MultiSure GK Link Blood Glucose and Ketone Monitoring System
Applicant
Apex BioTechnology Corp.
Product Code
NBW · Clinical Chemistry
Decision Date
Oct 15, 2021
Decision
SESE
Submission Type
Traditional
Regulation
21 CFR 862.1345
Device Class
Class 2
Attributes
Pediatric
Indications for Use
MultiSure GK Link Blood Glucose and Ketone Monitoring System is comprised of the MultiSure GK Blood Glucose and Ketone Meter, the MultiSure GK Blood Glucose Test Strips, and the MultiSure GK Blood Ketone test strips. The MultiSure GK Linle Blood Glucose and Ketone Monitoring System is intended to quantitatively measure blood glucose or blood ketone in fresh capillary whole blood drawn from fingertips. The system is intended for self-testing outside the body (in vitro diagnostic use) by people with diabetes mellitus at home as an aid in monitoring the effectiveness of diabetes control and should only be used by a single patient and it should not be shared. It is not intended for diagnosis or screening of diabetes or for neonatal use.
Device Story
System measures glucose and beta-hydroxybutyrate in capillary whole blood via fingerstick; uses amperometric technology with glucose oxidase or D-3-hydroxybutyrate dehydrogenase enzymes on test strips. Meter applies electrical current to strip; measures reaction-induced current changes; converts to quantitative concentration. Used by patients with diabetes at home for monitoring glycemic control. Data transmitted via USB or Bluetooth to mobile devices. Provides quantitative results on display; aids patient in diabetes management. Single-patient use only; requires specific disinfection protocols.
Clinical Evidence
Clinical study with 350 lay users for glucose and 100 for ketones. Glucose accuracy: 100% within ±15 mg/dL (<75 mg/dL) and 100% within ±15% (≥75 mg/dL). Ketone accuracy: 100% within ±0.30 mmol/L (<1.5 mmol/L) and 100% within ±20% (≥1.5 mmol/L). Bench testing confirmed precision, linearity, and interference profiles.
Technological Characteristics
Electrochemical biosensor; enzymes: Glucose Oxidase (GOD) for glucose, β-hydroxybutyrate dehydrogenase (HBDH) for ketones. Connectivity: USB and Bluetooth for data transmission. Meter form factor for capillary blood testing. Software-based data management.
Indications for Use
Indicated for people with diabetes mellitus for quantitative self-testing of blood glucose or blood ketone in fresh capillary whole blood from fingertips. Contraindicated for neonates, critically ill patients, or use in healthcare/assisted-use settings.
Regulatory Classification
Identification
A glucose test system is a device intended to measure glucose quantitatively in blood and other body fluids. Glucose measurements are used in the diagnosis and treatment of carbohydrate metabolism disorders including diabetes mellitus, neonatal hypoglycemia, and idiopathic hypoglycemia, and of pancreatic islet cell carcinoma.
Special Controls
*Classification.* Class II (special controls). The device, when it is solely intended for use as a drink to test glucose tolerance, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 862.9.
Predicate Devices
Nova Max Plus Blood Glucose and β-Ketone Monitoring System (k091547)
Submission Summary (Full Text)
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FDA U.S. FOOD & DRUG ADMINISTRATION
# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY
ASSAY AND INSTRUMENT
## I Background Information:
A 510(k) Number
K201880
B Applicant
Apex Biotechnology Corp.
C Proprietary and Established Names
MultiSure GK Link Blood Glucose and Ketone Monitoring System
D Regulatory Information
| Product Code(s) | Classification | Regulation Section | Panel |
| --- | --- | --- | --- |
| NBW | Class II | 21 CFR 862.1345 - Glucose Test System | CH - Clinical Chemistry |
| JIN | Class I, meets the limitation of exemption 21 CFR 862.9(c)(5) | 21 CFR 862.1435 - Ketones (nonquantitative) test system | CH - Clinical Chemistry |
## II Submission/Device Overview:
A Purpose for Submission:
Addition a blood ketone measurement functionality to a previously cleared blood glucose monitoring system (k170267) in a new meter shell.
B Measurand:
Glucose and $\beta$-hydroxybutyrate in capillary whole blood obtained from the finger.
Food and Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993-0002
www.fda.gov
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C Type of Test:
Quantitative, amperometry for glucose and $\beta$-hydroxybutyrate
III Intended Use/Indications for Use:
A Intended Use(s):
See Indications for Use below.
B Indication(s) for Use:
MultiSure GK Link Blood Glucose and Ketone Monitoring System is comprised of the MultiSure GK Blood Glucose and Ketone Meter, the MultiSure GK Blood Glucose Test Strips, and the MultiSure GK Blood Ketone test strips.
The MultiSure GK Linle Blood Glucose and Ketone Monitoring System is intended to quantitatively measure blood glucose or blood ketone in fresh capillary whole blood drawn from fingertips. The system is intended for self-testing outside the body (in vitro diagnostic use) by people with diabetes mellitus at home as an aid in monitoring the effectiveness of diabetes control and should only be used by a single patient and it should not be shared. It is not intended for diagnosis or screening of diabetes or for neonatal use.
