(90 days)
For Spinal Cord Stimulation
This 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 pain. 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 Nalu Neurostimulation system is consisted of five components. The implantable pulse generator (IPG) provides electrical stimulation pulses that are transmitted through the leads, through the dura, to the desired location of the spinal cord site. The leads are implantable and designed to deliver electrical pulses to the spinal cord in the epidural space via an array of eight cylindrical electrodes at the distal end. The leads may be secured in place with the Nalu Lead Anchor. The Trial Therapy Disc or the Therapy Disc houses the battery and electronics for RF power and controls the IPG for therapy delivery via the remote programmer. Implantation of the Nalu IPG and lead components for Spinal Cord Stimulation (SCS) is performed via standard SCS surgical tools and techniques, as described in (K183047).
The provided text is a 510(k) Summary for the Nalu Neurostimulation System, which is an implanted spinal cord stimulator for pain relief. The document focuses on demonstrating substantial equivalence to a previously cleared device (K183047) and specifically addresses updated magnetic resonance imaging (MRI) conditional labeling for full-body scans.
Here's an analysis of the acceptance criteria and the study information based on the provided text:
1. Table of acceptance criteria and the reported device performance
The document does not explicitly state numerical acceptance criteria for performance metrics (e.g., sensitivity, specificity, accuracy) because it is a submission for a spinal cord stimulator, not an AI/imaging device with such metrics. Instead, the "acceptance criteria" here relate to demonstrating safety and effectiveness for a broader indication (full-body MRI scans) and substantial equivalence to the predicate device.
The reported device performance primarily focuses on the Magnetic Resonance (MR) Conditional Labeling. The previous predicate device (K183047) had MR Conditional Labeling only for local RF coils (head, foot/ankle, knee, or wrist). The current submission proposes an update to include full-body MR Conditional Labeling.
The acceptance criteria implicitly derive from the standards and guidance documents listed, ensuring that the device's behavior in an MRI environment (e.g., displacement force, magnetically induced torque, image artifacts) is safe and within established limits for full-body scans.
| Acceptance Criteria Category | Reported Device Performance (Summary from text) |
|---|---|
| Intended Use & Indications | Substantially equivalent to predicate: "stimulation of the spinal cord for treatment of chronic, intractable pain" including full body pain. |
| Technological Characteristics | "All of the physical and therapeutic attributes... share the same technological characteristics and has no differences that would impact safety or effectiveness." |
| MRI Safety for Full Body | Nalu performed MRI testing on the standard horizontal MR bore system to support the safety of the RF body coil. Proposed an update to the MR Conditional Labeling with the full body scan. |
| Compliance with Standards | Device meets applicable standards and guidance documents, including ISO/TS 10974, ISO 14708, ASTM F2052-15, ASTM F2213-17, ASTM F2129-2013 (related to MRI safety). |
| Clinical Performance | Bench and non-clinical testing are sufficient; device is safe and effective as the predicate. Clinical performance data explicitly stated as not required. |
2. Sample size used for the test set and the data provenance
The document does not specify a "test set" in the context of an imaging AI device with a dataset of patient images. The testing conducted was primarily nonclinical performance testing (bench testing) related to MRI safety and device functionality.
- Sample Size: Not applicable in the typical sense of patient samples for an AI model. The testing involved physical devices or components. The number of hardware units tested for MRI compatibility is not specified.
- Data Provenance: Not applicable in the geopolitical or retrospective/prospective sense. The data is generated from laboratory (bench) testing.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
This information is not applicable to this 510(k) submission. Ground truth, in the context of expert consensus, is typically established for diagnostic or screening devices evaluating medical images. This submission is for an implanted neurostimulation system, and the primary focus of the new data is on MRI compatibility for the physical device, not an interpretation of clinical findings by experts.
4. Adjudication method for the test set
This information is not applicable for the same reasons as point 3. Adjudication methods are used to resolve discrepancies in expert ground truth labeling.
5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done
No, an MRMC comparative effectiveness study was not done. This type of study is relevant for diagnostic or screening devices where human readers provide interpretations, and the AI's impact on their performance is evaluated. This 510(k) is for a physical implantable device, and the new data concerns its safety in an MRI environment.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
This concept is not applicable to this device. A spinal cord stimulator does not have an "algorithm-only" performance in the sense of an AI diagnostic tool. Its performance is its ability to deliver stimulation and its safety profile, which was assessed through bench testing.
7. The type of ground truth used
The "ground truth" for the nonclinical testing primarily refers to established engineering and medical device safety standards for:
- MRI Compatibility: Defined by standards like ISO/TS 10974, ASTM F2052-15 (magnetically induced displacement force), ASTM F2213-17 (magnetically induced torque), and ASTM F2129-2013 (MR image artifacts). The "ground truth" is that the device must meet the safety limits defined by these standards when exposed to full-body MRI conditions.
- Biocompatibility: Assessed to ensure the materials are safe for implantation.
- Sterilization Validation: Ensures the device can be adequately sterilized.
- Functional Specifications: The device must meet its intended operational parameters (e.g., stimulation delivery).
8. The sample size for the training set
This information is not applicable. The device is an implanted hardware system, not an AI model trained on a dataset.
9. How the ground truth for the training set was established
This information is not applicable for the same reasons as point 8.
§ 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).