(159 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 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 component (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.
Here's a summary of the acceptance criteria and study information for the Stimwave Freedom Spinal Cord Stimulator (SCS) System, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Category / Test | Acceptance Criteria | Reported Device Performance |
|---|---|---|
| Biocompatibility (ISO 10993-1, Blue Book Memo G95-1) | No negative impacts from materials for cytotoxicity, sensitization, irritation/intracutaneous reactivity, acute systemic toxicity, genotoxicity, implantation (4, 8, & 13 weeks), subchronic toxicity. | The device materials met all biocompatibility requirements, demonstrating no negative impacts. Materials (Pellethane 55D, Pt-Ir 90:10) have an extensive record of chronic and carcinogenetic safety. |
| Temperature Change (AAMI ANSI ISO 14708-3:2008) | Functional, safe rating following post visual inspection. Passed temperature change testing. | Freedom-8A/4A Stimulator was functional and received a safe rating after post visual inspection, passing the temperature change testing. WAA met passing criteria for visual and functional inspections. |
| Atmospheric Pressure Change (AAMI ANSI ISO 14708-3:2008) | Functional following post testing functionality inspection. Passed atmospheric pressure change testing. | Freedom-8A/4A Stimulator was functional after post testing functionality inspection, passing the atmospheric pressure change testing. WAA met passing criteria for visual and functional inspections. |
| External Defibrillation (AAMI ANSI ISO 14708-3:2008) | Functional after exposure to external defibrillation. | Freedom-8A/4A Stimulator and Receiver were verified as functional after exposure to external defibrillation. |
| Thermal Shock | No irreversible damage, fully functional, no physical anomalies. | Freedom-8A/4A Stimulator had "no irreversible damage" and was fully functional, with no physical anomalies. |
| Leakage Current | Zero leakage current. | Freedom-8A/4A Stimulator produced zero leakage current on all tested paths for all samples. |
| Stylet Insertion/Withdrawal Force | Less than 2.5N for stylet, Less than 2.2N for Receiver/RF Stylet. No damage. | Stylet required less than 2.5N. Receiver/RF Stylet required less than 2.2N. No damage was present in any stimulator samples. |
| Mechanical Testing (Tensile, Torsion) | Passed all criteria, no visible damage to stimulator body or functional damage to components. | Freedom-8A/4A Stimulator passed all criteria, showing no visible damage or functional damage. |
| MRI RF-Induced Heating (ASTM F2182-11a) | Maximum temperature increase lower than allowable limit for 1.5T and 3T MRI. | Freedom-8A Stimulator produced a maximum temperature increase lower than the allowable limit for both 1.5T and 3T MRI, passing the testing. |
| MR Image Artifacts (ASTM F2119-07) | Does not produce image artifacts in 1.5T or 3T MRI. | Freedom-8A Stimulator showed it does not produce image artifacts in 1.5T or 3T MRI procedures. |
| Magnetically Induced Displacement Force (ASTM F2052-06) | Does not harm the patient due to displacement by forces induced by MRI. Passes ASTM acceptance criteria for deflection angle. | Freedom-8A Stimulator passes the ASTM acceptance criteria for deflection angle in 1.5T and 3T MRI, indicating no harm to the patient. |
| Magnetically Induced Torque (ASTM F2213-06) | Does not harm the patient due to torque by forces induced by MRI. | Freedom-8A Stimulator will not present an additional risk or hazard to a patient in 1.5T or 3T environments with regard to torque. |
| Stimulation Waveforms Post-MR Exposure | No component damage; fully functional. | No component damage observed; fully functional following 1.5T or 3T MR procedures. |
| IEC 60601-1 (WAA: Temperature Change, Atmospheric Pressure, Push/Drop/Impact/Mold Stress, Identification/Marking, Means of Protection/Creepage/Air Clearances) | WAA met passing criteria for visual and functional inspections. Robust to withstand expected damage. Complies with labeling and design requirements. | WAA met all passing criteria for these tests, demonstrating compliance with IEC 60601-1. |
| IEC 60529 (WAA: Ingress of Water, Particulate Matter) | WAA met passing criteria for visual and functional inspections. | WAA met all passing criteria for ingress of water and particulate matter, demonstrating compliance with IEC 60529. |
| IEC 60601-1-2 (WAA: Electromagnetic Compatibility) | Unit met all acceptance criteria for emissions, low-frequency magnetic fields, immunity, electrostatic discharge, radiated RF electromagnetic fields, electrical fast transients, magnetic fields. Operated within limits. | WAA operated within all test limits and met all acceptance criteria for electromagnetic compatibility. |
| Software Verification | All verification tests outlined passed. Design requirements met. | Software passed all verification tests, and design requirements for Software Verification were met. |
| Overall Design, Sterilization, Electrical Safety | Meets all requirements, confirms output meets design inputs/specifications. Passed all tests. | Freedom SCS System meets all requirements and passed all stated tests. |
| Performance - Additional Tx Antennas | No change to device performance and specification. | Performance testing for additional Tx Antennas demonstrated no change to device performance and specification. |
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly state a specific sample size for a "test set" in the traditional sense of a clinical trial or a specific number of devices tested for each non-clinical performance test. Instead, it refers to "all tested samples," "all tested stylets," etc. The studies were non-clinical performance tests conducted in a laboratory setting. There is no information about the country of origin or whether hypothetical "data" was retrospective or prospective, as these are engineering tests.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of those Experts
N/A. This was a submission for a medical device where the "ground truth" for non-clinical performance is defined by compliance with established international and national standards (e.g., ISO, ASTM, IEC) and the device's own design specifications. It does not involve human experts establishing ground truth in the context of diagnostic interpretation.
4. Adjudication Method for the Test Set
N/A. Adjudication methods like 2+1 or 3+1 typically apply to clinical studies where expert consensus is needed to resolve discrepancies in diagnostic interpretations. These were engineering and performance tests against pre-defined criteria.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No. The document explicitly states: "There was no clinical testing required to support the medical device, as the indications for use are equivalent to the legally marketed predicate devices." Therefore, no MRMC comparative effectiveness study was conducted.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, in the sense that the performance tests were conducted on the device components (Stimulator, WAA) in a standalone manner against technical specifications and standards. This is not "algorithm only" in the context of AI, but rather the device's engineering performance tests. The device itself is a spinal cord stimulator system, which implants a physical device and involves patient and clinician interaction.
7. The Type of Ground Truth Used
The "ground truth" for the performance tests was defined by:
- International and national standards: AAMI ANSI ISO 14708-3:2008, ASTM F2182-11a, ASTM F2119-07, ASTM F2052-06, ASTM F2213-06, IEC 60601-1, IEC 60529, IEC 60601-1-2.
- Device design requirements and specifications: e.g., leakage current = zero, specific force requirements for stylet insertion/withdrawal, requirements for no visible or functional damage.
- Biocompatibility standards: ISO 10993-1:2009 and Blue Book Memorandum G95-1.
8. The Sample Size for the Training Set
N/A. This submission describes an electromechanical medical device, not an AI/machine learning algorithm that requires a training set.
9. How the Ground Truth for the Training Set Was Established
N/A. This is not applicable to the type of device and submission described.
§ 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).