RealNow is an image processing software package to be used by trained professionals including physicians. The software runs on a standard "off-the-shelt" computer or a virtual platform, such as VMware, and can be used to perform image viewing, processing, analysis and communication of computed tomography (CT) perfusion scans of the brain. Data and images are acquired through DICOM compliant imaging devices.

RealNow provides viewing, analysis and communication capabilities for functional and dynamic imaging datasets that are acquired with CT Perfusion imaging protocols.

Analysis includes calculation of parameters related to tissue flow (perfusion) and tissue blood volume. Results of image processing which include CT perfusion parameter maps generated in the standard DICOM format and may be viewed on existing radiological imaging viewers.

Device Description

RealNow image analysis includes calculation of the following perfusion related parameters:

Cerebral Blood Flow (CBF)
Cerebral Blood Volume (CBV)
Mean Transit Time (MTT)
Residue function time-to-peak (TMax)
Arterial Input Function (AIF)

The primary users of RealNow are medical imaging professionals who analyze dynamic CT perfusion studies. The results of image analysis produced by RealNow should be viewed through appropriate diagnostic viewers when used in clinical decision making.

AI/ML Overview

The RealNow device is an image processing software package for CT perfusion scans of the brain. The acceptance criteria and the study proving the device meets these criteria are detailed below. The study's "ground truth" for non-clinical testing was the output of a legally marketed predicate device, RAPID (K121447).

1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria for RealNow were established by comparing its output to the RAPID predicate device. The performance was assessed through pixel-by-pixel comparison and volumetric analysis.

Acceptance Criterion (for each scan)	Reported Device Performance
Intraclass Correlation Coefficient (ICC) > 0.75 for all voxels within the brain tissue for parametric maps.	CBF, CBV, MTT, Tmax Parameter Maps: All proportion of acceptable maps (ICC > 0.75) were > 90% (p=0.0009 for CBF and CBV, p=0.0196 for MTT and Tmax). Specific ICC values are not provided, only the proportion of maps meeting the threshold.
Assessment of bias for volumetric comparison (e.g., CBF<20%, CBF<30%) between RealNow and RAPID.	Rapid_Volume (CBF<20%) vs RealNow_Volume (CBF<20%) & Rapid_Volume (CBF<30%) vs RealNow_Volume (CBF<30%): Assessment revealed bias is not significant. This indicates good agreement in these volumetric measurements.
Volumetric comparison for Tmax abnormality between RealNow and RAPID.	Tmax Abnormality: Assessment revealed a negative bias (mean Rapid Volume being smaller than mean Tmax volumetry) that increased as the average volume increased. Despite this bias, the document concludes "Good correlation in behavior between Rapid and RealNow volumetry was found." This suggests that while there may be a systematic difference, the trend and overall behavior are consistent.
Mismatch volume accuracy parameters for RealNow compared to RAPID.	Mismatch volumes (total data): < 50 ml. Mismatch volumes (stroke data): < 25 ml. The document states: "For Proposed Device RealNow mismatch analysis, mismatch volume has been established within the following accuracy parameters: < 50 ml for mismatch volumes (total data); < 25 ml for mismatch volumes (stroke data)." The phrasing suggests these were the target acceptance criteria, and the overall conclusion of "Good agreement and correlation in behavior between Rapid and RealNow was found" implies these were met.

2. Sample size used for the test set and the data provenance

Sample Size: Not explicitly stated as a number of unique patient cases. The study refers to "CTP images (Real-World Evidence)" which are "paired uploaded to RealNow and RAPID for perfusion analysis." The number of individual scans analyzed for comparison of parametric maps is implied to be enough to achieve the reported p-values for the proportion of acceptable maps.
Data Provenance: "Real-World Evidence" images. The country of origin is not specified, nor is whether the data was retrospective or prospective. Given the comparison to a predicate device's existing output, it is highly likely that the data was retrospective.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts

No human experts were used to establish the ground truth for the test set. The ground truth was established by the output of the legally marketed predicate device, RAPID.

4. Adjudication method for the test set

No human adjudication method (e.g., 2+1, 3+1) was used for the test set. The comparison was directly between the RealNow algorithm output and the RAPID algorithm output.

5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance

No MRMC comparative effectiveness study involving human readers was mentioned or performed in this submission. The study focuses solely on the non-clinical performance comparison between the RealNow software and the predicate RAPID software.

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

Yes, a standalone (algorithm only) performance study was done. The entire non-clinical test described compares the RealNow algorithm's output directly against the RAPID algorithm's output (which serves as the "ground truth" reference).

7. The type of ground truth used

The ground truth used was the output of a legally marketed predicate device (RAPID). This is a form of "reference standard" or "comparator" ground truth, where the performance is benchmarked against an already accepted technology rather than an independent gold standard like pathology or long-term outcomes.

8. The sample size for the training set

The document does not provide any information regarding a training set or its sample size. This is a non-clinical 510(k) submission, and the focus is on the validation of the device's performance against a predicate rather than the specifics of its development or training data.

