CaloPix

K250414 · Tribun Health · QKQ · May 14, 2025 · Pathology

Device Facts

• Record ID: K250414
• Device Name: CaloPix
• Applicant: Tribun Health
• Product Code: QKQ · Pathology
• Decision Date: May 14, 2025
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 864.3700
• Device Class: Class 2
• Attributes: Software as a Medical Device

Indications for Use

For in Vitro Diagnostic (IVD) Use. CaloPix is a software only device for viewing and management of digital images of scanned surgical pathology slides prepared from Formalin-Fixed Paraffin Embedded (FFPE) tissue. CaloPix is intended for in vitro diagnostic use as an aid to the pathologist to review, interpret and manage these digital slide images for the purpose of primary diagnosis. CaloPix is not intended for use with frozen sections, cytology, or non-FFPE hematopathology specimens. It is the responsibility of a qualified pathologist to employ appropriate procedures and safeguards to assure the quality of the images obtained and the validity of the interpretation of images using CaloPix. CaloPix is intended to be used with the interoperable components specified in the below Table. Scanner Hardware: Leica Aperio GT 450 DX scanner, Hamamatsu NanoZoomer S360MD Slide scanner. Scanner Output file format: SVS, NDPI. Interoperable Displays: Dell U3223QE, JVC Kenwood JD-C240BN01A.

Device Story

CaloPix is a web-based software-only device for viewing/managing digital Whole Slide Images (WSI) of FFPE tissue slides; inputs are digital images from FDA-cleared scanners (Leica Aperio GT 450 DX or Hamamatsu NanoZoomer S360MD). Software ingests images via LIS-integrated module; organizes slides into cases; provides viewer for pathologist review. Functionalities include continuous zooming/panning, distance/area measurements, manual annotations, manual counting, and multi-window comparison. Pathologist performs manual quality control before diagnostic review; diagnosis documented in external LIS. Used in clinical settings by pathologists; deployed on customer-managed or cloud infrastructure; accessed via web browser. Benefits include digital workflow efficiency for primary diagnosis while maintaining diagnostic accuracy equivalent to conventional light microscopy.

Clinical Evidence

Bench testing only. Performance validated per FDA guidance for digital pathology WSI devices. Pixel-wise color comparison (CIEDE2000 < 3) confirmed identical image reproduction compared to predicate viewers (NZViewMD, Aperio WebViewer DX). Measurement accuracy for distance and area verified against predicate systems. Turnaround times for loading, panning, and zooming met pre-defined acceptance criteria. Human factors validation study confirmed safety and effectiveness for intended users.

Technological Characteristics

Web-based software-only device; operates on Windows 10+ PCs via Chrome/Edge browsers. Supports SVS and NDPI file formats. Implements intentional image compression (JPEG Q=94 or 100). Connectivity via local network or cloud. No automated image analysis/CAD. Validated for use with specific scanners (Leica Aperio GT 450 DX, Hamamatsu NanoZoomer S360MD) and displays (Dell U3223QE, JVC Kenwood JD-C240BN01A).

Indications for Use

Indicated for use by pathologists to review, interpret, and manage digital images of FFPE surgical pathology slides for primary diagnosis. Not for use with frozen sections, cytology, or non-FFPE hematopathology specimens.

Regulatory Classification

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.

Special Controls

A whole slide imaging system must comply with the following special controls: (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; (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: (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 factors 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: The intended use statement must include the information described in paragraph (i) (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 paragraph (1)(ii) and (1)(iii) of this section, as appropriate. (iii) A description of the performance studies and the summary of results, including those that relate to paragraph (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.

*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.

