Evaluation of a Continuous Blood Glucose Monitor: A Novel and Non-Invasive Wearable Using Bioimpedance Technology

Background: Frequent blood glucose level (BGL) monitoring is essential for effective diabetes management. Poor compliance is common due to the painful finger pricking or subcutaneous lancet implantation required from existing technologies. There are currently no commercially available non-invasive devices that can effectively measure BGL. In this real-world study, a prototype non-invasive continuous glucose monitoring system (NI-CGM) developed as a wearable ring was used to collect bioimpedance data. The aim was to develop a mathematical model that could use these bioimpedance data to estimate BGL in real time. Methods: The prototype NI-CGM was worn by 14 adult participants with type 2 diabetes for 14 days in an observational clinical study. Bioimpedance data were collected alongside paired BGL measurements taken with a Food and Drug Administration (FDA)-approved self-monitoring blood glucose (SMBG) meter and an FDA-approved CGM. The SMBG meter data were used to improve CGM accuracy, and CGM data to develop the mathematical model. Results: A gradient boosted model was developed using a randomized 80-20 training-test split of data. The estimated BGL from the model had a Mean Absolute Relative Difference (MARD) of 17.9%, with the Parkes error grid (PEG) analysis showing 99% of values in clinically acceptable zones A and B. Conclusions: This study demonstrated the reliability of the prototype NI-CGM at collecting bioimpedance data in a real-world scenario. These data were used to train a model that could successfully estimate BGL with a promising MARD and clinically relevant PEG result. These results will enable continued development of the prototype NI-CGM as a wearable ring.

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Indole as a new tentative marker in exhaled breath for non-invasive blood glucose monitoring of diabetic subjects

Journal of Breath Research ◽

10.1088/1752-7163/ac4610 ◽

2021 ◽

Author(s):

Herbert Fink ◽

Tim Maihöfer ◽

Jeffrey Bender ◽

Jochen Schulat

Keyword(s):

Blood Glucose ◽

Diabetes Management ◽

Glucose Monitoring ◽

Blood Glucose Monitoring ◽

Glucose Measurement ◽

Diabetic Patients ◽

Exhaled Breath ◽

Invasive Approach ◽

Test Strips ◽

Non Invasive

Abstract Blood glucose monitoring (BGM) is the most important part of diabetes management. In classical BGM, glucose measurement by test strips involves invasive finger pricking. We present results of a clinical study that focused on a non-invasive approach based on volatile organic compounds (VOCs) in exhaled breath. Main objective was the discovery of markers for prediction of blood glucose levels (BGL) in diabetic patients. Exhaled breath was measured repeatedly in 60 diabetic patients (30 type 1, 30 type 2) in fasting state and after a standardized meal. Proton Transfer Reaction Time of Flight Mass Spectrometry (PTR-ToF-MS) was used to sample breath every 15 minutes for a total of six hours. BGLs were tested in parallel via BGM test strips. VOC signals were plotted against glucose trends for each subject to identify correlations. Exhaled indole (a bacterial metabolite of tryptophan) showed significant mean correlation to BGL (with negative trend) and significant individual correlation in 36 patients. The type of diabetes did not affect this result. Additional experiments of one healthy male subject by ingestion of lactulose and 13C-labeled glucose (n=3) revealed that exhaled indole does not directly originate from food digestion by intestinal microbiota. As indole has been linked to human glucose metabolism, it might be a tentative marker in breath for non-invasive BGM. Clinical studies with greater diversity are required for confirmation of such results and further investigation of metabolic pathways.

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Self-monitoring of blood glucose as a basis for diabetes management

Cardiosomatics ◽

10.26442/cs45036 ◽

2013 ◽

Vol 4 (1) ◽

pp. 47-54

Author(s):

A. Yu Mayorov ◽

O. G Melnikova ◽

Yu. I Filippov

Keyword(s):

Blood Glucose ◽

Diabetes Management ◽

Glucose Monitoring ◽

International Organization ◽

Diabetes Treatment ◽

Self Monitoring ◽

Antidiabetic Therapy ◽

New Methods ◽

Before And After ◽

External Conditions

The article represents the review of issues of self-monitoring of blood glucose (SMBG) in diabetes treatment. The therapeutic purposes are considered when carrying out SMBG before and after the meals, accepted in Russia, providing an individualization depending on age, existence of severe complications and the risk of hypoglycemia. SMBG frequency is presented at various options of the antidiabetic therapy. The value of carrying out SMBG for the patient and the doctor is discussed. The principles of the work photometric and electrochemical glucometers are given. Issues of accuracy of blood glucose measuring accepted by the International organization for standardization for the systems of SMBG are presented. The reasons of errors to the system evaluation of blood glucose are connected with incorrect hand washing, improper coding of test strips, external conditions (altitude, temperature, humidity), hematocrit, acidosis, hyperlipidemia, concentration of oxygen in blood, exogenous interfering substances (some medicines). The structure and rules of maintaining the diary as the main way of the storage of results of SMBG are presented. Data of the international and Russian studies on an assessment of efficiency of SMBG are shown. The SMBG new methods are discussed in the section on continuous glucose monitoring.

