FDA-approved implanted nerve cuff system that blocks pain from an amputated limb with 5 or 10 kHz alternating current, approved August 2024. Values come from the FDA summary of safety and effectiveness.
Independent, source-linked catalog sheet. Not a manufacturer-issued datasheet, regulatory decision or instructions for clinical use. Human evidence does not establish approval. Source-specific restrictions, conflicts and missing specifications are retained below.
Neuros Altius HFAC nerve block
The Altius System places a cuff electrode on the nerve of an amputated leg and delivers 5 or 10 kHz high-frequency alternating current to block post-amputation pain. This sheet comes from the FDA overview and summary for PMA P230020 (approved August 26, 2024). Arm-level trial numbers were not extracted and stay Unreported.
Identity
Field
Value and source scope
Device
Neuros Medical Altius Direct Electrical Nerve Stimulation System: implanted pulse generator, one or two cuff electrodes with leads, battery charger, patient controller and programmer wand [1][2]
Manufacturer
Neuros Medical, Inc., Aliso Viejo, California [1][2]
Interface class
Implanted nerve cuff electrode delivering high-frequency alternating current to a peripheral nerve [1][2]
QUEST subjects were treated between October 9, 2014 and September 13, 2021 [2]
First human implant
Unreported
Species studied
Human [2]
Regulatory status
PMA P230020 approved August 26, 2024 [1]
Function
High-frequency alternating current (HFAC) nerve block to reduce chronic phantom and residual lower limb post-amputation pain [1][2]
Target tissue
Target peripheral nerve proximal to the amputation terminus in the amputated leg [1][2]
Geometry and architecture
Field
Value and source scope
Interface type
Self-sizing silicone nerve cuff wrapped around the nerve, with a lead tunneled to the IPG [2]
Array layout
Cuff sizes 4, 6 and 9 mm minimum diameter; the IPG has two independent channels, A and B [2]
Electrode count
One or two cuff electrodes per system [1][2]
Pitch
Electrode band spacing 5 mm (4 mm cuff), 7 mm (6 mm cuff), 11 mm (9 mm cuff) [2]
Electrode lengths
Cuff width 15, 20 and 28 mm for the 4, 6 and 9 mm cuffs, per the SSED table [2]
Shank width and thickness
Unreported
Tip and exposed site geometry
Unreported
Contact coating
Unreported
Insulation
Silicone rubber cuff [2]
Insertion method
Unreported
Anchoring and fixation
Cuff wraps the nerve; lead retention force of 15 N with set screws engaged (acceptance criterion) [2]
Electrode and channel physics
Field
Value and source scope
Exposed site area
Unreported
Electrode material
Unreported
Impedance (with measurement frequency)
Unreported
Noise floor or SNR
Unreported
Recording modality
Unreported
Sampling rate
Unreported
Stimulation capability
Voltage-controlled HFAC at 5 kHz or 10 kHz on two independent channels with IS-1 connector ports [2]
Charge injection limit
Unreported
Reference and ground
Unreported
Tissue interface and bioresponse
Field
Value and source scope
Target tissue
Unreported
Insertion trauma and BBB disruption
Unreported
Vascular disruption risk
Unreported
Micromotion sensitivity
Unreported
Gliosis and encapsulation
Unreported
Neuron loss near sites
Unreported
Foreign-body response mitigation
Unreported
Typical failure modes
Unreported
System architecture
Field
Value and source scope
Onboard electronics
Implanted rechargeable IPG, about 68.5 mm high, 47.0 mm wide and 11.0 mm thick, typically placed in the abdomen [2]
Data path
Wireless links: programmer wand up to 3.5 cm, patient controller up to 5 cm, battery charger up to 2.5 cm (bench acceptance criteria) [2]
Telemetry bandwidth
Unreported
Sampling rate
Unreported
Power
Rechargeable lithium-ion battery charged wirelessly by an external charger; bench testing demonstrated a 10-year life at typical settings [2]
Thermal management
Unreported
Packaging and hermeticity
Unreported
MRI compatibility
Unreported
Surgical complexity
Cuff placement on the target nerve, lead tunneling and an abdominal IPG pocket [1][2]
Output connectors
Standard IS-1 connector ports; a silicone port plug is used when only one electrode is implanted [2]
Performance envelope
Field
Value and source scope
Acute yield
Unreported
Chronic yield
Unreported
Stability over time
Unreported
Longevity
10-year battery life at typical use per bench testing [2]
Revision and explant experience
Unreported
Adverse events
Unreported
Notable demonstrations
Unreported
Clinical and preclinical evidence
Field
Value and source scope
Human subjects
QUEST: 183 subjects underwent implant surgery (safety population); 180 in the full analysis set; the demographics table lists 85 Test and 85 Control (170), which does not match the 180 stated, so the figures are not reconciled here; 34 investigational sites [2]
Preclinical cohort
Unreported
Follow-up duration
Unreported
Indications
Aid in the management of chronic intractable phantom and residual lower limb post-amputation pain in adult amputees [2]
Trials and registries
QUEST, IDE G130203: multicenter, prospective, randomized, double-blinded, active-sham controlled [2]
Primary outcomes
Primary endpoint: responder rate in Test versus sham-control arm during months 1 to 3. FDA’s overview states studies report a clinically meaningful pain reduction of 50% or greater; arm-level percentages were not extracted here [1][2]
Key limitations
Arm-level responder rates and serious adverse event counts were not extracted from the SSED text read. Indicated only for lower limb post-amputation pain [1][2]
Engineering tradeoffs
Field
Value and source scope
Strengths
Rechargeable IPG with three cuff sizes [2]
Limitations
Unreported
Scaling constraints
Unreported
Version boundary
One approved configuration is described: IPG with two channels and 4, 6 or 9 mm cuffs.