C Special Conditions for Use Statement(s):
OTC - Over The Counter
- This device is not intended for use in healthcare or assisted-use settings such as hospitals, physician offices, or long-term care facilities because it has not been cleared by FDA for use in these settings, including for routine assisted testing or as part of glycemic control procedures. Use of this device on multiple patients may lead to transmission of Human Immunodeficiency Virus (HIV), Hepatitis C Virus (HCV), Hepatitis B Virus (HBV), or other bloodborne pathogens.
- Inaccurate results may occur in severely hypotensive individuals, patients in shock, in a hyperglycemic-hyperosmolar state with or without ketosis
- Do not use on critically ill patients.
- Do not use on neonates.
- Do not use the system above 10,335 feet (3,150 meters) in altitude.
- Do not use if hematocrit exceeds the acceptable range between 20% to 60%. when testing.
- Severe dehydration (excessive water loss) may cause inaccurate results.
- For single-patient use only.
D Special Instrument Requirements:
MultiSure GK Link Blood Glucose and Ketone Meter
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## IV Device/System Characteristics:
### A Device Description:
The MultiSure GK Link Blood Glucose and Ketone Monitoring System consists of the MultiSure GK Link Blood Glucose and Ketone Meter, MultiSure GK Blood Glucose test strips, MultiSure GK Blood Ketone test strips, Contrex Plus 4 Glucose Control Solution (Level 1, Level 2 and Level 3), and KET-1 ketone control solution (Level 1 and Level 2). The MultiSure GK Blood Glucose test strips, MultiSure GK Blood Ketone test strips, Contrex Plus 4 Glucose Control Solution, and KET-1 ketone control solution can be purchased separately.
MultiSure GK Link Blood Glucose and Ketone Monitoring System enables automatic transmission of stored data from the meter to a mobile device via USB cable (optional), or through Bluetooth when the meter is properly configured.
### B Principle of Operation:
The system uses amperometric technology for the detection of glucose and $\beta$-ketones. The glucose test strips contain an enzyme (glucose oxidase) that reacts to glucose present in blood, releasing electrons. The ketone test strips contain an enzyme (D-3-hydroxybutyrate dehydrogenase) that reacts with ketones present in blood, releasing electrons. The meter applies a small electrical current to the test strip and measures changes in the current caused by the reaction of glucose or ketone in the blood sample to the enzyme in the test strip. The meter converts the measured current into blood glucose or ketone reading that is displayed on the meter's display. Both the glucose and ketone test strips are plasma calibrated.
### C Instrument Description Information:
1. Instrument Name: MultiSure GK Link Blood Glucose and Ketone Meter
2. Specimen Identification: There is no sample identification function with this device. Samples are applied directly to the test strip as they are collected.
3. Specimen Sampling and Handling: Samples are to be tested immediately upon collection.
4. Calibration: The meter does not require calibration or coding by the user. The meter is automatically coded.
5. Quality Control: The sponsor manufactures three (3) levels of Contrex Plus 4 Glucose Control Solutions and (2) levels of KET-1 ketone control solutions. Each test strip vial includes a control solution range for each level. The user is instructed to compare the control results with the expected control ranges printed on the strip vial. Users are given instructions on when to conduct control solution testing and to call customer service if repeat testing with control material is
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out of range. The user is instructed to switch the meter manually to control testing mode prior to the application of control solutions to allow for control solution results to be marked with "ctl" when stored in the meter's memory and not be included in the result averages.
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V Substantial Equivalence Information:
A Predicate Device Name(s):
Nova Max Plus Blood Glucose and B-ketone Monitor System
B Predicate 510(k) Number(s):
K091547
C Comparison with Predicate(s):
| Device & Predicate Device(s): | K201880 | K091547 |
| --- | --- | --- |
| Device Trade Name | MultiSure GK Link