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Exhaled Breath Analysis for Diabetes Diagnosis and Monitoring: Relevance, Challenges and Possibilities

Biosensors ◽

10.3390/bios11120476 ◽

2021 ◽

Vol 11 (12) ◽

pp. 476

Author(s):

Kaushiki Dixit ◽

Somayeh Fardindoost ◽

Adithya Ravishankara ◽

Nishat Tasnim ◽

Mina Hoorfar

Keyword(s):

Blood Glucose ◽

Diabetes Management ◽

Glucose Monitoring ◽

Breath Analysis ◽

Blood Glucose Monitoring ◽

Diabetes Diagnosis ◽

Exhaled Breath ◽

Non Invasive ◽

Exhaled Breath Analysis ◽

Diabetes Monitoring

With the global population prevalence of diabetes surpassing 463 million cases in 2019 and diabetes leading to millions of deaths each year, there is a critical need for feasible, rapid, and non-invasive methodologies for continuous blood glucose monitoring in contrast to the current procedures that are either invasive, complicated, or expensive. Breath analysis is a viable methodology for non-invasive diabetes management owing to its potential for multiple disease diagnoses, the nominal requirement of sample processing, and immense sample accessibility; however, the development of functional commercial sensors is challenging due to the low concentration of volatile organic compounds (VOCs) present in exhaled breath and the confounding factors influencing the exhaled breath profile. Given the complexity of the topic and the skyrocketing spread of diabetes, a multifarious review of exhaled breath analysis for diabetes monitoring is essential to track the technological progress in the field and comprehend the obstacles in developing a breath analysis-based diabetes management system. In this review, we consolidate the relevance of exhaled breath analysis through a critical assessment of current technologies and recent advancements in sensing methods to address the shortcomings associated with blood glucose monitoring. We provide a detailed assessment of the intricacies involved in the development of non-invasive diabetes monitoring devices. In addition, we spotlight the need to consider breath biomarker clusters as opposed to standalone biomarkers for the clinical applicability of exhaled breath monitoring. We present potential VOC clusters suitable for diabetes management and highlight the recent buildout of breath sensing methodologies, focusing on novel sensing materials and transduction mechanisms. Finally, we portray a multifaceted comparison of exhaled breath analysis for diabetes monitoring and highlight remaining challenges on the path to realizing breath analysis as a non-invasive healthcare approach.

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PARAMETRIC AND NON-PARAMETRIC REGRESSION APPROACHES FOR NON-INVASIVE BLOOD GLUCOSE MONITORING

Biomedical Engineering Applications Basis and Communications ◽

10.4015/s101623722050043x ◽

2020 ◽

Vol 32 (06) ◽

pp. 2050043

Author(s):

Keshava N. Acharya ◽

M. G. Yashwanth Gowda ◽

M. Vijay ◽

S. Deepthi ◽

S. Malathi ◽

...

Keyword(s):

Health Care ◽

Blood Glucose ◽

Blood Glucose Level ◽

Glucose Level ◽

Glucose Monitoring ◽

Sensor Data ◽

Blood Glucose Monitoring ◽

Self Monitoring ◽

Non Invasive ◽

Non Parametric

Blood glucose monitoring systems (BGMSs) play a crucial role in health care applications. Invasive measurements are more accurate while non-invasive BGMS encourage self monitoring and reduce the cost of health care. Though multiple sensor data acquisition and suitable processing improve accuracy, self-monitoring becomes difficult in such non-invasive systems due to multiple signal acquisition. This paper investigates a non-invasive BGMS prototype that renders accurate measurements by statistically processing a single sensor data. The developed prototype is based on near-infrared (NIR) spectroscopy, which provides an electronic voltage that gets mapped to corresponding blood glucose level. This mapping is proposed using two different statistical regression approaches, parametric Bayesian Regression (BR) approach and the non-parametric Gaussian Process Regression (GPR) approach. Dataset is acquired from 33 subjects who visited Ramaiah Medical College Hospital, India. On each subject, voltage from the BGMS prototype and corresponding invasively obtained blood glucose level have been recorded. The BR and GPR approaches are trained with 75% of the data while the remaining 25% is used for testing. Test results show that BR approach renders root mean square error (RMSE) of 3.7[Formula: see text]mg/dL, while the mean absolute percentage error (MAPE) is around 2.5. The GPR with different radial basis function kernels revealed that a multiquadric kernel provides a lowest RMSE of 3.28[Formula: see text]mg/dL and lowest MAPE of 2.2, thus outperforming the parametric BR approach. Investigations also show that for a training data of less than 15 entries, BR renders better accuracy than the GPR approach.

