The NSite Scoliosis Assessment App is intended as an adjunct tool for qualified healthcare professionals to provide deformity measurements and guide management recommendations based on a calculated Asymmetry Index for patients with or at risk for idiopathic scoliosis, which will yield an output of clinically significant scoliosis, which is defined as a Cobb Angle greater than 20 degrees.

Device Description

NSite Medical leverages 3D scanning on a mobile device for scoliosis screening and monitoring. NSite's proprietary algorithm calculates the risk of having clinically significant scoliosis that may require treatment by a specialist.

The NSite Scoliosis Assessment App generates a 3D scan of the individual using a mobile device camera. Using the 3D scan, the application analyzes the asymmetry of the individual's back surface and calculates an Asymmetry Index (AI). The Asymmetry Index is a quantitative measure of the back asymmetry. The Asymmetry Index is then used to calculate a high/low risk stratification that a patient will have clinically significant scoliosis (defined as Cobb angle > 20 degrees) using a logistic regression model. This risk stratification, when considered in combination with the stated NSite Scoliosis Assessment App performance, is intended to provide health care providers with information that can be used for management recommendations. The model was developed using a database of patient Asymmetry Indexes with known Cobb angles.

AI/ML Overview

The provided text describes the NSite Scoliosis Assessment App, an adjunct tool for qualified healthcare professionals to assess scoliosis risk, and its clinical study to demonstrate substantial equivalence to a predicate device.

Here's an analysis of the acceptance criteria and study proving device performance, based only on the provided text, as some details are not explicitly stated:

1. Table of Acceptance Criteria and Reported Device Performance

The document states: "All predefined acceptance criteria for the performance testing were met." However, the specific acceptance criteria (e.g., sensitivity, specificity thresholds) and the numerical results for the device's performance (e.g., actual sensitivity and specificity achieved) are not detailed in the provided text. The output is described as a "low or high risk of clinically significant scoliosis, which is defined as a Cobb Angle greater than 20 degrees."

Acceptance Criteria (Stated)	Reported Device Performance (Stated)
All predefined acceptance criteria for performance testing were met.	"The results from the performance testing executed on the NSite Scoliosis Assessment App produced results consistently according to its intended use." The study "validated the accuracy of the predicated probability of major Cobb angle as compared to a Cobb angle obtained via radiograph." Specific performance metrics (e.g., sensitivity, specificity, AUC) are not provided in this document.
Reproducibility of scanning functionality	Assessed in clinical study; details of results not provided.
Reliability of scanning functionality	Assessed in clinical study; details of results not provided.
Accuracy of predicated probability of major Cobb angle vs. radiograph Cobb angle	Validated in clinical study; details of results not provided.
Safety and effectiveness for intended use	Demonstrated in clinical study.
Substantial equivalence to predicate device (K923792)	Demonstrated in clinical study.
No new questions of safety and effectiveness	Demonstrated in clinical study.

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

Test Set Sample Size: The document does not explicitly state the numerical sample size of the test set used in the clinical study. It mentions the study was performed using "adolescent patients spanning the age range where Adolescent Idiopathic Scoliosis (AIS) commonly presents and remains treatable" and "adolescents of gender and race at ratios where AIS is commonly observed."
Data Provenance: The text does not specify the country of origin of the data. The study is described as a "clinical study," suggesting it was prospective, but this is not explicitly stated as retrospective or prospective.

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

The document does not specify the number of experts used to establish the ground truth for the test set or their qualifications. It mentions "radiograph" as the basis for the Cobb angle, implying radiologists were involved, but details are absent.

4. Adjudication Method for the Test Set

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

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

The document does not mention that a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was done. Therefore, no effect size of human readers improving with AI vs. without AI assistance is provided. The app is intended as an "adjunct tool," implying human-in-the-loop, but a comparative effectiveness study is not detailed.

6. Standalone (Algorithm Only) Performance

The document does not explicitly state if a standalone (algorithm-only) performance study was conducted with specific metrics for that mode of operation. The primary intention is as an "adjunct tool" for healthcare professionals. The study "validated the accuracy of the predicated probability of major Cobb angle," which implies an algorithm output, but whether this was evaluated without human interaction or review is not clarified.

7. Type of Ground Truth Used

The ground truth used was:

Cobb Angle obtained via radiograph: This is the primary stated ground truth for validating the accuracy of the device's "predicated probability of major Cobb angle." This typically implies expert consensus (e.g., radiologists) on these radiographic measurements.