Blood Glucose and
Ketone Monitoring System | Nova Max Plus Blood
Glucose and β-Ketone
Monitoring System |
| General Device Characteristic Similarities | | |
| Intended Use | Quantitatively measure blood glucose or blood ketone in fresh capillary whole blood drawn from fingertips. The system is intended for self-testing outside the body (in vitro diagnostic use) by people with diabetes mellitus at home as an aid in monitoring the effectiveness of diabetes control and should only be used by a single patient and it should not be shared. It is not intended for diagnosis or screening of diabetes or for neonatal use. | Same |
| Glucose measuring range | 20-600 mg/dL | Same |
| Ketone measuring range | 0.1 – 8.0 mmol/L | Same |
| Glucose Test Strips Active reagent: | glucose oxidase | Same |
| Ketone Test Strips Active reagent | β-hydroxybutyrate dehydrogenase | Same |
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| General Device Characteristic Differences | | |
| --- | --- | --- |
| Battery | 2 × CR2032, 3 volt coin cell battery | 3 volt coin cell battery CL2450 |
| Operation Condition | 10°C - 40°C (50-104°F), 20~90% RH | 14°C - 40°C
10~90% RH |
| Hematocrit Range | 20%-60% | 25%-60% |
| Sample size | 0.5 μL glucose
0.8 μL ketone | 0.3 μL glucose
0.8 μL ketone |
## VI Standards/Guidance Documents Referenced:
IEC 61010-1 Edition 3.1 2017-01 Safety requirements for electrical equipment for measurement, control, and laboratory use - Part 1: General requirements
IEC 60601-1-2 Edition 4.0 2014-02 Medical electrical equipment - Part 1-2: General requirements for basic safety and essential performance - Collateral Standard: Electromagnetic disturbances - Requirements and tests
CLSI EP05-A3 Evaluation of Precision of Quantitative Measurement Procedures; Approved Guideline - Third Edition
IEC 62304 Edition 1.1 2015-06 CONSOLIDATED VERSION Medical device software - Software life cycle processes
## VII Performance Characteristics (if/when applicable):
### A Analytical Performance:
1. Precision/Reproducibility:
**Glucose:**
A within-run precision study using 3 lots of MultiSure GK Blood Glucose test strip was performed. Venous blood was spiked to 5 concentrations (30-50, 51-110, 111-150, 151-250, 250-400 mg/dL). For each sample concentration, 10 meters were used, with 10 measurements taken by each meter (i.e., 100 measurements per concentration per lot). Results are summarized below:
**Glucose Within Run Precision**
| Venous Blood Glucose Level (mg/dL) | Lot | N | Mean (mg/dL) | SD (mg/dL) | CV |
| --- | --- | --- | --- | --- | --- |
| Level 1 (30-50) | Lot 1 | 100 | 45 | 1.8 | 4.1% |
| | Lot 2 | 100 | 45 | 2.0 | 4.5% |
| | Lot 3 | 100 | 45 | 2.0 | 4.5% |
| | Combined | 300 | 45 | 2.0 | 4.4% |
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| Venous Blood Glucose Level (mg/dL) | Lot | N | Mean (mg/dL) | SD (mg/dL) | CV |
| --- | --- | --- | --- | --- | --- |
| Level 2 (51-110) | Lot 1 | 100 | 89 | 2.3 | 2.6% |
| | Lot 2 | 100 | 90 | 2.4 | 2.6% |
| | Lot 3 | 100 | 89 | 2.4 | 2.6% |
| | Combined | 300 | 89 | 2.3 | 2.6% |
| Level 3 (111-150) | Lot 1 | 100 | 119 | 3.4 | 2.8% |
| | Lot 2 | 100 | 119 | 3.0 | 2.6% |
| | Lot 3 | 100 | 119 | 3.3 | 2.8% |
| | Combined | 300 | 119 | 3.2 | 2.7% |
| Level 4 (151-250) | Lot 1 | 100 | 220 | 4.8 | 2.2% |
| | Lot 2 | 100 | 221 | 4.8 | 2.2% |
| | Lot 3 | 100 | 220 | 4.7 | 2.1% |
| | Combined | 300 | 220 | 4.8 | 2.2% |
| Level 5 (251-400) | Lot 1 | 100 | 330 | 7.7 | 2.3% |
| | Lot 2 | 100 | 330 | 7.5 | 2.3% |
| | Lot 3 | 100 | 329 | 8.0 | 2.4% |
| | Combined | 300 | 329 | 7.7 | 2.3% |
Intermediate precision of the MultiSure GK Link Blood Glucose and Ketone Monitoring System was evaluated using 5 levels of glucose control solutions (30-50, 51-110, 111-150, 151-250, 251-400 mg/dL) using 3 lots of MultiSure GK Blood Glucose test strip was performed on five levels of control solutions. The tests were conducted with 10 meters, one measurement per meter per day at the five different glucose ranges, for ten days for a total of 300 glucose results per each glucose level. Results are summarized below:
| Glucose Control Levels (mg/dL) | Strip lot | N | Mean (mg/dL) | SD (mg/dL) | CV |
| --- | --- | --- | --- | --- | --- |
| L1 (30-50) | Lot 1 | 100 | 41 | 0.7 | 1.7% |
| | Lot 2 | 100 | 40 | 1.0 | 2.6% |
| | Lot 3 | 100 | 40 | 1.3 | 3.4% |
| | Combined | 300 | 40 | 1.1 | 2.8% |
