The BTL-899 is a non-invasive therapeutic device is comprised of the main unit and applicators that deliver radiofrequency energy to the targeted tissue. The device two outputs enable hands-free simultaneous treatment by two applicators. The BTL-899 is equipped with a large color touch screen that significantly facilitates the use of the device. The on-screen information guides the user step-by-step through the entire therapy procedure. The therapeutic parameters are easily set using the touch screen of the device. During the therapy the device keeps information about the applied therapy type, remaining therapy time and main therapy parameters on the screen.

AI/ML Overview

Here's a breakdown of the acceptance criteria and the study details for the BTL-899 device, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

Acceptance Criteria	Reported Device Performance
Primary Endpoints
Abdominal circumference reduction of at least 1.5cm at the 3-month follow-up visit when compared to baseline.	Achieved: Responder analysis showed 88.1% (74%, 96%) subjects had a circumference reduction of 1.5cm or more. Average change was 3.2 ± 1.64 cm.
Evaluation of adverse events and side effects following the BTL-899 treatment throughout the study.	Achieved: No adverse events reported. Side effects were mild erythema, muscle soreness, improved body posture, and back pain relief.
Secondary Endpoints
Correct identification of baseline and 3-month follow-up visit photographs in at least 70% of treated subjects by two blinded evaluators.	Achieved: 76.19% correct identification by both evaluators (N=32).
Abdominal circumference reduction of at least 1.5cm at each study visit after the first treatment when compared to baseline.	Not explicitly detailed for each visit, but the primary endpoint covers the 3-month follow-up, which is the most critical.
Abdominal fat reduction at the last therapy visit, 1-month follow-up visit and 3-month follow-up visit when compared to baseline, evaluated using the ultrasound imaging device.	Achieved: Average fat reduction using ultrasound images at 3-month follow-up was 29.8 ± 3.38%.
Subject's satisfaction with the BTL-899 treatment at each study visit after the first treatment assessed using the Subject Satisfaction Questionnaire.	Achieved: Subjects reported overall satisfaction at follow-up visits (83.3%, 83.3%, and 88.1% respectively).
Subject's discomfort (pain) level after each treatment evaluated using the Therapy Comfort Questionnaire.	Achieved: 92.9% of subjects reported none to minimal discomfort.
Temperature Performance
Device to reach and maintain effective treatment temperature (40 - 43°C).	Achieved: Temperature Performance test shows the therapy temperature of 40 - 43°C was achieved and maintained for the remaining therapy time.
Histology
Induces non-invasive lipolysis (breakdown of fat) in the abdominal area.	Achieved: Histology showed pyknotic nuclei and cell membrane degeneration leading to fat cell lysis and a decrease in fat tissue.
No damage to keratinocytes, melanocytes, hair follicles, sweat or sebaceous glands.	Achieved: Histology showed normal morphology of the dermal layer with no damage to these components.

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

Sample Size: N=42 subjects completed the clinical study out of N=44 enrolled.
Data Provenance: The text does not explicitly state the country of origin, but it is a "Prospective open-label single-arm self-controlled study," indicating it was conducted specifically for this regulatory submission. It is a prospective study.

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

Number of Experts: Two blinded evaluators for photograph identification.
Qualifications: The specific qualifications of the evaluators are not mentioned, only that they were "blinded evaluators."

4. Adjudication Method for the Test Set

The text mentions "two blinded evaluators" for photograph identification. It does not explicitly state an adjudication method (e.g., 2+1, 3+1). The criterion was "Correct identification... in at least 70% of treated subjects by two blinded evaluators," and the result states "Both evaluators correctly identified subject's photographs in 76.19% of cases." This implies consensus or agreement between the two was the standard for a correct identification for a given subject.

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

No MRMC comparative effectiveness study was done to evaluate how human readers improve with AI vs. without AI assistance. This device is a treatment device, not an AI-assisted diagnostic or imaging interpretation tool.

6. Standalone (Algorithm only without human-in-the-loop performance) Study

This is not applicable as the BTL-899 is a medical device for treatment, not an algorithm, and its performance involves direct patient interface and effect. The clinical study evaluated the device's efficacy and safety in a human-in-the-loop context (administered by clinical staff).

