The Lactate test, as part of the i-STAT System, is intended for the in vitro measurement of the concentration of (lactate) lactic acid in fresh, arterial, venous or capillary whole blood. Blood samples may be untreated or treated with lithium heparin.
Device Story
i-STAT Lactate test is a single-use cartridge for point-of-care whole blood analysis. User introduces 2-3 drops of arterial, venous, or capillary blood into cartridge sample port; inserts cartridge into i-STAT Model 200 Portable Clinical Analyzer. Analyzer automatically performs sequence: identifies cartridge type via mechanical feature; calibrates sensors using internal aqueous calibrator; washes calibrator with blood sample; measures hydrogen peroxide generated by lactic acid oxidase reaction via amperometric sensors. Results displayed on analyzer; stored in memory; transmittable via infrared link to printers or computers. System enables rapid clinical decision-making regarding lactic acidosis, tissue hypoxia, and hyperlactatemia at point-of-care.
Clinical Evidence
Bench testing established linearity (0.3-20 mmol/L) and precision (CV 1.2-3.3%). Clinical study compared i-STAT Lactate to predicate (N=46) and lab plasma method (N=47). Deming regression showed high correlation (r=0.998 for both). Slope 0.993 (vs predicate) and 1.118 (vs lab); intercept 0.036 and -0.052 respectively. Results confirm acceptable performance within medically allowable error standards.
Technological Characteristics
Single-use cartridge containing biosensor chips; silicon/silicon dioxide substrate with patterned metallic layer; membrane coated with lactic acid oxidase. Amperometric sensing principle. Handheld portable analyzer; infrared connectivity. Automated calibration and fluid handling. No specific ASTM standards cited.
Indications for Use
Indicated for the diagnosis and treatment of lactic acidosis in conjunction with blood acid-base status measurements, monitoring tissue hypoxia and strenuous physical exertion, and diagnosis of hyperlactatemia in patients requiring whole blood lactate analysis.
Regulatory Classification
Identification
A lactic acid test system is a device intended to measure lactic acid in whole blood and plasma. Lactic acid measurements that evaluate the acid-base status are used in the diagnosis and treatment of lactic acidosis (abnormally high acidity of the blood).
Predicate Devices
Stat Profile® Plus Ultra/Lactic acid test
Submission Summary (Full Text)
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K982071
1
i-STAT Corporation
JUN 2 9 1998
# 510(k) SUMMARY
This summary of 510(k) safety and effectiveness information is being submitted in accordance with the requirements of SMDA 1990 and 21 CFR 807.92.
1982071
The assigned 510(k) number is:
# Summary Prepared on:
# Submitted by:
i-STAT Corporation 303 A College Road East Princeton, New Jersey 08550 Phone: 609-243-9300 Fax: 609-243-9311
# Contact:
Paul VanDerWerf, Ph.D., Vice President Regulatory Affairs and Quality Assurance
# Establishment Registration Number: 2245578
## Identification of the Device:
| Device Name: | Lactic Acid |
|-------------------------|--------------------------------------------|
| Proprietary/Trade Name: | i-STAT® Lactate test |
| Common Name: | Lactic Acid, Lactate |
| Classification Name: | Lactic acid test system. |
| Device Classification: | I |
| Regulation Number: | 21 CFR § 862.1450 |
| Panel: | Clinical Chemistry and Clinical Toxicology |
| Product Code: | KHP |
### Identification of the Predicate Device:
Device Name:
Stat Profile® Plus Ultra/Lactic acid test.
## Intended use of the Device:
The Lactate test, as part of the i-STAT System, is intended for the in vitro measurement of the concentration of (lactate) lactic acid in fresh, arterial, venous or capillary whole blood. Blood samples may be untreated or treated with lithium heparin.
## Description of the Device:
<sup>®</sup> i-STAT is a registered trademark of i-STAT Corporation, Princeton, NJ.
<sup>®</sup> Stat Profile is a registered trademark of Nova Biomedical, Waltham, MA.
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The i-STAT lactate test is contained in a single use cartridge. In use, two to three drops of blood are placed in the cartridge as described below. The cartridge is inserted into the thermally controlled i-STAT Model 200 Portable Clinical Analyzer and all analytical steps are performed automatically. Patient and user information may be entered into the analyzer via a keypad during the automated analysis cycle.
