K Number
K250716
Device Name
IMAGE ONE
Date Cleared
2025-07-23

(135 days)

Product Code
Regulation Number
892.2050
Reference & Predicate Devices
Predicate For
N/A
AI/MLSaMDIVD (In Vitro Diagnostic)TherapeuticDiagnosticis PCCP AuthorizedThirdpartyExpeditedreview
Intended Use

IMAGE ONE is a dental imaging software that is intended to provide viewer and image processing tools for maxillofacial radiographic images. These tools are available to view and interpret a series of DICOM compliant dental radiology images and are meant to be used by trained medical professionals such as radiologist and dentist.

IMAGE ONE is intended for use as software to acquire, view, and save 2D and 3D image files, to load DICOM project files from panorama, cephalometric, and intra-oral imaging equipment, and to provide 3D visualization and 2D analysis.

Device Description

IMAGE ONE software is an image management software which runs in a browser containing a user interface that allows the dentist to access and display patients' images or videos that have been taken during the course of a clinical practice.

IMAGE ONE is cloud-based Software which runs in a web browser with no access to hardware devices.

The only way that IMAGE ONE may retrieve files is by requesting them from the file system of the Operating System.

There are two scenarios involving the abovementioned files:

  • In the first one, the files may have been generated in the past by an external system, in which case IMAGE ONE allows the user to import and catalog them immediately.
  • The other one is when the files do not exist yet and are going to be generated during a clinical procedure by an external system. The user can request IMAGE ONE to wait for the user to complete an external acquisition process before importing and cataloging the files automatically.

IMAGE ONE software supports image and video standards commonly used in dentistry to date. These include X-ray radiographic images in PNG, JPEG, or BMP format, 3D models in STL format obtained from intraoral scans, intraoral video in MP4 format, and computed tomography images in DICOM format.

In addition to its image management functions, the software also offers through its user interface a visualization enhancement function (zoom and filters functions) for X-ray radiographic images in either PNG, JPEG, or BMP format. An additional distance measuring function is also included but strictly restricted to X-ray radiographic images in format PNG, JPEG, or BMP displaying a calibrator.

AI/ML Overview

The provided FDA 510(k) clearance letter for the IMAGE ONE device (K250716) is a summary of the clearance process, not a comprehensive study report. Therefore, it contains limited details regarding the specific acceptance criteria and the full study that proves the device meets these criteria. Medical device 510(k) submissions typically include extensive validation and verification documentation, which are summarized in the publicly available clearance letter.

Based on the provided text, here's what can be extracted and what information is missing:


1. Table of Acceptance Criteria and Reported Device Performance

The document states that "SW verification/validation and the measurement accuracy test were conducted to establish the performance, functionality and reliability characteristics of the modified devices. The device passed all of the tests based on pre-determined Pass/Fail criteria."

However, the specific "pre-determined Pass/Fail criteria" (acceptance criteria) and the quantitative "reported device performance" are not explicitly detailed in the provided 510(k) summary. These would typically be found in the full testing and validation reports submitted to the FDA, not in the public summary.

The "Performance Data" section merely states:

Feature/TestAcceptance Criteria (Implicit)Reported Device Performance (Summary)
Software Verification/ValidationAll tests based on pre-determined Pass/Fail criteriaDevice passed all tests
Measurement Accuracy TestAll tests based on pre-determined Pass/Fail criteriaDevice passed all tests
FunctionalityEstablished through SW V&VEstablished through SW V&V
ReliabilityEstablished through SW V&VEstablished through SW V&V

Missing Information: The specific numerical or qualitative thresholds for "Pass/Fail criteria" for accuracy, functionality, and reliability are not provided. For example, for measurement accuracy, it doesn't state "measurement error must be less than X mm."


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

The document does not specify the sample size used for the test set.

Data Provenance: The document does not specify the country of origin of the data or whether the data was retrospective or prospective.


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

The document does not specify the number of experts used or their qualifications for establishing ground truth for the test set. It only states that the device is "meant to be used by trained medical professionals such as radiologist and dentist." This implies that the ground truth would likely be established by such professionals, but no details are given about the validation process for the test set.