7. Type of Ground Truth Used

Clinical Measurements: Abdominal circumference reduction measured by tape.
Imaging: Abdominal fat reduction measured by ultrasound images.
Expert Consensus: Blinded evaluators for photograph identification.
Histology: Biopsies from a separate study of 8 subjects confirmed fat breakdown and skin morphology.
Patient Reported Outcomes: Subject satisfaction and discomfort questionnaires.

8. Sample Size for the Training Set

The document describes a clinical study to evaluate the device's performance, not a training set for an AI algorithm. Therefore, there is no mention of a "training set" in this context. The N=42 subjects are the test set for its clinical efficacy and safety.

9. How the Ground Truth for the Training Set Was Established

As there is no mention of an AI algorithm or a training set, this question is not applicable. The device's performance was established through the clinical efficacy and safety study on the N=42 subjects and confirmed by histology data.

Summary

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Image /page/0/Picture/0 description: The image shows the logo of the U.S. Food and Drug Administration (FDA). The logo consists of two parts: the Department of Health & Human Services logo on the left and the FDA logo on the right. The FDA logo is in blue and consists of the letters "FDA" stacked on top of the words "U.S. FOOD & DRUG" and "ADMINISTRATION".

December 5, 2019

BTL Industries, Inc. David Chmel, VP of Operation 362 Elm Street Marlborough, Massachusetts 01752

Re: K192224

Trade/Device Name: BTL-899 Regulation Number: 21 CFR 878.4400 Regulation Name: Electrosurgical Cutting and Coagulation Device and Accessories Regulatory Class: Class II Product Code: GEI Dated: November 1, 2019 Received: November 4, 2019

Dear David Chmel:

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. 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 located 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.

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

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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) for devices or postmarketing safety reporting (21 CFR 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 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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 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.

Long Chen, Ph.D. Assistant Director DHT4A: Division of General Surgery Devices OHT4: Office of Surgical and Infection Control Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health

Enclosure

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DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration

Indications for Use

510(k) Number (if known) K192224

Device Name BTL-899

Indications for Use (Describe)

BTL-899 is indicated to be used for:

· Non-invasive lipolysis (breakdown of fat) of the abdomen.
· Reduction in circumference of the abdomen
· The BTL-899 is intended for use with Skin Type I to Skin Type III.

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) CONTINUE ON A SEPARATE PAGE IF NEEDED. This section applies only to requirements of the Paperwork Reduction Act of 1995. DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW. The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to:

Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff PRAStaff@fda.hhs.gov

"An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number."

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Image /page/3/Picture/0 description: The image shows the alphanumeric string "K192224" in a simple, sans-serif font. The characters are uniformly sized and spaced, creating a clear and legible sequence. The string appears to be a code or identifier, possibly a serial number or product key. The black text contrasts sharply against the white background.

Image /page/3/Picture/1 description: The image shows the logo for BTL Industries. The logo consists of three interconnected blue squares on the left side, with the letters "BTL" inside the squares. To the right of the squares is the text "BTL Industries" in a gray, sans-serif font.

510(k) Summary

General Information

Sponsor:	BTL Industries, Inc.362 Elm StreetMarlborough, MA 01752Tel: +1-866-285-1656Fax: +1-888-499-2502
Applicant:	BTL Industries, Inc.362 Elm StreetMarlborough, MA 01752Tel: +1-866-285-1656Fax: +1-888-499-2502
Contact Person:	David ChmelBTL Industries, Inc.chmel@btlnet.com
Summary PreparationDate:	December 4, 2019

Device Name

Trade/Proprietary Name:	BTL-899
Primary Classification Name:	Electrosurgical, Cutting & Coagulation Device &Accessories
Classification Regulation:	878.4400, Class II
Classification Product Code:	GEI

Legally Marketed Predicate Device

The BTL-899 is a state-of-the-art high-frequency energy device with accessories and is substantially equivalent to the current product that is already cleared for distribution in the USA under the following 510(k) Premarket Notification numbers:

. SlimShape System (K163415)

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Image /page/4/Picture/1 description: The image shows the logo for BTL Industries. The logo consists of three nested squares, with the letters "BTL" inside the innermost square. To the right of the squares is the text "BTL Industries" in a sans-serif font. The squares are blue, and the text is gray.

