The i-STAT Alinity System with i-STAT Sodium test is intended for use or clinical laboratory settings. The i-STAT Alinity System with Sodium test is intended for the quantitative measurement of sodium in arterial and venous whole blood.

Sodium measurements are used for monitoring electrolyte imbalances.

For in vitro diagnostic use.

Device Description

The i-STAT Alinity System is a handheld, in vitro diagnostic analytical device designed to run i-STAT test cartridges. The system is designed for use at or near point of patient care, by trained medical professionals and is for prescription use only and is for use in point of care and laboratory settings.

The i-STAT Alinity System is comprised of the instrument, rechargeable battery, base station, electronic simulator, control material, printer and i-STAT test cartridges. The i-STAT Alinity Instrument features a barcode scanner, user interface with touch screen display and wireless capability. The instrument reports quantitative results within approximately 2 minutes.

The i-STAT cartridge contains test reagents which are located on the biosensors chips. The instrument interacts with the cartridge to move fluid across the biosensors and generate a quantitative result. Cartridges require two to three drops of whole blood which are typically applied to the cartridge using a syringe.

AI/ML Overview

Here's an analysis of the provided text regarding the acceptance criteria and study for the i-STAT Alinity System with i-STAT Sodium test:

1. Table of Acceptance Criteria and Reported Device Performance

The document doesn't explicitly state formal "acceptance criteria" for each performance characteristic in a table format. However, the performance studies report findings that implicitly serve as evidence that the device meets certain quality standards. I will infer the implied acceptance criteria based on the reported results and common professional standards for in vitro diagnostic devices.

Performance Characteristic	Implied Acceptance Criteria (Inferred from Study Design/Common Standards)	Reported Device Performance	Meets Criteria?
Precision (Aqueous Materials)	Within-run, between-run, and total precision (SD/%CV) should be minimal and acceptable for clinical use.	Max Total SD: 0.96 mmol/L; Max Total %CV: 0.60% (CV L4)	Yes (suggests good precision)
Precision (Whole Blood)	Within-instrument and total precision (SD/%CV) should be minimal and acceptable for clinical use across different concentration levels and sites.	Largest estimate of precision: 0.50 mmol/L (SD) / 0.43% (CV)	Yes (suggests good precision)
Linearity	Device should show linearity (or acceptable non-linearity) across the reportable range.	Non-linearity ranged from -0.40 to 0.66 mmol/L over reportable range (100 - 180 mmol/L). A second-order model was the best fit.	Yes (demonstrated linearity over the range)
Recovery	% Recovery should be close to 100%.	Ranged from 99.9% to 100.6%.	Yes (excellent recovery)
Limit of Quantitation (LoQ)	LoQ should be clinically relevant and accurately determined.	Determined to be 80 mmol/L.	Yes (a specific LoQ was established)
Interference	Minimal or no interference from common endogenous and exogenous substances; interfering substances should be identified.	Table 3 lists 18 non-interfering compounds at specified concentrations. Table 4 identifies Bromide (>16.65 mmol/L) and Sodium Thiosulfate (>3.57 mmol/L) as interfering, with quantitative effects.	Yes (interfering substances were identified and quantified)
Anticoagulant Study	Performance should be comparable between different sample types (e.g., heparinized vs. non-anticoagulated whole blood).	Deming regression: slope of 1.00, correlation coefficient of 1.00 (between heparinized and non-anticoagulated whole blood).	Yes (performance is comparable)
Method Comparison with Predicate Device	Performance should be substantially equivalent to the predicate device.	Weighted Deming regression: slope of 1.0, correlation coefficient of 0.999.	Yes (demonstrates substantial equivalence)

2. Sample Size Used for the Test Set and Data Provenance

Precision (Aqueous Materials): 80 tests per level (N=80) for 5 levels.
Precision (Whole Blood): 21 test results per sample for each of the 3 samples (total 63 tests per site, across 3 sites). The document refers to "venous whole blood (native or altered) samples."
Linearity: Not explicitly stated, but "a series of sodium concentration levels in whole blood."
Recovery: "a series of sodium concentration levels in whole blood."
Limit of Quantitation (LoQ): Not explicitly stated, but "whole blood that was altered to low sodium concentrations (< 100 mmol/L)."
Interference: "whole blood and plasma test samples"
Anticoagulant Study: 40 blood samples.
Method Comparison with Predicate Device: 174 subjects using whole blood (venous or arterial) samples.
Data Provenance: The studies are described as being conducted at "one site" for aqueous precision, "3 point of care sites" for whole blood precision, and "4 point of care sites" for the method comparison. The nature of these sites (e.g., hospitals, clinics) and their geographical location (e.g., country of origin) are not specified. The data is prospective as it involves testing the device under specific experimental conditions.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and the Qualifications of Those Experts

