(111 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 or bilateral 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.
For Peripheral Nerve Stimulation: This system is indicated for pain management in adults who have severe intractable chronic pain of peripheral nerve origin, as the sole mitigating agent, or as an adjunct to other modes of therapy used in a multidisciplinary approach. The system is not intended to treat pain in the craniofacial region. The trial devices are solely used for trial stimulation (no longer than 30 day) to determine efficacy before recommendation for a permanent (long term) device.
The Nalu Neurostimulation System has been cleared by the FDA for spinal cord stimulation, and peripheral nerve stimulation (K201618), to provide therapeutic relief for chronic, intractable pain of the trunk and/or limbs including unilateral, bilateral nerve pain. The Nalu Neurostimulation therapy utilizes pulsed electrical current to create an energy field that acts on nerves in the spinal cord or peripheral nerve 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 consists of several components. The implantable pulse generator (IPG) provides electrical stimulation pulses that are transmitted through the leads, to the desired location, either on the spinal cord or peripheral nerve site. The leads are implantable and designed to deliver electrical pulses to the nerves via an array of four or eight cylindrical electrodes at the distal end. 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) or peripheral nerve stimulation (PNS) is performed via standard surgical tools and techniques, as described in (K201618).
Here's a breakdown of the acceptance criteria and study information based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly present a table of acceptance criteria or performance metrics in the way one might expect for a diagnostic or AI-based device's clinical performance. Instead, the submission describes the Nalu Neurostimulation System and its substantial equivalence to predicate devices, focusing on technical specifications and safety rather than a measurable clinical outcome in a performance study.
The closest to "acceptance criteria" are the parameters defining the device's operational range, and the "reported device performance" is that these parameters are within acceptable limits compared to predicate devices, demonstrating substantial equivalence.
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Pulse Width Range | Subject Device: 12 to 2000 µs (Predicate: 12 to 1000 µs; Reference: 50 to 1000 µs) - Analysis: Available programmable pulse width will be capped to maintain Maximum Phase Charge and Maximum Charge Density within limits of Medtronic Xtrel reference device limit. No impact to safety and effectiveness. |
| Maximum Phase Charge (300 Ohms) | Subject Device: 18.0 µC/pulse (Predicate: 10.2 µC/pulse; Reference: 18.0 µC/pulse) - Analysis: Same as Medtronic Xtrel reference device. |
| Maximum Phase Charge (500 Ohms) | Subject Device: 18.0 µC/pulse (Predicate: 10.2 µC/pulse; Reference: 14.2 µC/pulse) - Analysis: Same as Medtronic Xtrel reference device at 300 Ohms. Maximum Phase Charge constant in current controlled system and enforced below maximum reference device value (at 300 Ohms). No impact to safety and effectiveness. |
| Maximum Phase Charge (800 Ohms) | Subject Device: 18.0 µC/pulse (Predicate: 10.2 µC/pulse; Reference: 10.5 µC/pulse) - Analysis: Same as Medtronic Xtrel reference device at 300 Ohms. Maximum Phase Charge constant in current controlled system and enforced below maximum reference device value (at 300 Ohms). No impact to safety and effectiveness. |
| Maximum Charge Density (300 Ohm) | Subject Device: 146.94 µC/cm² (Predicate: 83.3 µC/cm²; Reference: 150.0 µC/cm²) - Analysis: Within maximum limit as set by Medtronic Xtrel reference device. |
| Maximum Charge Density (500 Ohm) | Subject Device: 146.94 µC/cm² (Predicate: 83.3 µC/cm²; Reference: 118.3 µC/cm²) - Analysis: Same as Medtronic Xtrel reference device at 300 Ohms. Maximum Phase Charge constant in current controlled system and enforced below maximum reference device value (at 300 Ohms). No impact to safety and effectiveness. |
| Maximum Charge Density (800 Ohm) | Subject Device: 146.94 µC/cm² (Predicate: 83.3 µC/cm²; Reference: 87.5 µC/cm²) - Analysis: Same as Medtronic Xtrel reference device at 300 Ohms. Maximum Phase Charge constant in current controlled system and enforced below maximum reference device value (at 300 Ohms). No impact to safety and effectiveness. |
| Dosage Time Range | Subject Device: On spans 1 ms to 1000 ms, Off spans 1 ms to 2000 ms (Predicate: On spans 1 ms to 25 ms) - Analysis: This parameter has no impact on safety and effectiveness. Increasing the range allows the clinician to offer more flexibility to accommodate patient preferences. |
| All other parameters (Frequency, Current/Voltage Regulated, Output Voltage/Current, Waveform, Pulse Shape, Maximum Current Density, Net Charge, Average Phase Power/Density, Pulse Delivery Mode, Current Path Options, Program Cycle, Pulse Pattern, Daily Therapy Time, Transmit Frequency) | All "Same as predicate." or "Same as predicate/reference." indicating compliance with established safe and effective parameters. |
2. Sample Size Used for the Test Set and Data Provenance
The document does not describe a clinical performance study with a "test set" from real patient data in the context of an AI/diagnostic device. Instead, it refers to "testing" performed to support the safety and performance of the device. This testing appears to be primarily non-clinical (bench/laboratory) testing of electrical and software parameters.
Therefore, there is no mention of a sample size for a test set of patient data, nor data provenance (country of origin, retrospective/prospective).
3. Number of Experts Used to Establish Ground Truth and Qualifications
This information is not applicable and not provided. The study focuses on evaluating technical parameters against established medical device safety standards and comparison to predicate devices, not on a ground truth established by medical experts for diagnostic accuracy.
4. Adjudication Method
This information is not applicable and not provided, as the submission does not involve expert review or adjudication of clinical cases for diagnostic or performance accuracy.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done
No, an MRMC comparative effectiveness study was not done. This device is a neurostimulation system for pain relief, not a diagnostic imaging or AI-assisted diagnostic tool that would typically undergo MRMC studies to assess human reader improvement. The submission focuses on demonstrating substantial equivalence in technical characteristics and safety.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
This concept is not directly applicable. The "device" itself (Nalu Neurostimulation System) is a therapeutic electrical stimulator. The "software" changes described are modifications to its operational parameters. The performance testing referenced is likely to evaluate the hardware and software functionality as an integrated system, ensuring it operates within safe and effective limits. There isn't an "algorithm only" component in the sense of an AI interpreting inputs to provide diagnostic outputs.
7. The type of ground truth used
The "ground truth" for this submission appears to be regulatory and engineering standards, and the specifications and performance characteristics of legally marketed predicate and reference devices. The evaluation focuses on whether the subject device's technical specifications and functionality (particularly the updated software parameters) fall within the established safe and effective ranges of these comparable devices.
8. The sample size for the training set
This information is not applicable and not provided. The device is not an AI/ML model that would train on a dataset. The software changes are operational programming changes for the neurostimulator.
9. How the ground truth for the training set was established
This information is not applicable and not provided, as there is no "training set" for an AI/ML model.
§ 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).