The i-STAT System is an in vitro analytical system comprising a network of one or more portable clinical analyzers designed to be used at the point of patient care. The analyzers employ single-use test cartridges containing biosensor chips to perform diagnostic tests on whole blood. The system further comprises an infrared communications link from the analyzers to auxiliary information management devices such as printers, personal computers, laboratory information systems and hospital information systems.
The i-STAT analyzers, as part of the i-STAT System, are intended for use by health-care professionals for the in vitro analysis of arterial, venous or capillary whole blood at the point of patient care.
Tests with the i-STAT System are carried out in test cartridge. It houses the sensor array, aqueous calibrator, fluid channels, and a waste reservoir). Electrochemical sensors on biosensor chips are housed in cartridges in a variety of sensor test configurations appropriate to clinical needs.
Test panels are identified by name and color code on the cartridge label. In addition, test panel configurations are encoded into the cartridge in a mechanical feature in the cartridge housing. An array of electrical pins in the analyzer recognizes the mechanical feature and automatically identifies the cartridge test panel type.
In use, whole blood is introduced into the sample well of the cartridge at the sample port. After closure, the cartridge is inserted into the cartridge door of the analyzer. Insertion of the cartridge initiates a precisely controlled and monitored sequence of steps performed by the instrument without user intervention. These steps are:
- Electrical contact is made between the analyzer electronic input circuits and the . The analyzer identifies the type of cartridge being used and the tests cartridge. contained in the cartridge.
- Calibrator is positioned over the sensors. Each lactate test is calibrated with calibrator . fluid that contains a pre-determined amount of lactic acid.
- Calibration measurements are made as the sensors generate signals mathematically . related to analytic concentrations. In the i-STAT lactate test the concentration of lactate is directly related to the appearance of hydrogen peroxide (measured by amperometrically) generated by lactic acid oxidase acting on lactic acid in the calibrator fluid or in the blood sample.
- . Blood sample washes out the calibrator with the aid of an air bubble between the two.
- . Blood sample is positioned over the sensors.
- . Calculations of sample concentrations are performed and displayed.
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The displayed results are also stored in the analyzer memory and can be transmitted by infrared communication link to commercially available computers or printers.
The lactate test cartridge is assembled from plastic components that provide the conduits for fluid handling and house the sensor chips. In the cartridge containing the test for lactate, the sensors comprise a patterned metallic layer, supported on a silicon/silicon dioxide substrate, coated with a thin membrane containing lactic acid oxidase.
# Comparison of the Technological Features to the Predicate Device:
The following technological differences between the i-STAT lactate and the Nova test are noteworthy.
- 1. The Nova lactate has to be calibrated daily with a two-point calibration. The i-STAT lactate is automatically calibrated during each sample analysis cycle.
- 2. The Nova analyzer is a much larger multi-channel analyzer while the i-STAT system is a handheld device.
- 3. The Nova lactate sensor is a multiple-use analytical system and is therefore prone to contamination and carry-over while the i-STAT sensor is single use and free of such interferences.
#### Summary of Non-Clinical Test Performance in Support of Substantial Equivalence:
Studies using calibration verification solutions at five concentrations of lactic acid, has established that the i-STAT Lactate test is linear over the claimed reportable range of 0.3 to 20 mmol/L. The reportable range of the Nova Stat Profile Plus Ultra lactate test is also 0.3 to 20 mmol/L.
Imprecision of the i-STAT Lactate test was established over 20 days using duplicate aqueous controls. In the normal range the average (N=120) was 0.81 ± 0.03 mmol/L [3.3% c.v.]. In the abnormal range (N=120) was 6.35 ± 0.08 mmol/L [1.2% c.v.]. Within run precision (using control materials) for the Stat Profile Plus Ultra (N = 18-25) is reported to be 0.8 ± 0.05 mmol/L (6.1% c.v) in the normal range and 7.6 ± 0.19 mmol/L (c.v 2.5%) in the abnormal range.
#### Summary of Clinical Test Performance in Support of Substantial Equivalence:
Studies compared the i-STAT Lactate test (y) was to the predicate device (x) using blood (site 1) and to a standard laboratory instrument (x) using plasma (site 2). The methods were compared using Deming regression analysis. The results summarized in the table below indicate that the i-STAT test performance is similar to the predicate device.
