(384 days)
To be used for temporary relief of pain associated with sore and aching muscles in the upper and lower extremities (e.g., arm and/or leg) and lower back due to strain from exercise or normal household and work activities.
The 5000Z/Firefly is a portable, single channel TENS device with two pre-programmed operational modes. It is powered by 2 standard AAA alkaline or rechargeable batteries. All operational modes produce the Prizm Medical Bi-Sourced waveform. The user selects a pre-programmed mode by using the program buttons to select one of two program options. The user is able to adjust the intensity up or down. The 5000Z/Firefly is intended for Over-the-Counter sale. The 5000Z/Firefly battery icon on the LED will flash when the batteries need replacement.
This document is a 510(k) summary for the Prizm Medical 5000Z/Firefly Transcutaneous Nerve Stimulator (TENS) system. The purpose of this document is to demonstrate "substantial equivalence" to a predicate device, not to present a study proving the device meets specific acceptance criteria in the typical sense of a clinical trial for a new therapeutic claim.
Therefore, the requested information about acceptance criteria, study design, sample sizes, ground truth establishment, expert adjudication, and MRMC studies is largely not applicable in the context of this 510(k) submission. This document focuses on demonstrating that the new device has similar technological characteristics and performance to already cleared predicate devices.
However, I can extract information related to non-clinical testing that verifies the device meets its own product specifications, which could be considered its internal "acceptance criteria."
Here's the breakdown:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly list "acceptance criteria" in a quantitative, pass/fail manner for clinical efficacy. Instead, it provides a comparison of technological characteristics of the subject device (Prizm Medical 5000Z/Firefly) against several predicate devices. The "reported device performance" in this context refers to the technological specifications of the subject device.
| Product Characteristics | Acceptance Criteria (Implied: Match predicate characteristics/safe operation) | Reported Device Performance (Prizm Medical 5000Z/Firefly) |
|---|---|---|
| Power Source | Safe and effective power delivery | Two "AAA" standard alkaline batteries or rechargeable |
| Number of Output Modes | Consistent with predicate device functionality | 2 |
| Number of Output Channels | Consistent with predicate device functionality | 1 (twin peak, monophasic) |
| Regulated Current/Voltage | Yes (Safety and consistent output) | Yes |
| Software/Firmware/Microprocessor Control? | Yes (Functionality and safety) | Yes |
| Automatic Shut Off | Yes (Safety feature) | Yes |
| User Override Control | Yes (User control and safety) | Yes |
| Indicator Display: On/Off Status | Yes (User feedback) | Yes |
| Low Battery Indicator | Yes (User feedback) | Yes |
| Volt/Current Level Indicator | Yes (User feedback) | Yes |
| Timer Range (minutes) | Consistent with predicate device functionality | Nonadjustable 30 min / Nonadjustable 20 min |
| Compliance with 21 CFR 898 | N/A (no lead wires) | N/A (no lead wires) |
| Weight | Comparable to predicate devices | Approximately 1.8 oz. without battery |
| Size | Comparable to predicate devices | 3.75" x 2.0" x 1.0" |
| Housing Material | Durable and safe | ABS plastic |
| Waveform | Consistent with predicate device and intended TENS therapy | Monophasic, Twin peak |
| Maximum Output Voltage | Within safe and effective range (200V) | 200V |
| Maximum Output Current | Within safe and effective range (0.384 mA) | 0.384 mA |
| Pulse Duration | Consistent with predicate device and intended TENS therapy | 100 (usec) |
| Frequency / Hz | Consistent with predicate device and intended TENS therapy | 1 to 120Hz |
| Maximum Phase Charge | Within safe limits (3.2 µC (500 Ω load)) | 3.2 µC (500 Ω load) |
| Maximum current density (500Ω) | Within safe limits (0.0256 mA/cm²) | 0.0256 mA/cm² |
| Maximum Average Current (500Ω) | Within safe limits (0.64 mA) | 0.64 mA |
| Maximum Average Power Density (500Ω) | Within safe limits (5.12 mW/cm²) | 5.12 mW/cm² |
| Phase duration | Consistent with predicate device and intended TENS therapy | 100 microseconds (usec) |
| Output type | Consistent with predicate device and intended TENS therapy | Constant voltage |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set (for clinical efficacy): Not applicable. The document explicitly states: "The Prizm Medical 5000Z/Firefly TENS System does not require clinical testing in order to determine substantial equivalence to the predicate unmodified device because the programs and electrical output characteristics of the two devices are the same." Therefore, there was no clinical "test set" in the sense of patient data.
- Data Provenance: The "data" presented is largely engineering and technical specifications of the device and its predicates, not patient data.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
- Not applicable. As no clinical "test set" was used for efficacy, there was no ground truth to be established by experts in a clinical context. The "ground truth" here is the technical specifications of the device, established through engineering design and testing.
4. Adjudication Method for the Test Set
- Not applicable. No clinical test set.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- No. This type of study is for evaluating human performance (e.g., radiologists diagnosing images) with and without AI assistance. This device is a TENS unit, not an AI diagnostic tool, so an MRMC study is completely irrelevant.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
- Not applicable. This device is a TENS unit that directly delivers electrical stimulation to a user. It is not an algorithm that performs a standalone function without human interaction in the sense of diagnosis or interpretation. The "algorithm" here refers to the device's electrical output programs, which are inherent to its function. The non-clinical testing verifies that these programs perform according to specifications.
7. Type of Ground Truth Used
- For the non-clinical testing mentioned, the "ground truth" would be the engineering design specifications and recognized electrical safety standards. The device was tested to ensure it met these predetermined, objective, and measurable criteria (e.g., output voltage, current, frequency, timing, safety features).
8. Sample Size for the Training Set
- Not applicable. As this is a TENS device and not an AI/machine learning algorithm that requires a "training set" of data, there is no training set sample size.
9. How the Ground Truth for the Training Set Was Established
- Not applicable. No training set for an AI algorithm.
Summary of the Study that Proves the Device Meets its (Internal) Acceptance Criteria (Product Specifications):
The document describes Non-clinical Testing which includes:
- Software verification: Carried out according to FDA guidance for software in medical devices. This ensures the software embedded in the device functions as intended and safely.
- Electrical and mechanical tests: These tests were performed to demonstrate that the device meets its product specifications (the "acceptance criteria" in this context) across a range of operating and storage conditions. This would involve rigorous bench testing of the device's output (voltage, current, frequency, waveform), timer accuracy, button functionality, display indicators, battery life, and physical durability.
- Validation testing: This was conducted to show that the device meets user needs according to marketing requirements. This implies usability testing and confirmation that the device effectively delivers the intended stimulation.
The conclusion states: "The non-clinical testing demonstrates that the Prizm Medical 5000Z/Firefly TENS System performs as well as the predicate device(s). There are no new safety or effectiveness issues concerning the new device." This indicates that the results of the non-clinical tests confirmed that the device's performance aligns with its specifications and is comparable to previously cleared devices, thus deeming it substantially equivalent.
§ 882.5890 Transcutaneous electrical nerve stimulator for pain relief.
(a)
Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to electrodes on a patient's skin to treat pain.(b)
Classification. Class II (performance standards).