There is no mention of human experts being used to establish a "ground truth" for the test set in the traditional sense of diagnostic imaging or clinical subjective assessment. For this type of in vitro diagnostic device (quantitative measurement of sodium), the "ground truth" is typically established by:

Reference Methods: Highly accurate and precise laboratory methods (e.g., flame photometry, ion-selective electrodes on validated lab analyzers).
Predicate Device: For method comparison studies, the performance of an already legally marketed device (the i-STAT 1 Wireless Analyzer in this case) serves as the comparator or "reference."

Therefore, the concept of "number of experts" and their "qualifications" for establishing ground truth as one might find in an AI imaging study is not applicable here.

4. Adjudication Method for the Test Set

Adjudication methods (like 2+1, 3+1) are typically used in studies where there is subjective interpretation by multiple human readers (e.g., radiologists reviewing images). Since this is an in vitro diagnostic device for quantitative chemical analysis, there is no subjective human interpretation that would require an adjudication method. The output is a numerical value.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance

No. An MRMC comparative effectiveness study is designed for scenarios involving human readers (e.g., clinicians, radiologists) interpreting cases, often with and without AI assistance, to assess the impact of AI on their performance. This device is an automated, standalone in vitro diagnostic system that provides quantitative measurements of sodium. It does not involve human "readers" interpreting output in a way that an MRMC study would be applicable, nor does it involve "AI assistance" for human interpretation.

6. If a Standalone (i.e. algorithm only without human-in-the loop performance) was done

Yes, the studies described are all standalone performance evaluations of the i-STAT Alinity System. The device itself (instrument and cartridge) performs the measurement and generates a numerical result. The studies assess the analytical performance of this system without requiring human interpretation as part of the primary measurement process. The only "human" involvement is in operating the device and collecting samples, but not in interpreting a diagnostic output in a subjective manner.

7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)

For the quantitative measurement of sodium, the ground truth is established through:

Reference Methods / Known Concentrations: For precision, linearity, recovery, LoQ, and interference studies, the "ground truth" often involves materials (aqueous or whole blood) with known or precisely measured sodium concentrations using a highly accurate reference method.
Predicate Device Performance: For the method comparison study, the "ground truth" (or more accurately, the comparator) is the result obtained from the legally marketed predicate device (i-STAT 1 Wireless Analyzer). The goal is to show substantial equivalence, not necessarily absolute truth against a gold standard reference method for every sample, though the predicate itself would have been validated against such methods.

8. The Sample Size for the Training Set

The document describes performance evaluation studies for the finished device. It does not provide information on the sample size used for training or developing the algorithms within the i-STAT Alinity System. This kind of information is typically considered proprietary and not usually disclosed in a 510(k) summary, which focuses on validation of the final product.

9. How the Ground Truth for the Training Set was Established

Similar to point 8, the document does not provide information on how the ground truth for any potential training set was established, as it focuses on the validation of the final device's performance rather than its development. Any algorithms or internal calibration look-up tables in such a device would have been developed using internally generated data, with ground truth established through various analytical chemistry methods and potentially large datasets, but these details are not provided here.

Summary

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Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002

ABBOTT POINT OF CARE INC. MELISSA ROBINSON ASSOCIATE DIRECTOR REGULATORY AFFAIRS 400 COLLEGE ROAD EAST PRINCETON NJ 08540

July 8, 2016

Re: K153357

Trade/Device Name: i-STAT Alinity System with i-STAT Sodium test Regulation Number: 21 CFR 862.1665 Regulation Name: Sodium test system Regulatory Class: II Product Code: JGS Dated: June 27, 2016 Received: June 28, 2016

Dear Melissa Robinson:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Parts 801 and 809); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (OS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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If you desire specific advice for your device on our labeling regulations (21 CFR Parts 801 and 809), please contact the Division of Industry and Consumer Education at its toll-free number (800) 638 2041 or (301) 796-7100 or at its Internet address

http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to

http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.