8. Sample Size for the Training Set

The document does not state the specific sample size used for the training set. It mentions: "The model was developed using a database of patient Asymmetry Indexes with known Cobb angles."

9. How Ground Truth for the Training Set Was Established

The document states: "The model was developed using a database of patient Asymmetry Indexes with known Cobb angles." It implies that the Cobb angles for the training data were also established through similar means as the test set ground truth (i.e., likely from radiographs). However, the precise method for establishing the ground truth for the training set (e.g., number of readers, adjudication) is not detailed.

Summary

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Image /page/0/Picture/0 description: The image contains the logo of the U.S. Food and Drug Administration (FDA). On the left is the Department of Health and Human Services logo. To the right of that is a blue square with the letters FDA in white. To the right of the blue square is the text "U.S. FOOD & DRUG ADMINISTRATION" in blue.

November 15, 2023

NSite, Inc. Michael Gardner, MD Co-Founder & CEO 821 Stanford Ave. Menlo Park, California 94025

Re: K230463

Trade/Device Name: NSite Scoliosis Assessment App Regulatory Class: Unclassified Product Code: LDK Dated: October 16, 2023 Received: October 17, 2023

Dear Dr. Gardner:

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.

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).

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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 OS 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 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-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 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.

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-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,

Tushar Bansal -S

for Heather Dean, PhD Assistant Director, Acute Injury Devices Team DHT5B: Division of Neuromodulation and Rehabilitation Devices OHT5: Office of Neurological and Physical Medicine Devices Office of Product Evaluation and Quality

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Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known) K230463

Device Name NSite Scoliosis Assessment App

Indications for Use (Describe)

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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Image /page/4/Picture/0 description: The image shows a logo for NSITE. The logo features a stylized icon of three interconnected shapes stacked vertically, resembling a molecule or network. The icon is enclosed within a square frame with a gradient color scheme, transitioning from teal at the top to blue at the bottom. Below the icon, the word "NSITE" is written in a bold, sans-serif font, also with a gradient color scheme.

510(k) Summary

Date Prepared:	November 14, 2023
Submitter:	NSite, Inc.821 Stanford Ave.Menlo Park, CA 94025
Contact:	Michael J. Gardner, MDCo-Founder & CEONSite, Inc.917-584-6909mike@nsitemedical.com
Proprietary Name:	NSite Scoliosis Assessment App
Common Name:	Optical Contour Sensing Device
Classification:	Unclassified, Pre-AmendmentProduct Code: LDK
Review Panel:	Physical Medicine
SubstantiallyEquivalent Device:	K923792 - Quantec Image Processing Ltd. Quantec SpinalMeasurement System

Device Description:

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Image /page/5/Picture/0 description: The image is a logo for NSITE. The logo features a square frame with rounded corners, inside of which is a stack of three interconnected shapes resembling molecules or stylized links. The frame and the stacked shapes are rendered in a gradient that transitions from teal at the top to a deep blue-purple at the bottom. Below the frame is the word "NSITE" in a sans-serif font, also rendered in the same teal-to-purple gradient.

scoliosis (defined as Cobb angle > 20 degrees) using a logistic regression model. This risk stratification, when considered in combination with the stated NSite Scoliosis Assessment App performance, is intended to provide health care providers with information that can be used for management recommendations. The model was developed using a database of patient Asymmetry Indexes with known Cobb angles.

Indications for Use:

The NSite Scoliosis Assessment App is intended as an adjunct tool for qualified healthcare professionals to provide deformity measurements and guide management recommendations based on a calculated Asymmetry Index for patients with or at risk for idiopathic scoliosis, which will yield an output of low or high risk of clinically significant scoliosis, which is defined as a Cobb Angle greater than 20 degrees.

Comparison of Technological Characteristics:

The proposed NSite Scoliosis Assessment App and its predicate device, Quantec Spinal Measurement System (K923792), are similar with regards to their intended use, clinical indications, principle of operation and fundamental technology. In conclusion, NSite, Inc. believes that the NSite Scoliosis Assessment App does not introduce any new potential safety and/or effectiveness issues and is comparable to the identified predicate device, Quantec Spinal Measurement System (K923792).

