i-STAT TBI Cartridge with the i-STAT Alinity System

K234143 · Abbott Point of Care · QAT · Mar 27, 2024 · Immunology

Device Facts

• Record ID: K234143
• Device Name: i-STAT TBI Cartridge with the i-STAT Alinity System
• Applicant: Abbott Point of Care
• Product Code: QAT · Immunology
• Decision Date: Mar 27, 2024
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.5830
• Device Class: Class 2
• Attributes: AI/ML

Intended Use

The i-STAT TBI test is a panel of in vitro diagnostic immunoassays for the quantitative measurements of glial fibrillary acidic protein (GFAP) and ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) in whole blood and a semi-quantitative interpretation of test results derived from these measurements, using the i-STAT Alinity instrument. The interpretation of test results is used, in conjunction with other clinical information, to aid in the evaluation of patients, 18 years of age or older, presenting with suspected mild traumatic brain injury (Glasgow Coma Scale score 13-15), which may include one of the following four clinical criteria: 1) any period of loss of consciousness, 2) any loss of memory for events immediately before and after the accident, 3) any alteration in mental state at the time of accident, and/or 4) focal neurological deficits, within 24 hours of injury, to assist in determining the need for a CT (computed tomography) scan of the head. A 'Not Elevated' test interpretation is associated with the absence of acute traumatic intracranial lesions visualized on a head CT scan. The test is to be used with venous whole blood collected with EDTA anticoagulant in point of care or clinical laboratory settings by a healthcare professional.

Device Story

i-STAT TBI cartridge is a single-use multiplex immunoassay for quantitative measurement of GFAP and UCH-L1 biomarkers in venous whole blood. Used with i-STAT Alinity handheld instrument; performs automated electrochemical immunoassay. Instrument executes test cycle, processes electrical sensor signals, and provides semi-quantitative interpretation of results in ~15 minutes. Used in point-of-care or clinical laboratory settings by healthcare professionals. Output aids clinicians in evaluating patients with suspected mild TBI to determine necessity of head CT scan. 'Not Elevated' result correlates with absence of acute traumatic intracranial lesions on CT. Benefits include rapid triage and potential reduction in unnecessary CT scans.

Clinical Evidence

Prospective, multi-center, observational study (N=970) evaluated clinical performance in suspected mild TBI patients (GCS 13-15) within 24 hours of injury. Primary endpoint: classification of absence of acute intracranial lesions on head CT. Results: 96.5% sensitivity (95% CI: 93.6-98.1%), 40.3% specificity (95% CI: 36.7-44.0%), 96.5% NPV (95% CI: 93.7-98.1%). Adjusted NPV for 6% prevalence is 99.4%.

Technological Characteristics

Multiplex sandwich ELISA; electrochemical detection via microfabricated amperometric electrodes on silicon substrate. Analyte: GFAP and UCH-L1. Sample: 20 μL venous whole blood (K2EDTA). Instrument: i-STAT Alinity (handheld, microprocessor-controlled). Connectivity: Standalone/POC. Calibration: Pre-set during manufacture. Sterilization: Not specified.

Indications for Use

Indicated for patients 18+ years old presenting with suspected mild traumatic brain injury (GCS 13-15) within 24 hours of injury, exhibiting loss of consciousness, memory loss, mental status alteration, or focal neurological deficits, to assist in determining the need for a head CT scan.

Regulatory Classification

Identification

A brain trauma assessment test is a device that consists of reagents used to detect and measure brain injury biomarkers in human specimens. The measurements aid in the evaluation of patients with suspected mild traumatic brain injury in conjunction with other clinical information to assist in determining the need for head imaging per current standard of care.