Product Description

The BTL-899 is equipped with a large color touch screen that significantly facilitates the use of the device. The on-screen information guides the user step-by-step through the entire therapy procedure. The therapeutic parameters are easily set using the touch screen of the device. During the therapy the device keeps information about the applied therapy type, remaining therapy time and main therapy parameters on the screen.

Indications for Use

BTL-899 is indicated for non-invasive lipolysis (breakdown of fat) of the abdomen. The device is indicated for reduction in circumference of the abdomen. BTL-899 is intended for use with Skin Type I to Skin Type III.

Non-clinical Testing (Performance, Bench Testing)

The BTL-899 device has been thoroughly evaluated for electrical safety. The device has been found to comply with the following applicable medical device safety standards:

IEC 60601-1	Medical electrical equipment - Part 1: General requirements for basicsafety and essential performance
IEC 60601-1-2	Medical electrical equipment – Part 1–2: General requirements forbasic safety and essential performance - Collateral standard:Electromagnetic disturbances – Requirements and tests
IEC 62304	Medical device software - Software life cycle processes
ISO 14971	Medical devices – Application of risk management to medical devices
ISO 10993-1	Biological evaluation of medical devices – Part 1: Evaluation andtesting within a risk management process
ISO 10993-5	Biological evaluation of medical devices – Part 5: Tests for in vitrocytotoxicity
ISO 10993-10	Biological evaluation of medical devices - Part 10: Tests for irritationand skin sensitization

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Image /page/5/Picture/1 description: The image shows the logo for BTL Industries. The logo consists of three blue squares nested inside each other, with the letters "BTL" in white inside the innermost square. To the right of the square logo is the text "BTL Industries" in gray.

Clinical Testing

Clinical studies have been conducted to demonstrate performance, clinical efficacy and safety of the BTL-899 device for non-invasive lipolysis and circumference reduction of abdomen. The performance study has proven the device to reach and maintain effective treatment temperature.

Clinical efficacy study has proven that the therapy with the BTL-899 results in fat reduction of abdomen at the time of final therapy, and at one-month and three-month follow up.

In total, N=44 subjects were enrolled in the study. N=42 subjects received all treatments and finished the study. Of the 42 treated subjects, 29 are female and 13 are male. In terms of skin type treated, there are 5 subjects with Fitzpatrick Skin Type I, 29 with Fitzpatrick Skin Type II, 7 with Fitzpatrick Skin Type III and 1 with Fitzpatrick Skin Type IV.

Change in abdominal circumference at the last regular follow-up (3-month follow-up) visit was 3.2±1.64cm. Responder analysis showed 88.1% (74%, 96%) subjects had circumference reduction of 1.5cm and more when compared to baseline.

The secondary effectiveness endpoints demonstrated that the rate of correct identification of subjects' photographs was 76.19%.

Average fat reduction observed using the ultrasound images at the 3-month follow-up showed an average abdominal fat reduction of 29.8±3.38%.

Overall satisfaction with the study treatment was reported at all three regular follow-up visits, which was not the case at the therapy visits. 92.9% of subjects reported none to minimal discomfort during the study treatment.

Throughout the study, there were no adverse events reported. Observed side effects related to the therapy were mild erythema, muscle soreness, improved body posture and back pain relief.

