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Cholestech LDX high sensitivity C-Reactive Protein (hs-CRP) is an in vitro diagnostic test for the quantitative determination of CRP in whole blood or serum. Measurement of CRP is useful as an aid in the detection and evaluation of infection, tissue injury, inflammatory disorders and associated diseases.

The Cholestech LDX System combines immunoassay and solid-phase technology to measure CRP. Samples used for testing can be whole blood from a fingerstick (collected in a lithium heparin coated capillary tube), venous whole blood or serum. The sample is applied to a Cholestech LDX hs-CRP cassette. The cassette is then placed into the Cholestech LDX Analyzer where a unique system on the cassette separates the plasma from the blood cells. The resultant color in the reaction is measured by reflectance photometry. A brown magnetic stripe on each cassette contains the calibration information required for the Cholestech LDX Analyzer to convert the reflectance reading to the CRP concentration in mg/L.

Here's a breakdown of the acceptance criteria and the study that proves the device meets them, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

Note on Acceptance Criteria: The document does not explicitly state numerical acceptance criteria for slope, y-intercept, and "r" values. However, for a device claiming substantial equivalence to a predicate, the expectation is that these metrics demonstrate a strong correlation and agreement with the predicate. The reported values of r (correlation coefficient) being close to 1 (0.975, 0.976, 0.981) and slopes being close to 1 (1.01, 1.06, 1.08) with small y-intercepts (-0.02, 0.07, 0.22) indicate good agreement and likely meet the implicit acceptance criteria for substantial equivalence. The assay range and interference criteria are explicitly stated and met. Precision values are reported but no explicit acceptance thresholds are provided.

2. Sample Size and Data Provenance

• Test Set Sample Sizes:
  • Accuracy (Serum vs. Predicate): 70 matched serum samples
  • Accuracy (Whole Blood vs. Predicate): 76 whole blood samples (both venous and fingerstick)
  • Precision: 2 levels of controls (Low and High) and one serum sample (6.5 mg/L). Each control was tested in duplicate, twice a day, over 20 days (total 80 replicates per level).
  • Hematocrit Tolerance & Interference: No specific sample sizes provided, but tested with "evaluated levels" of endogenous substances.
• Data Provenance: Not explicitly stated, but clinical studies for such devices typically involve samples from a geographically diverse patient population. The document does not specify country of origin or whether the data was retrospective or prospective. Given the nature of a 510(k) submission for an in vitro diagnostic, it is generally assumed to be prospective clinical study data collected for the purpose of demonstrating device performance.

3. Number of Experts and Qualifications for Ground Truth (Test Set)

• Number of Experts: Not applicable. This study does not involve expert readers assessing images or clinical cases to establish ground truth.
• Qualifications of Experts: Not applicable.

4. Adjudication Method (Test Set)

• Adjudication Method: Not applicable. This study does not involve expert adjudication as it is a quantitative diagnostic test compared to a predicate device. The "ground truth" is established by the predicate device's measurement.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

• Was it done? No. This is not an imaging AI device that relies on human interpretation. It's an in vitro diagnostic test that provides a quantitative measurement.

6. Standalone (Algorithm Only) Performance Study

• Was it done? Yes. The entire accuracy study comparing the Cholestech LDX hs-CRP device to the Dade Behring N high sensitivity CRP test is a standalone performance study. The device's output (CRP concentration) is directly compared to the predicate's output. There is no human-in-the-loop component in the measurement itself.

7. Type of Ground Truth Used

• Ground Truth Type: Predicate device measurement. The Dade Behring N High Sensitivity CRP test on the BN100 (K991385) is used as the reference standard to establish the "ground truth" for the accuracy study. This is a common approach for demonstrating substantial equivalence for new in vitro diagnostic devices.

8. Sample Size for the Training Set

• Training Set Sample Size: Not applicable. This device is an in vitro diagnostic immunoassay, not a machine learning or AI algorithm that requires a "training set" in the conventional sense. The device's performance is determined by its inherent chemical and optical properties, and its "calibration information" is encoded on the magnetic stripe of each cassette, not learned from a dataset.

