The Aperio AT2 DX System is an automated digital slide creation and viewing system. The Aperio AT2 DX System is intended for in vitro diagnostic use as an aid to the pathologist to review and interpret digital pathology slides prepared from formalin-fixed paraffin embedded (FFPE) tissue. The Aperio AT2 DX System is not use with frozen section, cytology, or non-FFPE hematopathology specimens.

The Aperio AT2 DX System is composed of the Aperio AT2 DX scanner, the ImageScope DX review application and Display. The Aperio AT2 DX System is for creation and viewing of digital images of scanned glass slides that would otherwise be appropriate for manual visualization by conventional light microscopy. It is the responsibility of a qualified pathologist to employ appropriate procedures and safeguards to assure the interpretation of images obtained using the Aperio AT2 DX System.

Device Description

The Aperio AT2 DX System is an automated digital slide creation and viewing system. The system is comprised of an Aperio AT2 DX scanner instrument and a Viewing Workstation with a computer and a calibrated monitor executing ImageScope DX viewer software. The system capabilities include digitizing microscope slides at diagnostic resolution, retrieving and displaying digital slides, including support for remote intra-net access over computer networks, providing tools for annotating digital slides, entering data associated with digital slides and displaying the scanned slide images for primary diagnoses by Pathologists.

AI/ML Overview

Here's a breakdown of the acceptance criteria and study details for the Aperio AT2 DX System, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

Acceptance Criteria	Reported Device Performance	Met?
Upper bound of the two-sided 95% CI of the difference between overall major discrepancy rates of WSIR diagnoses and MSR diagnoses is < 4%.	Upper bound of the two-sided 95% CI of the difference was 1.03% (for 0.44% difference).	Yes
Upper bound of the two-sided 95% CI of the overall major discrepancy rate of the WSIR diagnoses is < 7%.	Upper bound of the two-sided 95% CI of the overall major discrepancy rate for WSIR diagnoses was 4.12% (for 3.64% rate).	Yes
Lower bounds of the 2-sided 95% confidence intervals (CIs) of the overall agreements for each precision component are ≥ 85%.	Intra-System: Overall lower bound 95% CI: 95.9%Inter-System/Site: Overall lower bound 95% CI: 93.6%Within-Pathologist: Overall lower bound 95% CI: 92.9%Between-Pathologist: Overall lower bound 95% CI: 91.7%	Yes

2. Sample Size for Test Set and Data Provenance

The text doesn't explicitly state the total number of unique cases used in the clinical study. However, we can infer some details from the precision studies:

Intra-System Study: "Pairwise Agreements" and "Comparison Pairs" numbers are provided for 3 systems, ranging from 193-201 agreements out of 201-204 pairs per system. This suggests hundreds of slides were used.
Inter-System/Site Study: "Pairwise Agreements" and "Comparison Pairs" numbers are provided for 3 system comparisons, ranging from 193-195 agreements out of 202 pairs per comparison.
Within- and Between-Pathologist Study: "Pairwise Agreements" and "Comparison Pairs" numbers are provided for 3 pathologists and 3 pathologist comparisons, ranging from 561-579 agreements out of 606-1818 pairs.

The total reads for the major discrepancy analysis were 7509 for WSIRD and 7522 for MSRD. This suggests a significantly larger number of samples or multiple reads per sample.

Data Provenance: Not explicitly stated (e.g., country of origin, retrospective/prospective). However, the study involved "three independent systems at three different sites" for the Inter-System/Site Precision study, implying a multi-site prospective clinical study for data collection. The use of "original sign-out pathologic diagnosis" as the gold standard implies retrospective access to patient records for comparison.

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

Ground Truth Experts: The text states that "the original sign-out pathologic diagnosis" was used as the gold standard reference diagnosis. This implies that the ground truth was established by multiple qualified pathologists in a routine clinical diagnostic setting as part of their standard practice.
Qualifications of Experts: The experts are described as "qualified pathologists" in the context of their ability to make clinically relevant decisions using conventional microscopes. Specific details like years of experience are not provided.

4. Adjudication Method for the Test Set

The text refers to the "original sign-out pathologic diagnosis" as the gold standard. This suggests that the ground truth was based on the final, adjudicated diagnosis made in a clinical setting, which typically involves consensus or final sign-out by a senior pathologist. There is no mention of a specific adjudication process (e.g., 2+1, 3+1) specifically for the test set ground truth if it differed from the original sign-out. The comparison was against this pre-existing ground truth.