Study design	Prospective open-label single-arm self-controlled study
Sample size	42 patients
Treatment andfollow-up visits	There were three treatment visits and three follow-ups at one month, two months and three months after the last treatment.
Inclusioncriteria	Age > 21 years Voluntarily signed informed consent form BMI ≤ $35 kg/m^2$ Women of child-bearing potential were required to use birth control measures during the whole duration of the study
	Subjects willing and able to abstain from partaking in any treatments other than the study procedure to promote body contouring during study participation Subjects willing and able to maintain his/her regular (pre-procedure) diet and exercise regimen without effecting significant change in either direction during study participation
Endpoints	Primary: Abdominal circumference reduction of at least 1.5cm at the 3-month follow-up visit when compared to baseline, evaluated using the tape measurement. Evaluation of adverse events and side effects following the BTL-899 treatment throughout the study. Secondary: Correct identification of baseline and 3-month follow-up visit photographs in at least 70% of treated subjects by two blinded evaluators. Abdominal circumference reduction of at least 1.5cm at each study visit after the first treatment when compared to baseline, evaluated using the tape measurement. Abdominal fat reduction at the last therapy visit, 1-month follow-up visit and 3-month follow-up visit when compared to baseline, evaluated using the ultrasound imaging device. Subject's satisfaction with the BTL-899 treatment at each study visit after the first treatment assessed using the Subject Satisfaction Questionnaire. Subject's discomfort (pain) level after each treatment evaluated using the Therapy Comfort Questionnaire.
Efficacy results	Primary endpoint achieved: abdominal circumference reduction of 1.5 cm and more after the last follow-up and when compared to baseline.Secondary endpoints achieved: Both evaluators correctly identified subject's photographs in 76.19% of cases (N=32). The average reduction in fat thickness measured at the time of the last regular follow-up visit (3 months after the last therapy)- the average fat reduction was by $29.8\pm3.38%$ . The subjects reported overall satisfaction at all three follow-up visits (83.3%, 83.3% and 88.1% respectively). At all three visits, 92.9% of subjects reported none to minimal discomfort during the study treatment.
Safety results	Throughout the whole study, there was no adverse event reported. One subject experienced mild erythema. Eleven subjects reported a feeling of muscle soreness after the study treatment. Additionally, during the study subjects reported an improved posture (7.1%) that resulted in a relief of back pain (N=2; 4.8%).

The below table contains the study design and results:

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Image /page/6/Picture/1 description: The image shows the logo for BTL Industries. The logo consists of three blue squares, each containing the letters "BTL". To the right of the squares is the text "BTL Industries" in a gray, sans-serif font. The logo is simple and modern.

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Image /page/7/Picture/1 description: The image shows the logo for BTL Industries. The logo consists of three blue squares that are nested inside of each other. To the right of the squares is the text "BTL Industries" in a gray sans-serif font.

In conclusion, treatment with the BTL-899 device has shown to be both effective and safe for non-invasive lipolysis and circumference reduction of abdomen.

Histology data from a study of 8 subjects confirmed the safety and effectiveness of the device. The skin histological evaluations showed normal morphology of the dermal layer with no damage to keratinocytes, melanocytes, hair follicles, sweat or sebaceous glands.

According to the histology results, the primary objective of the trial was met. The investigational device induces non-invasive lipolysis (breakdown of fat) in the abdominal area. Therapy effects such as pyknotic nuclei and cell membrane degeneration leading to fat cell lysis and hence a decrease of the fat tissue were observed.

The Temperature Performance test shows that the therapy temperature of 40 - 43°C was achieved and maintained for the remaining therapy time. No adverse events occurred. The objectives of this performance test were met.

Based on the clinical data of above mentioned clinical studies, the BTL-899 device demonstrated acceptable performance and safety profile of the device for lipolysis of the abdomen and non-invasive reduction of the circumference. Results further support substantial equivalence of the subject device compared to the predicate device.

Technological Characteristics

The BTL-899 device has identical indications for use and similar technological characteristics and principles of operation to its predicate device. The BTL-899 device and its predicates are comprised of a system console and applicator(s). The system console consists of the generators, computer, and the touch-screen control panel.

Generated radiofrequency energy is intended to interact with the tissues of the human body to achieve non-invasive lipolysis and circumference reduction.

The mechanism of action and technological similarities and differences between the BTL-899 device and the predicate device are described below in the comparison table. The differences do not raise any new types of safety or effectiveness questions.

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Image /page/8/Picture/1 description: The image shows the logo for BTL Industries. The logo consists of three blue squares nested inside each other, with the letters "BTL" in white inside the innermost square. To the right of the square logo is the text "BTL Industries" in a dark gray sans-serif font.

