Table 2.
Technological Features of NIO-GM, NIFS-GM, or MI-GM Identified Products (in Alphabetical Order Within Each Category of Invasiveness).
| Entry number | Product and manufacturer | Degree of invasiveness | Mechanism of glucose sensing | Matrix | Degree of accuracy | Interferences |
|---|---|---|---|---|---|---|
| 1 | No product name; Afon Technology | NIO-GM | Uses microwave spectroscopy. Sensor analyzes resonance shifts based on microwave signal to detect changes in glucose. Results reported for a clinical trial. 222 | Blood/ISF 222 | MARD: 21 ± 9% surveillance error grid: 48.9% in “no risk” zone, 47.1% in “slight risk” zone, 4% in “moderate risk” zone 4% 222 | No information available. |
| 2 | Alertgy NI-GM; Alertgy | NIO-GM | Uses dielectric spectroscopy. Wristband with integrated Microchip (dielectric sensor). The apparatus senses the electrical membrane permeability of cells and detects if the permeability varies from the norm. It then uses the difference between the measured permeability with the known permeability to sense glucose levels. Frequency range: 100 kiloherz–220 megaherz. Radiowave frequencies. 88 | Blood/ISF 88 | No information available. | No information available. |
| 3 | No product name; AnnNIGM | NIO-GM | Measuring principle not reported so far. Earlobe clip sensor. No description of their technology provided on their website. 223 | No information available. | No information available. | No information available. |
| 4 | Add on to the Apple Watch; Apple | NIO-GM | Uses absorption spectroscopy with light of certain wavelength to determine the concentration of glucose 224 | Blood/ISF 224 | No information available. | No information available |
| 5 | BioMKR; Prediktor Medical | NIO-GM | Uses absorption spectroscopy. An near infrared laser is used to generate an absorption spectrum for a certain measurement location of the user. A calibration model is then used to estimate blood glucose values from the infrared spectrum. 225 | Blood/ISF 225 | No information available. | None specified so far, but the device is intended for use in people age 18 or older. It is also only appropriate for use in certain cases. 226 |
| 6 | Blood Analysis Sensor; Brolis Sensor Technology |
NIO-GM | Based on integrated photonic package designed to measure glucose, lactate and ethanol. Wavelengths included at 1.7–2.5 microns. Uses laser-based sources. 227 | Blood/ISF 227 | MARD: 5.7% Clarke error grid: greater than 97% in zone A 227 | No specific information – claims that ethanol and lactate are not significant 227 |
| 7 | CompanionCM; Socrates Health Solutions | NIO-GM | Rotation of plane polarized radiation at a non-defined wavelength through a tissue phantom (mimics ear tissue). Preliminary data presented for several human subject experiments. Technology similar to CompanionSR. 228 | Tissue 228 | Resolution for the measurement of micro-radians: ±10 mg/dl. 228 | No information available. |
| 8 | CompanionSR; Socrates Health Solutions | NIO-GM | Rotation of plane polarized radiation at a non-defined wavelength through a tissue phantom (mimics ear tissue). Preliminary data presented for several human subject experiments. Technology similar to CompanionCM. 228 | Tissue 228 | Resolution for the measurement of micro-radians: ±10 mg/dl 228 | No information available. |
| 9 | D-Band; DiaMonTech | NIO-GM | Use of photothermal detection of the molecules after excitation with a mid-infrared laser (quantum cascade laser). A mid-infrared laser is used to detect glucose molecules in the ISF. The reflected wavelength is analyzed to gather data on the amount of glucose molecules. Data analysis involves a leave-one data set-out machine learning system. Technology similar to D-Base and D-Pocket. 100 | ISF 100 | No information available. | No information available. |
| 10 | D-Base; DiaMonTech | NIO-GM | Use of photothermal detection of the molecules after excitation with a mid-infrared laser (quantum cascade laser). A mid-infrared laser is used to detect glucose molecules in the ISF. The reflected wavelength is analyzed to gather data on the amount of glucose molecules. Data analysis involves a leave-one data set-out machine learning system. Technology similar to D-Band and D-Pocket. 100 | ISF 100 | MARD: 11.3%-12.1% medARD: 6.4%-6.5% Consensus error grid: 98.8%-99.1% in zones A+B 100 | Temperatures outside of the range of 10-30℃ may cause inaccurate readings. Temperature or residue on skin can interfere with accuracy. 102 |
