Effectiveness of noninvasive continuous glucose monitoring using OCT angiography-purified blood scattering signals
| ISRCTN | ISRCTN73626753 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN73626753 |
| Secondary identifying numbers | No. 2022-044 |
- Submission date
- 15/08/2023
- Registration date
- 16/08/2023
- Last edited
- 16/08/2023
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Nutritional, Metabolic, Endocrine
Plain English summary of protocol
Background and study aims
Diabetes is a chronic metabolic disease associated with severe complications such as heart disease, kidney problems, and strokes. Monitoring blood glucose levels is crucial for patients' overall well-being. Glucose levels are typically assessed in two compartments: blood and interstitial fluid (ISF). Blood glucose concentration (BGC) is commonly measured using enzymatic-based electrochemical devices which may lead to discomfort, infection risks, and poor compliance. ISF glucose concentration (IGC) can be continuously monitored using subcutaneous needle sensors, which is less accurate than blood glucose monitoring due to delayed ISF glucose level response. The development of a noninvasive and precise continuous glucose monitoring (CGM) technique holds significant potential.
Optical techniques utilizing near-infrared light scattering are promising for noninvasive glucose monitoring. The accuracy of CGM based on near-infrared scattering is challenged by mixed scattering signals from different compartments, where glucose can have opposite effects on the scattering. OCT angiography (OCTA), an extension of OCT, enables 3D mapping of blood perfusion down to the capillary level. OCTA vascular mapping has facilitated highly sensitive measurement of glucose-induced scattering changes in specific blood or ISF compartments, demonstrating a strong correlation between the blood optical scattering coefficient (BOC) and BGC in mouse retinas. Further investigation is needed to validate this correlation in humans and assess its practical utility for blood glucose monitoring.
The aim of this study is to explore the potential of using OCTA-purified blood scattering signals to achieve high accuracy in CGM.
Who can participate?
Healthy volunteers above 18 years old
What does the study involve?
Participants were enlisted to take part in both experimental and control study trials. In the experimental trial, each test comprised a 10-minute baseline period, succeeded by a 5-minute intake of a glucose solution and an 85-minute recovery phase to revert to baseline levels. Throughout the trial, OCTA imaging occurred every 5 minutes in the same region of interest on the finger. Concurrently, the blood glucose concentrations were measured by a portable blood glucose meter every 10 minutes. The control trial followed a comparable protocol, with water replacing the glucose solution.
What are the possible benefits and risks of participating?
The risks to the participants are minimal. The only possible "risk" is slight bruising on the site where the finger is pricked to take blood for glucose testing. There are no direct benefits to the participants.
Where is the study run from?
Zhejiang University (China)
When is the study starting and how long is it expected to run for?
January 2022 to April 2023
Who is funding the study?
The National Natural Science Foundation of China
Who is the main contact?
Mr Peng Li, peng_li@zju.edu.cn
Contact information
Scientific
State Key Lab of Modern Optical Instrumentation
College of Optical Science and Engineering
Zhejiang University
38 Zheda Road
Hangzhou
310027
China
| Phone | +86 (0)13615816901 |
|---|---|
| peng_li@zju.edu.cn |
Study information
| Study design | Single-centre pilot observational trial |
|---|---|
| Primary study design | Observational |
| Secondary study design | Cohort study |
| Study setting(s) | Hospital |
| Study type | Diagnostic |
| Participant information sheet | Not available in web format, please use the contact details to request a patient information sheet |
| Scientific title | A pilot study on noninvasive continuous glucose monitoring in healthy subjects using OCT angiography-purified blood scattering signals |
| Study acronym | OCTACGM |
| Study objectives | Test the feasible of a new technology (OCT angiography) for continuous noninvasive glucose monitoring: 1. Verify the correlation between the OCTA-purified blood scattering signals and the blood glucose levels in human skin in vivo 2. Develop a calibration method to calculate BGC based on the OCTA-purified blood scattering signals 3. Test the accuracy and reproducibility of the OCTA-based continuous glucose monitoring (CGM) |
| Ethics approval(s) |
Approved 29/09/2022, Ethics Committee of the College of Biomedical Engineering & Instrument Science, Zhejiang University (38 Zheda Road, Hangzhou, 310027, China; +86 (0)571 87951249; zjuethic@zju.edu.cn), ref: No. 2022-044 |
| Health condition(s) or problem(s) studied | Continuous glucose monitoring |
