This software is intended for use by qualified research and clinical professionals with specialized training in the use of EEG and PSG recording instrumentation for the digital recording, playback, and analysis of physiological signals. It is suitable for digital acquisition, display, comparison, and archiving of EEG potentials and other rapidly changing physiological parameters.

Device Description

The Natus Medical Incorporated (Natus) DBA Excel-Tech Ltd. (XLTEK) Grass® TWin ® (Grass TWin) is a comprehensive software program intended for Electroencephalography (EEG), Polysomnography (PSG), and Long-term Epilepsy Monitoring (LTM). TWin is incredibly powerful and flexible, but also designed for easy and efficient day-to-day use. Grass TWin is a software product only, and does not include any hardware.

AI/ML Overview

This document is a 510(k) summary for the Grass TWin, a software program intended for Electroencephalography (EEG), Polysomnography (PSG), and Long-term Epilepsy Monitoring (LTM). The focus of the provided text is on demonstrating the device's substantial equivalence to a predicate device and its compliance with regulatory standards for software and usability.

Based on the provided text, the Grass TWin software does not appear to have detailed acceptance criteria or a specific study proving device performance against those criteria in the typical sense of a clinical performance study with metrics like sensitivity, specificity, or accuracy. Instead, the "performance testing" described focuses on software verification and validation and bench testing for compliance with pre-determined specifications and regulatory standards.

Here's an analysis of the information, addressing your requests based only on the provided text:

1. A table of acceptance criteria and the reported device performance

The document does not explicitly present a table of quantitative "acceptance criteria" and "reported device performance" in terms of clinical outcomes or diagnostic accuracy. Instead, the acceptance criteria are framed as compliance with internal requirements and regulatory standards for software development, usability, and safety.

Acceptance Criteria Category	Reported Device Performance
Software Development	"The Grass TWin software was designed and developed according to a robust software development process, and was rigorously verified and validated." "Results indicate that the Grass TWin software complies with its predetermined specifications, the applicable guidance documents, and the applicable standards." (referencing FDA guidance documents and IEC 62304: 2006)
Usability	"The Grass TWin was verified for performance in accordance with internal requirements and the applicable clauses of the following standards: IEC 60601-1-6: 2010, Am1: 2013, Medical electrical equipment -Part 1-6: General requirements for basic safety and essential performance – Collateral standard: Usability; IEC 62366: 2007, Am1: 2014, Medical devices – Application of usability engineering to medical devices." "Results indicate that the Grass TWin complies with its predetermined specifications and the applicable standards."
Safety & Effectiveness	"Verification and validation activities were conducted to establish the performance and safety characteristics of the device modifications made to the Grass TWin. The results of these activities demonstrate that the Grass TWin is as safe, as effective, and performs as well as or better than the predicate devices."

2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

The document does not describe a "test set" in the context of clinical data or patient samples. The performance evaluation focuses on software verification/validation and bench testing. Therefore, information about sample size, data provenance, or whether it was retrospective/prospective is not applicable as described in this document.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

This information is not provided because the performance testing described is not based on a clinical test set requiring expert-established ground truth.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

This information is not provided because the performance testing described is not based on a clinical test set requiring expert adjudication.

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

The document does not mention an MRMC comparative effectiveness study, nor does it refer to AI or assistance for human readers. The device is software for recording, playback, and analysis of physiological signals, not an AI-driven interpretive tool.

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

While the Grass TWin is "software only" and can be considered a standalone algorithm in that it performs its functions without direct hardware integration, the performance evaluation documented here describes its compliance with specifications and standards, not a specific standalone clinical performance study with metrics like sensitivity or specificity. The "Indications for Use" explicitly state it is "intended for use by qualified research and clinical professionals with specialized training," implying human-in-the-loop operation.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)

The concept of "ground truth" as typically used in clinical performance studies (e.g., against pathology or expert consensus) is not directly applicable to the performance testing described. The "truth" against which the software was evaluated was its predetermined specifications and compliance with regulatory standards (e.g., correct operation of software features, adherence to usability principles).