Comparison with the Predicate Device

510(k) number	Not Assigned	K163415	Significant
Device name	BTL-899	SlimShape System	Difference
Companyname	BTL Industries, Inc.	Syneron Medical Ltd.
Product Codeand Regulation	General & PlasticSurgery	General & PlasticSurgery	None
	21 CFR 878.4400	21 CFR 878.4400
	GEI - Electrosurgical,Cutting & Coagulation &Accessories	GEI - Electrosurgical,Cutting & Coagulation &Accessories
Indications forUse	BTL-899 is indicated tobe used for:• Non-invasive lipolysis(breakdown of fat) ofthe abdomen.• Reduction incircumference of theabdomen	The SlimShape Systemis indicated for non-invasive lipolysis(breakdown of fat) of theabdomen.The device is indicatedfor reduction incircumference of theabdomen.	None
BasicTechnology	The system combinesbipolar radiofrequencywith electromagneticstimulation.	The system combinesbipolar radiofrequencywith mechanical suction.	Not significantlydifferentPlease see thediscussion andconclusion.
Clinical Use	Prescription use	Prescription use	None
ElectricalProtection	Class II, BF	Class I, Type BF	Not significantlydifferentPlease see thediscussion andconclusion.
User Interface	Touch screen	Touch screen	None
FirmwareControlled	Yes	Yes	None
RF Type	bipolar	bipolar	None
Max. RF Power	60 W (2x30 W)	80 W	Not significantly differentPlease see the discussion and conclusion.
RF Frequency	27.12 Mhz	1 Mhz	Not significantly differentPlease see the discussion and conclusion.
Temperature Sensor	Yes	Yes	None
Selection of parameters (Intensity, Time)	Yes	Yes	None
Application	Hands-free, applicator fixed by fixation belt	Hands-free, applicator fixed by fixation belt	None
Therapy Time	Up to 30 min	Up to 30 min	None
Energy Source	100 - 240 V AC, 50-60 Hz	110 - 230 V AC, 50-60 Hz	Not significantly different
System Dimensions (W×H×D)	23 x 39 x 29 in(592 x 985 x 730 mm)	19.6 x 40.7 x 20.7 in	Not significantly different
System Weight	85 kg	53 kg	Not significantly different
Operating Ambient Temperature	+10°C to +30°C	+10°C to +30°C	Not significantly different
Operating Relative Humidity	30% to 75%	30% to 80%	Not significantly different

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Image /page/9/Picture/1 description: The image contains the logo for BTL Industries. The logo consists of three nested squares, with the letters "BTL" inside the innermost square. To the right of the logo is the text "BTL Industries" in a sans-serif font. The logo and text are in a dark gray color.

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Image /page/10/Picture/1 description: The image shows the logo for BTL Industries. The logo consists of three interlocking blue squares, with the letters "BTL" inside the leftmost square. To the right of the squares is the text "BTL Industries" in a gray sans-serif font. The logo is simple and modern, and the use of blue and gray gives it a professional look.

Substantial Equivalence

The BTL-899 device is indicated to be used for non-invasive lipolysis (breakdown of fat) of the abdomen and reduction in circumference of the abdomen, as in the SlimShape System predicate (K163415). The BTL-899 device uses bipolar radiofrequency similar to the SlimShape System.

The main difference between the SlimShape System and the BTL-899 is in used frequency, maximal power and energy type enhancing the blood flow and lymphatic drainage. The emitting frequency of the BTL-899 is higher (27.12Mhz) compared to the SlimShape System predicate (1Mhz). Maximal radiofrequency power of the BTL-899 is lower than the one by the predicate device. The SlimShape System uses mechanical suction through vacuum, while the BTL-899 applies muscle stimulation resulting in induced muscle workout naturally increases local blood circulation and lymphatic drainage.

The results of clinical data indicate that the BTL-899 device is able to achieve equivalent treatment temperature and maintain it for required time. The data from clinical study indicate that the device is both effective and safe for non-invasive lipolysis and circumference reduction of abdomen.

Any differences between the predicate device and BTL-899 have no significant influence on safety or effectiveness of the BTL-899 device. Therefore, the BTL-899 is substantially equivalent to the predicate device.

Conclusion

Based upon the intended use and known technical information provided in this pre-market notification, the BTL-899 device has been shown to be substantially equivalent to currently marketed predicate device.

Regulation Number and Section

§ 878.4400 Electrosurgical cutting and coagulation device and accessories.

(a)
Identification. An electrosurgical cutting and coagulation device and accessories is a device intended to remove tissue and control bleeding by use of high-frequency electrical current.(b)
Classification. Class II.