(177 days)
The Freedom Spinal Cord Stimulator (SCS) System is intended as the sole mitigating agent, or as an adjunct to other modes of therapy used in a multidisciplinary approach for chronic, intractable pain of the trunk and/or lower limbs, including unilateral or bilateral pain. The Freedom-8A Trial Lead Kit is only used in conjunction with the Freedom-8A Stimulator Receiver Kit, and the Freedom-4A Trial Lead Kit is used for either the Receiver Kit Freedom-4A Stimulator or the Receiver Kit Freedom-8A Stimulator. The trial devices are solely used for trial stimulation (no longer than 30 days) to determine efficacy before recommendation for a permanent (long term) device.
The Stimwave Technologies Incorporated (Stimwave) Freedom Spinal Cord SCS System (System) is used for spinal column stimulation to provide therapeutic relief for chronic, intractable pain of the trunk and/or lower limbs including unilateral or bilateral pain. The therapy utilizes pulsed electrical current to create an energy field that acts on nerves near the spinal column. The System is comprised of an implantable stimulator (Freedom-8A/4A Stimulator), receiver (Receiver), and an externally worn transmitter (Wearable Antenna Assembly (WAA)) to power the device. The System is implanted only following a successful trial period with the Freedom-8A/4A Trial Lead.
This document describes the Stimwave Freedom Spinal Cord Stimulator (SCS) System (K160600) and its acceptance criteria, relying heavily on substantial equivalence to previously cleared predicate devices (K150517, K141399). Therefore, the "study that proves the device meets the acceptance criteria" largely refers to non-clinical performance data and the demonstration of equivalence to existing devices, rather than a de novo clinical trial.
Here's an analysis of the provided information:
1. Table of Acceptance Criteria and Reported Device Performance
The submission does not present a formal table of "acceptance criteria" with explicit numerical targets and corresponding "reported device performance" in a quantitative way for each criterion. Instead, it describes compliance with design requirements and applicable voluntary standards. The "reported device performance" is generally stated as "passed all criteria," "complies with," or "met the passing criteria."
However, we can infer some criteria and their met status from the non-clinical performance data section:
| Feature/Criterion Subjected to Testing | Acceptance Criteria (Inferred from standard/design requirement) | Reported Device Performance |
|---|---|---|
| Environmental Performance (AAMI ANSI ISO 14708-3:2008) | ||
| Temperature Change (Shipping & Storage) | Device functional, safe rating, no visual/physical anomalies | Passed post visual inspection and change of temperature testing. |
| Atmospheric Pressure Change | Device functional, no visual/physical anomalies | Passed atmospheric pressure change testing. |
| External Defibrillation Exposure | Device functional after exposure | Verified as functional after exposure. |
| Thermal Shock | No irreversible damage, fully functional, no physical anomalies | Passed, 'no irreversible damage' and fully functional. |
| Leakage Current | Zero leakage current on all paths | Produced zero leakage current. |
| Mechanical Performance | ||
| Stylet Insertion & Withdrawal Force | Less than 2.5N insertion/withdrawal force | Required less than 2.5N of force. |
| Receiver Insertion & Withdrawal Force | Less than 2.2N insertion/withdrawal force | Required less than 2.2N of force. |
| Visual Inspection (after insertion/withdrawal) | No damage present in stimulator samples | Confirmed no damage. |
| Tensile Testing (Stimulator) | No visible or functional damage to stimulator | Passed all criteria, no visible/functional damage. |
| Torsion Testing (Stimulator) | No visible or functional damage to stimulator | Passed all criteria, no visible/functional damage. |
| Wearable Antenna Assembly (WAA) Performance (IEC 60601-1) | ||
| Temperature Change (Shipping & Storage) | WAA functional, no physical damage | Met passing criteria, no physical damage, fully operational. |
| Atmospheric Pressure Change | WAA functional, no physical damage | Met passing criteria, no physical damage, fully operational. |
| Push, Drop, Impact, Mold Stress Relief | WAA robust to withstand expected damage, functional, no physical damage | Determined robust, met passing criteria, no physical damage, fully operational. |
| Identification, Marking, Documents | Complies with standard requirements, clear identification | Analysis of labeling determined compliance. |
| Means of Protection, Creepage Distances, Air Clearances | Satisfies standard requirements | Analysis of design determined satisfaction. |
| WAA Ingress Protection (IEC 60529) | ||