| L2 (51-110) | Lot 1 | 100 | 70 | 0.5 | 0.7% |
| | Lot 2 | 100 | 70 | 0.7 | 1.0% |
| | Lot 3 | 100 | 68 | 0.7 | 1.1% |
| | Combined | 300 | 69 | 1.3 | 1.8% |
| L3 (111-150) | Lot 1 | 100 | 121 | 0.6 | 0.5% |
| | Lot 2 | 100 | 121 | 0.9 | 0.7% |
| | Lot 3 | 100 | 121 | 1.2 | 1.0% |
| | Combined | 300 | 121 | 0.9 | 0.7% |
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| Glucose Control Levels (mg/dL) | Strip lot | N | Mean (mg/dL) | SD (mg/dL) | CV |
| --- | --- | --- | --- | --- | --- |
| L4 (151-250) | Lot 1 | 100 | 221 | 1.4 | 0.7% |
| | Lot 2 | 100 | 221 | 1.5 | 0.7% |
| | Lot 3 | 100 | 223 | 1.7 | 0.8% |
| | Combined | 300 | 222 | 1.7 | 0.8% |
| L5 (251-400) | Lot 1 | 100 | 328 | 2.2 | 0.7% |
| | Lot 2 | 100 | 329 | 2.6 | 0.8% |
| | Lot 3 | 100 | 331 | 1.7 | 0.5% |
| | Combined | 300 | 329 | 2.4 | 0.7% |
## Ketone:
The sponsor performed a ketone repeatability (within-run) precision study using 3 lots of MultiSure GK Blood Ketone test strip. Venous blood samples that were spiked to 5 ketone concentrations (0.4-0.6, 1.5-2.5, 3.0-4.5, 5.0-6.5, 6.5-8.0 mmol/L) were used. For each sample concentration, 10 meters were used, with 10 measurements taken by each meter (i.e., 100 measurements per concentration per lot). Results are summarized below:
Ketone Within Run Precision
| Venous Blood Ketone Level (mmol/L) | Lot | N | Mean (mmol/L) | SD (mmol/L) | CV (%) |
| --- | --- | --- | --- | --- | --- |
| Level 1 (0.4-0.6) | Lot 1 | 100 | 0.5 | 0.06 | 11.6% |
| | Lot 2 | 100 | 0.5 | 0.06 | 10.5% |
| | Lot 3 | 100 | 0.5 | 0.05 | 10.2% |
| | Combined | 300 | 0.5 | 0.06 | 10.8% |
| Level 2 (1.5-2.5) | Lot 1 | 100 | 2.2 | 0.07 | 3.1% |
| | Lot 2 | 100 | 2.2 | 0.07 | 3.3% |
| | Lot 3 | 100 | 2.2 | 0.07 | 3.4% |
| | Combined | 300 | 2.2 | 0.07 | 3.2% |
| Level 3 (3.0-4.5) | Lot 1 | 100 | 4.0 | 0.14 | 3.5% |
| | Lot 2 | 100 | 4.0 | 0.13 | 3.4% |
| | Lot 3 | 100 | 4.0 | 0.14 | 3.6% |
| | Combined | 300 | 4.0 | 0.14 | 3.5% |
| Level 4 (5.0-6.5) | Lot 1 | 100 | 6.0 | 0.18 | 3.1% |
| | Lot 2 | 100 | 6.0 | 0.19 | 3.1% |
| | Lot 3 | 100 | 6.0 | 0.20 | 3.4% |
| | Combined | 300 | 6.0 | 0.19 | 3.2% |
| Level 5 (6.5-8.0) | Lot 1 | 100 | 7.1 | 0.20 | 2.8% |
| | Lot 2 | 100 | 7.1 | 0.18 | 2.5% |
| | Lot 3 | 100 | 7.1 | 0.18 | 2.6% |
| | Combined | 300 | 7.1 | 0.19 | 2.6% |
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Intermediate precision was performed using two levels of $\beta$-ketone control solutions (0.1-0.7 and 1.4-2.0 mmol/L). Testing was conducted over 10 days with three test strip lots and 10 meters. For each control solution 10 replicates were taken each day resulting in 100 individual measurements per level:
| Ketone Control Level (mmol/L) | Strip lot | N | Mean (mmol/L) | SD (mmol/L) | CV (%) |
| --- | --- | --- | --- | --- | --- |
| L1 (0.1-0.7) | Lot 1 | 100 | 0.4 | 0.02 | 4.7% |
| | Lot 2 | 100 | 0.4 | 0.02 | 4.2% |
| | Lot 3 | 100 | 0.4 | 0.02 | 5.6% |
| | Combined | 300 | 0.4 | 0.02 | 5.1% |
| L2 (1.4-2.0) | Lot 1 | 100 | 1.7 | 0.01 | 0.3% |
| | Lot 2 | 100 | 1.7 | 0.02 | 1.4% |
| | Lot 3 | 100 | 1.7 | 0.02 | 0.9% |
| | Combined | 300 | 1.7 | 0.05 | 3.1% |
## 2. Linearity:
Glucose linearity from 20 to $600\mathrm{mg / dL}$ was previously established in k141036.
The ketone linearity of MultiSure GK Link Blood Ketone Monitoring System was evaluated using venous whole blood spiked with $\beta$-hydroxybutyrate. Seven whole blood samples were adjusted to the following $\beta$-hydroxybutyrate concentrations: 0.06, 0.55, 2.11, 4.49, 6.12, 7.35, and $8.40\mathrm{mmol / L}$. The concentrations were assigned using the Beckman Coulter AU480 analyzer with STANBIO $\beta$-Hydroxybutyrate LiquiColor Test Kit.
The summary of the linear regression analysis for each lot was as follow:
| Lot # | Slop | y-intercept | R² value |
| --- | --- | --- | --- |
| Lot 1 | 0.9833 | 0.0542 | 0.9992 |
| Lot 2 | 0.9909 | 0.0357 | 0.9992 |
| Lot 3 | 0.9928 | 0.0298 | 0.9993 |
The results of the study support the sponsor's claimed (β-ketone) measuring range of 0.1-0.8 mmol/L.
Validation testing was performed demonstrating that the meter displays a flashing Ket icon and 'HI' when the ketone measurement result is greater than $8.0\mathrm{mmol / L}$ and a flashing Ket icon with "LO" when the ketone measurement result is less than $0.1\mathrm{mmol / L}$ as intended.
## 3. Analytical Specificity/Interference:
Glucose interference was previously established in k141036.