You may obtain other general information on your responsibilities under the Act from the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address

http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm.

Sincerely yours,

Katherine Serrano -S

For : Courtney H. Lias, Ph.D. Director Division of Chemistry and Toxicology Devices Office of In Vitro Diagnostics and Radiological Health Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known) K153357

Device Name

i-STAT Alinity System with i-STAT Sodium test

Indications for Use (Describe)

Sodium measurements are used for monitoring electrolyte imbalances.

For in vitro diagnostic use.

Type of Use (Select one or both, as applicable)
☑ Prescription Use (Part 21 CFR 801 Subpart D) ☐ Over-The-Counter Use (21 CFR 801 Subpart C)	☑ Prescription Use (Part 21 CFR 801 Subpart D)	☐ Over-The-Counter Use (21 CFR 801 Subpart C)
☑ Prescription Use (Part 21 CFR 801 Subpart D)
☐ Over-The-Counter Use (21 CFR 801 Subpart C)

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510(k) Summary

The information in this 510(k) summary is being submitted in accordance with the requirements of 21CFR 807.92.

1.	Submitter InformationOwner	Abbott Point of Care Inc.400 College Road EastPrinceton, NJ 08540
	Contact	Primary: Melissa RobinsonAssociate Director Regulatory Affairsmelissa.robinson@abbott.comPhone: 609-454-9371
		Secondary: Susan TibedoDirector Regulatory Affairssusan.tibedo@abbott.comPhone: 609-454-9360
	Date Prepared	July 06, 2016
2.	Device InformationProprietary NameCommon NameRegulation NumberClassification CodeDevice Classification Name	i-STAT® Alinity System with i-STAT Sodium testi-STAT Alinity Instrument, i-STAT Alinity and handheld862.1665 (Class II)JGSElectrode, Ion Specific, Sodium
3.	Predicate DeviceProprietary NameCommon Name510(k) NumberRegulation NumberClassification CodeDevice Classification Name	i-STAT® 1 Wireless Analyzeri-STAT 1 Analyzer, i-STAT Analyzer and handheldK103195862.1665 (Class II)JGSElectrode, Ion Specific, Sodium

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4. Device Description

5. Intended Use Statement

The i-STAT Alinity System with i-STAT Sodium test is intended for use in point of care or clinical laboratory settings. The i-STAT Alinity System with Sodium test is intended for the quantitative measurement of sodium in arterial and venous whole blood. Sodium measurements are used for monitoring electrolyte imbalances. For in vitro diagnostic use.

Characteristics	Predicate Device(K103195)	Candidate Devicei-STAT Alinity system
Intended Use	The i-STAT 1 WirelessAnalyzer is used by trainedmedical professionals forrunning a variety ofclinical chemistry tests andtest panels contained ini-STAT test cartridges.The test for sodium, as partof the i-STAT System is	The i-STAT AlinityInstrument is intended to beused by trained medicalprofessionals for a variety ofin vitro diagnostic tests andtest panels using i-STAT testcartridges.The test for sodium, as partof the i-STAT System is
Characteristics	Predicate Device(K103195)	Candidate Devicei-STAT Alinity system
	intended for use in the invitro quantification ofsodium in arterial, venousor capillary whole blood.	intended for use in the invitro quantification ofsodium in arterial or venouswhole blood.
	Sodium measurements areused for monitoringelectrolyte imbalances	Sodium measurements areused for monitoringelectrolyte imbalances
Sample Type	Fresh arterial, venous orcapillary whole blood.	Fresh arterial or venouswhole blood.
Power	Two 9-volt lithiumbatteries, or rechargeablebattery.	Lithium-Ion rechargeablebattery
Principle ofMeasurement	Sodium: Ion selectiveelectrode	Same
Reagent Format	Cartridge	Same
Reagent Storage andStability	Storage: 2°C to 8°C (35-46°F)	Same
Quality Checks	A series of quality checksare automatically run eachtest cycle prior to thesystem generating a result.Quality checks verify theanalyzer motor, electrical,pressure and temperaturesystems and cartridgeelements.	Same
Data Storage	1,000 patient records	500 patient records
Connectivity	TCP/IP802.11 (WiFi) b/g	TCP/IP802.11 a/b/g/n
Barcode Technology	Class II laser bar codescanner	Imager that reads 1-D and2-D barcodes
User Interface	19 keys for data entry	LCD touch screen
User InterfaceScreen	A grey scale LCD (3.5 in.)	A color LCD screen (5 in.)