8. The sample size for the training set

The document does not refer to a "training set" for an algorithm, as it describes a software application that is verified and validated rather than trained using machine learning.

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

As there is no mention of a training set, this information is not provided.

In summary, the provided document describes a regulatory submission for software (Grass TWin) that demonstrates substantial equivalence by focusing on:

Technology Comparison: Showing direct equivalence in intended use and technological characteristics with a predicate device, noting minor differences that do not raise new questions of safety or effectiveness (e.g., operating system, additional features like PTT Trend Option, Montage Editor Summation Feature).
Software Verification and Validation: Adherence to robust software development processes and compliance with general FDA guidance documents and international standards (IEC 62304 for software lifecycle processes, IEC 60601-1-6 and IEC 62366 for usability).
Bench Performance Testing: Verification against internal requirements and applicable standards, specifically for usability.

The detailed clinical performance metrics typical for diagnostic or AI-assisted devices that you've asked about are not present in this 510(k) summary, as the device's nature (recording, playback, and analysis software for existing physiological signals, rather than a novel diagnostic algorithm) and the context of a substantial equivalence submission likely did not require them.

Summary

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Natus Medical Incorporated DBA Excel-Tech Ltd. (XLTEK) Shane Sawall Manager, Regulatory Affairs 2568 Bristol Circle Oakville, Ontario L6H 5S1 CA

March 9, 2018

Re: K173690

Trade/Device Name: Grass TWin Regulation Number: 21 CFR 882.1400 Regulation Name: Electroencephalograph Regulatory Class: Class II Product Code: OLV, GWQ Dated: February 12, 2018 Received: February 14, 2018

Dear Shane Sawall:

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. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

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

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (OS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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

For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/) and CDRH Learn (http://www.fda.gov/Training/CDRHLearn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (http://www.fda.gov/DICE) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

Sincerely,

Michael J. Hoffmann -S

Carlos Peña, Ph.D. for Director Division of Neurological and Physical Medicine Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known) K173690

Device Name Grass® TWin®

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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510(K) SUMMARY

Page 1 of 4

Submission Date:	30 November 2017
Submitter:	Natus Medical Incorporated DBA Excel-Tech Ltd. (XLTEK)2568 Bristol CircleOakville, Ontario, L6H 5S1Canada
Submitter andApplicationCorrespondent	Mr. Shane SawallPhone: +1 (608) 829-8673Fax: +1 (608) 829-8771Email: shane.sawall@natus.com
Manufacturing Site:	Natus Medical Incorporated DBA Excel-Tech Ltd. (XLTEK)2568 Bristol CircleOakville, Ontario, L6H 5S1Canada
Trade Name:	Grass® TWin®
Common andClassificationName:	Standard Polysomnograph With Electroencephalograph
ClassificationRegulation:	21 CFR §882.1400
Product Code:	OLV, GWQ
SubstantiallyEquivalent Devices:	New Model	Predicate 510(k)Number	PredicateManufacturer / Model
	XLTEK / Grass TWin	K012976	Grass-TelefactorDivision, Astro-Med,Inc. / Grass-TelefactorTWin PLUS
Device Description:	The Natus Medical Incorporated (Natus) DBA Excel-Tech Ltd.(XLTEK) Grass® TWin ® (Grass TWin) is a comprehensive softwareprogram intended for Electroencephalography (EEG), Polysomnography(PSG), and Long-term Epilepsy Monitoring (LTM). TWin is incrediblypowerful and flexible, but also designed for easy and efficient day-to-dayuse. Grass TWin is a software product only, and does not include anyhardware.

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Image /page/4/Picture/0 description: The image contains the logo for Natus Neurology. The word "natus" is written in a teal sans-serif font, with a small registered trademark symbol to the right of the word. Below "natus", the word "neurology" is written in a dark blue sans-serif font.

