(140 days)
The Nalu Neurostimulation System is indicated 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 limbs, including unilateral or bilateral pain.
The trial devices are solely used for trial stimulation (no longer thank 30 days) to determine efficacy before recommendation for a permanent (long term) device.
The Nalu Neurostimulation system (also referred to as the "Nalu System") is used for spinal cord stimulation to provide therapeutic relief for chronic, intractable pain of the trunk and/or limbs including unilateral or bilateral pain. The Nalu Neurostimulation system incorporates a miniature implanted neurostimulator, powered by an externally worn device. Similar to the predicate Stimwave system, the Nalu Neurostimulation therapy utilizes pulsed electrical current to create an energy field that acts on nerves in the spinal cord to inhibit the transmission of pain signals to the brain. The Nalu System is implanted only following a successful trial period using the Nalu Neurostimulation trial system.
The Nalu Neurostimulation System is comprised of 5 elements: Nalu Implantable Pulse Generator, Leads, Surgical and Trial Tools, Externally worn Therapy Discs, and Programmer, Remote.
This document is a 510(k) premarket notification for the Nalu Neurostimulation System, indicating that clinical performance data was not required for substantial equivalence. Therefore, there is no study described in this document that proves the device meets specific acceptance criteria based on human clinical data.
The acceptance criteria described in the document relate to non-clinical performance testing (bench testing, biocompatibility, and animal testing) to demonstrate safety and effectiveness relative to a predicate device.
Here's an breakdown of the information requested, based on the provided text:
1. A table of acceptance criteria and the reported device performance
Since no clinical acceptance criteria or performance metrics were provided in the document due to the nature of a 510(k) without clinical studies, I will summarize the general approach to substantial equivalence and the scope of non-clinical testing.
General Acceptance Criteria (Implied for 510(k) clearance): The Nalu Neurostimulation System is substantially equivalent to the predicate device (Stimwave Freedom SCS System K170141) in terms of:
- Intended Use
- Technological Characteristics
- Principles of Operation
Reported Device Performance (Non-Clinical):
| Acceptance Criteria Category | Reported Device Performance | Justification/Outcome |
|---|---|---|
| Substantial Equivalence (Overall) | Nalu Neurostimulation System vs. Stimwave Freedom SCS System (K170141) | No significant differences in physical and therapeutic attributes that would raise new questions of safety or effectiveness. Differences exist but do not alter intended therapeutic use or affect safety/effectiveness. |
| Biocompatibility | Compliance with ISO 10993-1:2009 | Components categorized by contact type (Implant, Externally Communicating, Surface) and duration, and subjected to testing including cytotoxicity, sensitization, irritation/intracutaneous reactivity, systematic toxicity, implant studies, and chemical characterization. Biocompatibility was demonstrated. |
| Animal Study | Evaluation in porcine model over 90 days | Six Nalu Neurostimulation IPGs and Lead systems implanted. Evaluated surgical usability, RF communication/stimulation, implanted device stability, and tissue response. All devices performed as expected with no device- or procedure-related complications or premature deaths. Preliminary validation of safety and use. |
| Electrical, Mechanical, Software Performance | Verification Testing | Device met target specifications over a range of operating and storage conditions. |
| Usability/Human Factors | Validation and Usability Testing | Device demonstrated to meet user needs as reflected in the functional specification. |
| Sterilization | Ethylene Oxide sterilization validation | Performed to ISO 11135-1:2014 standards. |
| Software Life Cycle Processes | Compliance with IEC 62304:2015 | Processes followed for medical device software. (Software Level of Concern: Moderate) |
| Risk Management | Compliance with EN ISO 14971:2012, ISO 14971:2007 | Application of risk management to medical devices. |
| Packaging | Compliance with ISO 11607-1:2006/Amd 1:2014 and -2:2006/Amd 1:2014 | Packaging for terminally sterilized medical devices. |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Test Set (Non-Clinical):
- Animal Study: Six Nalu Neurostimulation IPGs and Lead systems were used in a porcine model. This was a prospective animal study. The specific country of origin for the animal study is not mentioned.
- Bench Testing: The document does not specify exact sample sizes for each bench test (electrical, mechanical, software), but it implies sufficient testing was conducted to meet relevant international standards and guidance documents. This is typically prospective testing conducted in a laboratory setting.
- Biocompatibility Testing: The number of samples for biocompatibility testing is not specified but would follow established protocols for ISO 10993. This is typically prospective testing.
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)
- Not applicable for clinical studies. For the non-clinical tests described:
- Animal Study: The study was conducted by researchers/veterinary staff, but the "ground truth" was established by direct observation and measurement of device performance, tissue response, and lack of complications in the porcine model. No external experts for ground truth establishment were specifically mentioned in this context.
- Bench/Biocompatibility/Software Testing: Ground truth is established by engineering specifications, validated test methods, and compliance with recognized standards. Expertise would come from internal design and quality engineers, and potentially third-party testing laboratories, but not in the "expert medical consensus" sense.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Not applicable for clinical studies. For the non-clinical tests described, adjudication methods like 2+1 or 3+1 are not used. Results are based on objective measurements and compliance with predefined specifications and standards.
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
- No MRMC comparative effectiveness study was done. The document explicitly states: "Nalu Medical determined that bench and non-clinical testing are sufficient to demonstrate that the Nalu Neurostimulation system is as safe and effective as the predicate device. Note that the predicate device did not need clinical evidence to obtain a determination of substantial equivalence." This is a premarket notification (510(k)) that established substantial equivalence based on non-clinical data, not clinical performance or AI assistance for human readers.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Not applicable. The Nalu Neurostimulation System is an implantable medical device for pain relief, not an AI or imaging diagnostic tool. Therefore, standalone algorithm performance is not relevant to this submission.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
- Non-Clinical Ground Truth:
- Bench Testing: Engineering specifications, validated test methods, and compliance with national and international standards (e.g., ISO 14708, IEC 60601 series, ISO 11135, CISPR 11).
- Biocompatibility Testing: Standards-based evaluation (ISO 10993-1) of material interactions with biological systems.
- Animal Study: Direct observation of surgical usability, RF communication, device stability, and histopathological tissue response in the porcine model, as interpreted by veterinary and scientific experts.
8. The sample size for the training set
- Not applicable. This device is hardware for neurostimulation, not an AI/ML algorithm that requires a training set.
9. How the ground truth for the training set was established
- Not applicable. As stated above, this device does not use an AI/ML algorithm with a training set.
§ 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).