Special Controls

*Classification.* Class II (special controls). The special controls for this device are:(1) The 21 CFR 809.10(b) compliant labeling must include detailed descriptions of and results from performance testing conducted to evaluate precision, accuracy, linearity, analytical sensitivity, interference, and cross-reactivity. This information must include the following: (i) Performance testing of device precision must, at minimum, use one unmodified clinical specimen from the intended use population with concentration of the brain injury biomarker(s) near the medical decision point. Contrived specimens that have been generated from pooling of multiple samples or spiking of purified analyte to cover the measuring range may be used, but the contrived samples must be prepared to mimic clinical specimens as closely as possible. This testing must evaluate repeatability and reproducibility using a protocol from an FDA-recognized standard. (ii) Device performance data must be demonstrated through a clinical study and must include the following: (A) Data demonstrating clinical validity including the clinical sensitivity and specificity, and positive and negative predictive value of the test in the intended use population of patients with suspected mild traumatic brain injury ( *i.e.,* Glasgow Coma Score (GCS) of 13-15), or equivalent standard of care for determination of severity of traumatic brain injury (TBI).(B) Study must be performed using the operators and in settings that are representative of the types of operators and settings for which the device is intended to be used. (C) All eligible subjects must meet the well-defined study inclusion and exclusion criteria that define the intended use population. The prevalence of diseased or injured subjects in the study population must reflect the prevalence of the device's intended use population, or alternatively, statistical measures must be used to account for any bias due to enrichment of subpopulations of the intended use population. (D) All eligible subjects must have undergone a head computerized tomography (CT) scan or other appropriate clinical diagnostic standard used to determine the presence of an intracranial lesion as part of standard of care and must also be evaluated by the subject device. All clinical diagnostic standards used in the clinical study must follow standard clinical practice in the United States. (E) Relevant demographic variables and baseline characteristics including medical history and neurological history. In addition, head injury characteristics, neurological assessments, and physical evidence of trauma must be provided for each subject. This information includes but is not limited to the following: Time since head injury, time from head injury to CT scan, time from head injury to blood draw, GCS score or equivalent, experience of loss of consciousness, presence of confusion, episodes of vomiting, post-traumatic amnesia characteristics, presence of post-traumatic seizures, drug or alcohol intoxication, mechanism of injury, acute intracranial lesion type, neurosurgical lesion, and cranial fracture. (F) Each CT scan or other imaging result must be independently evaluated in a blinded manner by at least two board-certified radiologists to determine whether it is positive or negative as defined by the presence or absence of acute intracranial lesions. This independent review must be conducted without access to test results of the device. Prior to conducting the review, the criteria and procedures to be followed for scoring the images must be established, including the mechanism for determining consensus. (G) All the clinical samples must be tested with the subject device blinded to the TBI status and the neurological-lesion-status of the subject. (H) Details on how missing values in data are handled must be provided. (I) For banked clinical samples, details on storage conditions and storage period must be provided. In addition, a specimen stability study must be conducted for the duration of storage to demonstrate integrity of archived clinical samples. The samples evaluated in the assay test development must not be used to establish the clinical validity of the assays. (iii) Performance testing of device analytical specificity must include the most commonly reported concomitant medications present in specimens from the intended use population. Additionally, potential cross-reacting endogenous analytes must be evaluated at the highest concentration reported in specimens from the intended use population. (iv) Expected/reference values generated by testing a statistically appropriate number of samples from apparently healthy normal individuals. (2) The 21 CFR 809.10(a) and (b) compliant labeling must include the following limitations: (i) A limiting statement that this device is not intended to be used a stand-alone device but as an adjunct to other clinical information to aid in the evaluation of patients who are being considered for standard of care neuroimaging. (ii) A limiting statement that reads “A negative result is generally associated with the absence of acute intracranial lesions. An appropriate neuroimaging method is required for diagnosis of acute intracranial lesions.” (iii) As applicable, a limiting statement that reads “This device is for use by laboratory professionals in a clinical laboratory setting.”

Predicate Devices

• i-STAT TBI Plasma cartridge with the i-STAT Alinity System (K201778)

Submission Summary (Full Text)

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March 27, 2024

Abbott Point of Care Brian Ma Principal Specialist. Regulatory Affairs 400 College Road East Princeton, New Jersey 08540

Re: K234143

Trade/Device Name: i-STAT TBI Cartridge with the i-STAT Alinity System Regulation Number: 21 CFR 866.5830 Regulation Name: Brain Trauma Assessment Test Regulatory Class: Class II Product Code: QAT Dated: December 28, 2023 Received: December 29, 2023

Dear Brian Ma:

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 (the 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. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. 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.

Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).

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Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review. the OS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).

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 Part 801 and Part 809); medical device reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safetyreporting-combination-products); good manufacturing practice requirements as set forth in the quality systems (OS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.

For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email ([e-mail]) or phone [phone] or 301-796-7100).

Sincerelv.