Predicate Devices

• NanoZoomer S360MD Slide scanner system (K213883)
• Aperio GT 450 DX (K232202)

Submission Summary (Full Text)

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FDA

U.S. FOOD &amp; DRUG

ADMINISTRATION

# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY

## I Background Information:

A 510(k) Number

K250414

B Applicant

Tribun Health

C Proprietary and Established Names

CaloPix

D Regulatory Information

| Product Code(s) | Classification | Regulation Section | Panel |
| --- | --- | --- | --- |
| QKQ | Class II | 21 CFR 864.3700 - Whole Slide Imaging System | PA - Pathology |

## II Submission/Device Overview:

A Purpose for Submission:

New device

B Type of Test:

Software only device

## III Intended Use/Indications for Use:

A Intended Use(s):

See Indications for Use below.

B Indication(s) for Use:

Food and Drug Administration

10903 New Hampshire Avenue

Silver Spring, MD 20993-0002

www.fda.gov

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For in Vitro Diagnostic (IVD) Use.

CaloPix is a software only device for viewing and management of digital images of scanned surgical pathology slides prepared from Formalin-Fixed Paraffin Embedded (FFPE) tissue. CaloPix is intended for in vitro diagnostic use as an aid to the pathologist to review, interpret and manage these digital slide images for the purpose of primary diagnosis. CaloPix is not intended for use with frozen sections, cytology, or non-FFPE hematopathology specimens.

It is the responsibility of a qualified pathologist to employ appropriate procedures and safeguards to assure the quality of the images obtained and the validity of the interpretation of images using CaloPix.

CaloPix is intended to be used with the interoperable components specified in the below Table.

| Scanner Hardware | Scanner Output file format | Interoperable Displays |
| --- | --- | --- |
| Leica Aperio GT 450 DX scanner | SVS | Dell U3223QE |
| Hamamatsu NanoZoomer S360MD Slide scanner | NDPI | JVC Kenwood JD-C240BN01A |

# C Special Conditions for Use Statement(s):

Rx - For Prescription Use Only

# IV Device/System Characteristics:

# A Device Description:

CaloPix, version 6.1.0 IVDUS, is a web-based software-only device that is intended to aid pathology professionals in viewing, interpreting and managing digital Whole Slide Images (WSI) of glass slides prepared from FFPE tissue specimens acquired from FDA cleared digital pathology scanners and viewed on FDA cleared displays as specified in the intended use Table above. The WSIs undergo intentional compression when visualized in CaloPix, as shown in Table below.

| Scanner Hardware | Scanner Output file format | Compression Methods |
| --- | --- | --- |
| Leica Aperio GT 450 DX scanner | SVS | Compressed to 94% of the source of SVS file, or JPEG Q = 94 |
| Hamamatsu NanoZoomer S360MD Slide scanner | NDPI | Compressed to 100% of the source of NDPI file, or JPEG Q = 100. |

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CaloPix does not include any automated Image Analysis Applications that would constitute computer aided detection or diagnosis. CaloPix is for viewing digital images of scanned glass slides that would otherwise be appropriate for manual visualization by conventional light microscopy.

# CaloPix is operated as follows:

1. After the WSI image is acquired using one of the intended scanners, in accordance with the WSI scanner Instructions for Use Manual and any additional standard laboratory procedures, the WSI becomes available in the scanner's file system. The WSI is then sent to end-user-provided image storage attached to the local network. (not part of the subject device).
2. The WSI is then ingested into the CaloPix database at which point the CaloPix workflow is initiated. Ingestion of the slides is performed through an integrated module that allows their automatic indexation based on patient data retrieved from the Laboratory Information Systems (LIS). After their ingestion, image files are stored in a CaloPix-specific file storage environment, that can be on premises or in the cloud. After ingestion, scanned WSIs can be organized in the CaloPix database consisting of folders (cases) containing patient identification data and other information from a LIS.
3. The reading pathologist selects a case from a worklist within CaloPix, whereby CaloPix fetches the associated images from the image storage.
4. The image quality and other image data must be manually evaluated in the viewer by the pathologist and deemed acceptable, prior to reviewing a WSI for diagnosis.
5. The reading pathologist uses CaloPix to view and interpret the images using the following functionalities:

Continuous zooming and panning
Measuring distances
- Creating annotations during review using manual annotation tools and manual counting tools
Viewing and comparing multiple slide images simultaneously in multiple windows
- Tracking of visited areas and annotations and digital bookmarks.

