(88 days)
A transcutaneous electrical nerve stimulation (TENS) Mode which is indicated for the symptomatic relief and management of chronic intractable pain, and for temporary relief of pain associated with sore and aching muscles in the shoulder, waist, back, neck, upper extremities (arm) and lower extremities (leg) due to strain from exercise or normal household work activities., and
A powered muscle stimulation (PMS) mode which is indicated to improve and facilitate muscle performance in healthy muscles.
The ENSO Model 2 should be applied to normal, healthy, dry and clean skin of adult patients.
The Hinge Health ENSO® Device System consists of the main ENSO Device, a disposable Gel Pad, and a charging cable with AC adapter for recharging. The ENSO App is used to access and control the device.
ENSO 2 is a wearable medical device that provides professional-grade transcutaneous electrical nerve stimulation (TENS) therapy along with an easy-to-use interface within a compact design. The device system consists of the main ENSO 2 Device, a disposable Gel Pad, and a charging cable with AC adapter for recharging the Device. ENSO 2 is controlled wirelessly using the Hinge Health app on a compatible Mobile Device.
The provided text describes a 510(k) premarket notification for the ENSO (Model 2) device, which is a Transcutaneous Electrical Nerve Stimulator (TENS) and Powered Muscle Stimulator (PMS). The submission aims to demonstrate substantial equivalence to a predicate device (CUR Model 1, K160052) rather than proving the device meets specific acceptance criteria based on studies involving AI or human-in-the-loop performance.
Therefore, much of the requested information regarding AI model performance, expert ground truth establishment, MRMC studies, standalone algorithm performance, and training/test set details is not applicable to this 510(k) summary. This document primarily focuses on demonstrating that the modified device (ENSO Model 2) is substantially equivalent to a previously cleared predicate device, meaning it is as safe and effective, and does not require extensive new clinical studies or elaborate AI performance evaluations.
Here's a breakdown of the available information based on your request:
1. Table of acceptance criteria and the reported device performance:
Since this is a 510(k) demonstrating substantial equivalence, the "acceptance criteria" are primarily a comparison to the predicate device, showing that the new device meets or exceeds the specifications of the predicate without introducing new safety or effectiveness concerns. There are no explicit "acceptance criteria" for AI performance listed in this document, as the device doesn't claim AI capabilities in the context of diagnostic or prescriptive functions commonly associated with AI/ML medical devices that would require such performance metrics.
The performance is reported through various comparison tables against the predicate device. The "acceptance" is that the parameters are "Identical," "Equivalent," or "Better" where applicable, and that modifications do not negatively impact safety or effectiveness.
| Attribute/Parameter | Subject Device (ENSO 2, K233784) | Predicate (CUR Model 1, K160052) | Reported Performance/Comment (Acceptance) |
|---|---|---|---|
| Intended Use & Indications for Use | Same as predicate (TENS for symptomatic pain relief, PMS for muscle performance) | Same as predicate | Identical (except for device name and model). This is a core "acceptance criterion" for substantial equivalence. |
| Primary Modifications | Improved battery shelf life, minor software updates (add functionality, change system requirements), add over-the-air (OTA) firmware update ability, extended gel pad expiration date (12mo to 18mo, then to 24mo), removal of "implanted metal devices" from contraindications warning. | Original specifications | These are the key changes. The "acceptance" is that these modifications do not adversely affect safety or effectiveness, which is supported by bench and non-clinical testing. |
| Design Comparison | Wearable medical device providing TENS therapy, identical anatomical sites, similar design, same type of mating components. | Similar wearable medical device | Identical (overall design philosophy and function), except for the addition of "Large" size gel pad and 1.6g heavier weight, ~1mm taller dimension, and polycarbonate/PET case (vs. polycarbonate plastic) for housing, noted as "Equivalent with more durability." These differences are considered acceptable as they do not change the fundamental scientific technology or safety/effectiveness. |
| Electrical Output Specifications | |||
| TENS Mode - Waveform | Biphasic, Rectangular (Mode A: Asymmetrical, Modes B/C: Symmetrical) | Biphasic, Rectangular (Mode A: Asymmetrical, Modes B/C: Symmetrical) | Identical across all modes for waveform, shape, maximum output voltage, maximum output current, pulse duration, frequency, net charge, maximum phase charge, maximum current density, maximum average current, and maximum average power density. |