Ying Mao -S

Ying (Katelin) Mao, Ph.D. Branch Chief Division of Immunology and Hematology Devices OHT7: Office of In Vitro Diagnostics Office of Product Evaluation and Quality Center for Devices and Radiological Health

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# Indications for Use

Submission Number (if known)

K234143 Device Name

i-STAT TBI cartridge with the i-STAT Alinity System

#### Indications for Use (Describe)

The i-STAT TBI test is a panel of in vitro diagnostic immunoassays for the quantitative measurements of glial fibrillary acidic protein (GFAP) and ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) in whole blood and a semi-quantitative interpretation of test results derived from these measurements, using the i-STAT Alinity instrument. The interpretation of test results is used, in conjunction with other clinical information, to aid in the evaluation of patients, 18 years of age or older, presenting with suspected mild traumatic brain injury (Glasgow Coma Scale score 13-15), which may include one of the following four clinical criteria: 1) any period of loss of consciousness, 2) any loss of memory for events immediately before and after the accident, 3) any alteration in mental state at the time of accident, and/or 4) focal neurological deficits, within 24 hours of injury, to assist in determining the need for a CT (computed tomography) scan of the head. A 'Not Elevated' test interpretation is associated with the absence of acute traumatic intracranial lesions visualized on a head CT scan.

The test is to be used with venous whole blood collected with EDTA anticoagulant in point of care or clinical laboratory settings by a healthcare professional.

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)

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# 510(k) Summary

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

#### 1. Submitter Information

| Owner | Abbott Point of Care Inc.<br>400 College Road East<br>Princeton, NJ 08540 |
|---------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Contact | Primary: Brian Ma, PhD<br>Principal Specialist Regulatory Affairs<br>Phone: [phone]<br><br>Secondary: Mojgan Soleimani<br>Associate Director, Regulatory Affairs<br>Phone: [phone] |
| Date Prepared | March 25, 2024 |

#### 2. Device Information

Proprietary Name: i-STAT TBI cartridge with the i-STAT Alinity System

Glial fibrillary acidic protein (GFAP) Common Name: Ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1)

K234143 510(k) Number

| Product<br>Code | Device Classification Name | Regulation<br>Number | Class | Panel |
|-----------------|------------------------------|----------------------|--------------------------|------------|
| QAT | Brain trauma assessment test | 866.5830 | II (special<br>controls) | Immunology |

#### Predicate Device 3.

i-STAT TBI Plasma cartridge with the i-STAT Alinity System Proprietary Name 510(k) Number K201778

| Product<br>Code | Device Classification Name | Regulation<br>Number | Class | Panel |
|-----------------|------------------------------|----------------------|--------------------------|------------|
| QAT | Brain trauma assessment test | 866.5830 | II (special<br>controls) | Immunology |

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#### 4. Device Description

The i-STAT TBI cartridge is a multiplex immunoassay that contains assays for both ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) and glial fibrillary acidic protein (GFAP). The assays test for the presence of these biomarkers in a whole blood sample and vield a semi-quantitative test interpretation based on measurements of both UCH-L1 and GFAP in approximately 15 minutes. The i-STAT TBI cartridge is designed to be run only on the i-STAT Alinity instrument.

The i-STAT Alinity instrument is a handheld, in vitro diagnostic device. The instrument is the main user interface of the i-STAT Alinity System and functions as the electro-mechanical interface to the test cartridge. The instrument executes the test cycle, acquires and processes the electrical sensor signals converting the signals into quantitative results. These functions are controlled by a microprocessor.

The i-STAT Alinity System is comprised of the i-STAT Alinity instrument, the i-STAT test cartridges and accessories (i-STAT Alinity Base Station, Electronic Simulator and Printer).

Assaved quality control materials are also available for use with the i-STAT TBI cartridge and include i-STAT TBI Control Level 1, i-STAT TBI Control Level 2, and the i-STAT TBI Calibration Verification Levels 1-3.

The i-STAT TBI Controls are available to monitor the performance of glial fibrillary acidic protein (GFAP) and ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) assays on the i-STAT Alinity instrument.

The i-STAT TBI Calibration Verification Materials are available to verify the calibration of glial fibrillary acidic protein (GFAP) and ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) assays throughout the reportable range on the i-STAT Alinity instrument.

