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Automated scanning microscopy work station for histological identification of the enzyme leucocyte alkaline phosphatase in neutrophilic granulocytes to differentiate: Granulocytic leukemia; a malignant disease characterized by excessive overgrowth of granulocytes in bone marrow, and Reactions that resemble true leukemia, such as those occurring in severe infections.

The MD, 2000 Digital Analyzer is an automated intelligent microscope cell locating device that detects, by color and pattern recognition techniques, cells stained with alkaline phosphatase reagent system FAST VIOLET B SALT. The system consists of software resident in computer memory and includes keyboard, color monitors, microscope, printer, and an automatic slide handling and scanning mechanism controlled and operated by a health care professional.

The provided document describes the MDx 2000 Digital Analyzer, an automated intelligent microscope cell locating device. The document details the device's intended use and the clinical trials conducted to demonstrate its substantial equivalence to predicate devices. However, it does not explicitly state quantitative "acceptance criteria" for performance that the device was designed to meet. Instead, the study aims to show that the MDx 2000 performs "as well or better than the predicate devices."

Here's an analysis of the available information:

1. Table of Acceptance Criteria and Reported Device Performance

As mentioned, explicit, quantitative acceptance criteria are not presented in this summary. The evaluation focuses on demonstrating comparable performance and improvements over manual methods rather than meeting predefined numerical thresholds.

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

• Test Set Sample Size: 125 patients tested across 3 clinical sites.
• Data Provenance: Clinical trials were conducted at three different sites. There is no explicit mention of the country of origin, but given the context of a 510(k) summary for the U.S. FDA, it is highly likely the data is from the United States. The study was prospective in nature, as indicated by the "written MicroVision Medical Systems, Inc. protocol" and controlled clinical trials.

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

The document mentions "qualified medical technologists examining the slides" for the manual comparison (The number of qualified medical technologists examining the slides). However, it does not specify the exact number of experts or their specific qualifications (e.g., years of experience) used to establish the ground truth for the test set.

4. Adjudication Method for the Test Set

The document states, "The design of the double blind study." While a double-blind study suggests measures to reduce bias, it does not explicitly describe an adjudication method (like 2+1 or 3+1). The "manual count" by qualified technologists serves as the reference, but the process for resolving discrepancies among manual readers (if multiple were involved in the ground truth) is not detailed.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and the Effect Size

The summary does not explicitly describe a Multi-Reader Multi-Case (MRMC) comparative effectiveness study in the typical sense of measuring human reader improvement with AI assistance versus without. The study primarily compares the automated device's performance to a manual method performed by technologists.

However, the findings imply an "effect size" related to variability:

• The device "eliminated the considerable between-technologist variability that occurred at each of the study sites." This indicates a significant positive effect on consistency compared to unassisted human readers.
• The device "provided more between-site consistency in reported results than that for the comparative Sigma NAP kit manual method." This also suggests an improvement in consistency over a purely manual process.
  The document doesn't provide a quantitative effect size (e.g., percentage improvement in accuracy or reduction in reading time) due to AI assistance specifically.

6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done

Yes, the study primarily evaluates the standalone performance of the MDx 2000 Digital Analyzer algorithm (the "candidate device") against manual methods. The device is described as an "automated intelligent microscope cell locating device" that detects cells using "color and pattern recognition techniques." The assessments of precision, consistency, and accuracy are all of the automated system's output.

7. The Type of Ground Truth Used

The ground truth for the clinical trials was established by:

• Expert Consensus/Manual Count: The "average manual count" performed by "qualified medical technologists" based on "a scoring procedure... from ratings from zero to 4+ on the basis of quantity and intensity of precipitated dye within the cytoplasm of the cells." This manual method was based on established cytochemical techniques and a "scoring procedure" detailed in referenced literature.

8. The Sample Size for the Training Set

The document does not provide information on the sample size used for the training set. The focus of this 510(k) summary is on the clinical validation of the device, not its development or training process.

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

Since the document does not mention the training set size, it also does not specify how the ground truth for the training set was established. We can infer that the device's "color and pattern recognition techniques" would have been developed using some form of labeled data, likely derived from expert analysis of stained cells, but the specifics are not included in this regulatory submission summary.