4. Adjudication Method for the Test Set

The document does not specify any adjudication method (e.g., 2+1, 3+1, none) used for the test set.


5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done

The document does not mention a Multi-Reader Multi-Case (MRMC) comparative effectiveness study. The focus of this 510(k) is on the software's functionality and measurement accuracy rather than a comparative study of human readers with and without AI assistance. The device is described as "viewer and image processing tools" and "software to acquire, view, and save," implying it's a tool to assist, not an AI for diagnosis that would typically require MRMC studies.


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

The document suggests that the performance evaluation was primarily focused on the device's technical functionality and accuracy. The measurement accuracy test could be considered a form of standalone performance evaluation for that specific feature. However, it is not explicitly labeled as "standalone" performance for an AI algorithm. Given the description ("viewer and image processing tools"), the device's primary function seems to be assisting human interpretation rather than providing autonomous diagnostic outputs.


7. The Type of Ground Truth Used

The document does not explicitly state the type of ground truth used. However, for a "measurement accuracy test" on X-ray images, common ground truth methods would involve:

  • Physical measurements: Using a known, precisely measured object (like a caliper) on the image as a reference.
  • Expert Consensus: For features beyond simple measurements, radiologists/dentists providing a consensus reading.

The document heavily emphasizes the use of a "caliper of known size" for distance measurement, implying that physical measurement references (calipers) would form a key part of the ground truth for this specific function.


8. The Sample Size for the Training Set

The document does not mention a training set sample size or any details about a training set. This is consistent with the nature of the device, which is described as image viewing and processing software with specific tools (zoom, filters, linear measurement). The description does not indicate that it is an AI/ML device that requires a dedicated training set beyond standard software development and testing practices. The "Performance Data" section refers to "SW verification/validation and the measurement accuracy test," which are typical for traditional software, not necessarily AI model training.


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

Since the document does not mention a training set (as the device is not described as a machine learning model), the method for establishing ground truth for a training set is not applicable based on the provided information.

FDA 510(k) Clearance Letter - IMAGE ONE

Page 1

U.S. Food & Drug Administration
10903 New Hampshire Avenue Doc ID # 04017.08.00
Silver Spring, MD 20993
www.fda.gov

July 23, 2025

Infomed Software, S.L.
℅ Juan Tezak
Consultant
Compliance 4 Devices
118 W Prive Cr.
DELRAY BEACH, FL 33445

Re: K250716
Trade/Device Name: IMAGE ONE
Regulation Number: 21 CFR 892.2050
Regulation Name: Medical Image Management And Processing System
Regulatory Class: Class II
Product Code: LLZ
Dated: June 26, 2025
Received: June 26, 2025

Dear Juan Tezak:

We have reviewed your section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (the Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Page 2

K250716 - Juan Tezak Page 2

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

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

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting (reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reporting-combination-products); 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 Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.

All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/unique-device-identification-system-udi-system.

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

For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-

Page 3

K250716 - Juan Tezak Page 3

assistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

Sincerely,

Lu Jiang

Lu Jiang, Ph.D.
Assistant Director
Diagnostic X-Ray Systems Team
DHT8B: Division of Radiological Imaging
Devices and Electronic Products
OHT8: Office of Radiological Health
Office of Product Evaluation and Quality
Center for Devices and Radiological Health

Enclosure

Page 4

FORM FDA 3881 (8/23) Page 1 of 1

DEPARTMENT OF HEALTH AND HUMAN SERVICES
Food and Drug Administration

Indications for Use

Form Approved: OMB No. 0910-0120
Expiration Date: 07/31/2026
See PRA Statement below.

510(k) Number (if known): K250716
Device Name: IMAGE ONE

Indications for Use (Describe)

IMAGE ONE is a dental imaging software that is intended to provide viewer and image processing tools for maxillofacial radiographic images. These tools are available to view and interpret a series of DICOM compliant dental radiology images and are meant to be used by trained medical professionals such as radiologist and dentist.