| PMS Mode - Waveform | Biphasic, Symmetrical, Rectangular | Biphasic, Symmetrical, Rectangular | Identical for all specified parameters including waveform, shape, maximum output voltage, maximum output current, primary phase duration, pulse duration, frequency, net charge, maximum phase charge, maximum current density, maximum average current, and maximum average power density. |
| Safety/Compliance Standards | IEC 60601-1, IEC 60601-1-2, IEC 60601-2-10, ISO 10993-1, ISO 10993-5, ISO 10993-10, IEC 60601-1-6, IEC 60601-1-11, IEC 60529, IEC 62133-2, IEC 62368, FCC §15.107, FCC §15.109, FCC §1.1310, RSS-102, IEC 62304, IEC 62366-1, ASTM D6862, ASTM D3330/D3331, ASTM F1980. | IEC 60601-1, IEC 60601-1-2, IEC 60601-2-10, ISO 10993-5, ISO 10993-10 | Compliance with these extensive standards (many of which are also specified for the predicate directly or implied by its clearance) is the basis of "acceptance" for safety and performance under these general controls. The document states they are "identical" or "equivalent" in compliance. |
| Shelf Life | 2-year gel pad expiration date | 1-year gel pad expiration date | Gel pad expiry extended "based on validation testing." This indicates successful testing to support the improved shelf life, which is a positive "performance" outcome. |
2. Sample sized used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
This information is not provided in the document as it pertains to clinical studies often required for novel devices or significant changes. For a 510(k) relying on substantial equivalence and primarily bench/non-clinical testing for modifications, large clinical test sets are typically not needed. The document explicitly states: "Hinge Health determined that bench and non-clinical testing were sufficient to demonstrate that the ENSO Device System is as safe and effective as the predicate device."
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
This is not applicable/provided. The ground truth in this context is the performance and safety characteristics of the predicate device, which have already been established through its prior clearance. The evaluation for ENSO (Model 2) focuses on demonstrating that its modifications do not alter this established safety and effectiveness.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
This is not applicable/provided. Adjudication methods are relevant for clinical studies, particularly when establishing ground truth from multiple expert readings or interpretations. This 510(k) does not present such a study.
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
This is not applicable/provided. An MRMC study or AI assistance effect size would be relevant for devices involving image interpretation or clinical decision support where AI assists human clinicians. This device is a TENS/PMS unit, and its modifications do not involve AI in this diagnostic or interpretive capacity.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
This is not applicable/provided. The device does not present a standalone algorithm for diagnostic or clinical decision-making that would require such performance evaluation. The "software updates" mentioned are for functionality and system requirements, not for a clinical AI algorithm.
7. The type of ground truth used (expert concensus, pathology, outcomes data, etc)
The "ground truth" for this 510(k) submission is the established safety and effectiveness of the legally marketed predicate device (CUR Model 1, K160052). The submission aims to demonstrate that the modified ENSO (Model 2) device is substantially equivalent to this predicate, meaning it performs as intended and is as safe and effective under its updated specifications and features. This is primarily established through bench testing and non-clinical data comparing the new device's specifications to the predicate's.
8. The sample size for the training set
This is not applicable/provided. There is no indication that a machine learning or AI model was "trained" in the typical sense for clinical interpretation or predictive tasks.
9. How the ground truth for the training set was established
This is not applicable/provided for the reason stated above.
In summary, this 510(k) submission focuses on demonstrating substantial equivalence of a modified electrical stimulation device to a predicate, primarily through extensive bench and non-clinical testing addressing the modified features and compliance with relevant medical device standards. It is not an AI/ML device submission that would require clinical validation studies with detailed information on AI model performance, test set characteristics, or ground truth establishment based on expert consensus or outcome data.
§ 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).