The THØR DDII 1R Lamp System is intended to emit energy in the visible and infrared spectrum to provide topical heating for the purpose of elevating tissue temperature for the temporary relief of minor muscle and joint pain and stiffness, minor arthritis pain, or muscle spasm; the temporary increase in local blood circulation; and / or the temporary relaxation of muscle.

Device Description

The THØR DDII IR Lamp System is a portable, AC and battery operated noninvasive, low level infrared lamp that provides continuous heat therapy at a fixed frequency. The System consists of a Drive Unit/Power Supply that houses the electronics and controls and optional treatment probes that contain the visible and infrared radiating elements. Various Cluster Probes are available accessories with the Drive Unit.

AI/ML Overview

The THOR DDII IR Lamp System is designed to emit energy in the visible and near-infrared spectrum for topical heating. It aims to provide temporary relief from minor muscle and joint pain and stiffness, minor arthritis pain, or muscle spasm, temporarily increase local blood circulation, and/or temporarily relax muscles.

Acceptance Criteria and Device Performance:

Acceptance Criteria (Intended Use)	Reported Device Performance
Emit energy in the visible and near-infrared spectrum to provide topical heating.	Utilizes infrared diodes to generate topical heating.
For the purpose of elevating tissue temperature for the temporary relief of minor muscle and joint pain and stiffness, minor arthritis pain, or muscle spasm; the temporary increase in local blood circulation; and / or the temporary relaxation of muscle.	"The THØR DDII IR Lamp System is designed to comply with the generally accepted therapeutic heat performance specifications by producing a level of tissue temperature reported in literature and accepted by the Federal Food and Drug Administration." The device performs as intended and does not raise new safety or efficacy issues.
Maintain safety standards.	Functional performance testing and electrical safety testing were conducted. The device performs as intended and does not raise new safety or efficacy issues. The FDA determined the device to be substantially equivalent to legally marketed predicate devices, implying it meets established safety and effectiveness standards for this product type.

Study Information:

Sample Size used for the test set and data provenance:
The provided document does not specify a separate "test set" sample size for clinical validation. The testing seems to focus on functional performance and electrical safety rather than a clinical trial with a defined patient cohort. The data provenance is not explicitly stated as country of origin, but the submission is to the US FDA, and the company is based in the UK. The nature of the testing (functional/electrical) suggests neither retrospective nor prospective clinical data in the typical sense for algorithm evaluation. Instead, it's about physical device characteristics.
Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
Not applicable. The document does not describe a test set requiring expert-established ground truth in the context of diagnostic or interpretive performance. The "ground truth" for this device likely refers to meeting engineering specifications for heat output and electrical safety, and clinical intent is tied to established therapeutic heat principles.
Adjudication method (e.g. 2+1, 3+1, none) for the test set:
Not applicable. This type of adjudication is typically used in clinical studies where expert consensus is needed for interpreting medical images or patient outcomes. The provided document details functional and safety testing of a physical device.
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. The THOR DDII IR Lamp System is a therapeutic device (infrared lamp), not a diagnostic or interpretive AI-assisted system for human readers. Therefore, an MRMC study comparing human reader performance with and without AI assistance is not relevant to this submission.
If a standalone (i.e. algorithm only without human-in-the loop performance) was done:
Yes, in a sense. The testing was on the device's inherent performance (functional and electrical safety) in a standalone capacity, without human interpretive input as part of its primary function. It's a device that delivers physical therapy, not an algorithm providing diagnostic outputs.
The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
For functionality, the "ground truth" was likely engineering specifications and established therapeutic heat performance standards referenced in literature and accepted by the FDA. For safety, it would be compliance with electrical safety standards. The claim of "temporary relief of minor muscle and joint pain..." is based on the accepted physiological effects of therapeutic heat.
The sample size for the training set:
Not applicable. This is a medical device, not an AI/ML algorithm that requires a "training set" in the computational sense. The device is designed based on known physics and engineering principles for infrared heat generation, not statistical learning from a dataset.
How the ground truth for the training set was established:
Not applicable, as there is no "training set" for this type of device. The design and validation are based on established scientific principles of therapeutic heat and direct physical testing against performance and safety standards.

