(41 days)
The LipoSonix system delivers high intensity focused ultrasound (HIFU) energy that can disrupt subcutaneous adipose tissue (SAT) to provide a non-invasive approach to achieve a desired aesthetic effect.
The LipoSonix system is specifically indicated for non-invasive waist circumference reduction
The LipoSonix system is a cart-based medical device intended for non-invasive disruption of subcutaneous adipose tissue (SAT) by employing ultrasound energy. The system consists of a cart, a detachable handpiece and a user interface display in one unit.
The provided text describes the LipoSonix® system Model 2, a focused ultrasound stimulator for aesthetic use, and its performance evaluation in a clinical study.
Here's an analysis of the acceptance criteria and the study that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criterion (Implicit) | Reported Device Performance |
|---|---|
| Primary Efficacy Endpoint: Superiority to sham control in reducing waist circumference. | The 59 J/cm² treatment group demonstrated a 1.01 cm greater waist circumference reduction as compared to sham. The least square (LS) mean change from baseline to 12 weeks in the 59 J/cm² group was -2.44 cm. On average, the mean change in waist circumference was approximately 2.55 cm (1 inch) compared to baseline, which "could equal one dress or pant size." This met the pre-specified primary endpoint. |
| Safety Endpoint: Acceptable safety profile with mostly mild, short-lived, and resolvable adverse events. | The AEs (Adverse Events) resulting from treatment were mostly mild, short-lived in duration, and resolved without incident, assessed through 24 weeks post-treatment. There were no serious adverse events (SAEs) or unanticipated adverse device effects (UADEs) related to the treatment. This indicates an acceptable safety profile. |
| Non-clinical safety and performance (Thermal, electrical, electromagnetic, mechanical safety, etc.) | The system was found to conform to "essential specifications, thermal, electrical, electromagnetic and mechanical safety" and "FDA consensus, medical device safety standards and international harmonized standards." Specific risks from the FDA special control guidance document were addressed, including: Thermal Injury, Mechanical Injury, Ocular Injury, Electrical Shock, Inflammation/Foreign Body Response, and Use Error. (While no specific metrics are given for these, the statement confirms they were addressed and conformed to standards.) |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The document only refers to a "multicenter, randomized study." It does not explicitly state the total number of participants in the study or specifically the test set (which in this context is the entire study population used for evaluation). It only mentions the performance of the "59 J/cm² treatment group."
- Data Provenance: The document states it was a "multicenter, randomized study." While the specific countries are not mentioned, the context of a 510(k) submission to the FDA for a US company suggests it likely involved studies conducted in the USA or under internationally recognized clinical trial guidelines. It is a prospective study, given that it's a "randomized study" evaluating treatment effects over time (baseline to 12 weeks, safety assessed through 24 weeks).
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
This information is not provided in the document. The study measures objective outcomes (waist circumference reduction) and reports adverse events, which are typically assessed by clinical investigators and not
ground-truthed by independent experts in the same way an image interpretation study might be. Expert interpretation for efficacy assessment beyond the direct measurements is not applicable here.
4. Adjudication Method for the Test Set
This information is not provided in the document. For objective measurements like waist circumference, inter-observer variability would ideally be addressed by standardized measurement protocols rather than an adjudication process typically seen in subjective assessments. Adverse events are usually reported and classified by the treating physician/investigator.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and the Effect Size
An MRMC study is not applicable here as this is a device for physical intervention (waist circumference reduction) and not an imaging-based diagnostic or screening tool requiring human reader interpretation. The study was a "multicenter, randomized study" comparing the device to a sham control, focusing on objective physical measurements and safety.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
This is not applicable to this device. The LipoSonix system is a physical treatment device, not an AI algorithm. Its performance is the direct outcome of the device application.
7. The Type of Ground Truth Used
The ground truth for efficacy was direct physical measurement: "waist circumference reduction." This is an objective, quantifiable anatomical change.
For safety, the ground truth was clinical observation and recording of adverse events by medical professionals.
8. The Sample Size for the Training Set
This information is not applicable as the LipoSonix system is a medical device for physical intervention, not an AI algorithm that requires a training set.
9. How the Ground Truth for the Training Set Was Established
This information is not applicable for the same reason as above.
§ 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.