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

Yes, a form of comparative effectiveness study was done. The study directly compared "Whole Slide Image Review (WSIR) diagnoses" (AI-assisted, as the device is for creating and viewing digital slides) against "traditional light microscope slide review (MSR) diagnoses."

Effect Size / Improvement: The study focused on non-inferiority rather than explicit improvement of human readers with AI assistance compared to without AI assistance. The primary acceptance criteria were about ensuring digital review was not significantly worse than traditional microscope review.
- The difference in overall major discrepancy rates between WSIR and MSR was 0.44%, with a 95% CI of (-0.15%, 1.03%). This indicates that the WSIR diagnoses were statistically non-inferior to MSR diagnoses regarding major discrepancies. The upper bound of 1.03% implies that the WSIR method was not substantially worse than MSR (as it was well below the 4% acceptance criterion).

6. Standalone Performance Study

No, a standalone (algorithm only without human-in-the-loop performance) study was not explicitly mentioned or performed as part of the primary clinical evaluation. The device is described as an "aid to the pathologist to review and interpret digital pathology slides," meaning it's intended for human-in-the-loop use. The performance evaluation directly involved pathologists using the system (WSIR diagnoses).

7. Type of Ground Truth Used (Test Set)

The primary ground truth used for evaluating accuracy was the "original sign-out pathologic diagnosis," which represents expert consensus or final clinical pathology diagnosis.

8. Sample Size for the Training Set

The document does not specify the sample size for the training set. The descriptions focus on the performance evaluation (test set) for regulatory clearance.

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

As the training set information is not provided, how its ground truth was established is not detailed in this document.

Summary

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May 20, 2019

Image /page/0/Picture/1 description: The image contains the logo of the U.S. Food and Drug Administration (FDA). The logo consists of two parts: a symbol on the left and the text "FDA U.S. FOOD & DRUG ADMINISTRATION" on the right. The symbol on the left is a stylized representation of the Department of Health & Human Services seal. The text on the right is in blue, with "FDA" in a larger font size than the rest of the text.

Leica Biosystems Imaging, Inc. Christine Kishi Sr. RA Specialist 1360 Park Center Dr. Vista, CA 92081

Re: K190332

Trade/Device Name: Aperio AT2 DX System Regulation Number: 21 CFR 864.3700 Regulation Name: Whole slide imaging system Regulatory Class: Class II Product Code: PSY Dated: February 13, 2019 Received: February 14, 2019

Dear Christine Kishi:

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 device marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. 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 located 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.

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

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for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/CombinationProducts/GuidanceRegulatoryInformation/ucm597488.html; good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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

For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/) and CDRH Learn (http://www.fda.gov/Training/CDRHLearn). 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 (http://www.fda.gov/DICE) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

Sincerely,

Yun-Fu Hu, Ph.D. Deputy Director Division of Molecular Genetics and Pathology OHT7: Office of In Vitro Diagnostics and Radiological Health Office of Product Evaluation and Quality Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known) K190332

Device Name Aperio AT2 DX System

Indications for Use (Describe)

Type of Use (Select one or both, as applicable)X Prescription Use (Part 21 CFR 801 Subpart D)

Over-The-Counter Use (21 CFR 801 Subpart C)

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510(k) Summary Aperio AT2 DX System

I. Submitter

Leica Biosystems Imaging, Inc 1360 Park Center Dr. Vista, CA 92081

II. Contact Person

Christine Kishi Sr. Regulatory Affairs Specialist 1360 Park Center Dr. Vista, CA 92081 christine.kishi@leicabiosystems.com Phone: (760) 539-1194 Fax: (760) 539-1116

III. Device

Proprietary Name of the Device: Aperio AT2 DX System Classification Name: Whole Slide Imaging System Regulation Number: 21 CFR Part 864.3700 Regulatory Class: Class II Product code: PSY

IV. Predicate Device

Philips IntelliSite Pathology Solution (PIPS) DEN160056

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Device Description V.

Clearance of this premarket application will enable the Aperio AT2 DX System comprised of a scanner and a viewing station for the primary diagnosis of formalin-fixed paraffin-embedded tissue.