| 11 | D-Pocket; DiaMonTech | NIO-GM | Use of photothermal detection of the molecules after excitation with a mid-infrared laser (quantum cascade laser). A mid-infrared laser is used to detect glucose molecules in the ISF. The reflected wavelength is analyzed to gather data on the amount of glucose molecules. Data analysis involves a leave-one data set-out machine learning system. Technology similar to D-Band and D-Base. 100 | ISF 100 | No information available. | No information available. |
| 12 | GlucoBeam; RSP Systems | NIO-GM | This device uses Raman scattering spectroscopy to detect the amount of glucose in ISF. An excitation laser is shined into the finger and the Raman scatter from glucose molecules is analyzed. This technology used confocal methods to focus on a specific depth into the skin matrix. 106 | ISF 106 | medARD: 18.9%. consensus error grid: 93.1% in zones A+B. 229 | Substances that have similar structures to glucose (such as ethanol) could interfere with the accuracy of the results. |
| 13 | GlucoFit; GlucoActive | NIO-GM | Using spectrophotometry to measure the scattering of light by molecules such as glucose. Irradiates the skin with wavelength of light to determine glucose concentration. Technology similar to GlucoStation and GlucoWear. 230 | Skin 230 | No information available. | No information available. |
| 14 | Gluco Quantum; Genki Vantage Ltd | NIO-GM | Uses metabolic heat (in the form of radiation, convection, and evaporation) from the finger’s skin to detect blood flow velocity and make an extrapolation of glucose levels. Infrared light is shone onto the skin to measure the skin’s temperature. 109 | Skin 109 | MARD: 13.12% 231 | No information available. |
| 15 | Glucosense; Glucosense Diagnostics Ltd. | NIO-GM | Application of fluorescence measurement after excitation with a low-energy laser. Photonic chip with fluorescent ions. Uses infrared light and measures level of ion fluorescence to determine glucose concentration. The fluorescence ions are embedded with a silica glass photonic chip. These ions fluoresce in the infrared region of the spectrum (this could be near infrared close to the visible spectral range). 232 | Skin 232 | No information available. | No information available. |
| 16 | GlucoStation; GlucoActive | NIO-GM | Using spectrophotometry to measure the scattering of light by molecules such as glucose. Irradiates the skin with wavelength of light to determine glucose concentration. Technology similar to GlucoFit and GlucoWear. 233 | Skin 233 | No information available. | No information available. |
| 17 | GlucoTrack; Integrity Applications Ltd | NIO-GM | Ultrasonic, electromagnetic, and thermal parameters in earlobe tissue are measured to estimate blood glucose levels. 234 | Skin 234 | MARD: 17.5%- 19.7% consensus error grid: 62.4% in zone A, 37.6% in zone B 235 | Device can operate in an environmental temperature of +15°C to +35°C/ +59°F to +95°F. However, If the ambient sensor detects an environmental temperature that is beyond these temperatures, the device will present an error message 236 |
| 18 | GlucoWear; GlucoActive | NIO-GM | Using spectrophotometry to measure the scattering of light by molecules such as glucose. Irradiates the skin with wavelength of light to determine glucose concentration. Technology similar to GlucoFit and GlucoStation. 237 | Skin 237 | No information available. | No information available. |
| 19 | GlucoWise; MediWiSe | NIO-GM | Using low-power radio waves scattering. Radio waves (40 GHz) are transmitted through a thin layer of skin with adequate blood supply. Radiation passes through the skin layer (transflectance experiment). Uses a film technology that makes the skin transparent to the incident radiation, thereby giving consistent readings across different types of skin. 238 | Blood 238 | No information available. | No information available. |
| 20 | Glutrac; Add Care Ltd. |