6. The above steps are repeated as required.
7. After viewing all images for a case, the pathologist will make a diagnosis. The diagnosis will be documented in another system, e.g., a LIS.
8. Upon conclusion of using the system, the pathologist clicks "Sign Out" in the user menu.

CaloPix is designed to be deployed to a customer-managed infrastructure or in a cloud infrastructure and may be accessed on the user's workstation browser. CaloPix operates with and is validated for use with the components specified in the tables below.

Table 1: Interoperable Components for Use with CaloPix

| Manufacturer | Model |
| --- | --- |
| Hamamatsu Photonics K.K. | Scanner: NanoZoomer S360MD Slide scanner Display: JVC Kenwood JD-C240BN01A |
| Leica Biosystems Imaging, Inc. | Scanner: Aperio GT 450 DX scanner Display: Dell U3223QE |

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Table 2: Computer environment / System requirements

| Environment | Component | Minimum Requirements |
| --- | --- | --- |
| Hardware | Computer | PC computer |
| | Processor | Minimum: Intel® Core™ i5 / AMD Ryzen 5 Recommended: Intel® Core™ i7 / AMD Ryzen 7 |
| | Graphics card | Nvidia GeForce RTX 2060 / AMD Radeon RX 480 |
| | Memory | Minimum: 4GB / Recommended: 8GB |
| | Network connectivity | 10 Mbit/s between the client and the server |
| | Keyboard / Mouse / Trackpad | Standards keyboard and mouse supported by Windows 10 and higher versions Optional: 3D SpaceMouse Wireless, 3D SpaceMouse Pro from 3D connection |
| Software | Operating system | Windows 10 or higher |
| | Supported browsers | Google Chrome (version 91 and above) Microsoft Edge (version 106 and above) |

# B Instrument Description Information:

1. Instrument Name: CaloPix

2. Specimen Identification: CaloPix uses digital images of Hematoxylin and Eosin (H&amp;E) stained glass slides obtained from the NanoZoomer S360MD Slide scanner (K213883) or the Aperio GT 450 DX Scanner (K232202). The reading pathologist selects a case (patient folder) from a worklist whereby the subject device fetches the associated images from the image storage. The scanned images are identified based on the previously assigned specimen identifier such as patient identifiers, barcodes, etc. CaloPix includes an automatic import module that automatically associates digitized glass slides with the correct case (patient folder), using the assigned specimen identifier.

3. Specimen Sampling and Handling: Specimen sampling and handling are performed upstream and independent of the use of CaloPix. Specimen sampling includes surgical pathology specimens such as biopsy or resection specimens which are processed using standard histology techniques. The Formalin-Fixed Paraffin Embedded (FFPE) tissue sections are H&amp;E stained and scanned using the NanoZoomer S360MD slide scanner (K213883) or the Aperio GT 450 DX scanner (K232202).

4. Calibration: Not applicable

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5. Quality Control:
The scanning technician should perform quality control of all glass slides and WSIs following the scanner Instructions for Use and other laboratory procedures. Prior to using a WSI for diagnosis, the pathologist should ensure that all scanned slide images have been imported for every case and the images are of acceptable quality for diagnostic purposes. The pathologist reviews scanned images from all the slides associated with a case before rendering a diagnosis.