System:

Image Acquisition:

The Aperio AT2 DX has a 400 glass slides capacity via an autoloader. High numeric aperture 20x objective, as found on conventional microscopes, is used to produce high-quality images. The Aperio AT2 DX digital slide scanner employs a linear-array scanning technique that generates images and accounts for merging scan stripes along the scanning axis. The result is seamless digital slide images.

The image acquisition software components include Console DX and Controller DX. The Console DX application is a user-interface for the operator. It allows users to initiate scanning and select appropriate slide areas to scan. The Controller DX application is a software subsystem that runs on the Aperio AT2 DX scanner Control PC.

Image Viewing:

The remote image viewing capabilities of the ImageScope DX software subsystem supports reading digital slides on a calibrated monitor, enabling Pathologists to make clinically relevant decisions analogous to those they make using a conventional microscope. ImageScope DX includes support for locally or intranet connected image Viewing Workstation computers, which run digital slide viewing. The software includes elements to support data confidentiality and integrity.

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VI. Intended Use

The Aperio AT2 DX System is an automated digital slide creation and viewing system. The Aperio AT2 DX System is intended for in vitro diagnostic use as an aid to the pathologist to review and interpret digital images of surgical pathology slides prepared from formalin-fixed paraffin embedded (FFPE) tissue. The Aperio AT2 DX System is not intended for use with frozen section, cytology, or non-FFPE hematopathology specimens.

The Aperio AT2 DX System is composed of the Aperio AT2 DX scanner, the ImageScope DX review application and Display. The Aperio AT2 DX System is for creation and viewing of digital images of scanned glass slides that would otherwise be appropriate for manual visualization by conventional light microscopy. It is the responsibility of a qualified pathologist to employ appropriate procedures and safeguards to assure the validity of the interpretation of images obtained using the Aperio AT2 DX System.

Comparison of technological characteristics with the predicate VII. device

Item	Predicate DevicePhilips IntelliSite Pathology Solution(PIPS) (DEN160056)	Candidate DeviceAperio AT2 DX System
Intended Use/Indicationsfor Use	The Philips IntelliSite PathologySolution (PIPS) is an automated digitalslide creation, viewing, andmanagement system. The PIPS isintended for in vitro diagnostic use asan aid to the pathologist to review andinterpret digital images of surgicalpathology slides prepared fromformalin-fixed paraffin embedded(FFPE) tissue. The PIPS is notintended for use with frozen section,cytology, or non-FFPEhematopathology specimens.The PIPS comprises the ImageManagement System (IMS), the UltraFast Scanner (UFS) and Display. ThePIPS is for creation and viewing ofdigital images of scanned glass slidesthat would otherwise be appropriatefor manual visualization byconventional light microscopy. It is theresponsibility of a qualified	The Aperio AT2 DX System is anautomated digital slide creationand viewing system. The AperioAT2 DX System is intended for invitro diagnostic use as an aid tothe pathologist to review andinterpret digital images of surgicalpathology slides prepared fromformalin-fixed paraffin embedded(FFPE) tissue. The Aperio AT2DX System is not intended for usewith frozen section, cytology, ornon-FFPE hematopathologyspecimens.The Aperio AT2 DX System iscomposed of the Aperio AT2 DXscanner, the ImageScope DXreview application and Display.The Aperio AT2 DX System is for
Item	Predicate DevicePhilips IntelliSite Pathology Solution(PIPS) (DEN160056)	Candidate DeviceAperio AT2 DX System
	pathologist to employ appropriateprocedures and safeguards to assurethe validity of the interpretation ofimages obtained using PIPS.	creation and viewing of digitalimages of scanned glass slides thatwould otherwise be appropriatefor manual visualization byconventional light microscopy. Itis the responsibility of a qualifiedpathologist to employ appropriateprocedures and safeguards toassure the validity of theinterpretation of images obtainedusing the Aperio AT2 DX System.
Specimentype	Surgical pathology slides preparedfrom formalin-fixed, paraffin-embedded tissue	Same
Principle ofoperation	The technician loads the slides into theWSI scanner. The scanner scans theslides and generates WSI image foreach slide. The technician performsQuality Control (QC) on scanned WSIimages and rescan the slide when QCis failed. The acquired WSI images arestored in an end user provided imagestorage attached to the local network.During review, the pathologist opensWSI images acquired with the WSIscanner from the image storage,performs further QC and reads WSIimages of the slides to make adiagnosis.	Same
DeviceComponents	WSI scanner (PIPS Ultra FastScanner), Image Management Systemand color monitor display	Same (Aperio AT2 DX scanner,ImageScope DX application, andcolor monitor display)

