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. Its specifications and features are especially well suited to electroencephilography, polysomnographic sleep recordings, and long term recordings used in epilepsy diagnosis.
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, analysis, and archiving of EEG potentials and other rapidly changing physiological parameters.

Device Description

TWin PLUS will become the universal review package for all GRASS-Telefactor EEG systems. Further the TWin PLUS software package is intended for use with a number of hardware EEG inourterlices. It utilizes the windows operating system to manage four or more simultaneous ongoing tasks which include:

Real-time collection and formating of real time EEG and other physiological parameters
Real-time display of the foregoing parameters in waveform or numeric format as the data and user . may require.
Real time analysis of EEG waveform data to identify events which may be epileptoform in nature and hence require special attention from professionals in attendance - SZAC analysis.
Data collection and recording to disk of real time video and audio data, usually an image of the patient ● being monitored.
Review and analysis of previously recorded data including the ability to look-back to old data while ● real-time recording of ongoing data is in progress.

AI/ML Overview

The provided document describes the Grass-Telefactor TWin PLUS Software, an EEG Review Software. However, it does not contain explicit acceptance criteria or a detailed study proving the device meets specific performance metrics in the way modern medical device submissions typically do.

The document is a 510(k) premarket notification and focuses on establishing substantial equivalence to previously marketed devices rather than presenting a performance study against predefined acceptance criteria. Therefore, much of the requested information cannot be directly extracted from this document.

Here's an analysis based on the available information:

Key Takeaways from the Document:

Substantial Equivalence: The primary argument for market clearance is that the TWin PLUS software is "functionally equivalent in design and function" to GRASS GAMMA, Telefactor BEEHIVE, and Telefactor SZAC Seizure Analysis Computer. It is described as a "composite of the three referenced substantially equivalent devices with enhanced capacity."
No Diagnostic Claims: Crucially, the document explicitly states, "Grass-Telefactor makes no claims for diagnostic accuracy of this algorithm," and "None of the products claims to be in and of itself 'diagnostic'." Instead, it's intended to mark particular EEG passages for "diagnostic consideration" or for "professional review and classification." This significantly reduces the need for extensive diagnostic accuracy studies in the context of this 510(k) submission.
Professional Review: The document consistently emphasizes that "All of the products are designed to be operated by trained medical professionals and the data collected is reviewed in its entirety by trained medical professionals."
Algorithm Provenance: The "Flagging of Epileptoform EEG Data Sequences (SZAC)" module uses "the identical software algorithm developed and proven in the SZAC Computer previously marketed by Telefactor (K870450)." The "Semi Automatic Sleep Scoring System (SASSY K860219)" is also an "next iteration" of a previously cleared system. This suggests reliance on the prior clearance and established use of these specific algorithms.

Detailed Response to Requested Information (Based on Document and Inferences):

1. Table of Acceptance Criteria and Reported Device Performance

Acceptance Criteria: The document does not define specific quantitative acceptance criteria (e.g., sensitivity, specificity, accuracy thresholds). The implicit acceptance criterion for this 510(k) is "substantial equivalence" to predicate devices and demonstrating that the device enhancements (e.g., increased channels, modern OS) do not raise new questions of safety or effectiveness.
Reported Device Performance: The document does not report quantitative performance metrics (e.g., sensitivity, specificity, PPV, NPV) for the automated analysis features (SZAC, SASSY, apnea/desaturation/PLM marking).

Feature	Implicit Acceptance Criterion (based on document)	Reported Device Performance (from document)
Overarching purpose	Functionally equivalent to predicates (GRASS GAMMA, BEEHIVE, SZAC)	"Composite of the three referenced substantially equivalent devices"
SZAC (Epileptoform Marking)	Uses "identical software algorithm developed and proven in the SZAC Computer" (K870450)	"marks particular EEG passages for diagnostic consideration either as seizures or as spikes." "No claims for diagnostic accuracy."
SASSY (Sleep Scoring)	"Next iteration" of previously cleared SASSY (K860219)	"functions to display polysomnographic data... provides means a review operator to assign a sleep stage notation."
Apnea/Desaturation/PLM Marking	Functions for "professional review and classification." Decision thresholds adjustable.	"No diagnostic classification is made without a decision based on the review of a qualified professional." "Supplied without any claims for accuracy."
Safety	No new safety concerns compared to predicates	"None of the products features have any impact on the safety of the patient or operator."
Intended Use	For "qualified research and clinical professionals" to "assist" in analysis.	Device is not "diagnostic" in itself; human review is central.

2. Sample Sizes used for the Test Set and Data Provenance

Test Set Sample Size: The document does not mention a specific test set sample size. Given the nature of a 510(k) focusing on substantial equivalence and the device's non-diagnostic claims, a formal clinical performance study with a dedicated test set exhibiting specific performance metrics would likely not have been required or performed.
Data Provenance: Not applicable, as no specific performance study is detailed.

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

Not applicable, as no specific performance study against a ground truth is detailed. The ground truth for the algorithms themselves (SZAC and SASSY) would have been established during their initial development and clearance (K870450, K860219), but this document doesn't provide those details. The current device's use relies on subsequent human expert review.