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

• Ground Truth Establishment (Training Set): Not applicable, as there is no "training set" in the context of this device. The device's calibration is factory-set and encoded on each cassette.

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The Cholestech LDX aspartate aminotransferase (AST) test is for the in vitro quantitative determination of AST in whole blood or serum on the Cholestech LDX Analyzer. AST measurements are used in the diagnosis and treatment of certain liver diseases (e.g., viral hepatitis and cirrhosis), and heart diseases.

The Cholestech LDX System combines enzymatic methodology and solid-phase technology to measure AST. Samples used for testing can be whole blood from a fingerstick (collected in a lithium heparin coated capillary tube), venous whole blood or serum. The sample is applied to a Cholestech LDX AST cassette. The cassette is then placed into the Cholestech LDX Analyzer where a unique system on the cassette separates the plasma from the blood cells. The plasma flows to both sides of the cassette and is transferred to the AST reaction pad. The Cholestech LDX Analyzer measures Aspartate aminotransferase by an enzymatic method based on the method formulation of Katsuyama et al. 12- Aspartic acid aminotransferase catalyzes the transfer of amino groups from L-Aspartic acid to alpha-Ketoglutarate producing oxaloacetate and glutamate. Oxaloacetate Decarboxylase converts the Oxaloacetate to Pyruvate by the removal of CO2. Pyruvate oxidase, in the presence of oxygen, oxidizes the pyruvate to acetylphosphate and hydrogen peroxide. In a reaction catalyzed by horseradish peroxidase, the peroxide reacts with an indicator dye to form a blue color at a rate proportional to the AST concentration of the sample. The resultant color in the reaction is measured by reflectance photometry. A brown magnetic stripe on each cassette contains the calibration required for the Cholestech LDX Analyzer to convert the reflectance reading to the AST concentration in U/L. 37°C.

The Cholestech LDX aspartate aminotransferase (AST) Test, a colorimetric assay for the determination of AST, has been found substantially equivalent to the Synchron CX® AST system. The device uses enzymatic methodology and solid-phase technology to measure AST in whole blood or serum.

1. Table of Acceptance Criteria and Reported Device Performance

The submission does not explicitly state pre-defined acceptance criteria with pass/fail thresholds for each performance metric. Instead, it presents performance data for accuracy, precision, and linearity, which are implicitly compared against the performance characteristics of the predicate device (Synchron CX® AST) and laboratory standards.

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

• Accuracy (LDX AST vs. Synchron CX AST): 109 matched serum samples.
• Accuracy (LDX AST: Venous Whole Blood vs. Serum): 46 matched samples.
• Accuracy (LDX AST: Fingerstick Whole Blood vs. Serum): 21 matched samples.
• Precision: 2 levels of controls tested in duplicate, twice a day, over 20 days (80 replicates per level). One whole blood sample tested with the same protocol (80 replicates).

Data Provenance: The document does not specify the country of origin for the data or explicitly state whether the studies were retrospective or prospective. Given the nature of a 510(k) submission for a new device, it is highly likely that these were prospective studies conducted in a controlled environment as part of the device's validation. No specific patient demographics or disease states are detailed beyond the general "diagnosis and treatment of certain liver diseases (e.g., viral hepatitis and cirrhosis), and heart diseases."

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

N/A. This is an in vitro diagnostic device for quantitative determination of a biomarker (AST). The "ground truth" for the test set is established by comparative measurements against a legally marketed predicate device (Synchron CX® AST system) or by internal comparison to reference methods/sample types within the new device's system. It does not involve human expert interpretation of images or clinical assessments to establish a ground truth in the way medical imaging AI devices do. Therefore, no experts for ground truth establishment are applicable in this context.

4. Adjudication Method for the Test Set

N/A. This is not applicable as the test set involves quantitative measurements against a comparator device and internal comparisons, not subjective assessments requiring expert adjudication.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

N/A. This is an in vitro diagnostic device, not a medical imaging AI device requiring human reader interpretation or multi-reader studies. The device provides a quantitative measurement, and its effectiveness is determined by its analytical performance metrics (accuracy, precision, linearity) compared to established methods.