V Substantial Equivalence Information:

A Predicate Device Name(s):
NanoZoomer S360MD Slide scanner system, Aperio GT 450 DX

B Predicate 510(k) Number(s):
K213883, K232202

C Comparison with Predicate(s):

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| Device & Predicate Device(s): | K250414 | K213883 | K232202 |
| --- | --- | --- | --- |
| Device Trade Name | CaloPix | NanoZoomer S360MD Slide scanner system | Aperio GT 450 DX |
| General Device Characteristic Similarities |
| Intended Use/Indications For Use | For in Vitro Diagnostic (IVD) Use.CaloPix is a software only device for viewing and management of digital images of scanned surgical pathology slides prepared from Formalin-Fixed Paraffin Embedded (FFPE) tissue.CaloPix is intended for in vitro diagnostic use as an aid to the pathologist to review, interpret and manage these digital slide images for the purpose of primary diagnosis.CaloPix is not intended for use with frozen sections, cytology, or non-FFPE hematopathology specimens.It is the responsibility of a qualified pathologist to employ appropriate procedures and safeguards to assure the quality of the images obtained and the validity of the interpretation of images using CaloPix.CaloPix is intended to be used with the interoperable components specified in the below Table. | The NanoZoomer S360MD Slide scanner system (“NanoZoomer System”) is an automated digital slide creation, viewing, and management system. The NanoZoomer 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 NanoZoomer System is not intended for use with frozen section, cytology, or non-FFPE hematopathology specimens.The NanoZoomer System comprises the NanoZoomer S360MD Slide scanner, the NZViewMD Software and the JVC Kenwood JD-C240BN01A display. The NanoZoomer 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 NanoZoomer System. | The Aperio GT 450 DX is an automated digital slide creation and viewing system. The Aperio GT450 DX 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 GT 450 DX is for creation and viewing of digital images of scanned glass slides that would otherwise be appropriate for manual visualization by conventional light microscopy.Aperio GT 450 DX is comprised of the Aperio GT 450 DX scanner, which generates images in the Digital Imaging and Communications in Medicine (DICOM) and in the ScanScope Virtual Slide (SVS) file formats, the Aperio WebViewer DX viewer, and the displays. The Aperio GT 450 DX is intended to be used with the interoperable components specified in Table 1.Table 1: Interoperable components of Aperio GT 450 DX |
| Scanner Hardware | Scanner Output file format | Interoperable Displays | Scanner Hardware | Scanner output file format | Interoperable Displays |
| Leica Aperio GT 450 DX scanner | SVS | Dell U3223QE | Aperio GT 450 DX scanner | SVS | Aperio WebViewer DX | Barco MDPC-8127 Dell UP3017 Dell U3023E Dell U3223QE |
| Hamamatsu NanoZoomer | NDPI | JVC Kenwood | Aperio GT 450 DX scanner | SVS | Sectra Digital Pathology Module (3.3) | Dell U3223QE |
| |

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| | S360MD
Slide scanner | JD-C240BN01A | | specimens. 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 GT 450 DX. |
| --- | --- | --- | --- | --- |
| Principle of Operation | After the WSIs are acquired by using the NanoZoomer S360MD Slide scanner or the Leica Aperio GT 450 DX scanner, the WSI are stored in customer provided image storage. During image review, the pathologist opens the WSI (in NDPI or SVS format, depending on the scanner used for digitization) from the image storage using CaloPix 6.1.0 IVDUS; performs further QC and then reads the WSI to make a diagnosis | | The NanoZoomer System is a WSI system. The system’s embedded image processing software is responsible for image acquisition and the processing of individual tiles prior to image composition or stitching. The NZAcquireMD software organizes all WSI tiles into a single NDPI file, which is a proprietary file format. WSI are automatically saved to the hard disk during scanning and may be viewed later by using the included viewing software. During the review, the pathologist opens WSI from the image storage attached to the local network, performs further QC and reads WSI of the slides to make a diagnosis. | The Aperio GT 450 DX is a WSI system. The technician places the slides into the Aperio GT 450 DX scanner. The scanner automatically loads the slides, takes the micro images, finds the tissues, and scans the slides. The scanner also automatically performs quality control (QC) and notifies the user of any image quality issue during the image acquisition. The image data is sent to end-user-provided image storage attached to the local network. During the review, the pathologist opens WSI images acquired with the WSI scanner from the image storage, performs further QC, and reads WSI images of the slides to make a diagnosis. |
| Specimen Type | Digitized surgical pathology slides prepared from FFPE tissue | | Same | Same |
| Image storage | Images are stored in the end-user-provided image storage attached to the local network or in the cloud. | | Images are stored in the end-user-provided image storage attached to the local network | Images are stored in the end-user-provided image storage attached to the local network. |
| Type of Software Application | Internet browser-based application | | PC-based installed application | Same |
| **General Device Characteristic Differences** | | | | |
| Device Components | CaloPix image viewing software | | WSI scanner (NanoZoomer S360MD Slide scanner), Image Management System (NZViewMD), Display | WSI scanner (Aperio GT450 DX scanner), Image Management System (Aperio WebViewer DX image viewing software), Display |
| Diagnostic Image File Formats | Hamamatsu NDPI.
Leica SVS. | | Hamamatsu NDPI. | Leica SVS and DICOM. |
| Image Manipulation Functions | Panning, zooming, image adjustments, annotations, distance/area measurements and manual counting. | | Panning, zooming, image adjustments, annotations, distance/area measurements. | Panning, zooming, gamma functions, annotations, and measurements (distance). |
| End User’s Interface | CaloPix | | NZViewMD | Aperio WebViewer DX for Leica SVS,
Sectra Digital Pathology Module (3.3) for Leica SVS and DICOM |