IMAGE ONE is intended for use as software to acquire, view, and save 2D and 3D image files, to load DICOM project files from panorama, cephalometric, and intra-oral imaging equipment, and to provide 3D visualization and 2D analysis.

Type of Use (Select one or both, as applicable)
☒ Prescription Use (Part 21 CFR 801 Subpart D)
☐ Over-The-Counter Use (21 CFR 801 Subpart C)

CONTINUE ON A SEPARATE PAGE IF NEEDED.

This section applies only to requirements of the Paperwork Reduction Act of 1995.
DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.

The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to:

Department of Health and Human Services
Food and Drug Administration
Office of Chief Information Officer
Paperwork Reduction Act (PRA) Staff
PRAStaff@fda.hhs.gov

"An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number."

Page 5

510(k) Summary

K250716

Prepared July 15, 2025

I) Applicant

Submitter: Infomed Software, S.L.
Address: Vía Augusta 158 – 4th floor.
08006. Barcelona, Spain.
Contact: Mrs. Iris López
Telephone: +34 934 144 340
E-mail: iris.lopez@grupoinfomed.es

II) Device

Trade Name: IMAGE ONE
Common Name: Picture Archiving and Communications System
Classification Name: Medical image management and processing system
Regulation Number: 892.2050
Product Code: LLZ

III) Predicate Device

510(k) Number: K230468
Applicant: Ewoosoft Co., Ltd.
Trade Name: EzDent Web
Classification Name: Medical image management and processing system
Regulation Number: 892.2050

IV) Indication For Use

IMAGE ONE is a dental imaging software that is intended to provide viewer and image processing tools for maxillofacial radiographic images. These tools are available to view and interpret a series of DICOM compliant dental radiology images and are meant to be used by trained medical professionals such as radiologist and dentist.

IMAGE ONE is intended for use as software to acquire, view, and save 2D and 3D image files, to load DICOM project files from panorama, cephalometric, and intra-oral imaging equipment, and to provide 3D visualization and 2D analysis.

V) Device Description

IMAGE ONE software is an image management software which runs in a browser containing a user interface that allows the dentist to access and display patients' images or videos that have been taken during the course of a clinical practice.

IMAGE ONE is cloud-based Software which runs in a web browser with no access to hardware devices.

Page 6

Page 2 of 4

The only way that IMAGE ONE may retrieve files is by requesting them from the file system of the Operating System.

There are two scenarios involving the abovementioned files:

  • In the first one, the files may have been generated in the past by an external system, in which case IMAGE ONE allows the user to import and catalog them immediately.
  • The other one is when the files do not exist yet and are going to be generated during a clinical procedure by an external system. The user can request IMAGE ONE to wait for the user to complete an external acquisition process before importing and cataloging the files automatically.

IMAGE ONE software supports image and video standards commonly used in dentistry to date. These include X-ray radiographic images in PNG, JPEG, or BMP format, 3D models in STL format obtained from intraoral scans, intraoral video in MP4 format, and computed tomography images in DICOM format.

In addition to its image management functions, the software also offers through its user interface a visualization enhancement function (zoom and filters functions) for X-ray radiographic images in either PNG, JPEG, or BMP format. An additional distance measuring function is also included but strictly restricted to X-ray radiographic images in format PNG, JPEG, or BMP displaying a calibrator.