6. Standalone Performance Study

Yes, a standalone performance study was done in the sense that the Cholestech LDX AST device's performance was evaluated independently through precision studies, interference testing, hematocrit tolerance, and then compared to a predicate device (Synchron CX AST) as well as within its own system for different sample types. The reported accuracy metrics directly compare the LDX AST to the predicate and also compare results from various sample types processed by the LDX AST itself (venous whole blood, fingerstick whole blood vs. serum). This represents the algorithm's (device's) performance in generating the quantitative AST value.

7. Type of Ground Truth Used

The primary ground truth used for performance evaluation is comparative measurement against a legally marketed predicate device (Synchron CX® AST system) for accuracy. Additionally, internal comparisons of different sample types (venous whole blood, fingerstick whole blood) against serum samples measured by the same device serve as a verification of consistency and accuracy across intended sample matrices. The precision studies use control materials with known or established AST levels.

8. Sample Size for the Training Set

The document does not specify a separate training set or its sample size. For in vitro diagnostic (IVD) devices like this, the development process might involve initial experimentation and optimization, but the "training set" concept common in machine learning for image analysis or risk prediction is typically not directly applicable in the same way. Performance data presented relates to validation studies, not necessarily a distinct "training set" as understood in AI/ML contexts.

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

N/A. As mentioned above, the concept of a "training set" with established ground truth as it applies to AI/ML is not explicitly detailed or typically relevant for this type of quantitative IVD submission in the same manner. The device's methodology is based on established enzymatic reactions, and its parameters would likely have been optimized during development rather than "trained" on a dataset with a defined ground truth in a machine learning sense.

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The Cholestech L·D·X Alanine aminotransferase Test (ALT) is for the in vitro quantitative determination of alanine aminotransferase (ALT) in whole blood or serum on the Cholestech L.D.X Analyzer.

Alanine aminotransferase measurements are used in the diagnosis and treatment of certain liver diseases (e.g., viral hepatitis and cirrhosis) and heart diseases.

The Cholestech L·D·X Alanine Aminotransferase Test (ALT) combines an enzymatic methodology and a solid-phase technology to measure ALT in whole blood or serum. Blood from a fingerstick is collected into a lithium heparin coated capillary tube (venous whole blood serum is also acceptable) and dispensed into a L·D·X cassette. The cassette is then placed into the Cholestech L·D·X where a unique system separates the plasma from the blood cells. The plasma flows to both sides of the cassette and is transferred to the ALT reaction pad.

The Cholestech L•D•X Analyzer measures alanine aminotransferase by an enzymatic method based on the method formulation of Katsuyama et al. Alanine aminotransferase catalyzes the transfer of amino groups from L-Alanine and α-Ketoglutarate to pyruvate and glutamate. Pyruvate oxidase, in the presence of oxygen, oxidizes the pyruvate to acetylphosphate and hydrogen peroxide. In a reaction catalyzed by horseradish peroxidase, the peroxide reacts with an indicator dye to form a blue color at a rate proportional to the ALT concentration of the sample. The resultant color in the reaction is measured by reflectance photometry.

L-Alanine + α -Ketoglutarate Alanine Aminotransferase → Pyruvate + Glutamate
Pyruvate + Phosphate + O2 + H2O Pyruvate Oxidase → Acetylphosphate + CO2 + H2O2
Indicator + H2O2 Peroxidase → Colored Blue Dye + H2O

A brown magnetic stripe on each cassette contains the calibration information required for the Cholestech L•D•X Analyzer to convert the reflectance reading to the ALT concentration in U/L at 37° C.

Here's an analysis of the provided text regarding the Cholestech L·D·X Alanine aminotransferase (ALT) Test, focusing on acceptance criteria and study details:

1. Table of Acceptance Criteria and Reported Device Performance

The submission primarily focuses on demonstrating substantial equivalence to a predicate device (Roche Diagnostics Reflotron GPT (ALT) test) rather than explicitly stating pre-defined acceptance criteria in the format of pass/fail thresholds. However, we can infer the performance characteristics the submitter aimed to demonstrate as being comparable or superior to the predicate.