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Evaluation of a New Noninvasive Glucose Monitoring Device by Means of Standardized Meal Experiments

Journal of Diabetes Science and Technology ◽

10.1177/1932296818758769 ◽

2018 ◽

Vol 12 (6) ◽

pp. 1178-1183 ◽

Cited By ~ 9

Author(s):

Andreas Pfützner ◽

Stephanie Strobl ◽

Filiz Demircik ◽

Lisa Redert ◽

Johannes Pfützner ◽

...

Keyword(s):

Blood Glucose ◽

Glucose Monitoring ◽

Relative Difference ◽

Glucose Levels ◽

Non Invasive ◽

Invasive Component ◽

Patients With Diabetes ◽

Individual Calibration ◽

Mathematical Algorithms ◽

Invasive Device

Background: Frequent blood glucose readings are the most cumbersome aspect of diabetes treatment for many patients. The noninvasive TensorTip Combo Glucometer (CoG) component employs dedicated mathematical algorithms to analyze the collected signal and to predict tissue glucose at the fingertip. This study presents the performance of the CoG (the invasive and the noninvasive components) during a standardized meal experiment. Methods: Each of the 36 participants (18 females and males each, age: 49 ± 18 years, 14 healthy subjects, 6 type 1 and 16 type 2 patients) received a device for conducting calibration at home. Thereafter, they ingested a standardized meal. Blood glucose was assessed from capillary blood samples by means of the (non)invasive device, YSI Stat 2300 plus, Contour Next at time points –30, 0, 15, 30, 45, 60, 75, 90, 120, 150, and 180 minutes. Statistical analysis was performed by consensus error grid (CEG) and calculation of mean absolute relative difference (MARD) in comparison to YSI. Results: For the noninvasive (NI) CoG technology, 100% of the data pairs were found in CEG zones A (96.6%) and B (3.4%); 100% were seen in zone A for the invasive component and Contour Next. MARD was calculated to be 4.2% for Contour Next, 9.2% for the invasive component, and 14.4% for the NI component. Conclusions: After appropriate individual calibration of the NI technology, both the NI and the invasive CoG components reliably tracked tissue and blood glucose values, respectively. This may enable patients with diabetes to monitor their glucose levels frequently, reliably, and most of all pain-free.

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Accuracy Beyond ISO: Introducing a New Method for Distinguishing Differences Between Blood Glucose Monitoring Systems Meeting ISO 15197:2013 Accuracy Requirements

Journal of Diabetes Science and Technology ◽

10.1177/1932296818762509 ◽

2018 ◽

Vol 12 (3) ◽

pp. 650-656

Author(s):

Scott Pardo ◽

Rimma M. Shaginian ◽

David A. Simmons

Keyword(s):

Blood Glucose ◽

Real World ◽

Glucose Monitoring ◽

Blood Glucose Monitoring ◽

Sensitivity Analyses ◽

Monitoring Systems ◽

Self Monitoring ◽

Drug Dosing ◽

Using Data ◽

Glycemic Targets

Background: Diabetes treatment is intended to maintain near-normal glycemic levels. Self-monitoring of blood glucose (SMBG) allows patients to track their BG levels compared with glycemic targets and is associated with improved health outcomes. Because of the importance of SMBG, it is essential that results are accurate to prevent errors in nutritional intake and drug dosing. This study presents a new methodology to evaluate the accuracy of BG monitoring systems (BGMSs). Methods: Sensitivity analyses were performed using real and simulated BGMS data to compute probabilities that, for any BG value, the BGMS result would be within prescribed error bounds and confidence limits compared with laboratory reference values. Multiple BG value ranges were used. Results: Probability curves were created using data from 3 simulated BGMSs and anonymized data from 3 real-world BGMSs. Accuracy probability curves from capillary fingertip blood samples (actual clinical data) showed that all 3 real-world BGMSs met EN ISO 15197:2015 accuracy criteria, since 99.63%, 99.63%, and 99.81% of results from the 3 BGMSs were within ±15 mg/dL or ±15% of reference for BG <100 mg/dL and ≥100 mg/dL, respectively. However, there was identifiable variability between BGMSs if BG was <70 mg/dL; one BGMS showed further reductions in accuracy if BG was <50 mg/dL. Conclusions: Probability curves highlight the importance of BGMS accuracy to help achieve optimal glycemic control while avoiding hypoglycemia or hyperglycemia. This may be especially significant in very low BG ranges where small errors in BGMS measurements can have substantial impacts on patient-related outcomes, including hypoglycemia risk.