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| Statistic | Definition | Blood | Plasma |
|-----------|------------------------------------------------------------|-------------|------------|
| | | Pred Device | Lab Device |
| N pairs | The number of patient samples | 46 | 47 |
| Mean | The average of the comparative method | 5.92 | 3.25 |
| Sx | The standard deviation of comparative method results | 3.485 | 2.091 |
| Syx | Standard error of the estimate of the regression of y on x | 0.154 | 0.146 |
| Slope | Deming linear regression slope | 0.993 | 1.118 |
| Intercept | Deming linear regression intercept | 0.036 | -0.052 |
| Range | Range of comparative method results | 0.9-13.2 | 0.81-13.2 |
| r | Correlation coefficient | 0.998 | 0.998 |
| Sxx | Pooled imprecision of x duplicates | 0.125 | 0.027 |
| Syy | Pooled imprecision of y duplicates | 0.106 | 0.054 |
## Conclusions:
Based on the non-clinical data, the new i-STAT lactate test is usable over the range of 0.3 to 20 mmol/L. Studies using controls indicate adequate precision at normal and medical decision levels. Clinical data indicates acceptable correlation to plasma and whole blood instruments. Based on data from CAP Surveys, the medically allowable error associated with the new test is within the standards accepted by the medical community. Thus, the safety and effectiveness of the new i-STAT Lactate test is established as substantially equivalent to that of a predicate device previously cleared for distribution and sale.
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Image /page/4/Picture/1 description: The image is completely white and contains no discernible content. There are no objects, shapes, or patterns visible. The image appears to be a blank canvas.
Image /page/4/Picture/3 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo features a stylized eagle-like symbol with three curved lines representing wings or feathers. The text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" is arranged in a circular fashion around the symbol.
Food and Drug Administration 2098 Gaither Road Rockville MD 20850
JUN 29 1998
Paul VanDerWerf, Ph.D. . Vice President, Regulatory Affairs and Quality Assurance i-STAT Corporation 303 College Road East Princeton, New Jersey 08540
Re : K982071 i-STAT®¹ Lactate Test Regulatory Class: I Product Code: КНР Dated: June 10, 1998 Received: June 12, 1998
Dear Dr. VanDerWerf:
We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to 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). 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.
If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Requlations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the Current Good Manufacturing Practice requirements, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic QS inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory In addition, FDA may publish further announcements action. concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.
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#### Page 2
This letter will allow you to begin marketing your device as This lecter will arrow you co reget notification. The FDA described in your 510(x) premaince of your device to a legally marketed predicate device results in a classification for your marketed predicate device robated in oproceed to the market.
device and thus, permits your device to proceed to the ling device and thus, permice your device for your device on our labeling If you desire Specific advise Lodditionally 809.10 for in regulation (21 crk rares), please contact the Office of Vitro diagnoscic deviceb/, productionally, for questions on Compliance at (301) 354 4500. the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to
the regulation entitled, "Misbranding by reference for may information on your responsibilities under the Act may be Information on your responsible of Small Manufacturers Assistance obcathed from the Driver (800) 638-2041 or (301) 443-6597 or at its internet address "dsmo@fdadr.cdrh.fda.gov".
Sincerely yours,
Steven Autman
Steven I. Gutman, M.D., M.B.A. Director Division of Clinical Laboratory Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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#### III INDICATIONS FOR USE
510(k) Number (if known):
Device Name: Lactic Acid test.
The i-STAT lactate test is useful for (1) the diagnosis and treatment of lactic acidosis in conjunction with measurements of blood actifbase status, (2) monitoring tissue hypoxia and strenuous physical exertion, and (3) diagnosis of hyperlactatemia.
71
(Please do not write below this limecontinue on another page if needed.)
Concurrence of CDRH, Office of Device Evaluation (ODE)
Prescription Use V
OR
Over-The-Counter-Use
(Per 21 CFR 801.109)
(Optional Format 1-2-96)
Carol C. Benson / Alfred Monty
Division of Clinical Laboratory Devices 510(k) Number
Page l of I
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.