NIO-GM | Employs absorption spectroscopy, electrocardiography, photoplethysmography, and dynamic metabolic heat monitoring to collect data. Machine learning and artificial intelligence is then used to estimate the user’s blood glucose. 119 | Blood 119 | No information available. | No information available. |
| 21 | HELO Extense; Wor(l)d Master Distributors | NIO-GM | Photoplethysmography to measure glucose concentrations. 239 | Blood122,239 | Instead of blood glucose numbers, the device provides a color coded scale for glucose. 121 No information on accuracy. | No information available. |
| 22 | HELO LX PRO; Wor(l)d Master Distributors | NIO-GM | Photoplethysmography to measure glucose concentrations. 122 | Blood 122 | No information available. | No information available. |
| 23 | LIFELEAF; LifePlus | NIO-GM | Optical Sensor using photoplethysmography (detection of the reflection of infrared light) to detect glucose. 240 | Blood 240 | No information available. | No information available. |
| 24 | Movano Wearable; CGM Movano | NIO-GM | Scattering of high-frequency radio waves (in mm range). One antenna transmits a radio frequency below the skin surface. The amplitude and phase data (impedance) of the reflected waves are then processed by processing circuits and outputs a relevant value for blood glucose levels in the wrist. The sensor uses a frequency of around 60 GHz to penetrate deeper past the skin and illuminate a wider range. Uses a 122-126 GHz spectral range for measurement of glucose, blood pressure, and heart rate. Also uses Doppler measurements to isolate signals corresponding to relative movements. 241 | Blood 241 | No information available. | No information available. |
| 25 | No product name; Omni Sciences, Inc. | NIO-GM | Near infrared spectroscopy after excitation with fiber lasers. 242 | No information available | No information available. | No information available. |
| 26 | Sanmina; Sanmina Corporation | NIO-GM | Optical measurement: detect several photoplethysmography signals (detection of the reflection of infrared light) in interstitial tissue 243 | Blood volume and vascular wall 243 | MARD: 8%. Consensus error grid: 98% in zone A, 1.9% in zone B 243 | No information available. |
| 27 | TensorTip Combo Glucometer; Cnoga Medical Ltd | NIO-GM | Measurement of infra-red light (600-1000 nm) passing through the fingertip (after partial absorption in the finger). Real-time color images related to the blood glucose level in the capillaries are translated into a vector that can be used to identify patterns of glucose concentration 244 | Blood/ISF 244 | MARD: 14-18.1%. Consensus error grid: 91.1% in zone A and 7.8% in zone B133,245 | The finger would have to be adequately warmed up to ensure blood flow to the capillaries. Results might also be affected if the skin or device screen is dirty. 244 |
| 28 | Uband; Know Labs, Inc. | NIO-GM | Spectroscopy techniques combined with radio waves are used to detect glucose concentrations in the body. 246 | Blood 246 | No information available. | No information available. |
| 29 | Bios; GraphWear Technologies Inc. | NIFS-GM | Detection of biomolecules from the surface of skin: Nanotechnology to measure glucose that comes out of the skin surface through sweat89,247 | Sweat 89 | No information available. | Tattoos or other skin alterations 248 |
| 30 | gSense; Nutrix | NIFS-GM | Detection of biomolecules. Uses nanotechnology to detect glucose changes (concentration of molecules) in saliva. 249 | Saliva 249 | No information available. | No information available. |
| 31 | NextGen CGM; Echo Therapeutics | NIFS-GM | Uses technology that enhances skin permeation (using ultrasound) to measure analytes. Sensor includes a hydrogel component and electrodes. The hydrogel contains glucose oxidase to measure glucose. 250 | ISF 250 | MARD: 12.4%-20.4% Clarke error grid: 70.7%-89.6% in zone A, 9.6%-26.2% in zone B 250 | No information available. |
| 32 | Saliva Glucose Biosensor; Gbs Inc. | NIFS-GM | Glucose oxidase is used to detect glucose in a saliva sample through an electrochemical method. 251 | Saliva 251 | No information available. | No information available. |