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To evaluate the effect of potential interfering exogenous and endogenous substances on the ketone measurement function, three venous whole blood samples with ketone concentrations of 0-0.8 mmol/L, 2.0-3.5 mmol/L and 5.0-7.0 mmol/L were used. Each sample was divided into a control sample (with no added interferent) and a test sample (with added potential interferent). The results from the test samples obtained using the candidate system were compared to the results obtained with the control samples using the candidate system. The sponsor defined no significant interference as bias within 0.3 mmol/L for β-ketone < 1.5 mmol/L and ≤ 20% for β-ketone ≥ 1.5 mmol/L. The following table lists the highest tested concentration of each substance at which no significant interference was detected.
| Substance | Highest concentration at which no significant interference is observed (mg/dL) |
| --- | --- |
| Acetaminophen | 20 |
| Acetone | 10 |
| Acetoacetate | 10 |
| Ascorbic acid | 4 |
| Bilirubin | 10 |
| Captopril | 10 |
| Cholesterol | 500 |
| Creatinine | 6 |
| Dopamine | 2 |
| Glucose | 900 |
| Ibuprofen | 50 |
| L-DOPA | 3 |
| Methyl-Dopa | 7.5 |
| N-acetylcysteine | 10 |
| Tetracycline | 10 |
| Tolazamide | 15 |
| Triglyceride | 750 |
| Uric acid | 20 |
| Salicylate | 60 |
| Tolbutamide | 100 |
The sponsor includes the following glucose limitations in the labeling for the MultiSure GK Link Blood Glucose and Ketone Monitoring System:
- If you are taking acetaminophen or acetaminophen containing drugs (for example Tylenol; at blood concentrations > 10 mg/dL) you may get inaccurate results with this system.
- If you are taking Tolbutamide at blood concentrations > 15 mg/dL, you may get inaccurate results with this system.
- If you are taking Ibuprofen or Ibuprofen containing drugs as Advil at blood concentrations > 40 mg/dL, you may get inaccurate results with this system.
- If you are taking Paralidoxime Iodide (PAM) or Paralidoxime Iodide (PAM) containing drugs at blood concentrations > 50 mg/dL, you may get inaccurate results with this system.
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- If you have a disease or condition in which uric acid levels in your blood may be elevated (>15 mg/dL), such as gout, you may get inaccurate results with this system.
- Do not use during or soon after xylose absorption testing since xylose may cause inaccurate glucose results. Ask your doctor how long to wait before performing a glucose test.
4. Assay Reportable Range:
20 - 600 mg/dL for glucose
0.1 - 8.0 mmol/L for ketone
5. Traceability, Stability, Expected Values (Controls, Calibrators, or Methods):
Traceability
The system reports plasma-equivalent glucose values and is calibrated by using the YSI 2300 STAT PLUS Glucose Analyzer, which is traceable the NIST SRM 917b glucose reference material.
The system reports plasma-equivalent ketone values and is calibrated by using STANBIO β-Hydroxybutyrate LiquiColor Test Kit and STANBIO β-Hydroxybutyrate Linearity Standard on the Beckman Coulter AU480 analyzer.
Test Strip Stability
Both the MultiSure GK Blood Glucose Test Strips and the MultiSure GK Ketone Glucose Test Strips are provided packaged in vials and as individually wrapped single strips.
Shelf-life and open vial stability for the MultiSure GK Blood Glucose Test Strips were previously evaluated in k141036 to support the claimed shelf life of 24 months when stored under conditions of 39-86°F and a relative humidity of 10-85% and a 6 month open vial claim when stored under these same conditions.
Shelf-life for the individually wrapped MultiSure GK Blood Glucose Test Strips was assessed with real-time testing. The study protocols and acceptance criteria were reviewed and found acceptable to support the sponsor's claimed shelf-life stability of 24 months when stored at recommended storage conditions of 39-86°F (10-30°C) and 10-85% relative humidity.
Shelf-life and open vial stability for the MultiSure GK Ketone Test Strips were evaluated using real-time testing. Study protocols and acceptance criteria were reviewed and found acceptable to support the sponsor's claimed shelf life of 18 months when stored at the recommended storage conditions of 39-86°F (10-30°C) and 10-85% relative humidity and an open vial stability of 3 months when stored under these same conditions.
Shelf-life for the individually wrapped MultiSure GK Ketone Test Strips was previously evaluated in k182593 to support the claimed shelf life of 18 months when stored under conditions of 39-86°F and a relative humidity of 10-85%.
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6. Detection Limit:
See VII.A.2 above.
7. Assay Cut-Off:
Not applicable.
8. Accuracy (Instrument):
Not applicable.
9. Carry-Over:
Not applicable. The device uses single-use strips.
## B Comparison Studies:
1. Method Comparison with Predicate Device:
See the lay-use studies below, section VII.C.3, for glucose and ketone accuracy performance in the hands of the intended user.