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

Information on how the ground truth for any potential training set was established is not provided in this document.

Summary

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Image /page/0/Picture/0 description: The image shows the logo of the U.S. Food and Drug Administration (FDA). The logo consists of two parts: the Department of Health and Human Services logo on the left and the FDA logo on the right. The FDA logo features the letters "FDA" in a blue square, followed by the words "U.S. FOOD & DRUG ADMINISTRATION" in blue text.

YIWEI Medical Technology Co., Ltd. % Diana Hong General Manager Mid-Link Consulting Co., Ltd. P.O.box 120-119 Shanghai. 200120 CHINA

Re: K213891

February 24, 2023

Trade/Device Name: RealNow Regulation Number: 21 CFR 892.2050 Regulation Name: Medical image management and processing system Regulatory Class: Class II Product Code: LLZ Dated: January 29, 2023 Received: January 30, 2023

Dear Diana Hong:

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 (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

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801); medical device reporting of medical device-related adverse events) (21 CFR 803) for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-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 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 https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-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/medicaldevices/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-device-advice-comprehensive-regulatoryassistance/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.

Jessica Lamb

Jessica Lamb, Ph.D. Assistant Director Imaging Software Team DHT 8B: Division of Radiological Imaging Devices and Electronic Products OHT 8: Office of 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) K213891

Device Name RealNow

Indications for Use (Describe)

RealNow provides viewing, analysis and communication capabilities for functional and dynamic imaging datasets that are acquired with CT Perfusion imaging protocols.

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)

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510(k) Summary

This 510(k) Summary is being submitted in accordance with requirements of Title 21, CFR Section 807.92.

The assigned 510(k) Number: K213891

1. Date of Preparation: 2/23/2023
1. Sponsor Identification

YIWEI Medical Technology Co., Ltd

Room 1001, MaiKelong Building, No. 6, Gaoxin South 6th Road, Dist.Gaoxin, Yuehai Street, Dist.Nanshan, Shenzhen, 518057, China.

Establishment Registration Number: Not registered yet.

Contact Person: Eric Ke Position: Management Representative Tel: +86-0755-82333762 Email: rick.ke@drbrain.com.cn

1. Designated Submission Correspondent
  Ms. Diana Hong (Primary Contact Person) Ms. Jing Cheng (Alternative Contact Person)

Mid-Link Consulting Co., Ltd

P.O. Box 120-119, Shanghai, 200120, China

Tel: +86-21-22815850 Fax: 360-925-3199 Email: info@mid-link.net

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4. Identification of Proposed Device

Trade Name: RealNow Common Name: Picture Archiving Communications System

Regulatory Information

Classification Name: Picture archiving and communications system Classification: II; Product Code: LLZ; Regulation Number: 21CFR 892.2050 Review Panel: Radiology;

Indication for Use:

RealNow is an image processing software package to be used by trained professionals, such as physicians. The software runs on a standard "off-the-shelf" computer or a virtual platform, such as VMware, and can be used to perform image viewing, processing, analysis and communication of computed tomography (CT) perfusion scans of the brain. Data and images are acquired through DICOM compliant imaging devices.

RealNow provides viewing, analysis and communication capabilities for functional and dynamic imaging datasets that are acquired with CT Perfusion imaging protocols.

Device Description

RealNow image analysis includes calculation of the following perfusion related parameters:

Cerebral Blood Flow (CBF)
Cerebral Blood Volume (CBV)
Mean Transit Time (MTT)
· Residue function time-to-peak (TMax)
· Arterial Input Function (AIF)

Identification of Predicate Device న.

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510(k) Number: K121447 Product Name: RAPID Manufacturer: iSchemaView, Inc.

Non-Clinical Test Conclusion 6.

The software verification and validation testing was conducted on the proposed device

CTP images (Real-World Evidence) are paired uploaded to RealNow and RAPID for perfusion analysis. The parametric maps from the subject device's output have been directly compared to the Rapid outputs in the additional study. The RealNow resulting CBF maps were compared on a pixel by pixel basis to the "ground truth" RAPID CBF maps. Intraclass Correlation Coefficient of the all the pixel values per scan was calculated to assess correlation, of the CBF estimates to the reference values. Volumetry from our device's out to RAPID on the same patient data have been statistically analyzed using MedCalc, and Bland-Altman analysis statistics been performed.

For each scan, parametric map is considered acceptable when the ICC is greater than 0.75, which ICC was calculated per scan from all the voxels within the brain tissue. All Proportion of Acceptable (CBF Parameter Maps, CBV Parameter Maps, MTT Parameter Maps, Tmax Parameter Maps, ) more than the 90% (p=0.0009, p=0.0009, p=0.0196.).The assessment revealed bias is not significant for Rapid_Volume (CBF<20%) Vs RealNow_Volume (CBF<20%) \ Rapid_Volume (CBF<30%) Vs RealNow Volume (CBF<30%).The assessment revealed a negative bias in Tmax abnormality (mean Rapid Volume being smaller than mean Tmax volumetry) that increased as the average volume increased. For Proposed Device RealNow mismatch analysis, mismatch volume has been established within the following accuracy parameters:< 50 ml for mismatch volumes (total data); < 25 ml for mismatch volumes (stroke data). Good correlation in behavior between Rapid and RealNow volumetry was found.