Technology

Comparison:

This software is intended for use by qualified research and clinical Intended Use: professionals with specialized training in the use of EEG and PSG recording instrumentation for the digital recording, playback, and analysis of physiological signals. It is suitable for digital acquisition, display, comparison, analysis, and archiving of EEG potentials and other rapidly changing physiological parameters.

The Grass TWin employs the same technological characteristics as the predicate device.

System Characteristic	Grass-Telefactor Division,Astro-Med, Inc.Grass-Telefactor TWin PLUS(K012976)	XLTEK Grass TWin(Proposed Device)
Intended Use	This software is intended for useby qualified research and clinicalprofessionals with specializedtraining in the use of EEG andPSG recording instrumentationfor the digital recording.playback, and analysis ofphysiological signals. It issuitable for digital acquisition,display, comparison, analysis, andarchiving of EEG potentials andother rapidly changingphysiological parameters.	Same.
Personal ComputerOperating System	Microsoft® Windows 98 or 2000	Microsoft® Windows 7 andWindows Server 2008
Recording SystemCompatibility	AURA PSG Wireless/AmbulatoryRecorder	AURA PSG Wireless/AmbulatoryRecorder
	AURA PSG LiteAmbulatory/Wireless SleepScreener	AURA PSG LiteAmbulatory/Wireless SleepScreener
	SleepTrek3 Portable SleepScreener	SleepTrek3 Portable SleepScreener
	Comet Series PSG	Comet and Comet-PLUS SeriesPSG
	Comet Series EEG	Comet and Comet-PLUS SeriesEEG
	AURA24 Ambulatory EEG	AURA24 Ambulatory EEG
	TREA Ambulatory EEG	TREA Ambulatory EEG
	Beehive Horizon for Long-TermMonitoring	Beehive Horizon for Long-TermMonitoring
Pulse Transit Time(PTT) Trend Option	No	Yes
Montage EditorSummation Feature	No	Yes

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510(K) SUMMARY

Summary of Performance Testing:

Software

The Grass TWin software was designed and developed according to a robust software development process, and was rigorously verified and validated. Software information is provided in accordance with internal requirements and the following FDA guidance documents and standards:

. The content of premarket submissions for software contained in medical devices, 11 May 05.
Off-the-shelf software use in medical devices, 09 Sep 99. ●
General principles of software validation; Final guidance for industry . and FDA staff, 11 Jan 02.
Content of premarket submissions for management of cybersecurity in medical devices, 02 Oct 14.
. Cybersecurity for networked medical devices containing off-the-shelf (OTS) software, 14 Jan 05
. IEC 62304: 2006, Medical device software – Software life cycle processes

Results indicate that the Grass TWin software complies with its predetermined specifications, the applicable guidance documents, and the applicable standards.

Performance Testing - Bench The Grass TWin was verified for performance in accordance with internal requirements and the applicable clauses of the following standards:

. IEC 60601-1-6: 2010, Am1: 2013, Medical electrical equipment -Part 1-6: General requirements for basic safety and essential performance – Collateral standard: Usability
. IEC 62366: 2007, Am1: 2014, Medical devices – Application of usability engineering to medical devices.

Results indicate that the Grass TWin complies with its predetermined specifications and the applicable standards.

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510(K) SUMMARY

PAGE 4 of 4

Verification and validation activities were conducted to establish the Conclusion performance and safety characteristics of the device modifications made to the Grass TWin. The results of these activities demonstrate that the Grass TWin is as safe, as effective, and performs as well as or better than the predicate devices.

Therefore, the Grass TWin is considered substantially equivalent to the predicate devices.

Regulation Number and Section

§ 882.1400 Electroencephalograph.

(a)
Identification. An electroencephalograph is a device used to measure and record the electrical activity of the patient's brain obtained by placing two or more electrodes on the head.(b)
Classification. Class II (performance standards).