**Ketone Method Comparison:**
To assess ketone measurement system accuracy performance, results from the MultiSure GK Link Blood Glucose and Ketone Monitoring System obtained in the hands of trained professionals were compared to the comparator method, STANBIO β-Hydroxybutyrate LiquiColor Test Kit tested with Beckman Coulter AU480 Analyzer. A total of one hundred (100) capillary whole blood samples, ranging in ketone concentrations of 0.04 -7.99 mmol/L, were tested using three ketone test strip lots. To obtain blood samples with β-ketone values at the higher end of the claimed ketone measurement range, capillary blood samples were spiked with β-ketone. The results relative to the comparator method are summarized below:
| System Accuracy Results for Ketone concentration <1.5 mmol/L | | |
| --- | --- | --- |
| Within ± 0.15 mmol/L | Within ± 0.225 mmol/L | Within ± 0.30 mmol/L |
| 32/34 (94.1%) | 34/34 (100%) | 34/34 (100%) |
| System Accuracy Results for Ketone concentration ≥1.5 mmol/L | | |
| --- | --- | --- |
| Within ± 10% | Within ± 15% | Within ± 20% |
| 64/66 (97.0%) | 66/66 (100%) | 66/66 (100%) |
Linear regression analysis: $y = 0.9886x + 0.049$ , $R^2 = 0.9967$
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2. Matrix Comparison:
Not applicable. The device is only intended for use with fresh capillary whole blood from a fingerstick.
C Clinical Studies:
1. Clinical Sensitivity:
Not Applicable.
2. Clinical Specificity:
Not Applicable.
3. Other Clinical Supportive Data (When 1. and 2. Are Not Applicable):
To assess the glucose accuracy performance of the combined MultiSure GK Link Blood Glucose and Ketone Monitoring System in the hands of the intended user the sponsor performed studies where lay users obtained their own glucose and ketone results.
Glucose:
A total of 350 lay-user participants obtained their own fingerstick samples and glucose results using only the system components and instructions provided in the labeling. Three glucose test strip lots were used for the study. The glucose concentrations of the participant samples ranged from 65 to 500 mg/dL as measured by the comparator method (YSI 2300 analyzer). Glucose results obtained by the participants using the candidate device were compared to results obtained using the comparator method and are summarized in the tables below:
| For glucose concentration <75 mg/dL | | | |
| --- | --- | --- | --- |
| within ± 5 mg/dL | within ± 10 mg/dL | within ± 15 mg/dL | within ± 20 mg/dL |
| 9/12 (75%) | 12/12 (100%) | 12/12 (100%) | 12/12 (100%) |
| For glucose concentration ≥75 mg/dL | | | |
| --- | --- | --- | --- |
| within ± 5 % | within ± 10% | within ± 15% | within ± 20% |
| 147/338 (44.6%) | 307/338 (91.1%) | 338/338 (100%) | 338/338 (100%) |
| For combined glucose concentrations | | | |
| --- | --- | --- | --- |
| Within ± 5 % | Within ± 10 % | Within ± 15 % | Within ± 20 % |
| 153 / 350 (43.7%) | 317 / 350 (90.6%) | 350 / 350 (100%) | 350 / 350 (100%) |
Linear regression analysis: $y = 0.9955x + 1.8314$ , $R^2 = 0.9716$
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Extreme Glucose Study:
An additional study was conducted to evaluate the glucose accuracy performance of MultiSure GK Link Blood Glucose and Ketone Monitoring System in the extreme lower and upper ends of the claimed measuring range using 100 altered capillary fingerstick samples and 3 test strip lots. Fifty (50) samples were glycolyzed to achieve samples with glucose concentrations less than 80 mg/dL (21-79 mg/dL) and 50 samples are spiked to achieve concentrations greater than 250 mg/dL (260 -593 mg/dL). Results from the candidate device were compared to results obtained using the comparator method (YSI 2300 analyzer) and are summarized in the tables below:
| For glucose concentration <80 mg/dL | | | |
| --- | --- | --- | --- |
| Within ± 5 % | Within ± 10 % | Within ± 15 % | Within ± 20 % |
| 18/50 (36%) | 40/50 (80%) | 50/50 (100%) | 50/50 (100%) |
| For glucose concentration >250 mg/dL | | | |
| Within ± 5 % | Within ± 10 % | Within ± 15 % | Within ± 20 % |
| 34/50 (68%) | 42/50 (84%) | 50/50 (100%) | 50/50 (100%) |
Ketone:
A total of 100 lay user participants obtained their own fingerstick samples and ketone results using only the system components and instructions provided in the labeling. The ketone concentrations in the participant samples ranged from 0.05-2.65 mmol/L as measured by the comparator method (STANBIO β-Hydroxybutyrate LiquiColor Test Kit tested with Beckman Coulter AU480 Analyzer). Ketone results obtained by the participants using the candidate device were compared to results obtained using the comparator method and are summarized in the tables below:
| System Accuracy Results for Ketone Concentration <1.5 mmol/L | | |
| --- | --- | --- |
| Within ± 0.15 mmol/L | Within ± 0.225 mmol/L | Within ± 0.30 mmol/L |
| 76/90 (84.4%) | 87/90 (96.7%) | 90/90 (100%) |
| System Accuracy Results for Ketone concentration ≥1.5 mmol/L | | |
| --- | --- | --- |
| Within ± 10% | Within ± 15% | Within ± 20% |
| 8/10 (80%) | 9/10 (90%) | 10/10 (100%) |
Linear regression analysis: $y = 0.977x + 0.0347$ ; $R^2 = 0.998$
Usability Assessment:
The usability of the system was assessed by questionnaires given to the operators of the system following the conclusion of the glucose and ketone lay user studies where the participants read the labeling documents without any assistance or guidance. The study participants then independently completed meter setup, performed glucose/ketone measurement using blood/control and retrieved/marked the test results in the same way as
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home users. The study participants were asked to complete a usability questionnaire regarding ease of understanding of information in the user manual and the ease of use when performing a blood ketone test. The study demonstrated that users of the device were able to understand and follow the instructions provided in the labeling to perform tasks involved in blood glucose/ketone testing.
