(48 days)
InTone is intended to provide electrical stimulation and/or visual biofeedback (via manometry) for the treatment of female urinary incontinence.
The InTone device includes three parts: an Insertion Unit, a Control Unit, and a Software Application for clinicians.
- The Insertion Unit includes an inflation pump and an inflatable probe. The inflatable probe is inserted into the vagina and the inflation pump is used by the patient to manually inflate the probe, ensuring a customized fit. Electrical stimulation is delivered via stainless steel electrodes on the inflatable probe to induce a contraction of the pelvic floor muscles. Biofeedback is monitored via a pressure sensor within the Insertion Unit which records changes in pressure related to volitional muscle contraction.
- The Control Unit includes user keys to initiate and control treatment sessions, and a visual biofeedback graph to encourage muscle re-training. The Control Unit is designed to record and store results of the electrical stimulation and biofeedback sessions for clinician review at follow-up visits.
- The Software Application is utilized by the clinician to program the Control Unit and display the results of electrical stimulation and biofeedback sessions. The Software Application allows the clinician to select and lock in the appropriate electrical stimulation level necessary to stimulate pelvic floor contraction.
This document is a 510(k) premarket notification for the InTone device, seeking a determination of substantial equivalence to previously marketed predicate devices (InTone K110179 and InToneMV K134020). The document asserts that the new InTone device is substantially equivalent based on similarities in intended use, technology, engineering, performance, user interface, and prior testing conducted on the predicate devices.
Here's an analysis of the acceptance criteria and study information provided, focusing on what is stated and what is not:
1. Table of Acceptance Criteria and Reported Device Performance:
The document does not provide a formal table of "acceptance criteria" for the new InTone device in the sense of predefined thresholds for performance metrics. Instead, it presents a "Substantial Equivalence Comparison Table" (Table 7.3) that compares features and functions of the new InTone with its predicate devices (K110179 and K134020). The reported "performance" is implicitly demonstrated through this comparison, indicating that the new device operates similarly to or within the parameters of the predicate devices. When a feature is "Substantially equivalent" or "Identical," the impact on safety and performance is noted as "None," implying that the new device's performance is acceptable because it matches that of legally marketed devices.
Key performance-related comparisons include:
| Feature/Function | New InTone Performance (Comparison to Predicates) | Impact on Safety and Performance |
|---|---|---|
| Intended Use | Substantially equivalent | None |
| Primary Function | Identical to InToneMV | None |
| Warnings or Precautions | Substantially equivalent | None |
| Contraindications | Identical to InToneMV | None |
| Labeling Summary | Substantially equivalent | None |
| Environmental Specifications | Identical | None |
| Power Source | Identical | None |
| Method of line current isolation | Identical | None |
| Patient leakage current | Identical | None |
| Number of output modes | Identical | None |
| Number of output channels | Identical | None |
| Regulated current or voltage? | Identical | None |
| Firmware controlled? | Identical | None |
| Automatic Overload Trip? | Identical to InToneMV | None |
| Automatic No-Load Trip? | Identical to InToneMV | None |
| Automatic Shut Off? | Identical | None |
| Indicator Display On/Off Status / Low Battery | Identical to InToneMV | None |
| Waveform, shape | Monophasic, alternating polarity, square pulses (Substantially equivalent to dual phase, rectangular pulses) | None |
| Frequency (Stress, Urge) | 50 Hz, 13 Hz (Identical to InToneMV) | None |
| Pulse width | 200 µs/phase (Identical) | None |
| Time (On, Off) | 1s on/2s off at 50Hz, 2s on/2s off at 13Hz (Identical to InToneMV) | None |
| Total Session Time | Approx. 12 minutes (Identical to InToneMV) | None |
| Max output voltage (500Ω) | 40 Vdc (Substantially equivalent to 50 Vdc) | None |
| Max output current (500Ω) | 80 mA (Substantially equivalent to 100 mA) | None |
| Maximum phase charge (500Ω) | 16 µC (Substantially equivalent to 20 µC) | None |
| Electrode surface area | 6.00 cm² ± 0.5 cm² (x 2) (Substantially equivalent to 10.5 cm² x 2 and 2.5 cm² ± 0.5 cm² (x 2)) | None |
| Max current density | 13.3 mA/cm- (Substantially equivalent to 9.5 mA/cm- and 40 mA/cm-) | None |