Summary

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MAR 1 7 2004

ecember 9, 2003.

K033923
16F2

APPENDIX B

510(k) PREMARKET NOTIFICATION SUMMARY

(Per 21 CFR 807.92)

THØR DDII IR Lamp Systems

I. Applicant:

JHØR International Ltd. Caer Sidhe Chiltern Road Amersham HP6 SPH United Kingdom Telephone: +44 1494 433 736 Facsimile: +44 1494 431 481 Email: james@thorlaser.com

Key Contact: James Carrol

II. Device Name

Proprietary Name:	THØR DD II IR Lamp System
Common / Usual Name:	Infrared Lamp
Classification Name:	Infrared Lamp (21 CFR 890.555)
Product Code:	ILY

III. Predicate Device

The THØR DDII IR Lamp System is substantially equivalent to other infrared lamps currently in commercial distribution such as the Super Nova / Acubeam systems manufactured by Light Force Technology, Inc., and BioFlex Professional Therapy System manufactured by Meditech International, Inc.

IV. Intended Use of the Device

The THØR IR Lamp System is intended to emit energy in the visible and near infrared spectrum to provide topical heating for the purpose of elevating tissue temperature for the temporary relief of minor muscle and joint pain and stiffness, minor arthritis pain, or muscle spasm; the temporary increase in local blood circulation; and / or the temporary relaxation of muscle,

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V. Description of the Device

Summary of the Technical Characteristics of the Thor DDII IR Lamp VI. System as Related to the Referenced Predicate Devices.

The THØR DDII IR Lamp System and the aforementioned predicate devices are infrared lamps as clefined in 21 CFR 890.5500. These devices utilize infrared diodes to generate topical heating for the purpose of elevating tissue temperatures for the temporary relief of minor muscle and joint pain and stiffness, minor arthritis pain, or muscle spasm, the temporary increase in local circulation and the temporary relaxation of muscle. The Systems are intended to be placed directly on the skin to provide heating.

Testing VII.

Testing of the THØR DDII IR Lamp System included functional performance testing and electrical safety testing.

VIII. Conclusions

Pursuant to the testing and comparison to the predicate devices, the THØR DDII IR Lamp System has the same intended uses, with similar functional and performance characteristics. The THØR DDII IR Lamp System is designed to comply with the generally accepted therapeutic heat performance specifications by producing a level of tissue temperature reported in literature' and accepted by the Federal Food and Drug Administration.

The THØR DDII IR Lamp System performs as intended and do not raise any new safety or efficacy issues.

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Image /page/2/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the perimeter. Inside the circle is an abstract image of an eagle, represented by three stylized lines forming the wings and body.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

MAR 1 7 2004

Thor International Ltd. C/o M. Joyce Heinrich Texas Applied Biomedical Services, Inc. 12101 - A Cullen Boulevard Houston, Texas 77047

Re: K033923

Trade/Device Name: Thor DDII IR Lamp System Regulation Number: 21 CFR 890.5500 Regulation Name: Infrared lamp Regulatory Class: II Product Code: ILY Dated: December 15, 2003 Received: January 16, 2004

Dear Ms. Heinrich:

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 - M. Joyce Heinrich

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), please contact the Office of Compliance at (301) 594-4659. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). 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) 443-6597 or at its Internet address http://www.fda.gov/cdrh/dsma/dsmamain.html

Sincerely vours.

R. Merle A. Millikan

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

Enclosure

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ATTACHMENT C

INDICATIONS FOR USE

510(k) Number (if known): K033923

Device Name: THØR DDII IR Lamp System

Indications for Use:

AND/OR Prescription Use: X (Part 21 CFR 801 Subpart D)

Over the Counter Use: (21 CFR 807 Subpart C)

(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)

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

510(k) Number K033923

Page 1 of 1

Regulation Number and Section

§ 890.5500 Infrared lamp.

(a)
Identification. An infrared lamp is a device intended for medical purposes that emits energy at infrared frequencies (approximately 700 nanometers to 50,000 nanometers) to provide topical heating.(b)
Classification. Class II (special controls). The device, when it is an infrared therapeutic heating lamp, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 890.9.