis is carried out.ResultsThe proposed technique utilizing a 950 nm reflective sensor yields efficient results compared to existing literature. Real-time data analysis using the proposed sensor method shows an increase in the coefficient of determination (R2) value and mean absolute difference to 0.99% and 3.02 mg/dl, respectively. Additionally, the root mean square error and mean absolute relative difference are calculated as 4.81 mg/dl and 1.61%, respectively. The SEG analysis reveals that the proposed method falls within the 100% acceptable zone.Conclusion
The 950 nm non-invasive method for glucose detection has great potential for further development and practical application in the field of glucose monitoring, as it can be further enhanced as a portable device. From a statistical point of view, the collected samples are limited, and more samples need to be collected.
A difficulty when applying partial least squares (PLS) in multivariate calibration is that overfitting may occur. This study proposes a novel approach by combining PLS and boosting. The latter is said to be resistant to overfitting. The proposed method, called boosting PLS (BPLS), combines a set of shrunken PLS models, each with only one PLS component. The method is iterative: the models are constructed on the basis of the residuals of the responses that are not explained by previous models. Unlike classical PLS, BPLS does not need to select an adequate number of PLS components to be included in the model. On the other hand, two parameters must be determined: the shrinkage value and the iteration number. Criteria are proposed for these two purposes. BPLS was applied to seven real data sets, and the results demonstrate that it is more resistant than classical PLS to overfitting without loosing accuracy.
18 chemical structure
- Cell Robotics
Cell Robotics....................................... 18
chemical structure............................... 27
chemometrics...................................... 39
74 color-matching 100 company stores 51 Consensus Error Grid 53 continuous measurements
- Clinitest............................................ Loop........................................ Telemetrix
Clinitest............................................. 8, 9
closed-loop.......................................... 22
CME Telemetrix................................. 74
color-matching.................................. 100
company stores.................................... 15
conjunctiva.......................................... 51
Consensus Error Grid.......................... 62
consultant............................................ 80
contact lenses...................................... 48
contamination...................................... 53
continuous measurements................... 22
copper sulfate...................................... 17
cornea.................................................. 46
correlation........................................... 67
Correlation.......................................... 58
correlation coefficient......................... 59
111 diffuse reflectance
- Dick Wiesner
Dick Wiesner.................................... 111
diffuse reflectance............................... 37
dipsticks................................................ 8
107 gastric motility
- Gary Root
Gary Root.......................................... 107
gastric motility.................................... 60
28 gold standard 58 grape glove
- .............................................................................................. Glycosylated Hemoglobin
Glycosylated hemoglobin................... 28
gold standard....................................... 58
grape glove........................................ 110
30 in-vitro 61 in-vivo
- Investigational Device
Investigational Device........................ 30
in-vitro................................................. 61
in-vivo................................................. 61
iontophoresis....................................... 52
iris....................................................... 46
76 linear regression
- Lighttouch Medical
LightTouch Medical............................ 76
linear regression.................................. 59
8 milligrams per deciliter
- Miles Laboratories
Miles Laboratories................................ 8
milligrams per deciliter....................... 27
millimolar............................................ 27
74 oxygen saturation
- Oulu University
Oulu University................................... 45
overfit.................................................. 74
oxygen saturation................................ 26
oxyhemoglobin................................... 26