6. Summary Comparision of Technological Characteristics

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7. Performance Characteristics

Analytical Performance

a. Precision

Precision 20 days (aqueous materials)

The precision of the i-STAT Sodium Test on the i-STAT Alinity Instrument was evaluated using 5 levels of aqueous materials. This 20-day multi-day precision testing was was based on CLSI document EP05-A3: Evaluation of Precision of Quantitative Measurement Procedures; Approved Guideline-Third Edition. The study was conducted using 10 instruments and one cartridge lot over 20 days at one site. The results of the 20-day precision study using the initial runs (including any outlying runs) are shown in Table 1.

CalibrationVerificationMaterial Level	N	Mean(mmol/L)	ST(mmol/L)	CVT(%)	Sr(mmol/L)	CVr(%)	Srr(mmol/L)	CVrr(%)	Sdd(mmol/L)	CVdd(%)
CV L1	80	99.6	0.43	0.43	0.36	0.36	0.22	0.22	0.00	0.00
CV L2	80	121.2	0.32	0.27	0.31	0.26	0.02	0.017	0.09	0.074
CV L3	80	133.7	0.34	0.26	0.29	0.22	0.17	0.13	0.00	0.00
CV L4	80	160.9	0.96	0.60	0.96	0.60	0.00	0.00	0.00	0.00
CV L5	80	180.2	0.56	0.31	0.38	0.21	0.42	0.23	0.00	0.00

Table 1: 20-day Precision Study Results (including outlying runs)

Precision (whole blood)

The whole blood precision of the i-STAT Sodium Test on the i-STAT Alinity Instrument was evaluated using venous whole blood (native or altered) samples targeted to be within a low abnormal, normal and high abnormal sodium levels.

One cartridge lot was used across 3 point of care sites. At each site, each sample was tested 3 times on each of 7 i-STAT Alinity Instruments (total of 21 test results per sample). The largest estimate of precision was 0.50 mmol/L as shown in Table 2.

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ConcentrationLevel	Site	N	Mean(mmol/L)	Within-Instrument		Total
				SD	%CV	SD	%CV
<138 mmol/L(abnormal low)	1	21	114.6	0.50	0.43	0.50	0.43
<138 mmol/L(abnormal low)	2	21	115.0	0.38	0.33	0.38	0.33
<138 mmol/L(abnormal low)	3	21	114.2	0.44	0.38	0.44	0.38
138 to 146 mmol/L(normal)	1	21	140.0	0.00	0.00	0.00	0.00
138 to 146 mmol/L(normal)	2	21	139.8	0.31	0.22	0.45	0.32
138 to 146 mmol/L(normal)	3	21	141.6	0.49	0.34	0.51	0.36
>146 mmol/L(abnormal high)	1	21	156.0	0.38	0.24	0.38	0.25
>146 mmol/L(abnormal high)	2	21	155.1	0.36	0.23	0.36	0.23
>146 mmol/L(abnormal high)	3	21	165.9	0.30	0.18	0.30	0.18

Table 2: Whole Blood Precision Results

b. Linearity

The study was designed based on CLSI EP06-A: Evaluation of the Linearity of Quantitative Measurement Procedures. The linearity of the i-STAT Sodium Test was evaluated on the i-STAT Alinity Instruments by preparing a series of sodium concentration levels in whole blood that spanned the reportable range of the test. The best fitting regression model was a second order model, and the non-linearity ranged from -0.40 to 0.66 mmol/L. The linearity of the i-STAT Sodium Testused with the i-STAT Alinity Instruments was demonstrated over the reportable range (100 - 180 mmol/L).

c. Recovery

The recovery of the i-STAT Sodium test was evaluated on the i-STAT Alinity Instrument by creating a series of sodium concentration levels in whole blood, measuring their expected value on the predicate and determining the recovery bias and % recovery. The % recovery ranged from 99.9% to 100.6%.

d. Limit of Quantitation (LoQ)

The study was based on the CLSI EP17-A2: Evaluation of Detection Capability for Clinical Laboratory Measurement Procedures. The LoQ of the i-STAT Sodium Test was evaluated on the i-STAT Alinity Instruments using whole blood that was altered to low sodium concentrations (< 100 mmol/L) and two cartridge lots. The LoQ for the i-STAT Sodium Test on the i-STAT Alinity Instrument was determined to be 80 mmol/L.