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

• Precision Studies:
  • Within-run:
    • Cholestech L·D·X ALT: N=20 for each of 3 levels (Level 1, Level 2, Serum Pool).
    • Predicate: N=20 for each of 3 levels (Level I, Level II, Pool).
  • Total/Day to Day:
    • Cholestech L·D·X ALT: N=20 for each of 3 levels (Level 1, Level 2, Serum Pool).
    • Predicate: N=15 for each of 2 levels (Level I, Level II).
• Method Comparison Studies (Cholestech L·D·X ALT vs. predicate Reflotron GPT (ALT)):
  • Capillary Whole Blood (x) vs. Capillary Whole Blood (y): n = 24
  • Venous Whole Blood (x) vs. Venous Whole Blood (y): n = 53
  • Serum (x) vs. Serum (y): n = 52
• Method Comparison Studies (Predicate Reflotron GPT (ALT) vs. GPT (ALT) IFCC Method): (Note: This data is for the predicate device's performance against a reference method, not the current device.)
  • Venous Heparin Blood (x) vs. Heparin Plasma (y): n = 69
  • Serum (x) vs. Serum (y): n = 36
  • Venous Heparin Plasma (x) vs. Venous Heparin Plasma (y): n = 69
  • Capillary Heparin Blood (x) vs. Capillary Heparin Plasma (y): n = 26

Data Provenance: The document does not specify the country of origin for the data or whether the studies were retrospective or prospective. Given the nature of laboratory testing submissions, it is generally assumed these are prospective controlled studies conducted in a lab environment.

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

This type of information is not applicable to this submission. This device is an in vitro diagnostic (IVD) device for quantitative biochemical measurement (Alanine aminotransferase, ALT). The "ground truth" for such a device is typically established against a recognized reference method (like the IFCC method for ALT) or by comparison to a legally marketed predicate device with established clinical utility and accuracy. It does not involve human expert interpretation of images or clinical cases that would require adjudication.

4. Adjudication Method for the Test Set

This is not applicable. As explained above, the assessment of an IVD involves quantitative measurements and comparisons to reference methods or predicate devices, not human interpretation that requires adjudication.

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

This is not applicable. This submission concerns an in vitro diagnostic assay (a lab test), not an AI-assisted diagnostic imaging device that would involve human readers interpreting cases. Therefore, no MRMC study or AI assistance effect size is mentioned or relevant.

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

This is not applicable. The Cholestech L·D·X ALT Test is a standalone IVD device (a test kit used with an analyzer), but it's not an AI algorithm. Its performance is inherent to the chemical reactions and reflectance photometry. The performance values reported (precision, method comparison) are the standalone performance of the device without human interpretation.

7. The Type of Ground Truth Used

The ground truth used for method comparison was primarily the predicate device, Roche Diagnostics Reflotron GPT (ALT) test, which itself was likely compared against a reference method such as the GPT (ALT) IFCC Method (as referenced in the predicate's method comparison section). For precision studies, the ground truth is the statistical properties of the measurements of known samples.

8. The Sample Size for the Training Set

The document does not explicitly mention a "training set" in the context of machine learning or AI. For an IVD device like this, the "training" (calibration and optimization) of the assay methodology and the L·D·X Analyzer itself would have been done during the product development phase (R&D). The reported data represents performance characteristics verified subsequently. The sample sizes for these internal development and validation studies are not provided in this 510(k) summary.

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

As there is no explicit mention of a "training set" in the AI/ML sense, this question is not fully applicable. However, for the development and optimization of the assay and instrument (analogous to "training" for an IVD):

• The ground truth would have been established through known concentrations of ALT in control materials, reference methods (like the IFCC method), and potentially split-sample comparisons against established laboratory instruments.
• This process would involve extensive experimentation to optimize reagent concentrations, reaction times, measurement parameters, and calibration curves to ensure accuracy and precision across the intended assay range. The details of these internal R&D processes are typically proprietary and not provided in a 510(k) summary.