Altogether, good agreement and correlation in behavior between Rapid and RealNow was found. The outputs of the subject device are essentially the same as the outputs of the previously cleared RAPID. Subject device is essentially useful for CT brain perfusion and analysis, the same as the previously cleared RAPID.

7. Clinical Test Conclusion

No clinical study is included in this submission.

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8. Summary of Technological Characteristics

ITEM	Proposed Device	Predicate DeviceK121447	Remark
Product name	RealNow	RAPID	/
Product Code	LLZ	LLZ	Same
Regulation Number	21 CFR 892.2050	21 CFR 892.2050	Same
Class	II	II	Same
Indication for Use	RealNow is an image processing software package to be used by trained professionals, such as physicians. The software runs on a standard “off-the-shelf” computer or a virtual platform, such as VMware, and can be used to perform image viewing, processing, analysis and communication of computed tomography (CT) perfusion scans of the brain. Data and images are acquired through DICOM compliant imaging devices.RealNow provides viewing, analysis and communication capabilities for functional and dynamic imaging datasets that are acquired with CT Perfusion imaging protocols.Analysis includes calculation of parameters related to tissue flow (perfusion) and tissue blood volume. Results of image processing which include CT perfusion parameter maps generated in the standard DICOM format and may be viewed on	iSchemaView's RAPID is an image processing software package to be used by trained professionals, including but not limited to physicians and medical technicians. The software runs on a standard “off-the-shelf” computer or a virtual platform, such as VMware, and can be used to perform image viewing, processing, analysis of brain images. Data and images are acquired through DICOM compliant imaging devices.iSchemaView's RAPID provides both viewing and analysis capabilities for functional and dynamic imaging datasets that are acquired with CT Perfusion imaging and MRI including a Diffusion Weighted MRI (DWI) Module and a Dynamic Analysis Module (dynamic contrast enhanced imaging data for MRI and CT).The DWI Module is used to visualize local water diffusion properties from the analysis of	Different

	existing radiological imagingviewers.	diffusionweighted MRI data.
PACS Functionality		The Dynamic Analysis Module isused for visualization and analysisof dynamic imaging data,showing properties of changes incontrast over time. Thisfunctionality includes calculationof parameters related to tissueflow (perfusion) and tissue bloodvolume.
Basic PACSFunctions	Yes	Yes	Same
ComputerPlatform	Standard "Off-the-Shelf" PCWorkstation or VMWare	Standard "Off-the-Shelf" PCWorkstation or VMWare	Same
DICOMCompliance	Yes	Yes
FunctionalOverview	RealNow is a software packagethat provides for the visualizationand study of changes of tissueperfusion in digital imagescaptured by CT. RealNow allowsviewing and quantification	RAPID is a software package thatprovides for the visualization andstudy of changes of tissueperfusion in digital imagescaptured by CT. RAPID allowsviewing and quantificationPAPID also has DWI Module tovisualize local water diffusionproperties from the analysis ofdiffusionweighted MRI data.	Different
DataAcquisition	Acquires medical image datafrom DICOM compliant imagingdevices and modalities.	Acquires medical image data fromDICOM compliant imagingdevices and modalities.	Same
Data/ImageTypes	Computed Tomography (CT)	Computed Tomography (CT)Magnetic Resonance Imaging(MRI)	Different
Acquisition and Modalities Features for Tissue Perfusion
CT	CT Perfusion (CTP)	CT Perfusion (CTP)	Same
Computed Parameter Maps for perfusion CT
Perfusion CT	Cerebral Blood Flow (CBF)	Cerebral Blood Flow (CBF)	Same
	Cerebral Blood Volume (CBV)	Cerebral Blood Volume (CBV)	Same
	Mean Transit Time (MTT)	Mean Transit Time (MTT)	Same
	Tissue residue function time to	Tissue residue function time to	Same
	peak (TMax)	peak (TMax)	Same
Measurements/Tools
CT Tools	Arterial Input Function (AIF)	Arterial Input Function (AIF)	Same
	Brain mask	Brain mask	Same
	Export perfusion files to PACSandDICOM file systems	Export perfusion files to PACSandDICOM file systems	Same
	Acquire, transmit, process, andstore medical images.	Acquire, transmit, process, andstore medical images.	Same

Table 1 Comparison of Technology Characteristics

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Substantially Equivalent (SE) Conclusion 9.
The conclusions drawn from the nonclinical tests demonstrate that the proposed device is as safe, as effective, and performs as well as the legally marketed predicate device K121447.

Regulation Number and Section

§ 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).