| 33 | sugarBEAT; Nemaura Medical | NIFS-GM | Reverse iontophoresis for sampling and electrochemical sensing with glucose oxidase. Adhesive skin patch. Electrochemical signal of ISF glucose via glucose oxidase reaction using reverse iontophoresis by stimulating the migration of glucose from the ISF through an electrical current. 252 | ISF 252 | MARD: 11.92%-12.4% 252 | No information available. |
| 34 | Tear Glucose Sensor; NovioSense | NIFS-GM | Electrochemical sensing with glucose oxidase as a receptor for the biomarker, glucose. The amount of H2O2 generated is an indicator for the amount of glucose in the lacrimal fluid.36,253 | Lacrimal Fluid36,253 | medARD: 12.5% Consensus error grid: 90% in zones A+B 253 | Ascorbic acid, acetaminophen, citric acid, lactic acid, pyruvic acid, and urea are all interfering substances 253 |
| 35 | AiDex CGM; GlucoRx (Rebranding of MicroTech Medical)146,147 | MI-GM | Electrochemical sensing with glucose oxidase. 254 | ISF 254 | Consensus error grid: 89.96% in zone A 255 | No information available. |
| 36 | Biolinq CGM; Biolinq | MI-GM | Electrochemical signal of ISF glucose via glucose oxidase reaction. Using patch with microneedles 149 | ISF 149 | No information available. | No information available. |
| 37 | Care Sense Air; i-SENS | MI-GM | Electrochemical signal of ISF glucose via glucose oxidase reaction. 256 | ISF 256 | No information available. | No information available. |
| 38 | Cascade CGM System; Waveform | MI-GM | Electrochemical signal of ISF glucose via glucose oxidase reaction. 257 | ISF 257 | MARD: 9.9%, MAD: 14.5 mg/dL Consensus error grid: 86.5% of the data pairs in zone A, greater than 98.6% in zones A+B 152 | Limited interference concerns. Does not interfere with acetaminophen. 151 |
| 39 | CT-100; POCTech X Ascensia | MI-GM | Electrochemical signal of ISF glucose via glucose oxidase reaction. 258 | ISF 258 | MARD: 8.67%-10.22% Clarke error grid: 86.7%-91.6% in zone A, 8.4%-12.7% in zone B259,260 | No information available. |
| 40 | Dexcom G6; Dexcom | MI-GM | Electrochemical signal of ISF glucose via glucose oxidase reaction. GO+Perm-selective membrane coating 261 | ISF 261 | MARD: 9% 159 | Hydroxyurea |
| 41 | Dexcom G7; Dexcom | MI-GM | No information available. | No information available. | No information available. | No information available. |
| 42 | Eclipse 3 iCGM; GlySens | Implanted MI-GM | Glucose oxidase and a potentiostatic oxygen sensor work together in the sensor to sense glucose and allow for long-term implanting of the sensor. 262 | ISF 262 | MARD: 8.2%-28.1%. Consensus error grid: 75.2% in zone A, 23.7% in zone B, 1.1% in zone C 262 | No information available. |
| 43 | Eversense; Senseonics | Implanted MI-GM | Nonenzymatic electrochemical fluorescent-based polymer 263 | ISF 263 | MARD: 8.5%-9.6% 263 | Mannitol, Tetracycline 264 |
| 44 | FiberSense Technology CGM; EyeSense | MI-GM | Optical fiber fluorescence photometer measures concentration of glucose. Uses a receptor molecule that binds glucose and also binds a competitor molecule. 265 | ISF 265 | MARD: 8%-9% 265 | No information available. |
| 45 | FreeStyle Libre 14 day; Abbott Diabetes Care | MI-GM | Electrochemical signal of ISF glucose via glucose oxidase. GO+Redox sensing, use of a mediator of osmium oxide 266 | ISF 266 | MARD: 9.4% 267 | Ascorbic acid, salicylic acid267,268 |
| 46 | FreeStyle Libre 2; Abbott Diabetes Care | MI-GM | Electrochemical signal of ISF glucose via glucose oxidase. GO+Redox sensing, use of a mediator of osmium oxide 269 | ISF 269 | Adult MARD: 9.2%, pediatric MARD: 9.7% 269 | Ascorbic acid 269 |
| 47 | Freestyle Libre 3; Abbott Diabetes Care | MI-GM | Electrochemical signal of ISF glucose via glucose oxidase. GO+Redox sensing, use of a mediator of osmium oxide 270 | ISF 270 | Adult MARD: 9.2% 270 | No information available. |
| 48 | Glucomen Day CGM; Menarini Diagnostics | MI-GM | Electrochemical signal of ISF glucose via glucose oxidase. Electrochemical enzymatic sensor. 271 | ISF 271 | MARD: 9.7%. Consensus error grid: 84.9% in zone A, 12.9% in zone B 272 | No information available. |
| 49 | Glunovo i3 CGM; Infinovo Medical Co Ltd. | MI-GM | Electrochemical signal of ISF glucose via glucose oxidase electrochemical sensor. 273 | ISF 273 | No information available. | No information available. |