| Ingress of Water | WAA functional, no physical damage | Met passing criteria, no physical damage, fully operational. |
| Particulate Matter | WAA functional, no physical damage | Met passing criteria, no physical damage, fully operational. |
| Electromagnetic Compatibility (IEC 60601-1-2) | ||
| Radiated RF Electromagnetic Fields | Met all acceptance criteria | Met all acceptance criteria, operated within all limits. |
| Radiated Immunity | Met all acceptance criteria | Met all acceptance criteria, operated within all limits. |
| Wireless Coexistence | Met all acceptance criteria | Met all acceptance criteria, operated within all limits. |
| Software Verification | Met design requirements, passed verification tests | Passed all verification tests, design requirements met. |
| Overall Safety and Effectiveness | Substantially equivalent to legally marketed predicate devices | Determined substantially equivalent after all testing. |
2. Sample Sizes Used for the Test Set and Data Provenance
- Sample Size: The document does not specify the exact number of units tested for each non-clinical performance test (e.g., how many stimulators for thermal shock, how many WAAs for drop tests). It uses general terms like "all tested samples," "representative subassemblies," and "all tested paths for all tested samples."
- Data Provenance: The data is entirely non-clinical performance data, meaning it's derived from lab testing and analysis of the device itself.
- It is not patient data from a specific country or collected retrospectively/prospectively.
- A significant portion of the testing (e.g., for WAA, environmental performance, mechanical performance, biocompatibility) is "leveraged" from previous 510(k) submissions (K150517 and K141399) because the components or their relevant characteristics remained unchanged. New testing was performed where modifications or new components were introduced (e.g., specific tests for the Receiver).
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
Not applicable. This device's safety and effectiveness were demonstrated through non-clinical performance testing and substantial equivalence, not through a study involving expert-established ground truth on patient data.
4. Adjudication Method for the Test Set
Not applicable. This was not a study requiring adjudication of expert opinions on patient data. The non-clinical tests have objective pass/fail criteria.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No. An MRMC study is typically associated with diagnostic imaging devices where human readers interpret medical images. This is a medical implant (spinal cord stimulator) for pain relief, and its submission relies on non-clinical performance and equivalence to predicates, not a comparative effectiveness study with human readers interpreting imaging.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) Was Done
In a sense, all the non-clinical performance testing described (environmental, mechanical, electrical safety, EMC, software verification) can be considered "standalone" in that it evaluates the device's inherent performance characteristics without human involvement in its operation/interpretation during the test, other than setting up and monitoring the test itself. There is no "algorithm" in the sense of AI being evaluated here, but rather the electro-mechanical and software functions of the device.
7. The Type of Ground Truth Used
The "ground truth" for the non-clinical performance studies is adherence to established engineering specifications, design requirements, and recognized voluntary standards (e.g., AAMI ANSI ISO 14708-3, IEC 60601-1, IEC 60529, IEC 60601-1-2, ISO 10993-1). For biocompatibility, it's the biological response demonstrating no negative impacts as per ISO 10993-1. For the overall submission, the "ground truth" of safety and effectiveness is tied to its substantial equivalence to previously cleared predicate devices for the same intended use.
8. The Sample Size for the Training Set
Not applicable. There is no mention of a "training set" as this is not an AI/machine learning device that would require such data for its development.
9. How the Ground Truth for the Training Set Was Established
Not applicable. No training set was used.
§ 882.5880 Implanted spinal cord stimulator for pain relief.
(a)
Identification. An implanted spinal cord stimulator for pain relief is a device that is used to stimulate electrically a patient's spinal cord to relieve severe intractable pain. The stimulator consists of an implanted receiver with electrodes that are placed on the patient's spinal cord and an external transmitter for transmitting the stimulating pulses across the patient's skin to the implanted receiver.(b)
Classification. Class II (performance standards).