**Readability:**
The MultiSure GK Link Blood Glucose and Ketone Monitoring System user manual and the MultiSure GK blood glucose and ketone test strips were assessed for readability using the Flesch-Kincaid assessment demonstrating that the labeling was written at an 8th grade reading level or less.
**D Clinical Cut-Off:**
Not Applicable.
**E Expected Values/Reference Range:**
The sponsors included the following in the labeling:
**Glucose**
The ideal ranges for adults without diabetes are:
- Under 100 mg/dL before meals.
- Under 140 mg/dL after meals.
American Diabetes Association, Standard of Medical Care in Diabetes 2020, Vol. 43 (Suppl. 1).
**Ketone**
Based on published literature, the sponsor included < 0.6 mmol/L as the expected value for ketones and cites the following reference:
Tietz NW. Clinical Guide to Laboratory Tests. 3rd ed. Philadelphia, PA: WB Saunders Company; 4th Edition.
**F Other Supportive Instrument Performance Characteristics Data:**
**Hematocrit:**
Previously established in k141036 and k182593 to support the claimed hematocrit range of 20-60% for glucose and ketone testing, respectively
**Altitude:**
Previously established in k141036 and k182593 to support the use of the device up to 10,335 ft. (3150 meters) for glucose and ketone testing, respectively.
**Operating Conditions:**
The sponsor performed operating condition studies to evaluate the operating temperature
K201880 - Page 14 of 15
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and relative humidity (RH) ranges of the new combination system. The results support the claimed operating condition range of 10°C~40°C (50 °F to 104°F) and 20~90% relative humidity for both glucose and ketone functionalities.
## Sample Volume:
Established in k141036 and k182593 to support a 0.5 μL sample volume for glucose and 0.8 μL sample volume for ketone.
## Infection Control:
The device system is intended for single patient use only. Disinfection efficacy studies were performed previously in k131750 on the materials comprising the meter by an outside commercial testing lab demonstrating complete inactivation of hepatitis B virus (HBV) with the chosen disinfectant, Clorox Healthcare Bleach Germicidal Wipes (EPA Registration # 67619-12). Robustness studies were also performed by the sponsor demonstrating that there was no change in ketone or glucose performance or external materials of the meter after 260 cleanings and disinfection steps with the Clorox Healthcare Bleach Germicidal wipes. The robustness studies were designed to simulate 5 years of single-patient use. Labeling was reviewed for adequate instructions for the validated cleaning and disinfection procedures.
## Flex Studies:
Studies were performed to assess the effect of the following on both the glucose and ketone measurement functions of the candidate system: used test strip insertion, test strip removal during measurement countdown, intermittent sampling, sample perturbation, and dropping. The testing demonstrated that the MultiSure GK Link Blood Glucose and Ketone Monitoring System is robust to these use scenarios and that either an error message is returned, or an accurate result is displayed.
## EMC:
EMC testing was certified and compliance certificates provided documenting that acceptable electromagnetic testing (EMC) had been performed.
## Glucose Test Strip Lot Release Protocol:
Glucose test strip lot release protocols and criteria were reviewed and found to be acceptable.
## VIII Proposed Labeling:
The labeling supports the finding of substantial equivalence for this device.
## IX Conclusion:
The submitted information in this premarket notification is complete and supports a substantial equivalence decision.
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Learn the FDA Browser
Two short videos show you everything — or skip straight to the written tutorial if you'd rather read. You can reopen this any time from the Tutorial button in the top bar.
Part 1 — Search, results, and everyday workflows 16 min
Part 2 — Embeddings: the galaxy map 3 min
1. Search: exact and fuzzy
Type a phrase like "coronary artery calcification" into the search box. You get two kinds of results. Exact results match the literal phrase — prefix searches work ("coronary artery calcificati") but suffix searches do not. Fuzzy results match on the meaning and intent of your phrase rather than the exact words, and are sorted by relevance score. Hover over the Exact or Fuzzy badge on any row to see exactly why it matched.
Use the checkboxes above the results to narrow: SaMD keeps only software-only devices, AI / ML keeps only devices with AI.
Exact vs. fuzzy search: what's the difference?
Exact matches on the literal phrase (prefix search works, suffix does not). Fuzzy matches on the meaning and intent of the phrase rather than the exact words. Hover over the badge on any row to see why it matched.
You search "coronary artery calcification" and want only software devices with AI. What two filters do you apply?
Narrow by SaMD (software-only devices), then narrow by AI/ML (devices with AI).