VI) Comparison of Technological Characteristics

CharacteristicsSubject DevicePredicate Device
Device nameIMAGE ONEEzDent Web
510K numberK250716K230468
ManufactureInfomed Software, S.L.Ewoosoft Co., Ltd
Indications for useIMAGE ONE is a dental imaging software that is intended to provide viewer and image processing tools for maxillofacial radiographic images. These tools are available to view and interpret a series of DICOM compliant dental radiology images and are meant to be used by trained medical professionals such as radiologist and dentist.IMAGE ONE is intended for use as software to acquire, view, and save 2D and 3D image files, to load DICOM project files from panorama, cephalometric, and intra-oral imaging equipment, and to provide 3D visualization and 2D analysis.EzDent Web is a dental imaging software that is intended to provide viewer and image processing tools for maxillofacial radiographic images. These tools are available to view and interpret a series of DICOM compliant dental radiology images and are meant to be used by trained medical professionals such as radiologist and dentist.EzDent Web is intended for use as software to acquire, view, and save 2D and 3D image files, to load DICOM project files from panorama, cephalometric, and intra-oral imaging equipment, and to provide 3D visualization and 2D analysis.
Technology/Principle of OperationThe visualization enhancement tools of the IMAGE ONE software, allow for better visualization of a given tooth structure. They include:- zoom function (maximum magnification X10)- and filter functions (brightness, contrast, color inversion, color, smoothing,EzDent Web is a device that provides various features to acquire, transfer, edit, display, store, and perform digital processing of medical images. EzDent Web is a patient & image management software specifically for digital dental radiography. It also provides server/client model so that the users upload and download clinical diagnostic images and

Page 7

Page 3 of 4

CharacteristicsSubject DevicePredicate Device
Device nameIMAGE ONEEzDent Web
510K numberK250716K230468
sharpness and relief).About the measurement of dental structures on 2D images of X-ray radiographs; measurements can only be performed on 2D images containing a caliper of known size. IMAGE ONE cannot perform measurements on 2D images obtained from computed tomography (CT) or computed tomography (CAT) scans, as the caliper is not directly present within the image. In these specific cases, the caliper information is encoded within the DICOM metadata format of the image. The IMAGEONE software cannot retrieve such information from the DICOM metadata.Therefore, the use of the IMAGEONE software for measurement purposes is indicated only for intraoral and extraoral radiographs captured on flat films and digital sensors. The images produced are two-dimensional shadow plots, representing the absorption of the incident X-ray beam as it penetrates the various structures before exposing the image receptor.The caliper or caliper must be present directly on the image. It may take the form of a caliper or an object of known size. To achieve sufficient resolution, it is not recommended that the caliper be less than 50 mm in length.patient information from any workstations in the network environment.EzDent Web supports general image formats such as JPG and BMP for 2D,3D image viewing as well as DICOM format.
PlatformGoogle Chrome Version 100 or higherIBM-compatible PC or PC network
Operating SystemMicrosoft Windows 10 or higherMicrosoft Windows 10 or Higher
User InterfaceNo public interfaces definedMouse, Keyboard
Image Input SourcesX-ray images in PNG, JPEG, or BMP format, 3D models in STL format obtained from intraoral scans, intraoral video in MP4 format, and CT images in DICOM format.Images can be scanned, loaded from digital cameras or card readers, or imported from a radiographic imaging device
Image formatRadiographic images in PNG, JPEG, or BMP format, 3D models in STL format obtained from intraoral scans, intraoral video in MP4 format, and computed tomography images in DICOM formatDICOM, JPG, BMP
Patient Database CompatibilitySQL server for image managementSQL
Includes Image MeasurementtoolsLinear distance, angleLinear distance, Angle, Profile
Image viewingFull, gallery, thumbnailFull, side by side, gallery, thumbnail