4. Adjudication method for the test set

Not applicable, as no specific performance study against a ground truth is detailed.

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, a multi-reader multi-case (MRMC) comparative effectiveness study is not described or referenced in this document. The device's components (like SZAC and SASSY) are described as tools for expert review, not replacements for it.

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

No, a standalone performance study is not described. In fact, the document disclaims standalone diagnostic performance: "Grass-Telefactor makes no claims for diagnostic accuracy of this algorithm," and "No diagnostic classification is made without a decision based on the review of a qualified professional." The device's function is explicitly described as "computer assisted" and for "professional review."

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

The document does not describe the ground truth used for any performance evaluation of the TWin PLUS software itself. For the embedded algorithms (SZAC and SASSY), their "proven" status from prior 510(k) clearances implicitly means a ground truth was established, likely by expert interpretation of EEG/PSG data, but specifics are not in this document.

8. The sample size for the training set

The document does not mention the sample size for a training set. The algorithms (SZAC, SASSY) were developed prior to this submission, and details about their training would be in the original K870450 and K860219 submissions if applicable.

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

The document does not provide this information for TWin PLUS or its components. For the predicate algorithms (SZAC and SASSY), it would have been established during their original development, likely through expert annotation of physiological data.

In summary: K012976 is a 510(k) submission focused on demonstrating substantial equivalence and the integration of previously cleared functionalities into a new software platform with modern capabilities. It explicitly positions the software as a tool for trained professionals, not as an independent diagnostic device, thereby sidestepping the need for extensive de novo performance studies with defined acceptance criteria and ground truth validation for its automated features within this particular submission. The "proof" is largely based on the prior clearance and established use of the predicate devices and embedded algorithms.

Summary

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K 012976
2-12-02

EXHIBIT A

Grass-Telefactor Division

Astromed-Med, Inc.

West-Warwick, RI 02893 USA

Tel: (401) 828-4000

Fax: (401) 822-2430

Contact Person: Jim Bryan

August 15, 2001

1. Identification of the Device

Classification Name: Electroencephalograph, 84GWQ, Reg. #882.1400 (1)

Common/Usual Name: EEG Review Software

Proprietary-Trade Name: Grass-Telefactor TWin PLUS Software

2. Equivalent Legally Marketed Devices

This software is functionally equivalent in design and function to that of the GRASS GAMMA software package and the Telefactor BEEHIVE, and the Telefactor SZAC Seizure Analysis Computer.

3. Indications for Use

4. Theory of Operation and Description of the Device

Real-time collection and formating of real time EEG and other physiological parameters ●

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Real-time display of the foregoing parameters in waveform or numeric format as the data and user . may require.
. Real time analysis of EEG waveform data to identify events which may be epileptoform in nature and hence require special attention from professionals in attendance - SZAC analysis.
Data collection and recording to disk of real time video and audio data, usually an image of the patient ● being monitored.
Review and analysis of previously recorded data including the ability to look-back to old data while ● real-time recording of ongoing data is in progress.

EEG Input Ampliffers:

The TWin PLUS software package is intended to work with a number of different amplifier systems with various digital interface modes. Each of these hardware devices have or will have their own separate 510(k) marketing authority, ---

These amplifiers choices include:

Current BEEHIVE amplifiers which use a special purpose digital interface card for already digitized . data.
The same BEEHIVE amplifiers using a USB interface for the data. .
GRASS-Telefactor TS amplifiers using a computer resident card for A to D conversion of their . multiplexed analog data stream.

Data Formatting and Storage:

All data is stored in a format (TUFF) as near the original input as possible at sample rates appropriate for the data type. Primary storage is either local or remote hard disk (network server). Provisions exist for archiving to several appropriate digital archive media, most frequently CD ROM.

Montaging Capability:

The TWIN PLUS software has provision for labeling data channels with electrode names and then displaying waveforms as the algebraic difference of any electrode pair. The playback montage also specifies default digital filter settings.

Analysis;

Specific sections of data can be selected easily for further analysis including frequency and amplitude measurement, potential mapping, spectral analysis, and frequency band mapping.

Flagging of Epileptoform EEG Data Sequences (SZAC):

The SZAC program module uses the identical software algorithm developed and proven in the SZAC Computer previously marketed by Telefactor (K870450) This system is in wide use in the medical community, particularly in epilepsy centers around the world. Grass-Telefactor makes no claims for diagnostic accuracy of this algorithm, it is merely a device which marks particular EEG passages for diagnostic consideration either as seizures or as spikes.

EEG Data BASE:

An EEG data base feature associates stored EEG data with patient name, date and appropriate clinical parameters entered by the operator, and provides convenient means for accessing that data for review.

Digital Video Recording:

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TWIN software uses the output of an appropriate video capture card in the host computer to digitize, compress and store patient image data. Provision is included to play back video data synchronized with the EEG waveform display.