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VI Standards/Guidance Documents Referenced:

1. FDA Guidance “Technical Performance Assessment of Digital Pathology Whole Slide Imaging Devices”. April 20, 2016.
2. FDA Guidance “Applying Human Factors and Usability Engineering to Medical Devices”. February 3, 2016.
3. FDA Guidance “Content of Premarket Submissions for Device Software Functions”. June 14, 2023.
4. FDA Guidance “Cybersecurity in Medical Devices: Quality System Considerations and Content of Premarket Submissions”. September 27, 2023.
5. ISO 14971 Third Edition 2019-12, 5-125, Medical devices – Applications of risk management to medical devices.
6. IEC 62304 Edition 1.1 2015-06 CONSOLIDATED VERSION, 13-79. Medical device software – Software life cycle processes.
7. IEC 62366-1 Edition 1.1 2020-06 CONSOLIDATED VERSION, 5-129, Application of usability engineering to medical devices.
8. IEC 82304-1 Edition 1.0 2016-10, 13-97, Health software - Part 1: General requirements for product safety.
9. ISO CIE 11664-6 Second edition 2022-08, 9-148, Colorimetry - Part 6: CIEDE2000 colour-difference formula
10. ISO 20417 First edition 2021-04 Corrected version 2021-12, 5-135, Medical devices - Information to be supplied by the manufacturer.
11. ISO 15223-1 Fourth edition 2021-07, 5-134, Medical devices - Symbols to be used with information to be supplied by the manufacturer - Part 1: General requirements.

VII Performance Characteristics (if/when applicable):

A Analytical Performance:

1. Precision/Reproducibility: Not applicable
2. Linearity: Not applicable
3. Analytical Specificity/Interference: Not applicable
4. Accuracy (Instrument): Not applicable
5. Carry-Over: Not applicable

B Other Supportive Instrument Performance Characteristics Data:

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Technical performance testing was conducted with the subject device, CaloPix as specified below.

1. Bench Testing - Pixelwise comparison test

Pixel-wise comparison testing to demonstrate identical image reproduction was conducted to compare WSIs reproduced by the subject device and the comparators as listed in Table 3 below. The subject device was compared to the predicate device's image review manipulation software (IRMS, as defined in FDA guidance document, "Technical Performance Assessment of Digital Pathology Whole Slide Imaging Devices" dated April 20, 2016) using the quantitative pixel-wise comparison method. The basis for the comparison was the CIEDE2000 color difference equation, $\Delta E_{00}$. The devices were tested as operating with the intended components, including the scanner, specific file format, image management systems (subject device with the intended browsers and the comparator [predicate device IRMS]) and displays, as specified in the Table 3 below.