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To estimate bone mineral content (BMC, grams) and bone mineral density (BMD, grams/cm').

The DTX-200 candidate device is a dual energy system, where the measured object, in this case the forearm, by the software, i s divided into two compartments, bone and soft-tissue. Having two energies, and two compartments (unknowns) it is possible to establish and solve two formulae with two unknowns. The X-Ray generator is driven at 55 kV , with a current of 300 yAmps. The beam is filtered with Tin (Sn), using the K-Edge of this material to enhance the separation of the low and the high energy. The average energy peaks are approximately 29 keV, and 46 keV respectively. A highly stable X-Ray output, together with a source collimation of 1 mm and a pixel resolution of 0.4mm X 0.4mm, yields images of very high quality. The detector is a sandwich construction, using solid state photodiodes consisting of two diodes with scintillation material. The two energies are separated by the sandwich construction. The X-ray beam meets the first scintillator, where predominantly the low energy is detected, and then it meets the second scintillator, where the rest of the energy is detected. The typical time to estimate bone mineral content and bone mineral density is approximately 4 minutes. The effective patient dose is estimated to be 0.1 micro Sievert per scan.

Here's a breakdown of the acceptance criteria and the studies performed for the DTX-200 Bone Densitometer, based on the provided 510(k) summary:

1. Table of Acceptance Criteria and Reported Device Performance

The provided text focuses on demonstrating substantial equivalence to predicate devices rather than explicit, numerical acceptance criteria for a novel device. The primary performance metrics evaluated are functional correlation and precision.

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

• Functional Correlation Study:

  • Sample Size: 81 individuals
  • Data Provenance: Not explicitly stated whether retrospective or prospective, nor the country of origin. However, the study was sponsored by the device manufacturer (Osteometer Meditech A/S, Denmark), suggesting it was likely conducted in or around their location.

• Precision Study:

  • Sample Size: 15 individuals
  • Data Provenance: Not explicitly stated whether retrospective or prospective, nor the country of origin. Similar to the correlation study, sponsored by the manufacturer.

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

The studies described in the 510(k) summary do not involve "experts" establishing a ground truth in the traditional sense of diagnostic interpretation. Instead, the ground truth is established by the measurements from the predicate device (DTX-100) for the functional correlation study, and the repeated measurements by the DTX-200 itself for the precision study. Therefore, no information on the number or qualifications of experts is provided for determining ground truth in these specific studies.

4. Adjudication Method for the Test Set

Not applicable. The studies are based on quantitative measurements from devices, not human interpretation requiring adjudication.

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, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. The DTX-200 is a bone densitometer (device-only measurement), not an AI-assisted diagnostic tool that would involve human readers.

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

Yes, the studies presented are effectively standalone evaluations of the device's performance. The DTX-200 bone densitometer operates as an algorithm-only device (though it lacks AI in the modern sense) without human intervention in the measurement process itself, beyond operating the machine. The studies evaluate the device's measurements directly.

7. The Type of Ground Truth Used

• Functional Correlation Study: The "ground truth" for the DTX-200's performance was the measurements obtained from the predicate device, the DTX-100 bone densitometer. The study aimed to show strong correlation with an already accepted device.
• Precision Study: The "ground truth" for evaluating precision was the mean of the multiple repeated measurements from the DTX-200 itself for each individual. The goal was to quantify the variability of the device's own measurements.
• For the referenced published literature (2A-2E), the ground truth varies depending on the study (e.g., in vivo bone mineral measurements, in vitro phantom measurements, cadaver studies, comparative measurements between different densitometry methods).

8. The Sample Size for the Training Set

The provided 510(k) summary describes performance evaluation studies (test sets) but does not mention any "training set." This is consistent with devices from this era, where machine learning/AI models requiring training data were not typically employed in this manner for medical device clearance. The DTX-200 uses established physics-based principles (DXA) rather than a data-driven model that would necessitate a training set.

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

Not applicable, as there is no mention of a training set for the DTX-200.

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