Semi Automatic Sleep Scoring:

TWin PLUS includes the next iteration of the Semi Automatic Sleep Scoring System (SASSY K860219). This system functions to display polysomnographic data in standard page sizes and provides means a review operator to assign a sleep stage notation to each page.

Report generation and printout are provided for each study with reported parameters which can be tailored by the particular laboratory using the device.

A software option is provided for automatic analysis of SaO2 and respiration data to mark apnea and desaturation events for professional review and classification. A similar module analyzes EMG waveforms to mark periodic leg movements. In each case no diagnostic classification is made without a decision based on the review of a qualified professional.

These routines are supplied without any claims for accuracy and the professional can use or ignore them at his own discretion. In each case decision thresholds are adjustable and can be set by the person reviewing the data.

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5 Comparison Matrix

TechnicalCharacteristic	GRASS-TelefactorTWin PLUS	GRASSGAMMA	TelefactorSZAC 16Seizure AnalysisComputer	TelefactorBEEHIVE 64
Device Class	CLASS II	CLASS II	CLASS II	CLASS II
Intended User	MedicalProfessional	MedicalProfessional	MedicalProfessional	MedicalProfessional
Operating System	Windows 98 or2000	Windows 98 Or2000	DOS	DOS
Max Channels	136	36	16	64 (128 for othermodels)
Sample Rate	1000 Hz Max	1000 Hz Max	200	200
Amplifier control	RS232	RS232	Manual	RS232
Recorder UpdateMode	Wiper Bar	Wiper Bar	Scrolled Display	Scrolled Display
MonitorResolution	1600 x 1200	1600 x 1200	1024 x 440	1024 x440
Data Storage	Local or Remotehard disk	Local or remotehard disk	Local or remotehard disk	Digital VCR
Primary DataAccess	Random	Random	Random	VCR sequential
User Input	Mouse/keyboard	Mouse/keyboard	Keyboard	Keyboard
SynchronizedPatient Video	Yes			Yes
Seizure EventMarking	Yes		Yes
Spike EventMarking	Yes		Yes
Apnea EventMarking	Yes	Yes
Desaturation EventMarking	Yes	Yes
PLM Marking	Yes	Yes
Staging/scoringmethod	Manual/computerassisted	Manual/computerassisted
Sleep ReportParameters	Yes	Yes
EpilepsyParameters	Yes		Yes	Beehive 7

6 Discussion:

The TWin PLUS software is primarily a composite of the three referenced substantially equivalent devices with enhanced capacity permitted by the state-of-the-art in electronic data handling. Faster computers, less expensive disk capacity and multi-tasking operating systems have permitted combining all the figatives, of the referenced products into a single useful modular software package.

None of the products features have any impact on the safety of the patient or operator. Although both TWin PLUS and GRASS GAMMA (NIGHT VISION) have the capability to control the data aquisition

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amplifier settings, neither are required for the safe operation of the amplifiers that they are designed to control, nor are they capable of impacting on the safety of the amplifier systems.

All of the products are designed to be operated by trained medical professionals and the data collected is reviewed in its entirety by trained medical professionals. None of the products claims to be in and of itself "diagnostic".

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Image /page/5/Picture/1 description: The image shows the logo for the Department of Health & Human Services USA. The logo consists of a stylized eagle with three stripes forming its body and wing. The eagle is facing right. The text "DEPARTMENT OF HEALTH & HUMAN SERVICES USA" is arranged in a circular fashion around the eagle.

Food and Drug Administration 10903 New Hampshire Avenue Document Control Room -WO66-G609 Silver Spring. MD 20993-0002

Mr. John B. Chatten President Grass-Telefactor Division Astro-Med, Inc. West-Warwick. Rhode Island 02893

Re: K012976

Trade/Device Name: Grass-Telefactor Twin PLUS Software Regulation Number: 21 CFR 882.1400 Regulation Name: Electroencephalograph Regulatory Class: II Product Code: OLV, GWQ Dated (Date on orig SE ltr): December 7, 2001 Received (Date on orig SE Itr): December 11, 2001

APR - 9 2012

Dear Mr. Chatten:

This letter corrects our substantially equivalent letter of February 12, 2002.

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.

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Page 2 - Mr. John B. Chatten

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 803); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please go to http://www.fda.gov/AboutFDA/CentersOffices/CDRH/CDRHQffices/ucm115809.htm for the Center for Devices and Radiological Health's (CDRH's) Office of Compliance. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR 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/ReportalProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.

You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address

http://www.fda.gov/MedicalDevices/Resourcesfor You/Industry/default.htm.

Sincerely yours,

Kesia Alexander

Malvina B. Eydelman, M.D. Director Division of Ophthalmic, Neurological, and Ear. Nose and Throat Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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12012976 510(k) Number (if known):

Device Name: _TWIN_Plus

Indications for Use:

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, analysis, and archiving of EEG potentials and other rapidly changing physiological parameters.

(PL.FASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IIT NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODDE)

Miriam C. Provost

(Division Sign-Off) Division of General, Restorative and Neurological Devices

510(k) Number K012976

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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).