The Rainbow® GT-4A machine is indicated for the symptomatic relief and management of chronic, intractable pain and adjunctive treatment for post-surgical and post-trauma acute pain.

Device Description

The Rainbow® GT-4A is a tetrad channel traditional TENS device. It is powered by an AC adaptor. All operation modes produce the GT Bi-phasic waveform. The GT-4A requires the use of a set of lead wires and a pair of electrodes for each channel.

AI/ML Overview

The provided text describes a 510(k) premarket notification for the Rainbow GT-4A Pain Relief Machine (TENS Unit). This submission claims substantial equivalence to a predicate device, the Empi Epix XL Model 989, and therefore does not include a study proving the device meets specific acceptance criteria based on clinical performance metrics.

Instead, the acceptance criteria and "proof" are based on the device's technical specifications and a comparison to the predicate, arguing that the technical differences do not raise new questions of safety or effectiveness.

Here’s a breakdown based on the provided information, addressing your points where possible, and noting when information is not present in the document:

1. Table of Acceptance Criteria and Reported Device Performance

Acceptance Criteria (Implied)	Reported Device Performance
Safety: Device must be electrically safe.	Meets UL2601 Standards for electrical safety.
Effectiveness: Must be as effective as the predicate device.	Technical characteristics are considered "not really differences" from the predicate. Differences in modes and channels do not require testing to establish equivalence. Functional testing confirms it meets product specifications.
Intended Use: Comparable to predicate device.	Indicated for symptomatic relief and management of chronic, intractable pain and adjunctive treatment for post-surgical and post-trauma acute pain (identical to predicate's presumed intended use).
Technical Specifications: (e.g., waveform, output settings)	Produces GT Bi-phasic waveform. Outputs 2 and 100 Hz rates (predicate had more options). Has 4 independent channels (predicate had 2). Powered by AC adaptor (predicate used battery). No Low Battery Indicator.

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

No clinical test set was used. The submission states: "No clinical testing is needed."
Data provenance: Not applicable as no clinical data was generated for this submission. The comparison is against the predicate device's established performance and general TENS technology.

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

Not applicable. No clinical test set and thus no ground truth established by experts for performance evaluation.

4. Adjudication method for the test set

Not applicable. No test set or clinical study requiring 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

No. This is a TENS unit, not an AI-powered diagnostic device. An MRMC study is not relevant to this type of device and was not performed.

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

Not applicable. This section is relevant for AI/ML devices. The Rainbow GT-4A is a hardware medical device (TENS unit).

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

Not applicable for clinical performance. The "ground truth" for the submission is the predicate device's established safety and effectiveness. The GT-4A's performance is deemed acceptable if its technical specifications are sufficiently similar to (or justified as not raising new questions compared to) the predicate device. Functional testing was performed against product specifications to ensure the device operates as designed (which is distinct from clinical performance).

8. The sample size for the training set

Not applicable. This is a hardware medical device, not an AI/ML model that requires a training set.

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

Not applicable. No training set was used.

Summary

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510(k) Number:
Applicant Name:	Sino-Us Information, Inc.
Applicant Address:	85-13 88th Avenue
	Woodhaven, NY 11421
Contact Person:	Yitang Sheng
Phone:	(718)846-6868
Date Prepared:	May 5, 2003
Classification Name:	Transcutaneous Electrical Nerve Stimulator
Common/Usual Name:	TENS Unit
Trade/Proprietary Name:	Rainbow GT-4A Pain Relief Machine (GT-4A)
Equivalent Devices:	Empi Epix XL Model 989

Product Description

The Rainbow® GT-4A is a tetrad channel traditional TENS device. It is powered by an AC adaptor. All operation modes produce the GT Bi-phasic waveform.