#### 5. Intended Use Statement

The i-STAT TBI test is a panel of in vitro diagnostic immunoassays for the quantitative measurements of glial fibrillary acidic protein (GFAP) and ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) in whole blood and a semi-quantitative interpretation of test results derived from these measurements, using the i-STAT Alinity instrument. The interpretation of test results is used, in conjunction with other clinical information, to aid in the evaluation of patients, 18 years of age or older, presenting with suspected mild traumatic brain injury (Glasgow Coma Scale score 13-15), which may include one of the following four clinical criteria: 1) any period of loss of consciousness, 2) any loss of memory for events immediately before and after the accident. 3) any alteration in mental state at the time of accident. and/or 4) focal neurological deficits, within 24 hours of injury, to assist in determining the need for a CT (computed tomography) scan of the head. A "Not Elevated" TBI test interpretation is associated with the absence of acute traumatic intracranial lesions visualized on a head CT scan.

The test is to be used with venous whole blood collected with EDTA anticoagulant in point of care or clinical laboratory settings by a healthcare professional.

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| Similarities and Differences: System (Test and Instrument) | | |
|------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Feature or<br>Characteristic | Candidate Device:<br>i-STAT TBI cartridge with the i-STAT<br>Alinity System | Predicate Device:<br>i-STAT TBI Plasma cartridge with the<br>i-STAT Alinity System<br>(K201778) |
| Intended Use | The i-STAT TBI test is a panel of in vitro<br>diagnostic immunoassays for the<br>quantitative measurements of glial<br>fibrillary acidic protein (GFAP) and<br>ubiquitin carboxyl-terminal hydrolase<br>L1 (UCH-L1) in whole blood and a<br>semi-quantitative interpretation of<br>test results derived from these<br>measurements, using the i-STAT Alinity<br>instrument. The interpretation of test<br>results is used, in conjunction with<br>other clinical information, to aid in the<br>evaluation of patients, 18 years of age<br>or older, presenting with suspected<br>mild traumatic brain injury (Glasgow<br>Coma Scale score 13-15), which may<br>include one of the following four<br>clinical criteria: 1) any period of loss of<br>consciousness, 2) any loss of memory<br>for events immediately before and<br>after the accident, 3) any alteration in<br>mental state at the time of accident,<br>and/or 4) focal neurological deficits,<br>within 24 hours of injury, to assist in<br>determining the need for a CT<br>(computed tomography) scan of the<br>head. A 'Not Elevated' test<br>interpretation is associated with the<br>absence of acute traumatic intracranial<br>lesions visualized on a head CT scan.<br>The test is to be used with venous<br>whole blood collected with EDTA<br>anticoagulant in point of care or<br>clinical laboratory settings by a<br>healthcare professional. | The i-STAT TBI Plasma test is a<br>panel of in vitro diagnostic<br>immunoassays for the quantitative<br>measurements of glial fibrillary acidic<br>protein (GFAP) and ubiquitin carboxyl-<br>terminal hydrolase L1 (UCH-L1) in<br>plasma and a semi- quantitative<br>interpretation of test results derived<br>from these measurements, using the<br>i-STAT Alinity Instrument. The<br>interpretation of test results is used,<br>in conjunction with other clinical<br>information, to aid in the evaluation<br>of patients, 18 years of age or older,<br>presenting with suspected mild<br>traumatic brain injury (Glasgow Coma<br>Scale score 13-15) within 12 hours of<br>injury, to assist in determining the<br>need for a CT (computed tomography)<br>scan of the head. A 'Not Elevated' test<br>interpretation is associated with the<br>absence of acute traumatic<br>intracranial lesions visualized on a<br>head CT scan.<br>The test is to be used with plasma<br>prepared from EDTA anticoagulated<br>specimens in clinical laboratory<br>settings by a healthcare professional.<br>The i-STAT TBI Plasma test is not<br>intended to be used in point of care<br>settings. |
| Similarities and Differences: System (Test and Instrument) | | |
| Feature or<br>Characteristic | Candidate Device:<br>i-STAT TBI cartridge with the i-STAT<br>Alinity System | Predicate Device:<br>i-STAT TBI Plasma cartridge with the<br>i-STAT Alinity System<br>(K201778) |
| Intended Use<br>Setting | Clinical Laboratory and Point of Care | Clinical Laboratory |
| Measurands | GFAP and UCH-L1 | Same |
| Assay<br>Technology | Enzyme-linked immunosorbent assay | Same |
| Assay Format | Single use multiplex cartridge (both<br>assays (GFAP and UCH-L1) in one<br>cartridge) | Same |
| Detection<br>Technology | Electrochemical | Same |
| Sample Type | Whole Blood | Plasma |
| Sample Volume | 20 μL | Same |
| Automation | Test and wash cycles are fully<br>automated after sample loading step | Same |
| Analytical<br>Measuring<br>Interval | GFAP: 47 - 10,000 pg/mL<br>UCH-L1: 87 - 3,200 pg/mL | GFAP: 30 - 10,000 pg/mL<br>UCH-L1: 200 - 3,200 pg/mL |
| Time to Result | 15 minutes | Same |
| Reportable<br>Result | Quantitative results for GFAP and<br>UCH-L1 and semi-quantitative<br>interpretation | Same |
| Instrument<br>Platform | i-STAT Alinity | Same |
| Calibration | No calibration needed by the end<br>user, calibration is pre-set during<br>manufacture of the cartridge | Same |
| Controls | GFAP and UCH-L1 combined:<br>i-STAT TBI Controls (Levels 1 and 2)<br>i-STAT TBI Calibration Verification<br>Materials (Levels 1, 2, 3) | Same |
| Traceability | GFAP and UCH-L1 values assigned to<br>i-STAT controls and calibration<br>verification materials are traceable to<br>Abbott's working calibrators prepared<br>using recombinant GFAP and UCH-L1<br>(expressed and purified from E. coli). | Same |
| Assay Cut-off | GFAP: 65 pg/ml<br>UCH-L1: 360 pg/ml | GFAP: 30 pg/ml<br>UCH-L1: 360 pg/ml |