Characteristic	Proposed DeviceNSite, Inc.NSite ScoliosisAssessment App(K230463)	Predicate DeviceQuantec Image ProcessingLtd.Quantec SpinalMeasurement System(K923792)	SimilaritiesandDifferences
Classification	Unclassified	Unclassified	Identical
Regulation	Unclassified	Unclassified	Identical
Product Code	LDK	LDK	Identical
Prescription	Yes	No	Difference –Both devicesare intended to
Characteristic	Proposed DeviceNSite, Inc.NSite ScoliosisAssessment App(K230463)	Predicate DeviceQuantec Image ProcessingLtd.Quantec SpinalMeasurement System(K923792)	SimilaritiesandDifferences
			be used byhealth careprofessionals.The restrictionto use theproposed NSiteScoliosisAssessmentApp byprescriptiononly does notraise newquestions ofsafety andeffectiveness.
Indicationsfor Use	The NSite ScoliosisAssessment App isintended as an adjunct toolfor qualified healthcareprofessionals to providedeformity measurementsand guide managementrecommendations based ona calculated AsymmetryIndex for patients with or atrisk for idiopathic scoliosis,which will yield an output oflow or high risk of clinicallysignificant scoliosis, whichis defined as a Cobb Anglegreater than 20 degrees.	Quantec SpinalMeasurement System isindicated as an opticalcontour sensing device toprovide topographicalimages for the 3Dassessment of backasymmetries.	SimilarBoth devicesare intended tobe used byhealth careprofessionals.Both devicesare opticalsensing devicesintended togenerate 3Dsurface imagesof a patient'sback and trunkand quantifysurfacealignment anddeformityparameters.
PatientPopulation	Child / Adolescent age 10-18	Adult or pediatricpopulations	Similar - Bothdevices includepediatricpatients in theirintended use.
Characteristic	Proposed DeviceNSite, Inc.NSite ScoliosisAssessment App(K230463)	Predicate DeviceQuantec Image ProcessingLtd.Quantec SpinalMeasurement System(K923792)	SimilaritiesandDifferences
IntendedUsers	Health care medicalprofessionals, such asprimary care providers,pediatricians, orthopaedicsurgeons, physicaltherapists, orthotists,school nurses, andchiropractors.	Health specialists such aspodiatrists, pedorthists,orthopedist,physiotherapists,chiropractors, osteopaths,and kinesiotherapists.	Similar - Bothdevices areintended to beused by healthcareprofessionals.
Environment	Health care facilities	Health care facilities	Identical
Technique	Surface Topography -structured light projection	Surface Topography -structured light projection	Identical
Method	Non-Tactile	Non-Tactile	Identical
Measurement	Static	Static	Identical
Principle ofOperation	Based upon TrueDepthvertical-cavity surface-emitting laser (VCSEL)technology scanningtechnology, the image isobtained with iOS mobiledevice camera.	Based upon digitalphotogrammetry	Similar - Bothdevices utilizedigital camerasto obtain patientimages
HardwareComponent	None - The NSite ScoliosisAssessment App is asoftware only device.The minimum mobiledevice hardwarerequirements are defined inthe IFU.	Digital Camera;Quartz halogen lightBooth	Similar - Bothdevices operateon compatiblehardware, theNSite ScoliosisAssessmentApp is installedon usersuppliedhardware.
Software	Software provides userinterface to acquire images,identify regions of interest,perform asymmetrycalculations, reportasymmetry results andpatient scan images.	Software to control thecamera, measure the 3Dtrunk images and to recordand quantify deformities(3D assessment)	Similar - Bothdevices utilizesoftware toanalyze imagesand reportdeformityvalues.
Characteristic	Proposed DeviceNSite, Inc.NSite ScoliosisAssessment App(K230463)	Predicate DeviceQuantec Image ProcessingLtd.Quantec SpinalMeasurement System(K923792)	SimilaritiesandDifferences
Use of BodyMarkers	No	Yes	Difference -The proposeddevice ismanuallysegmented.Once the 3Dmesh isannotated, thescan points areautomaticallymeasured andthe AsymmetryIndex and heatmap iscalculated andreported.The predicatedevice featuresbody markersthe user placesin specifiedlocations tohelp identifyand referenceanatomicallandmarks inthephotographs.The annotationmethod andproposeddevice resultshave beendemonstratedto performsubstantiallyequivalent tothe predicatedevice method.

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Image /page/6/Picture/0 description: The image shows a logo for NSITE. The logo features a square frame with rounded corners, colored in a gradient from teal to purple. Inside the frame is a stylized graphic of three vertically stacked, interconnected shapes resembling molecules or interconnected nodes. The word "NSITE" is written in a bold, sans-serif font below the frame, also colored in the same teal-to-purple gradient.