For each of the configurations in Table 3 below, the device was tested with multiple slides across multiple regions of interest (ROI) at multiple magnification levels. A total of 30 FFPE glass slides of normal and tumor tissues from various human anatomical organs were used in the testing. For each configuration, the glass slides were scanned on a corresponding intended scanner to obtain 30 WSIs. For each of the 30 WSIs, 3 ROIs from different locations were selected by qualified personnel to represent various features in the tissue samples. Each ROI was captured at 2 magnification levels (20x, 40x).

Screenshots were captured for the intended display while viewing with the subject device and predicate device IRMS. The screenshots were cropped and registered to be pixelwise comparable. The cropped image included most of the pixels in the image except for those in the viewer-specific user interface areas.

For each configuration, two sets of images were collected: comparator (predicate device IRMS) and the subject device (CaloPix with the intended browser). Each image set included 180 images that covered all combinations of 30 slides, 3 ROIs and 2 magnification levels. The testing data, including the overview images of the 30 glass slides with annotations of the ROIs, registration/cropping information, and captured images, were provided in the FDA specific format.

The comparator (predicate device IRMS) image set was used as the reference to compare the subject device image set to determine whether all the 180 image-pairs were identical for each configuration and each intended display. Two images are considered identical if the 95th percentile of the pixelwise differences, computed using the International Commission on Illumination (CIE) color difference metric CIEDE2000 ($\Delta E_{00}$), is less than $3\Delta E_{00}$. Testing results showed that the pixelwise differences across all 180 image-pairs per configuration and per intended display were less than $3\Delta E_{00}$. The maximum (max), minimum (min), and mean of the 95th percentile $\Delta E_{00}$ value were reported in Table 3. Testing results demonstrated that WSIs reproduced by CaloPix are identical to images reproduced by the predicate devices.

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Table 3: CaloPix Pixelwise Comparison Testing Results

| Scanner | Image File Format | Subject Device /Browser | Comparator (Predicate device IRMS) | Display | Results |
| --- | --- | --- | --- | --- | --- |
| Hamamatsu NanoZoomer S360MD Slide scanner | NDPI | CaloPix /Chrome | NZViewMD | Display JVC Kenwood JD-C240BN01A | max (95th percentile ΔE00) = 1.2452 |
| | | | | | min (95th percentile ΔE00) = 0.3661 |
| | | | | | mean (95th percentile ΔE00) = 0.6214 |
| | | CaloPix /Edge | NZViewMD | | max (95th percentile ΔE00) = 1.2452 |
| | | | | | min (95th percentile ΔE00) = 0.3661 |
| | | | | | mean (95th percentile ΔE00) = 0.6214 |
| Leica Aperio GT450DX scanner | SVS | CaloPix /Chrome | Aperio WebViewer DX/Chrome | Display Dell U3223QE | max (95th percentile ΔE00) = 2.0310 |
| | | | | | min (95th percentile ΔE00) = 0.4540 |
| | | | | | mean (95th percentile ΔE00) = 1.0303 |
| | | CaloPix /Edge | Aperio WebViewer DX/Edge | | max (95th percentile ΔE00) = 2.0310 |
| | | | | | min (95th percentile ΔE00) = 0.4540 |
| | | | | | mean (95th percentile ΔE00) = 1.0309 |

# 2. Turnaround Time

Turnaround times (TAT) for image loading, panning and zooming were tested with CaloPix when using all the supported browsers, as listed in table 4 below. A total of 20 biological glass slides, from a diverse set of human anatomic sites, were scanned using the intended scanners to generate 20 WSI in NDPI format and 20 WSI in SVS format. Below acceptance criteria was used:

- $&lt; 10$ seconds to load and fully display an image in Field of View (FOV) across all images
- $&lt; 7$ seconds to render the FOV while zooming and panning across all images

Test results for different scenarios met the test acceptance criteria and showed acceptable turnaround time for the intended use of the subject device, as shown in table 4 below.