The GT-4A requires the use of a set of lead wires and a pair of electrodes for each channel. But no electrodes and lead wires are provided by this device. Patients must choose the products recommended by their clinician.. Selecting high quality of electrodes and lead wires is necessary for use of GT-4A and it has been observed that the quality of the electrodes may impact the ability of the GT-4A to operate efficiently, i.e. if the electrode does not adhere to the skin well the stimulative current (output) will not be delivered well.

Intended use

The Rainbow® GT-4A is indicated for the symptomatic relief and management of chronic, intractable pain and adjunctive treatment for post-surgical and post-trauma acute pain.

Comparison of Equivalent Device to the New Device

Summary of Technical Differences:

The Rainbow® GT-4A is technically identical to the Empi Epix XL Model 989, a predicate device, except that (1) an AC adaptor instead of the 9 V Alkaline Battery (or Empi rechargeable bettery), (2) only 2 and 100 Hz rates output rather than 2, 10, 20, 40, 60, 80, 100 and 150 Hz output, (3) 4 independent channels rather than 2 channels and (4) No Low Battery Indicator.

The adopted AC adaptor meets UL2601 Standards and the whole GT-4A device meets it too. i.e. it is of safety electrically. In addition, some predicate devices, e.g. Arista SD Plus TENS (K970429), are powered by an AC Adaptor too.

So this difference does not raise new questions of safety and effectiveness, and the GT-4A is as safe and as effective as the legally marketed device.

The differences in (2), (3) and (4) are not really differences in technological characteristics since underlying technology is the same as equivalent device.

Those differences do not require testing to establish equivalence.

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Summary of Performance-Nonclinical

The GT-4A machine performs identically to the Epix XL 989. No clinical testing is needed.

Product Verification and Validation

The functional testing was performed and the results analyzed against product specifications demonstrates that the product meets requirements and is acceptable for its intended use.

Conclusions

This 510(k) premarket notification has demonstrated Substantial Equivalence as defined and understood in the FD&C Act and various guidance documents issued by CDRH.

Comparison of Product Specifications

See the following chart for details on the similarities and differences of the predicate device and GT-4A.

(See next pages)

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Image /page/2/Picture/1 description: The image is a black and white logo for the U.S. Department of Health & Human Services. The logo features a stylized image of an eagle with three curved lines representing its wings. The words "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" are arranged in a circular pattern around the eagle.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

NOV 1 3 2003

Yitang Sheng, President Sino-U.S. Information, Inc. 85-13 88th Avenue Woodhaven, New York 11421

Re: K031546

Trade/Device Name: Rainbow GT-4A Pain Relief Machine Regulation Number: 21 CFR 882.5890 Regulation Name: Transcutaneous Electrical Nerve Stimulator Regulatory Class: Class II Product Code: GZJ Dated: October 15, 2003 Received: October 20, 2003

Dear Mr. Sheng:

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.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to such 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); 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.

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Page 2 - Yitang Sheng

This letter will allow you to begin marketing your device as described in your Section 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 21 CFR Part 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4659. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address

http://www.fda.gov/cdrh/dsma/dsmamain.html

Sincerely vours,

Sincerely yours,

Mark N Millerson

Celia M. Witten, Ph.D., M.D. Director Division of General, Restorative and Neurological Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Page__________________________________________________________________________________________________________________________________________________________________________

510(k) Number: K031546

Device Name: Rainbow® GT-4A

Indications For Use:

The Rainbow® GT-4A machine is indicated for the symptomatic relief and management of chronic, intractable pain and adjunctive treatment for post-surgical and post-trauma acute pain.

Concurrence of CDRH, Office of Device Eveluation (ODE)

Mark A. Milker

(Division Sign-Off)

1 Restorative

(Division Sign-Orl), Restorative Divisiourological Devices

.510(k) Number -

(OptionalFormat 3-10-98)

Regulation Number and Section

§ 882.5890 Transcutaneous electrical nerve stimulator for pain relief.

(a)
Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to electrodes on a patient's skin to treat pain.(b)
Classification. Class II (performance standards).