| 50 | Glyde CGM; GluSense | Implanted MI-GM | Glucose detection is performed using a proprietary fluorescent. Biosensor protein. Biosensor uses the fluorescent resonant energy transfer effect. 186 When glucose is bound to the biosensor, it changes its fluorescence emission. | ISF 186 | No information available. | No information available. |
| 51 | Indigo CGM; Indigo | Implanted MI-GM | Glucose measurement with near infrared spectroscopy in a small subcutaneously implanted spectrometer, measure glucose and ketones up to 2 years 274 | ISF 274 | (Measured in swine model) MARD: 6.4%-6.5%. Consensus error grid 99.3%-99.4% in zone A, 0.6% in zone B, 0%-0.1% in zone C 275 | No information available. |
| 52 | No product name; Integrated Medical Sensors | Implanted MI-GM | Electrochemical signal of ISF glucose via glucose oxidase reaction 190 | ISF 190 | (Measured in swine model) MARD: Better than 12%. Clarke error grid: 96% in Zones A+B 190 | No information available. |
| 53 | No product name; One Drop (acquired Sano Intelligence, Inc., which was developing patch biosensor glucose monitor) 192 | MI-GM | Biosensor patch with microneedles that measures ISF for glucose concentration.192,194,276 Glucose forecast by using artificial intelligence. | ISF 194 | No information available. | No information available. |
| 54 | K’Watch; PKvitality | MI-GM | Electrochemical signal of ISF glucose via glucose oxidase reaction. Measured through microneedles277,278 | ISF277,278 | No information available. | No information available. |
| 55 | Lumee; Profusa | Implanted MI-GM | Biosensor inserted into the body will have porous smart gel and will emit fluorescent signal in response to certain analytes like glucose 279 | ISF 279 | No information available. | No information available. |
| 56 | Medtronic Guardian Connect (Powered by Medtronic Guardian Sensor 3); Medtronic MiniMed | MI-GM | Electrochemical signal of ISF glucose via glucose oxidase reaction 280 | ISF 280 | MARD: 8.7% 281 | Acetaminophen hydroxyurea 280 |
| 57 | Medtronic Synergy; Medtronic MiniMed | MI-GM | No information available. | ISF 282 | No information available. | No information available. |
| 58 | Medtronic Zeus; Medtronic MiniMed | MI-GM | No information available. | ISF 282 | Pivotal results indicate possibility of iCGM standard 12 | No information available. |
| 59 | No product name; Metronom Health | MI-GM | Electrochemical opto-enzymatic sensor. 283 | ISF 283 | No information available. | No interferences with commonly taken substances 283 |
| 60 | PercuSense CGM; PercuSense | MI-GM | Electrochemical enzymatic sensor combining measurement of glucose and ketone on a single sensor. Multi-analyte function. 284 | ISF 284 | No information available. | No information available. |
| 61 | Sanvita; Sanvita Medical, LLC and LifeScan | MI-GM | No information available. | ISF 285 | No information available. | No information available. |
| 62 | Sencell; LifeCare AS | Implanted MI-GM | Implantable 3D printed nano-sensor with an osmotic pressure sensing core. Cantilever based glucose sensing. 286 Utilization of the reversible affinity sensing principle of ConA and dextran with glucose (change of binding in the presence of glucose and therefore change of osmotic pressure at a membrane). | ISF 286 | No information available. | No information available. |
| 63 | SugarSenz; Glucovation | MI-GM | Electrochemical non-enzymatic sensor 287 | ISF 287 | No information available. | No information available. |
| 64 | SynerG; Pacific Diabetes Technologies | MI-GM | Insulin infusion set and CGM sensor combined into one integrated device. CGM sensor is hollow. Uses redox mediator technology. 216 | ISF 216 | MARD:10-14%216,217 | No information available. |
| 65 | TouchCare System A6; Medtrum | MI-GM | Electrochemical signal of ISF glucose via glucose oxidase reaction. 219 | ISF 219 | MARD: 9% 288 | May be affected by strong radiation, such as MRI, X-ray, or CT scans. 118 |
Abbreviations: CGM, continuous glucose monitor; ConA, Concanavalin A; CT, computed tomography; ISF, interstitial fluid; MAD, mean absolute difference; MARD, mean absolute relative difference, medARD, median absolute relative difference; MI-GM, minimally invasive glucose monitor; MRI, magnetic resonance imaging; NIFS-GM, noninvasive fluid sensing glucose monitor; NIO-GM, noninvasive glucose monitor.