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SELF-MONITORING OF BLOOD GLUCOSE WITH A NON-INVASIVE METHOD USING NEAR INFRARED SENSOR

SANITAS : Jurnal Teknologi dan Seni Kesehatan ◽

10.36525/sanitas.2020.10 ◽

2020 ◽

Vol 11 (2) ◽

pp. 111-121

Author(s):

Rinda Nur Hidayati ◽

Nur Hasanah Ahniar ◽

Gita Rindang Lestari ◽

Atika Hendryani ◽

Faris Al Hakim

Keyword(s):

Blood Glucose ◽

Glucose Level ◽

Glucose Monitoring ◽

Blood Glucose Monitoring ◽

Self Monitoring ◽

Glucose Levels ◽

Non Invasive ◽

Chronic Hyperglycemia ◽

Invasive Method ◽

Minimum System

Diabetes mellitus or commonly called diabetes is a worldwide epidemic caused by chronic hyperglycemia. Simplify the blood glucose monitoring and easy to use is an essential part of diabetes management. Currently, the use of blood glucose meters conventional in clinical practice needs sufficient reliability. Therefore, self-monitoring of blood glucose with a non-invasive method was presented. A non-invasive blood glucose monitoring device was initially for information on glucose level measurements. A non-invasive method to determine the level of glucose by applying the physical properties of the absorption of the laser sensor that can produce a voltage change at various glucose levels. In this paper, a glucose monitoring module was fabricated with dimensions of 25x27x15 cm which has a minimum system, sensor, and LCD as a display of glucose levels. A minimum system to control the output of data digital value using microcontroller Android nano v.3. Experimentally, testing this module is by comparing the glucose monitoring modules that have been made with a gold standard. The result showed that non-invasive glucose monitoring is the potential for glucose level measurement a sensitivity, resolution, and accuracy of 0.86 mg/dL, 0.01 mg/dL, and 98.96%, respectively. The purposed module of glucose level monitoring offered simple testing for the rapid measurement of glucose levels.

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Performance and User Experience Evaluation of a Non-Invasive Glucose Monitoring Device

International Journal of Diabetes & Metabolic Disorders ◽

10.33140/ijdmd/00009 ◽

2016 ◽

Vol 1 (2) ◽

Keyword(s):

User Experience ◽

Diabetes Management ◽

Glucose Monitoring ◽

Relative Difference ◽

Diabetic Patients ◽

Monitoring Device ◽

Type 2 Diabetic Patients ◽

Non Invasive ◽

Invasive Device ◽

Willingness To Use

Background: An accurate, low-maintenance, comfortable and easy-to-use glucose monitoring device might be the key to successful diabetes management. This research evaluated the performance of user experience with GlucoTrack®, a commercially available non-invasive device. Specifically, following one individual calibration, accuracy was assessed during a six month period equivalent to device sensors’ lifespan. Materials and Methods: GlucoTrack’s accuracy during six months was evaluated in 17 type-2 diabetic patients. User experience and device acceptance were assessed using questionnaires obtained from 95 naïve people with diabetes who used GlucoTrack at home. Results: GlucoTrack’s overall mean absolute relative difference (ARD) was 22.8% and 98.0% of points were in the clinically acceptable zones A and B of the Clarke Error Grid. The 95% confidence intervals of ARD standard deviation values of the first and sixth months (15.3-17.2% and 16.6-18.7%, respectively) overlapped. A favorable response to the easiness of device use and measurement performance, as well as to the comfort of the device and its screen, were reported in 75%, 86%, 87% and 95% of the users, respectively. These results did not depend on age, gender and level of education. Additionally, 83% of users expressed willingness to use the device regularly and 75% stated they would measure their glucose more frequently compared to the use of invasive device. Conclusions: GlucoTrack maintained its accuracy for six months, pointing to its low maintenance. The device was also highly accepted among diabetic patients. These findings attest the potential of GlucoTrack to enhance diabetic patients’ glucose monitoring routine.