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Differences
Item	Device	Predicate
Whole Slide ImagingScanner	Aperio AT2 DX scannerwith loading capacity of400 slides	Ultra Fast Scanner withloading capacity of 300slides
Graphical User Interface	ImageScope DX	Image ManagementSystem
Monitor Display	Dell MR2416 monitor	PS27QHDCR

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VIII. Performance Data

The performance testing was conducted via a series of studies that included Accuracy, Intra-System, Inter-System/Site. Within-Pathologist and Between-Pathologist precision.

The accuracy was evaluated by analyzing the concordance of the diagnoses made using the Aperio AT2 DX System (also known as WSIR diagnosis) with the gold standard reference diagnoses (the original sign-out pathologic diagnosis), and the concordance of traditional light microscope slide review (MSR) diagnoses with the gold standard reference diagnoses. Accuracy was assessed by analyzing major discrepancy rates for each study modality versus the gold standard reference diagnosis and calculating the difference between the major discrepancy rates for WSIR diagnosis and MSR diagnosis. Major discrepancy was defined as a difference in diagnoses that resulted in a clinically important difference in patient management.

The acceptance criteria were as follows:

The upper bound of the two-sided 95% CI of the difference between the overall major discrepancy rates of WSIR diagnoses and MSR diagnoses is <4%.
The upper bound of the two-sided 95% CI of the overall major discrepancy . rate of the WSIR diagnoses is <7%.

The precision of the Aperio AT2 DX System was evaluated in 3 studies.

For the Intra-System Precision study, the objective was to assess precision within each of three independent systems, and overall within system precision.
. For the Inter-System/Site Precision study, the objective was to assess precision between systems/sites (three independent systems at three different sites) and overall between system/site precision.
For the Within- and Between-Pathologist Precision study, the objective was to . assess precision within and between pathologists (using images generated from a single system), overall within pathologist precision, and overall between pathologist precision.

The Precision was considered acceptable if the lower bounds of the 2-sided 95% confidence intervals (CIs) of the overall agreements for each precision component (e.g. intra-system, inter-system/site) were ≥ 85%.

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	Number of	Number of	Agreement Rate and 95% CI*
System	PairwiseAgreements	ComparisonPairs	0/0Agreement	Lower	Upper
System 1	193	201	96.0%	91.0%	100%
System 2	201	201	100%	98.2%	100%
System 3	199	204	97.5%	93.6%	100%
Overall	593	606	97.9%	95.9%	99.5%

Table 1. Intra-System Study: Agreement Within Systems

A bootstrap approach was used to calculate 95% CIs with the following exception. When the agreement estimate was 100%, the Arcsine (variance stabilizing transformation) approach that corrected for the continuity was used to calculate CIs (Pires and Amado, 2008).

Table 2. Inter-System/Site Study: Agreement Between Systems

	Number ofPairwiseAgreements	Number ofComparisonPairs	Agreement Rate and 95%CI*
System			%Agreement	Lower	Upper
System 1 vs System 2	195	202	96.5%	94.1%	99.0%
System 1 vs System 3	194	202	96.0%	93.1%	98.5%
System 2 vs System 3	193	202	95.5%	92.6%	98.0%
Overall	582	606	96.0%	93.6%	98.2%

*A bootstrap approach was used to calculate 95% CIs.

Table 3. Within/Between -Pathologist Study: Agreement Within Pathologists

	Number of	Number of	Agreement Rate and 95% CI*
Pathologist	Pairwise	Comparison	% Agreement	Lower	Upper
	Agreements	Pairs
Pathologist 1	561	୧୦୧	92.6%	89.6%	95.7%
Pathologist 2	રેતેર	୧୦୧	98.2%	96.3%	99.7%
Pathologist 3	571	୧୦୧	94.2%	91.4%	96.9%
Overall	1727	1818	95.0%	92.9%	96.8%

*A bootstrap approach was used to calculate 95% CIs.