Page 8

Page 4 of 4

CharacteristicsSubject DevicePredicate Device
Device nameIMAGE ONEEzDent Web
510K numberK250716K230468
sharpness and relief).About the measurement of dental structures on 2D images of X-ray radiographs; measurements can only be performed on 2D images containing a caliper of known size. IMAGE ONE cannot perform measurements on 2D images obtained from computed tomography (CT) or computed tomography (CAT) scans, as the caliper is not directly present within the image. In these specific cases, the caliper information is encoded within the DICOM metadata format of the image. The IMAGEONE software cannot retrieve such information from the DICOM metadata.Therefore, the use of the IMAGEONE software for measurement purposes is indicated only for intraoral and extraoral radiographs captured on flat films and digital sensors. The images produced are two-dimensional shadow plots, representing the absorption of the incident X-ray beam as it penetrates the various structures before exposing the image receptor.The caliper or caliper must be present directly on the image. It may take the form of a caliper or an object of known size. To achieve sufficient resolution, it is not recommended that the caliper be less than 50 mm in length.patient information from any workstations in the network environment.EzDent Web supports general image formats such as JPG and BMP for 2D,3D image viewing as well as DICOM format.
PlatformGoogle Chrome Version 100 or higherIBM-compatible PC or PC network
Operating SystemMicrosoft Windows 10 or higherMicrosoft Windows 10 or Higher
User InterfaceNo public interfaces definedMouse, Keyboard
Image Input SourcesX-ray images in PNG, JPEG, or BMP format, 3D models in STL format obtained from intraoral scans, intraoral video in MP4 format, and CT images in DICOM format.Images can be scanned, loaded from digital cameras or card readers, or imported from a radiographic imaging device
Image formatRadiographic images in PNG, JPEG, or BMP format, 3D models in STL format obtained from intraoral scans, intraoral video in MP4 format, and computed tomography images in DICOM formatDICOM, JPG, BMP
Patient Database CompatibilitySQL server for image managementSQL
Includes Image Measurement toolsLinear distance, angleLinear distance, Angle, Profile
Image viewingFull, gallery, thumbnailFull, side by side, gallery, thumbnail
Image manipulationZoom function (maximum enhancement X10), and filter functions including brightness, contrast, invert colours, colour, softening, sharpening and relief.Brightness, contrast, sharpness, inverse, film view, rotate, zooming, draw canal, memo, implant simulations
Implant moduleN/AGeneric implant libraries
Image annotationText, paint, ellipse, pointer, select, draw, line, rectangle, polygon.Text, paint, ellipse, pointer, select, draw, magnify, line, rectangle, polygon, ruler, protractor, reduction, select region, copy / paste

IMAGE ONE and its predicate EzDent Web are very similar products in terms of their intended use, composition and effectiveness in providing image viewing and processing tools for maxillofacial radiographic imaging.

VII) Technological Characteristics

IMAGE ONE is a software device that does not contact the patient, nor does it control any life sustaining devices.

  • The IMAGE ONE software allows the viewing of dental X-ray, 3D models in STL format obtained from intraoral exploration, intraoral video in MP4 format and CT images in DICOM format, taken with the purpose of helping diagnosis and preventing and/or treating diseases of the mouth.
  • The human anatomical areas covered by the IMAGE ONE software are limited to the oral cavity, including the oral vestibule and its bone structure, namely the jaw, maxilla, and palatine bones.
  • The display enhancement functions (zoom and filter functions) can be used for X-ray images in PNG, JPEG or BMP format.
  • The distance measurement function is restricted to 2D X-ray images in PNG, JPEG or BMP format, showing a calibrator.
  • Use of both the display enhancement and the distance measurement features gives professional users (dentists) preliminary information about the patient's dental health.
  • The distance measurement function of the IMAGE ONE software is not to be used in preparing for any kind of dental surgery, including dental implants or orthognathic surgery.
  • The distance measuring function of IMAGE ONE software shall not be used for orthodontic treatment planning and/or diagnosis.

VIII) Performance Data

SW verification/validation and the measurement accuracy test were conducted to establish the performance, functionality and reliability characteristics of the modified devices. The device passed all of the tests based on pre-determined Pass/Fail criteria.

IX) Conclusion

The subject device is substantially equivalent in the areas of technical characteristics, general function, application and indications of use to the predicate device K230468.

§ 892.2050 Medical image management and processing system.

(a)
Identification. A medical image management and processing system is a device that provides one or more capabilities relating to the review and digital processing of medical images for the purposes of interpretation by a trained practitioner of disease detection, diagnosis, or patient management. The software components may provide advanced or complex image processing functions for image manipulation, enhancement, or quantification that are intended for use in the interpretation and analysis of medical images. Advanced image manipulation functions may include image segmentation, multimodality image registration, or 3D visualization. Complex quantitative functions may include semi-automated measurements or time-series measurements.(b)
Classification. Class II (special controls; voluntary standards—Digital Imaging and Communications in Medicine (DICOM) Std., Joint Photographic Experts Group (JPEG) Std., Society of Motion Picture and Television Engineers (SMPTE) Test Pattern).