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For the quantitative determination of Blood Urea Nitrogen and creatinine in whole blood. Creatinine values are used as indications of renal function. Blood Urea Nitrogen values are valuable in the diagnosis of renal diseases. For professional in vitro diagnostic use only.

Not Found

The provided document is a 510(k) clearance letter from the FDA for a device called "Cholestech BUN/Creatinine Test System II". This document does not contain the detailed information necessary to answer all the questions about acceptance criteria and study design as typically found in a clinical study report or a more comprehensive summary of safety and effectiveness.

However, based on the information available in the document, here's what can be deduced, along with what cannot be provided:

1. A table of acceptance criteria and the reported device performance

• Acceptance Criteria: Not explicitly stated in this document. 510(k) clearances are based on substantial equivalence, meaning the new device performs as well as, or better than, a legally marketed predicate device. The specific performance criteria (e.g., accuracy, precision targets) that Cholestech had to meet are not detailed here. They would typically be found in the 510(k) submission itself.
• Reported Device Performance: Not detailed in this clearance letter. The letter only states that the FDA "determined the device is substantially equivalent... to devices marketed in interstate commerce prior to May 28, 1976." This implies that performance data was submitted and found acceptable, but the actual data (e.g., bias, CV, correlation) is not presented.

2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

• This information is not available in the provided document.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

• This information is not applicable as this is an in vitro diagnostic device, not an imaging device requiring expert interpretation for ground truth. For IVD devices, ground truth is typically established using a reference method or a well-characterized predicate device. The number and qualifications of individuals performing these reference tests are not in this document.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

• This information is not applicable for an in vitro diagnostic device in the context of expert consensus/adjudication. If adjudication refers to discrepancy resolution between the new device and a reference method, that detail is not provided.

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

• This information is not applicable as this is an in vitro diagnostic device, not an AI-powered diagnostic imaging interpretation device for human readers.

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

• This device is an in vitro diagnostic test system that provides quantitative results. Its "standalone performance" would be its analytical performance (accuracy, precision, linearity, etc.) when tested in a laboratory setting. The specific results of such standalone performance are not detailed in this document. The indications for use state "For professional in vitro diagnostic use only," implying it's used by human operators, but the "performance" is of the device/reagent system itself, not an AI algorithm.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)

• For an in vitro diagnostic device like the Cholestech BUN/Creatinine Test System II, the "ground truth" for determining its performance (e.g., accuracy) would typically be established by:
  • Reference laboratory methods: Assays performed in a high-complexity laboratory using established, often more expensive or time-consuming, gold standard methods for BUN and Creatinine.
  • Predicate device comparison: Directly comparing results from the new device with a legally marketed predicate device on the same patient samples.
• The document does not specify which type of ground truth was used for their submission.

8. The sample size for the training set

• This information is not available in the provided document. The concept of a "training set" is more directly relevant to machine learning/AI development, though IVD systems also involve extensive development and testing with samples.

9. How the ground truth for the training set was established

• This information is not available in the provided document. Similar to point 7, it would likely involve reference methods or predicate device comparison if a training phase (e.g., for algorithm development in a more complex IVD) was explicitly conducted.

Summary of available information from the document:

• Device Name: Cholestech BUN/Creatinine Test System II
• Intended Use: Quantitative determination of Blood Urea Nitrogen and Creatinine in whole blood. Creatinine values are used as indications of renal function. Blood Urea Nitrogen values are valuable in the diagnosis of renal diseases. For professional in vitro diagnostic use only.
• Regulatory Outcome: Found "Substantially Equivalent" (K972012) to a predicate device.
• Regulatory Class: Not explicitly stated in the letter, but implied as a general controls device with potential for additional controls if Class II or III.
• Product Code: CDN, JFY
• Date of Clearance: July 24, 1997

To obtain the detailed information requested, one would typically need to refer to the full 510(k) submission document or a summary of safety and effectiveness (SSE) for K972012, which are sometimes publicly available through the FDA website but are not part of this clearance letter.

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