Table 4. Within- and Between-Pathologist Study: Agreement Between Pathologists

PathologistComparison	Number ofPairwiseAgreements	Number ofComparisonPairs	Agreement Rate and 95% CI*
Pathologist 1 vsPathologist 2	572	606	94.4%	91.6%	96.9%

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Pathologist 1 vsPathologist 3	562	606	92.7%	89.9%	95.4%
Pathologist 2 vsPathologist 3	579	606	95.5%	93.1%	97.7%
Overall	1713	1818	94.2%	91.7%	96.4%

*A bootstrap approach was used to calculate 95% CIs.

Table 5. Overall Major Discrepancy Rates for the WSIR and MSR Modalities and the Difference Between the Overall Major Discrepancy Rates

	WSIRD MajorDiscrepancy*			MSRD MajorDiscrepancy*			Difference in MajorDiscrepancy Rates(WSIRD minusMSRD)
	TotalReads	Rate(%)	Model95% CI	TotalReads	Rate(%)	Model95% CI	%	Model95% CI
Observed		3.73	-		3.28	-	0.45	-
Model	7509	3.64	(3.21,4.12)	7522	3.20	(2.80,3.65)	0.44	(-0.15%, 1.03%)

MSRD = MSR diagnosis, WSIRD = WSIR diagnosis

IX. Conclusions

The clinical study results demonstrate that AT2 DX System is substantially equivalent to the predicate device.

Regulation Number and Section

§ 864.3700 Whole slide imaging system.

(a)
Identification. The whole slide imaging system is an automated digital slide creation, viewing, and management system intended as an aid to the pathologist to review and interpret digital images of surgical pathology slides. The system generates digital images that would otherwise be appropriate for manual visualization by conventional light microscopy.(b)
Classification. Class II (special controls). The special controls for this device are:(1) Premarket notification submissions must include the following information:
(i) The indications for use must specify the tissue specimen that is intended to be used with the whole slide imaging system and the components of the system.
(ii) A detailed description of the device and bench testing results at the component level, including for the following, as appropriate:
(A) Slide feeder;
(B) Light source;
(C) Imaging optics;
(D) Mechanical scanner movement;
(E) Digital imaging sensor;
(F) Image processing software;
(G) Image composition techniques;
(H) Image file formats;
(I) Image review manipulation software;
(J) Computer environment; and
(K) Display system.
(iii) Detailed bench testing and results at the system level, including for the following, as appropriate:
(A) Color reproducibility;
(B) Spatial resolution;
(C) Focusing test;
(D) Whole slide tissue coverage;
(E) Stitching error; and
(F) Turnaround time.
(iv) Detailed information demonstrating the performance characteristics of the device, including, as appropriate:
(A) Precision to evaluate intra-system and inter-system precision using a comprehensive set of clinical specimens with defined, clinically relevant histologic features from various organ systems and diseases. Multiple whole slide imaging systems, multiple sites, and multiple readers must be included.
(B) Reproducibility data to evaluate inter-site variability using a comprehensive set of clinical specimens with defined, clinically relevant histologic features from various organ systems and diseases. Multiple whole slide imaging systems, multiple sites, and multiple readers must be included.
(C) Data from a clinical study to demonstrate that viewing, reviewing, and diagnosing digital images of surgical pathology slides prepared from tissue slides using the whole slide imaging system is non-inferior to using an optical microscope. The study should evaluate the difference in major discordance rates between manual digital (MD) and manual optical (MO) modalities when compared to the reference (
e.g., main sign-out diagnosis).(D) A detailed human factor engineering process must be used to evaluate the whole slide imaging system user interface(s).
(2) Labeling compliant with 21 CFR 809.10(b) must include the following:
(i) The intended use statement must include the information described in paragraph (b)(1)(i) of this section, as applicable, and a statement that reads, “It is the responsibility of a qualified pathologist to employ appropriate procedures and safeguards to assure the validity of the interpretation of images obtained using this device.”
(ii) A description of the technical studies and the summary of results, including those that relate to paragraphs (b)(1)(ii) and (iii) of this section, as appropriate.
(iii) A description of the performance studies and the summary of results, including those that relate to paragraph (b)(1)(iv) of this section, as appropriate.
(iv) A limiting statement that specifies that pathologists should exercise professional judgment in each clinical situation and examine the glass slides by conventional microscopy if there is doubt about the ability to accurately render an interpretation using this device alone.