#### 6. Summary Comparison of Technological Characteristics

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#### Performance Characteristics 7.

#### A. Analytical Performance

### a. Precision/Reproducibility:

Semi-quantitative 20-day precision: The precision of the GFAP and UCH-L1 assays in the i-STAT TBI cartridge with the i-STAT Alinity System was evaluated using plasma samples spiked with native or recombinant GFAP and UCH-L1 antigens at various levels across the reportable range of the GFAP and UCH-L1 assays, and two (2) controls (i- STAT TBI Control L1 and Control L2). The study was executed over 20 non-consecutive days, two (2) runs per day that were separated by minimum two (2) hours, by at least two (2) operators using three (3) lots of i-STAT TBI cartridges. Due to the inability to store or freeze whole blood samples to maintain sample stability over multiple days, plasma samples were used for this study. The study followed the standard single-site 20x2x2 experimental design based on guidance provided in CLSI EP05-A3; Evaluation of Precision of Quantitative Measurement Procedures; Approved Guideline -Third Edition. The components of variability were estimated for GFAP and UCH-L1 and the precision results for the plasma panel are shown in Table 2, and for the i-STAT TBI Controls in Table 3.

| Table 1: Estimate of GFAP Assay Precision | | | | | | | | | | | | |
|-------------------------------------------|-----|---------|---------------|------|-------------|------|-------------|------|-------------|------|-------------------|------|
| | | | Repeatability | | Between-run | | Between-day | | Between-lot | | Within-Laboratory | |
| Plasma | N | Mean | SD | CV | SD | CV | SD | CV | SD | CV | SD | CV |
| Sample | | (pg/mL) | (pg/mL) | (%) | (pg/mL) | (%) | (pg/mL) | (%) | (pg/mL) | (%) | (pg/mL) | (%) |
| 1B | 240 | 78.8 | 3.04 | 3.86 | 0.85 | 1.07 | 0.57 | 0.72 | 2.17 | 2.76 | 3.90 | 4.95 |
| 2B | 240 | 98.6 | 6.03 | 6.12 | 1.40 | 1.42 | 0.72 | 0.73 | 2.57 | 2.61 | 6.78 | 6.87 |
| 3A | 240 | 880.6 | 21.29 | 2.42 | 15.78 | 1.79 | 1.66 | 0.19 | 9.76 | 1.11 | 28.79 | 3.27 |
| 4A | 240 | 4415.3 | 144.73 | 3.28 | 67.27 | 1.52 | 17.25 | 0.39 | 135.59 | 3.07 | 212.16 | 4.81 |
| 5A | 240 | 8346.7 | 285.03 | 3.41 | 151.07 | 1.81 | 56.69 | 0.68 | 347.63 | 4.16 | 479.49 | 5.74 |