Table 4: CaloPix Turnaround Time Testing Results

| Scanner | Image File Format | Subject Device/Browser | Results (Seconds) | | |
| --- | --- | --- | --- | --- | --- |
| | | | Loading and Display | Panning | Zooming |
| Leica Aperio GT 450 DX scanner | SVS | CaloPix/Chrome | Max = 2.0104 | Max = 0.6852 | Max = 6.0337 |
| | | | Min = 0.0323 | Min = 0.0042 | Min = 0.0029 |
| | | | Mean = 0.9439 | Mean = 0.0029 | Mean = 0.3437 |
| | | CaloPix/Edge | Max = 2.5425 | Max = 3.4777 | Max = 5.4922 |
| | | | Min = 0.4061 | Min = 0.0063 | Min = 0.0048 |
| | | | Mean = 1.0743 | Mean = 0.0050 | Mean = 0.1273 |
| Hamamatsu NanoZoomer S360MD Slide scanner | NDPI | CaloPix/Chrome | Max = 0.2649 | Max = 0.4053 | Max = 1.2409 |
| | | | Min = 0.0444 | Min = 0.0025 | Min = 0.0050 |
| | | | Mean = 0.1106 | Mean =0.0345 | Mean = 0.1093 |
| | | CaloPix/Edge | Max = 0.2091 | Max = 3.4992 | Max = 3.3322 |
| | | | Min = 0.0234 | Min = 0.0054 | Min = 0.0068 |
| | | | Mean = 0.0820 | Mean = 0.0529 | Mean = 0.1675 |

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# 3. Measurement - length and area

Measurement accuracy testing was performed to demonstrate that CaloPix accurately represents length and area measurements across all the multiple magnification levels for each configuration as listed in below table 5. A total of 5 H&amp;E-stained FFPE tissue glass slides from a diverse set of human anatomic sites were scanned using the intended scanners. All the supported browsers (Google Chrome, Microsoft Edge), 3 different magnifications, a minimum of 2 different orientations, and 2 types of measurements (length and area) were tested. Measurements accuracy was verified by comparing the measurements of markings made in CaloPix viewer to the measurements of markings made in NZViewMD viewer for the same Regions of Interest on slides. These measurement checks were also carried out between the CaloPix viewer and the Aperio WebViewer DX. Test results as listed in Table 5 show that the acceptance criteria which were pre-specified as the percentage error between measurements taken in CaloPix and in NZViewMD viewer or WebViewer DX viewer must be less than $1\%$ were met. The subject device performed accurate measurements of length across multiple magnification settings with respect to its intended use.

Table 5: CaloPix Measurement Results

| Scanner | Image File Format | Subject Device/Browser | Percentage Error (%) | |
| --- | --- | --- | --- | --- |
| | | | Length Measurement | Area Measurement |
| Hamamatsu NanoZoom er S360MD Slide scanner | NDPI | CaloPix/Chrome | ≤ 0.90 | ≤ 0.99 |
| | | CaloPix/Edge | ≤ 0.94 | ≤ 0.91 |
| Leica Aperio GT 450 DX scanner | SVS | CaloPix/Chrome | ≤ 0.73 | ≤ 0.94 |
| | | CaloPix/Edge | ≤ 0.73 | ≤ 0.81 |

# 4. Human Factor (Usability) Testing

The usability test was conducted per FDA guidance "Applying Human Factors and Usability Engineering to Medical Devices (2016)". A summative human factors test, designed around critical user tasks and use scenarios using multiple representative users (pathologists), was conducted. All tasks associated with reviewing and reporting results for cases including confirmation that all slides belonging to specific cases are reviewed before reporting results were included in the study. The CaloPix device has been found to be safe and effective for the intended users, uses and use environments.

# VIII Proposed Labeling:

The labeling supports the finding of substantial equivalence for this device.

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IX Conclusion:

The submitted information in this premarket notification is complete and supports a substantial equivalence decision.

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