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Image /page/7/Picture/1 description: The image is a logo for NSITE. The logo features a square frame with rounded corners, and the frame is colored with a gradient that transitions from teal at the top to purple at the bottom. Inside the frame is a symbol that looks like three interconnected molecules or beads stacked vertically. The symbol is also colored with a gradient that transitions from teal at the top to purple at the bottom. Below the frame, the word "NSITE" is written in a bold, sans-serif font, and the word is also colored with a gradient that transitions from teal at the top to purple at the bottom.

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Image /page/8/Picture/0 description: The image shows a logo for NSITE. The logo features a stylized image of three vertically stacked, rounded shapes, each connected by a small dot in the center. The shapes are enclosed within a square frame. Below the frame, the word "NSITE" is written in a bold, sans-serif font. The logo uses a gradient color scheme, transitioning from a lighter blue at the top to a darker blue at the bottom.

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Image /page/9/Picture/0 description: The image is a logo for NSITE. The logo features a square border with rounded corners, inside of which is a stylized image of three vertically stacked, connected shapes that resemble molecules or interconnected nodes. The word "NSITE" is written in capital letters below the square border. The color scheme of the logo transitions from a teal color at the top to a blue color at the bottom.

The general intended use and technology are equivalent between the predicate and the NSite Scoliosis Assessment App. The predicate device is not limited to use by prescription, whereby the proposed NSite Scoliosis Assessment App in intended to be used by prescription only. Further, the NSite Scoliosis Assessment App is intended to be used by healthcare professionals. The restriction to the use of the proposed NSite Scoliosis Assessment App does not raise new questions of safety and effectiveness. The difference in technology is that the predicate quantifies related alignment and deformity parameters that corresponds to given anatomical markers placed by the user, whereas the NSite Scoliosis Assessment App quantifies surface alignment and deformity parameters that correspond to manually segmented regions of interest (ROIs). The method was found to be appropriate and reproducible for its intended use per a clinical study.

Non-Clinical Testing Summary:

The following design control, risk management and quality assurance methodologies were utilized to develop the NSite Scoliosis Assessment App:

. Risk Analysis
Requirements Review .
. Design Reviews
Testing on Unit Level (Verification) .
. Integration Testing (System Verification)
Performance Testing (V&V) .
Safety Testing (V&V) .
. Simulated Use Testing (Validation)

Software documentation for Moderate Level of Concern software per the FDA's "Guidance for the Content of Premarket Submissions for Software Contained in Medical Devices", issued on May 11, 2005, was established and maintained for the NSite Scoliosis Assessment App. The NSite Scoliosis Assessment App was tested in accordance with NSite's verification and validation procedures.

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Image /page/10/Picture/0 description: The image shows a logo for NSITE. The logo features a stylized icon of three vertically stacked, rounded shapes resembling connected molecules or links. The icon is enclosed within a square frame, and the word "NSITE" is written in a bold font below the icon. The color scheme transitions from a teal at the top to a purple at the bottom.

All predefined acceptance criteria for the performance testing were met. The results from the performance testing executed on the NSite Scoliosis Assessment App produced results consistently according to its intended use.

Clinical Testing Summary:

A clinical study of the NSite Scoliosis Assessment App was conducted to assess the reproducibility and reliability of the scanning functionality and validate the accuracy of the predicated probability of major Cobb angle as compared to a Cobb angle obtained via radiograph. The clinical study was performed using adolescent patients spanning the age range where Adolescent Idiopathic Scoliosis (AIS) commonly presents and remains treatable. The clinical study was performed using adolescents of gender and race at ratios where AIS is commonly observed. The clinical study demonstrated that the NSite Scoliosis Assessment App is safe and effective for its intended use, substantially equivalent to the currently cleared predicate device (K923792), and raises no new questions of safety and effectiveness.

Conclusions Drawn from Non-Clinical and Clinical Tests:

The subject device and the predicate devices are substantially equivalent, with respect to intended use, design features, technological characteristics, performance, and safety and effectiveness. The subject device is substantially equivalent to the predicate device, K923792.

Conclusion:

The non-clinical and clinical software testing performed on the NSite Scoliosis Assessment App demonstrates that the NSite Scoliosis Assessment App performs according to its intended use. NSite, Inc. considers the NSite Scoliosis Assessment App (subject device) to be similar to the legally marketed predicate device, K923792, and is as safe and effective as the predicate device without raising any new safety and/or effectiveness concerns.

Regulation Number and Section

N/A