2. The results table
Scroll right in the results table. The intended use is extracted for you — no need to open the PDF. The device story gives a high-level snapshot of what the device does and how it's used. The AI Performance sub-table shows each output name, acceptance criteria, observed values, and development/test dataset descriptions — the same format Innolitics uses for regulatory strategy outputs, and the fastest high-level fingerprint of an AI device. It is AI-generated but has been very reliable in practice.
Where do you find a device's intended use without opening the PDF?
Scroll right in the search results table. The intended use column is extracted for you; no need to dig into the 510(k) summary PDF.
What does the AI Performance sub-table show, and why is it useful?
Output name, acceptance criteria, observed values, development dataset description, and test dataset description. It's the same format we use for regulatory strategy output and Fast 510(k) input, and the fastest high-level fingerprint of an AI device. AI-generated but reliable in practice.
3. Judging fuzzy relevance
Fuzzy results trail off in relevance as you scroll. Use three signals to decide how far down to go: the fuzzy badge explanations, the intended use column, and whether your target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, you're past the relevant zone. A top hit with a low score (~0.4) and a stretched explanation is a hint the closest predicates are far away — the project may be headed for De Novo. Note the fuzzy search is a pattern match: it doesn't handle negation ("not") well, and hardware devices can appear — filter by SaMD/AI ML to cut them.
How do you judge how far down fuzzy search results to go?
Use the relevancy signals: the fuzzy badge explanations, the intended use column, and whether the target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, results are trailing off in relevancy.
4. Device detail page: chat and citations
Click a device name to open its detail page: device facts on the left, a chat window on the right. Ask something like "Describe the training data". The answer carries little citation bubbles — click one to jump to the highlighted passage in the source PDF, so you can verify every AI answer against the document. There's also a Download PDF button for sharing.
How do you verify an AI chat answer on the device detail page?
Click the citation bubbles to jump to the relevant highlight in the source document.
Reading rule for every project: how many summaries do you read in full?
At least the three most relevant 510(k) or De Novo summaries, in full. After that, use targeted chat questions to confirm your memory quickly. The tool supports this professional habit — it doesn't replace it.
5. Side-by-side comparison
Select multiple rows in the results table (aim for under ~10), then open the PDF Viewer tab. Ask one question — it goes to all selected devices in parallel, each with citations. This is the fastest way to compare and contrast devices: training data, PCCP scope, how they handled adding new scanners, and so on.
What does the side-by-side PDF viewer mode do?
Select multiple devices, open the PDF viewer tab, and ask one question (e.g., "Describe the training data"). It queries all selected devices simultaneously with citations, so you can compare and contrast quickly.
6. Collections
With rows selected, go to the Collections tab and create a labeled collection (e.g., "Cobb Angle Project"). Reload that selection any time — before a client call, pull up the collection and ask questions across all of its devices at once.
How do you save a set of selected devices for later use?
Select the rows, go to the Collections tab, and create a labeled collection (e.g., "Cobb Angle Project"). You can reload the selection anytime and carry it into the PDF viewer and other tabs that support selections.
7. Product codes and the regulations tree
Click a product code in the results to jump to it in the regulations tree — identification text, sibling product codes, and devices you can open in a PDF viewer on the right. Click a regulation number to see its identification, special controls, and related product codes. You can also search by product code or regulation number at the top of the tree. Always read the special controls if any exist for your device — it broadens your search and sharpens pre-kickoff research.
What can you do from the regulations tree view?
Browse product codes and regulation numbers, read the identification text and special controls, browse sibling product codes, open device PDFs on the right, and search by product code or regulation number at the top of the tree.
8. Chart view
Click Show Chart and segment by regulation number (or product code) to see which regulations dominate your result set. Clicking a regulation takes you into the regulations tree. Great for spotting that most matches are, say, hardware laparoscopic devices — a cue to go back and filter.
How do you see which regulations dominate a search result set?
Click "Show Chart" and segment by Regulation Number. Clicking a regulation takes you to the regulations tree.
9. The predicate graph
Open the Predicates tab for a family-tree view of predicate relationships. Click a node to trace its parents and children; selections from search carry over pre-selected. Commonly predicated devices are worth reading — a lot of people predicated them for a reason. The visual lineage is also handy on client calls, e.g. to show how a predicate family evolved and justify why your predicate still holds.
In the predicate graph, why are commonly predicated devices worth reading?
A lot of people predicated them for a reason. Clicking a node traces parents and children, and selections from search carry over pre-selected.
10. Embeddings: the galaxy map
The Embeddings tab plots every matching document in a 2-D "galaxy map" where semantically similar devices cluster together. Hover or click clusters to explore, and let AI label the clusters for you. Embeddings beat product codes for grouping: two devices can carry different product codes (LLZ vs. QIH) yet do the same thing — the embedding captures the meaning of the intended use and device story. This is also exactly how retrieval-augmented generation (RAG) works under the hood, and it makes a great visual on client calls.
Try it yourself
Head to the search page and work through a few of these AI/ML fuzzy searches to build intuition: perivascular fat on CT · aortic valve calcification opportunistic screening on noncontrast CT · breast cancer prediction on digital pathology slides · autism detection · gestational age prediction · a hearing aid that can also detect a pulse · foundation model based analysis of ECG · large language models · penetration test. Watch how the relevance scores, intended use, and AI Performance tables tell you when results stop being meaningful.