(211 days)
The Digitimer DS7AP Constant Current Stimulator is indicated for use as an adjunct in the treatment of high and low anorectal malformations by helping in the identification of the striated muscles to be used in anal reconstructions.
The DS7AP Constant Current Stimulator has been specially designed to meet the requirements of pediatric surgeons who need a reliable and easy to use muscle locating stimulator when carrying out the Peña, "Pull-through" or posterior sagittal anorectoplasty (PSARP) anorectal reconstruction technique.
The Digitimer DS7AP Constant Current Stimulator is indicated for use as an adjunct in the treatment of high and low anorectal malformations by helping in the identification of the striated muscles to be used in anal reconstructions.
Here's a breakdown of the acceptance criteria and supporting study information:
1. Table of Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria (Measured Characteristics of the Device Compared to Predicate) | Reported Device Performance (DS7AP) | Predicate Device Performance (PS-1) |
|---|---|---|
| Intended Use | Used to identify striated muscle in the treatment of high and low anorectal malformations | Used to identify striated muscle in the treatment of high and low anorectal malformations |
| Indications for Use | Adjunct in the treatment of high and low anorectal malformations by helping in identification of the striated muscle to be used in anal reconstructions | Adjunct in the treatment of high and low anorectal malformations by helping in identification of the striated muscle to be used in anal reconstructions |
| Classification | Class II | Class II |
| Product Code | IPF | IPF |
| Regulation Number | CFR 890.5850 | CFR 890.5850 |
| Power Source | Supply Mains (115/230V; 50/60Hz) | Primary battery (PP3 / 1604) |
| Number of Output Channels | One | One |
| Output Control | Constant Current | Constant Current |
| Firmware Control? | No | No |
| Automatic Overload Trip? | Yes | No |
| Compliance with 21 CFR 898? | Yes | No |
| Weight | 4.85lb | 1.52lb |
| Dimensions (wxhxd) | 8.6"x4.4"x 9.9" | 3.75"x3.5"x6.25" |
| Housing Materials | Thermo-plastic with metal front and rear panels | Thermo-plastic with metal front and rear panels |
| Waveform | Pulsed mono-phasic | Pulsed mono-phasic |
| Waveform Shape | Rectangular | Rectangular |
| Maximum Output Voltage (at 500Ω) | 56V | 122V |
| Maximum Output Voltage (at 2kΩ) | 126V | 220V |
| Maximum Output Current (at 500Ω) | 112mA | 244mA |
| Maximum Output Current (at 2kΩ) | 63mA | 110mA |
| Maximum Output Current (at 10kΩ) | 13mA | 22mA |
| Pulse Width | 200µs / 500µs | 175µs |
| Pulse Frequency | 50Hz | 65Hz |
| Maximum Phase Charge (at 500Ω) | 56µC | 42.2µC |
| Maximum Current Density (at 500Ω) | 0.127mA/cm² | 0.117mA/cm² |
| Maximum Power Density (at 500Ω) | 0.191W/cm² | 0.161W/cm² |
| Electrical Performance (DS7AP Specific) | Power: 100-120V or 200-240V, 47-63Hz, 12VA. Class 1 with Type BF applied part. Pulse duration: LO (200µs) or HI (500µs). Current: 0-100mA. Compliance voltage: 100V. Output frequency: 50Hz. | N/A (predicate has different power source) |
Notes on Acceptance and Performance:
The primary acceptance criteria for the DS7AP were related to demonstrating substantial equivalence to the predicate device (Radionics Pena Muscle Stimulator PS-1 - K980448) in terms of intended use, indications for use, and technological characteristics.
While there are differences in specific electrical output values (e.g., maximum output voltage and current, pulse width, pulse frequency), power source, and some safety features (automatic overload trip, compliance with 21 CFR 898), the manufacturer argued and the FDA determined that these differences do not raise different questions of safety or effectiveness. For instance, regarding the power source difference, the subject device's power supply is "identical to that of the Digitimer DS7A/AH Constant Current Stimulators, which are approved for marketing under number K051357."
2. Sample size used for the test set and the data provenance:
- Sample Size: Not applicable. The submission states that no clinical tests were required for this submission. The evaluation was based on non-clinical testing and comparison of technological characteristics to a predicate device.
- Data Provenance: Not applicable for a test set as no clinical tests were performed.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not applicable as no clinical tests were conducted and thus no expert-established ground truth for a test set was established.
4. Adjudication method for the test set:
- Not applicable as no clinical tests were conducted.
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:
- Not applicable. This device is a constant current stimulator, not an AI-assisted diagnostic tool for human readers. No MRMC study was performed.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Not applicable. This is a medical device (constant current stimulator), not an algorithm. Its function is to directly stimulate muscles, not to provide an output that requires standalone evaluation against a ground truth in the way an algorithm would.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc):
- Not applicable. The substantial equivalence determination was based on non-clinical testing to national and international standards (e.g., EN 60601-1, IEC 60601-1-2, IEC 62366-1, ISO 14971, EN 60601-2-10) and a comparison of technological characteristics to a legally marketed predicate device.
8. The sample size for the training set:
- Not applicable as this is a medical device, not an AI/machine learning model that requires a training set.
9. How the ground truth for the training set was established:
- Not applicable as no training set was used.
§ 890.5850 Powered muscle stimulator.
(a)
Identification. A powered muscle stimulator is an electrically powered device intended for medical purposes that repeatedly contracts muscles by passing electrical currents through electrodes contacting the affected body area.(b)
Classification. Class II (performance standards).