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e. Interference

The interference performance of the i-STAT Sodium Test on the i-STAT Alinity Instrument was evaluated using whole blood and plasma test samples based on CLSI EP07-A2: Interference Testing in Clinical Chemistry; Approved Guideline - Second Edition. The effect of each potentially interfering compound was evaluated by comparing the performance of a test sample spiked to a high concentration of the compound and a control test sample spiked with an equal volume of solvent. A compound was identified as an interferent if the difference between the spiked test sample and the control was > 4 mmol/L. Compounds that do not interfere with the i-STAT Sodium Test are shown in Table 3; those compounds that do interfere are shown in Table 4.

	Test Concentration
Substance	mmol/L(unless specified)	(mg/dL)*
Acetaminophen	1.33	20.10
Acetyl Cysteine	10.2	166.45
Ascorbic Acid	0.342	6.02
Bromide (therapeutic)	2.5	19.98
β-Hydroxybutyric Acid	6.0	62.47
Calcium (Total)	5.0	20.04
Lactate	6.6	58.79
Magnesium	15	36.46
Salicylic Acid	4.34	59.94
Ibuprofen	2.425	50.03
Heparin	3 U/mL	n/a
Ammonium	2.0	10.70
Lithium	3.2	2.22
Acetyl Salicyclic Acid	3.62	65.22
Bilirubin	0.342	20.01
Hemoglobin	2 g/L	200.00
Triglyceride	37	3233.80
Uric Acid	1.4	23.54

Table 3: Non-Interfering Compounds and Test Concentrations

The molecular weight of the substance tested was used to convert the test concentration from mmol/L to mg/dL. The molecular weight of each substance could vary depending on the form chosen.

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Compound	Test Concentration(mmol/L)	(mg/dL)
Bromide	37.5	299.64
Nithiodote (sodium thiosulfate)	16.7	264.04

Table 4: Interfering Compounds and Interfering Concentrations

A bromide concentration above 16.65 mmol/L may give a falsely decreased i-STAT Sodium Test result of more than 4 mmol/L.

A sodium thiosulfate concentration above 3.57 mmol/L mav give a falsely increased i-STAT Sodium Test result of more than 4 mmol/L.

f. Anticoagulant Study

The sample type comparison study was performed using the i-STAT Sodium Test on the i-STAT Alinity Instrument and 40 blood samples ranging from 100 to 180 mmol/L. The comparator condition for this study was heparinized whole blood and the test condition was non-anticoagulated whole blood. The Deming regression result was a slope of 1.00 and a correlation coefficient of 1.00.

g. Method Comparison with Predicate Device

The method comparison study compared the clinical results of the i-STAT Sodium Test on the i-STAT Alinity Instrument to the i-STAT Sodium Test performance on the i-STAT 1 Wireless Analyzer (predicate). This study was conducted across 4 point of care sites. The study included 174 subjects using whole blood (venous or arterial) samples covering the measuring range 100 to 180 mmol/L. The Weighted Deming regression for all 4 sites combined had a regression slope of 1.0 and correlation coefficient of 0.999.

8. Conclusion

Analytical and clinical studies have shown the i-STAT Alinity System to be safe and effective for its intended use. The results of these studies demonstrate that performance of the i-STAT Alinity System is substantially equivalent to the predicate device.

Regulation Number and Section

§ 862.1665 Sodium test system.

(a)
Identification. A sodium test system is a device intended to measure sodium in serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of aldosteronism (excessive secretion of the hormone aldosterone), diabetes insipidus (chronic excretion of large amounts of dilute urine, accompanied by extreme thirst), adrenal hypertension, Addison's disease (caused by destruction of the adrenal glands), dehydration, inappropriate antidiuretic hormone secretion, or other diseases involving electrolyte imbalance.(b)
Classification. Class II.