| Max average power density (500Ω) | 5.33 mW/cm² (Substantially equivalent to 4.8 mW/cm- and 20 mW/cm-) | None |
| Biofeedback | Manometric, Air pressure, 0-2 psi (Identical to InToneMV) | None |
| Dimensions | Substantially equivalent | None |
| Control housing material | Identical | None |
| Insertion material | Identical | None |
| Tubing Material | Identical to InTone | None |
| Packaging or Expiration Dating | Identical to InTone | None |
| Sterilization | Identical | None |
| Operational Method: Clinical Use | Identical | None |
| Patient Interaction: Functions Controllable | Identical | None |
| Patient Interaction: Programming Capability | Identical | None |
| Override | Identical | None |
| Patient Interaction: Operator Requirements | Identical | None |
| Software Level of Concern | Identical | None |
2. Sample size used for the test set and the data provenance:
- No specific sample size for a "test set" for the new device is provided. The document states that "New software verification and validation, electrical safety, EMC, and biocompatibility testing did not need to be performed to demonstrate the equivalent safety and effectiveness of this new version of the InTone."
- Instead, the reliance is on testing performed on the predicate devices:
- Data Provenance: The document does not explicitly state the country of origin or whether the testing data for the predicate devices was retrospective or prospective. It only mentions that the testing was "conducted on the predicate InToneMV" and "for the predicate InTone."
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- This information is not provided in the document. The document relies on engineering and biological testing and a clinical literature review for validation, not on expert-established ground truth from a test set in the conventional sense of a clinical study assessing diagnostic performance.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set:
- This information is not applicable/not provided. The document describes technical testing (software V&V, electrical safety, EMC, biocompatibility) and a literature review, not a clinical study involving adjudication of results.
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 MRMC comparative effectiveness study was done as described. The device is for electrical stimulation and biofeedback therapy for urinary incontinence, not an AI-assisted diagnostic tool that would involve human readers.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Not applicable in the context of diagnostic algorithms. The InTone device is a therapeutic device (electrical stimulator and biofeedback) with software, not a standalone diagnostic algorithm. The software verification and validation were performed on the predicate device's software, which was considered "moderate" level of concern.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- The concept of "ground truth" as typically used in diagnostic algorithm validation is not directly applicable to this submission. The validation relies on:
- Compliance with recognized standards: IEC 60601-1, IEC 60601-2-10, IEC 60601-1-2, ISO 10993-1.
- Software verification and validation: Against specifications and requirements.
- Biocompatibility testing: Chemical/biological safety evaluation.
- Clinical Literature Review: Documented evidence of safety and efficacy of electrical stimulation for female urinary incontinence in published articles and a MAUDE search for adverse events. This implicitly serves as "outcomes data" at a high level, validating the therapy type rather than specific device performance metrics against a gold standard for a new study.
8. The sample size for the training set:
- Not applicable/Not provided. The InTone device is not an AI/machine learning model that requires a training set in this context. Its function is based on established electrical stimulation and biofeedback principles.
9. How the ground truth for the training set was established:
- Not applicable/Not provided for the same reason as in point 8.
§ 876.5320 Nonimplanted electrical continence device.
(a)
Identification. A nonimplanted electrical continence device is a device that consists of a pair of electrodes on a plug or a pessary that are connected by an electrical cable to a battery-powered pulse source. The plug or pessary is inserted into the rectum or into the vagina and used to stimulate the muscles of the pelvic floor to maintain urinary or fecal continence. When necessary, the plug or pessary may be removed by the user. This device excludes an AC-powered nonimplanted electrical continence device and the powered vaginal muscle stimulator for therapeutic use (§ 884.5940).(b)
Classification. Class II (performance standards).