(115 days)
The UltraShape System delivers focused ultrasound energy that can disrupt subcutaneous adipose tissue (SAT) for lipolysis (breakdown of fat) to provide a non-invasive approach to achieve a desired aesthetic effect. It is intended for non-invasive reduction in abdominal circumference and for use on the flanks.
The UltraShape System is comprised of multiple components, including the control unit and two ultrasonic transducers. The UltraShape System selectively targets subcutaneous adipose tissue via focused ultrasound for the purpose of non-invasive aesthetic body contouring. The transducers are electro-mechanical devices that convert an electrical signal into mechanical (acoustical) energy. The operating parameters of the UltraShape System achieve selective disruption of adipose tissue without damaging neighboring tissues such as blood vessels, nerves, or muscle. The UltraShape System has two treatment modes available, the Single Focus Deep Mode and the Super Mode.
The Synergy UltraShape System, a focused ultrasound stimulator for aesthetic use, was evaluated for safety and effectiveness in non-invasive lipolysis of the flanks. The device delivers focused ultrasound energy to disrupt subcutaneous adipose tissue (SAT) for fat breakdown.
Here's a breakdown of the acceptance criteria and the study proving it meets those criteria:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criterion (Primary Endpoint) | Reported Device Performance | Met? |
|---|---|---|
| Fat reduction in flanks evaluated by visual assessment of randomized photographs of before (baseline) versus after (16 weeks following last treatment), as well as treated versus control flanks, by 2 blinded reviewers. | Primary: Met endpoint; blinded reviewers identified correctly (by agreement between the blinded reviewers) both the pre-/post-treatment photographs as well as the treated/un-treated flanks in 80% (36 of 45) subjects. | |
| (Sensitivity analysis: If one subject with poor photo quality, for whom fat reduction was observed, was imputed as a failure, the success rate would be 78%, which would not meet the 80% threshold. However, this subject was excluded from the primary endpoint assessment due to photograph quality, and the presented result is based on 45 subjects.) | Yes | |
| Secondary Effectiveness Endpoints: | Secondary: | |
| * Fat thickness reduction on the treated flank compared to the control flank, measured by ultrasound. | * Fat thickness reduction results following UltraShape treatment were statistically significantly greater compared to controls as measured by ultrasound. | Yes |
| * Fat thickness reduction on the treated flank compared to the control flank, measured by caliper. | * Fat thickness reduction results following UltraShape treatment were greater compared to controls as measured by caliper (reaching statistical significance in absolute fat thickness reduction at 16 week follow up). | Yes |
| * Investigator satisfaction assessment. | * Investigators were satisfied with results following UltraShape treatment for 70% of the subjects at 4 week follow up, 53% of the subjects at 8 week follow up, and 43% of the subjects at 16 week follow up. | N/A |
| * Subject satisfaction self-assessment. | * At 4, 8 and 16 weeks following end of treatments, 43%, 47%, and 41% of the subjects were satisfied or very satisfied. | N/A |
| * Subjects' comfort level assessed immediately after each treatment. | * Subjects reported no to minimal pain for each of the three treatments. | N/A |
| Safety Results: No reported adverse events and anticipated immediate responses (mild erythema, edema) resolved completely within days without intervention. | No adverse events were reported after 141 treatment sessions. The only immediate responses recorded were mild and resolved completely within days without any intervention. | Yes |
2. Sample Size for the Test Set and Data Provenance
- Sample Size: 48 subjects were enrolled and treated in the study, with 46 subjects completing the study. The primary endpoint assessment was based on 45 subjects due to the poor quality of one post-treatment photograph.
- Data Provenance: The study was a prospective, single-arm, self-controlled, multicenter clinical study conducted at 3 U.S. sites. The data is thus prospective and from the U.S.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
- Number of Experts: 2 blinded reviewers.
- Qualifications: The document does not explicitly state the specific qualifications (e.g., radiologist, years of experience) of the blinded reviewers. It only specifies that they were "blinded reviewers."
4. Adjudication Method for the Test Set
- The primary endpoint was met "by agreement between the blinded reviewers." This implies a consensus-based adjudication, specifically that both reviewers had to agree on the correct identification of pre/post-treatment and treated/untreated flanks.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- No, a multi-reader multi-case (MRMC) comparative effectiveness study was not explicitly stated as being performed to evaluate human reader improvement with or without AI assistance. This study focused on the device's efficacy in achieving fat reduction through visual assessment and physical measurements, not the performance of human readers assisted by AI.
6. Standalone (Algorithm Only) Performance
- This study did not focus on standalone algorithm performance. The UltraShape System is a device for physical treatment and relies on visual and measurement assessments by human observers (investigators, subjects, blinded reviewers) and physical measurement tools (ultrasound, caliper) to determine its effectiveness. While the device has software components for control and guidance, the performance evaluation is for the device's physical effect on the body, not a diagnostic algorithm.
7. Type of Ground Truth Used
- The ground truth for the primary endpoint was established by expert consensus (agreement between 2 blinded reviewers) on photographic assessments.
- For secondary endpoints, objective measurements (ultrasound, caliper) were used to quantify fat thickness reduction, and subjective assessments (investigator and subject satisfaction, comfort level) were collected.
8. Sample Size for the Training Set
- The document refers to "several separate prospective studies" for clinical evaluation and states that nonclinical performance testing was "previously conducted" and "In vivo testing in an animal model was performed." However, it does not explicitly state a separate "training set" for the UltraShape System's clinical evaluation in the context of this 510(k) submission. The clinical data presented here is the definitive study for the device's substantial equivalence to the predicate. The UltraShape System itself is a physical device, and its "training" might refer to development phases or prior versions, but not a dataset for an AI algorithm in the way it's typically understood. The presented clinical study is the test set for this specific submission's claims.
9. How the Ground Truth for the Training Set Was Established
- As noted above, a distinct "training set" for the clinical effectiveness of this specific device version isn't detailed in the same manner as an AI algorithm's training data. The device's development and prior clearances (K141708, K133238, K160896) would have involved extensive R&D and testing, where engineers and clinicians established desired performance characteristics. The nonclinical testing (biocompatibility, beam profile, acoustic power, thermal measurements, software verification, electrical safety, in vivo animal testing) described in the document served to validate the device's core functionality and safety prior to humanitarian clinical trials. The "ground truth" for these aspects would be derived from laboratory measurements, adherence to standards, and observation of physical effects.
§ 878.4590 Focused ultrasound stimulator system for aesthetic use.
(a)
Identification. A Focused Ultrasound Stimulator System for Aesthetic Use is a device using focused ultrasound to produce localized, mechanical motion within tissues and cells for the purpose of producing either localized heating for tissue coagulation or for mechanical cellular membrane disruption intended for noninvasive aesthetic use.(b)
Classification. Class II (special controls). The special control for this device is FDA's “Class II Special Controls Guidance Document: Focused Ultrasound Stimulator System for Aesthetic Use.” See § 878.1(e) for the availability of this guidance document.