| Intervention | Experimental group: Each test involved a 10-minute baseline period, followed by the ingestion of a glucose solution for 5 minutes and an 85-minute recovery period to return to baseline levels. OCTA imaging was performed at the same region of interest on the finger every 5 minutes during the trial. A fingertip blood sample was taken every 10 minutes, using a portable blood glucose meter to measure the BGC. Control group: Similar experiments were conducted with the glucose solution replaced by water to serve as the control group. |
| Intervention type | Other |
| Primary outcome measure | 1. 3D OCT structure images and 3D OCT angiography (OCTA) images of skin. The 3D OCT structure images of human skin were acquired by the swept source OCT system, and 3D OCTA images were generated by applying the inverse signal-to-noise ratio and decorrelation OCTA (ID-OCTA) algorithm on the 3D OCT structure at -10, -5, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85 and 90 min 2. Reference blood glucose concentrations (BGC) were measured every 10 minutes using a portable blood glucose meter on a sample taken from the finger at -10, 0, 10, 20, 30, 40, 50, 60, 70, 80 and 90 min |
| Secondary outcome measures | 1. Blood optical scattering coefficient (BOC) extracted from the depth attenuation of backscattered light in OCT and then spatially purified under the guidance of a 3D OCTA vascular map in human skin at -10, -5, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85 and 90 min 2. Correlation between BOC and reference blood glucose concentrations (BGC), linearly fitted based on the least squares criterion at -10, 0, 10, 20, 30, 40, 50, 60, 70, 80 and 90 min 3. Optical BGC, calculated from the BOC through a linear calibration at -10, 0, 10, 20, 30, 40, 50, 60, 70, 80 and 90 min 4. Accuracy of glucose measurements based on OCT angiography (OCTA), evaluated using Parke's error grid, ISO 15197 standards, and mean absolute relative difference at -10, 0, 10, 20, 30, 40, 50, 60, 70, 80 and 90 min 5. Tissue optical scattering coefficient (TOC), extracted from the depth attenuation of backscattered light in OCT and then spatially purified under the guidance of a 3D OCTA vascular map in the dermis layer of the skin at -10, -5, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85 and 90 min 6. Correlation between TOC and reference blood glucose concentrations (BGC), linearly fitted based on the least squares criterion at -10, 0, 10, 20, 30, 40, 50, 60, 70, 80 and 90 min 7. Optical interstitial fluid glucose concentration (IGC), calculated from the TOC through a linear calibration at -10, 0, 10, 20, 30, 40, 50, 60, 70, 80 and 90 min 8. Lag time between IGC and BGC, assessed as the temporal delay between optical IGC and the reference BGC at -10, -5, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85 and 90 min |
| Overall study start date | 01/01/2022 |
| Completion date | 30/04/2023 |
Eligibility
| Participant type(s) | Healthy volunteer |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Sex | Both |
| Target number of participants | 10 |
| Total final enrolment | 10 |
| Key inclusion criteria | 1. Adults (18 years old or above) 2. In good health 3. Not taking any medication 4. Able to consent to participate |
| Key exclusion criteria | 1. Children and young adults (younger than 18 years old) 2. Having chronic disease 3. Unable to consent to participate |
| Date of first enrolment | 01/12/2022 |
| Date of final enrolment | 30/04/2023 |
Locations
Countries of recruitment
- China
Study participating centre
College of Optical Science and Engineering
38 Zheda Road
Hangzhou
310027
China
Sponsor information
University/education
State Key Lab of Modern Optical Instrumentation
College of Optical Science and Engineering
38 Zhada Road
Hangzhou
310027
China
| Phone | +86 (0)571 87951197 |
|---|---|
| optzju@zju.edu.cn | |
| Website | http://opt.zju.edu.cn/ |
Funders
Funder type
Government
Government organisation / National government
- Alternative name(s)
- Chinese National Science Foundation, Natural Science Foundation of China, National Science Foundation of China, NNSF of China, NSF of China, 国家自然科学基金委员会, National Nature Science Foundation of China, Guójiā Zìrán Kēxué Jījīn Wěiyuánhuì, NSFC, NNSF, NNSFC
- Location
- China
Results and Publications
| Intention to publish date | 15/08/2024 |
|---|---|
| Individual participant data (IPD) Intention to share | No |
| IPD sharing plan summary | Data sharing statement to be made available at a later date |
| Publication and dissemination plan | Planned publication in a high-impact peer-reviewed journal |
| IPD sharing plan | The current data sharing plans for this study are unknown and will be available at a later date |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Protocol file | 16/08/2023 | No | No |
Additional files
Editorial Notes
16/08/2023: Study's existence confirmed by the Ethics Committee of the College of Biomedical Engineering & Instrument Science, Zhejiang University.