్ Pooled plasma from normal donors spiked with <5% v/v recombinant GFAP antigen

8 Pooled plasma from normal donors spiked with <5% v/v GFAP from pooled TBI patient plasma

| Table 2: Estimate of UCH-L1 Assay Precision | | | | | | | | | | | | |
|---------------------------------------------|-----|-----------------|---------------|-----------|---------------|-----------|---------------|-----------|---------------|-----------|-------------------|-----------|
| | | | Repeatability | | Between-run | | Between-day | | Between-lot | | Within-Laboratory | |
| Plasma<br>Sample | N | Mean<br>(pg/mL) | SD<br>(pg/mL) | CV<br>(%) | SD<br>(pg/mL) | CV<br>(%) | SD<br>(pg/mL) | CV<br>(%) | SD<br>(pg/mL) | CV<br>(%) | SD<br>(pg/mL) | CV<br>(%) |
| 1A | 240 | 159.9 | 11.91 | 7.45 | 3.44 | 2.15 | 0.76 | 0.48 | 4.92 | 3.08 | 13.54 | 8.47 |
| 2A | 240 | 255.7 | 18.11 | 7.08 | 4.97 | 1.94 | 3.17 | 1.24 | 6.21 | 2.43 | 20.33 | 7.95 |
| 3B | 240 | 488.8 | 26.47 | 5.42 | 15.02 | 3.07 | 5.93 | 1.21 | 11.56 | 2.37 | 33.53 | 6.86 |
| 4A | 240 | 826.2 | 49.40 | 5.98 | 23.07 | 2.79 | 12.72 | 1.54 | 24.38 | 2.95 | 61.92 | 7.49 |
| 5A | 240 | 1763.7 | 100.60 | 5.70 | 26.56 | 1.51 | 29.57 | 1.68 | 84.62 | 4.80 | 138.92 | 7.88 |
| 6A | 240 | 2190.3 | 126.88 | 5.79 | 46.79 | 2.14 | 23.66 | 1.08 | 105.13 | 4.80 | 176.27 | 8.05 |

A Pooled plasma from normal donors spiked with <5% v/v recombinant UCH-L1 antigen

8 Pooled plasma from normal donors spiked with <5% v/v UCH-L1 from pooled TBI patient plasma

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| Table 3: Estimate of GFAP and UCH-L1 Assay Precision with i-STAT TBI Controls | | | | | | | | | | | | |
|-------------------------------------------------------------------------------|------------|-----------------|---------------|---------------|-------------|---------------|-------------|---------------|-------------|---------------|-------------------|---------------|
| Control<br>Level | N | Mean<br>(pg/mL) | Repeatability | | Between-run | | Between-day | | Between-lot | | Within-Laboratory | |
| | | | | SD<br>(pg/mL) | CV<br>(%) | SD<br>(pg/mL) | CV<br>(%) | SD<br>(pg/mL) | CV<br>(%) | SD<br>(pg/mL) | CV<br>(%) | SD<br>(pg/mL) |
| | GFAP Assay | | | | | | | | | | | |
| L1 | 240 | 161.2 | 6.80 | 4.22 | 1.77 | 1.10 | 1.78 | 1.11 | 2.54 | 1.57 | 7.76 | 4.81 |
| L2 | 240 | 4645.0 | 166.40 | 3.58 | 45.04 | 0.97 | 45.91 | 0.99 | 148.68 | 3.20 | 234.60 | 5.05 |
| UCH-L1 Assay | | | | | | | | | | | | |
| L1 | 240 | 466.2 | 28.55 | 6.12 | 7.27 | 1.56 | 6.43 | 1.38 | 16.60 | 3.56 | 34.75 | 7.45 |
| L2 | 240 | 1597.6 | 93.98 | 5.88 | 39.23 | 2.46 | 19.79 | 1.24 | 65.97 | 4.13 | 124.87 | 7.82 |

Qualitative 20-day precision: The qualitative agreement of cartridge results relative to the expected sample result (mean) was evaluated for the 80 measurements per sample per cartridge lot for each assay above. The mean, total number of replicates, total number of elevated results, and % correct call for each sample level is presented in Table 4 for GFAP and Table 5 for UCH-L1.

| Table 4: GFAP Assay Results for Qualitative Precision Analysis | | | | | |
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