(93 days)
The SkinStylus SteriLock® MicroSystem is intended to be used as a treatment to improve the appearance of surgical or traumatic hypertrophic scars on the abdomen in adults aged 22 years or older.
The SkinStylus SteriLock® MicroSystem is a handheld device that creates microinjuries into the skin, by virtue of a 1A DC motor that rapidly reciprocates an array of 32 gauge microneedles that are no longer than 2.5mm. The device consists of a power source, a motor body with depth adjustment, a removable nosecone interface, and a disposable, single use cartridge containing an array of microneedles.
The provided text is a 510(k) Summary for the SkinStylus SteriLock® MicroSystem, a microneedling device. It describes the device, its intended use, and the results of clinical and non-clinical studies conducted to demonstrate its safety and effectiveness.
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided text:
1. A table of acceptance criteria and the reported device performance
The primary effectiveness endpoint established for the clinical study was the acceptance criterion.
| Acceptance Criterion (Primary Effectiveness Endpoint) | Reported Device Performance |
|---|---|
| A 10 mm (Minimal Clinical Important Difference - MCID for the validated Visual Analogue Scale) improvement in the treatment side of the scar using the 100 mm validated VAS scale observed by at least 2 out of 3 blinded graders compared to the non-treatment side 90 days after the last of 3 treatments. The treatment site photos were also correlated to the graded non-treatment side control photos. | Out of 30 abdomen subjects, 22 subjects (73% responder rate with 95% CI from 58% to 89%) had at least a 10 mm improvement compared to the non-treated side, according to at least 2 of the 3 blinded evaluators. The mean difference in VAS scores on the treatment side was found to be greater than on the control side. |
| Secondary Effectiveness Endpoints: | |
| * Self-assessed Scar Improvement Scale completed by subjects at 90 days after last of 3 treatments on the same side. | 28 out of 30 subjects (93% with 95% CI from 84% to 100%) had SASIS scores of 1 or greater (indicating perceived improvement). 19 out of 30 subjects (63% with 95% CI from 46% to 81%) had SASIS scores of 3 or greater (indicating >50% improvement). |
| * Subject Global Aesthetic Improvement Scale completed by subjects at 90 days after last of 3 treatments on the same side. | 27 out of 30 subjects (90% with 95% CI from 79% to 100%) had SGAIS scores of 3 or lower (indicating satisfaction/improvement). |
| Safety Endpoint: | Reported Safety Performance: |
| Adverse event monitoring at each visit; treatment 2, treatment 3, 90 days after treatment 3, and 6 months after treatment 3. | 10 out of 30 subjects (33%) experienced common treatment responses (scabbing/peeling, dryness, discomfort, redness/swelling), all of which resolved within days. 2 out of 34 subjects (6%) experienced hyperpigmentation that resolved within 6 months. No other adverse events were reported or observed. |
2. Sample size used for the test set and the data provenance
- Test Set Sample Size:
- 34 subjects completed the study.
- Of these, 30 subjects had a scar located on the abdomen, which was the focus of the primary effectiveness endpoint analysis.
- Data Provenance:
- Country of origin: Not explicitly stated, but the sponsor and contact information suggest a US-based submission (Chapel Hill, NC, Scottsdale, AZ). The manufacturer is in Guangzhou, China. The clinical study was conducted at a "single center," but the country is not specified.
- Retrospective or Prospective: Prospective clinical study. Treatments were conducted on specific days (1, 15, 31) with pre-defined follow-up visits.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- Number of Experts: 3 blinded graders.
- Qualifications:
- 1 Board Certified Dermatologist
- 2 Board Certified Plastic Surgeons
4. Adjudication method for the test set
- The primary effectiveness endpoint required "at least 2 out of 3 blinded graders" to observe a 10mm improvement in the VAS score. This serves as the adjudication method.
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 was not an MRMC comparative effectiveness study involving AI assistance for human readers. This study evaluated the direct effectiveness of the microneedling device itself, with expert readers assessing images for scar improvement. There is no mention of AI.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- No, this study evaluated a physical medical device (microneedling system), not an algorithm or AI. All assessments were performed by human experts or through patient-reported outcomes.
7. The type of ground truth used
- The primary ground truth for effectiveness was an expert consensus of subjective visual assessment using a validated Visual Analogue Scale (VAS) based on photographs.
- This was supported by patient-reported outcomes using the Self-assessed Scar Improvement Scale (SASIS) and Subject Global Aesthetic Improvement Scale (SGAIS).
- Safety ground truth was established through adverse event monitoring via patient interviews and investigator observation.
8. The sample size for the training set
- The document describes a clinical study for device approval, but it does not mention a training set for an algorithm or AI model. This is a traditional medical device approval based on direct clinical evidence.
9. How the ground truth for the training set was established
- As there is no mention of a training set or AI model, this question is not applicable.
§ 878.4430 Microneedling device for aesthetic use.
(a)
Identification. A microneedling device for aesthetic use is a device using one or more needles to mechanically puncture and injure skin tissue for aesthetic use. This classification does not include devices intended for transdermal delivery of topical products such as cosmetics, drugs, or biologics.(b)
Classification. Class II (special controls). The special controls for this device are:(1) The technical specifications and needle characteristics must be identified, including needle length, geometry, maximum penetration depth, and puncture rate.
(2) Non-clinical performance data must demonstrate that the device performs as intended under anticipated conditions of use. The following performance characteristics must be tested:
(i) Accuracy of needle penetration depth and puncture rate;
(ii) Safety features built into the device to protect against cross-contamination, including fluid ingress protection; and
(iii) Identification of the maximum safe needle penetration depth for the device for the labeled indications for use.
(3) Performance data must demonstrate the sterility of the patient-contacting components of the device.
(4) Performance data must support the shelf life of the device by demonstrating continued sterility, package integrity, and device functionality over the intended shelf life.
(5) Performance data must demonstrate the electrical safety and electromagnetic compatibility (EMC) of all electrical components of the device.
(6) Software verification, validation, and hazard analysis must be performed for all software components of the device.
(7) The patient-contacting components of the device must be demonstrated to be biocompatible.
(8) Performance data must validate the cleaning and disinfection instructions for reusable components of the device.
(9) Labeling must include the following:
(i) Information on how to operate the device and its components and the typical course of treatment;
(ii) A summary of the device technical parameters, including needle length, needle geometry, maximum penetration depth, and puncture rate;
(iii) Validated methods and instructions for reprocessing of any reusable components;
(iv) Disposal instructions; and
(v) A shelf life.
(10) Patient labeling must be provided and must include:
(i) Information on how the device operates and the typical course of treatment;
(ii) The probable risks and benefits associated with use of the device; and
(iii) Postoperative care instructions.