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An alternative sensor-based method for glucose monitoring in children and young people with diabetes

Archives of Disease in Childhood ◽

10.1136/archdischild-2016-311530 ◽

2017 ◽

Vol 102 (6) ◽

pp. 543-549 ◽

Cited By ~ 63

Author(s):

Julie Edge ◽

Carlo Acerini ◽

Fiona Campbell ◽

Julian Hamilton-Shield ◽

Chris Moudiotis ◽

...

Keyword(s):

Blood Glucose ◽

Young People ◽

Glucose Monitoring ◽

Paediatric Population ◽

Relative Difference ◽

Self Monitoring ◽

Children And Young People ◽

Freestyle Libre ◽

The Uk ◽

Flash Glucose Monitoring System

ObjectiveTo determine accuracy, safety and acceptability of the FreeStyle Libre Flash Glucose Monitoring System in the paediatric population.Design, setting and patientsEighty-nine study participants, aged 4–17 years, with type 1 diabetes were enrolled across 9 diabetes centres in the UK. A factory calibrated sensor was inserted on the back of the upper arm and used for up to 14 days. Sensor glucose measurements were compared with capillary blood glucose (BG) measurements. Sensor results were masked to participants.ResultsClinical accuracy of sensor results versus BG results was demonstrated, with 83.8% of results in zone A and 99.4% of results in zones A and B of the consensus error grid. Overall mean absolute relative difference (MARD) was 13.9%. Sensor accuracy was unaffected by patient factors such as age, body weight, sex, method of insulin administration or time of use (day vs night). Participants were in the target glucose range (3.9–10.0 mmol/L) ∼50% of the time (mean 12.1 hours/day), with an average of 2.2 hours/day and 9.5 hours/day in hypoglycaemia and hyperglycaemia, respectively. Sensor application, wear/use of the device and comparison to self-monitoring of blood glucose were rated favourably by most participants/caregivers (84.3–100%). Five device related adverse events were reported across a range of participant ages.ConclusionsAccuracy, safety and user acceptability of the FreeStyle Libre System were demonstrated for the paediatric population. Accuracy of the system was unaffected by subject characteristics, making it suitable for a broad range of children and young people with diabetes.Trial registration numberNCT02388815.

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Real-time continuous glucose monitoring versus self-monitoring of blood glucose in adults with insulin-treated type 2 diabetes: a protocol for a randomised controlled single-centre trial

BMJ Open ◽

10.1136/bmjopen-2020-040648 ◽

2021 ◽

Vol 11 (1) ◽

pp. e040648

Author(s):

Nanna Lind ◽

Dorte Lindqvist Hansen ◽

Signe Sætre Rasmussen ◽

Kirsten Nørgaard

Keyword(s):

Type 2 Diabetes ◽

Blood Glucose ◽

Peer Support ◽

Continuous Glucose Monitoring ◽

Data Protection ◽

Treatment Options ◽

Glucose Monitoring ◽

Single Centre ◽

Self Monitoring

IntroductionMedical treatment options for type 2 diabetes (T2D) have increased over the last decade and enhance the possibility of individualised treatment strategies where insulin is still one of them. In spite of the advancements in treatment options, less than one-third of the population with T2D obtain their optimal glycaemic goal. In persons with type 1 diabetes, continuous glucose monitoring (CGM) has shown to be the most important driver for improvement in glycaemic control, even more than insulin-pump therapy. The use of technology in T2D has only been investigated in few studies.The overall objective of the research study is to examine the effectiveness of the use of CGM versus self-monitoring of blood glucose (SMBG) in persons with insulin-treated T2D on glycaemic variables and patient-reported outcomes on treatment satisfaction, health behaviour and well-being. The independent effect of peer support will also be studied.Methods and analysisThe study is a single centre, prospective, randomised, open-labelled, three-armed study with the randomisation 2:1:2 in group A with CGM, group B with CGM and peer support, and group C as a control group with SMBG. The participants receive a training course unique for the allocation group. The study runs for 12 months and includes 100 adult participants with insulin-treated T2D, treated at the outpatient clinic at Steno Diabetes Center Copenhagen. Primary outcome is difference in change in time in range. Recruitment begins in August 2020 and ends in July 2021. Final 12-month follow-up is anticipated to be in August 2022.Ethics and disseminationThe study will be carried out in accordance with the Helsinki Declaration and is approved by the Scientific Ethics Committee of the Capital Region (H-20000843). Data collection and handling will be performed in accordance with the General Data Protection Regulation and is approved by the Danish Data Protection Agency (J-2020-100). Dissemination will be in international peer-reviewed journals, conferences and a plain-language summary for participants.Trial registration numberClinicalTrials.gov Registry (NCT04331444).Protocol versionV.3, 11 December 2020.

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