Closed-loop spinal cord stimulation
Saluda Medical
Saluda's Evoke system measures the spinal cord's response to stimulation and uses it as a feedback signal on a pulse-by-pulse basis. Its pivotal trial used a double-blind randomized comparison of closed-loop and open-loop stimulation.
At a glance
- Signature technology
- ECAP-controlled closed loop
- Adjustment rate
- >100 times per second
- Trial design
- Double-blind closed-loop vs open-loop RCT
- Longest published follow-up
- 36 months from the EVOKE trial
The first ECAP-controlled closed-loop system, adjusting on every pulse.
The Signature Technology
Pulse-by-pulse ECAP control
After each stimulation pulse, Evoke records the amplitude of the resulting evoked compound action potential, compares it against a target the physician set, and adjusts the current of the very next pulse to close the gap. The intent is to keep neural activation inside the therapeutic window continuously — not too little as the cord drifts away from the lead, not too much as it drifts closer. The system can adjust more than a hundred times per second, and Saluda reports having now measured over a trillion ECAPs across its implanted base.
How It Works
From lead placement to therapy delivery
- 01
Leads are placed in the epidural space, and the physician establishes the patient's therapeutic window — the range of neural activation between 'just perceptible' and 'too much'.
- 02
A target ECAP amplitude is set within that window.
- 03
From then on the device measures and corrects continuously, so the amount of nerve fibre activation stays consistent whether the patient is lying down, standing, walking or coughing.
The Platforms
The system
Each system in this family is built on the same underlying technology, but they differ in power source, size and intended use.
Evoke
ECAP-controlled closed-loop SCS
A rechargeable closed-loop system with objective neurophysiological measurement built into everyday therapy delivery.
- Adjusts more than 100 times per second
- Objective ECAP data available to the care team
- Rechargeable generator
The Evidence
What has been published
Each study is given with its design, who was actually in it, what it found and where it falls short — then a link to the paper itself, so you can check any of it. Most device trials are manufacturer-funded; that is normal in this field and it is labelled here rather than glossed over.
EVOKE — 12 months
The pivotal double-blind randomized controlled trial comparing closed-loop against open-loop stimulation, with 12-month results published in The Lancet Neurology.
EVOKE — 36 months
Three-year results reported sustained pain relief and a superior holistic treatment response for closed-loop versus open-loop, along with greater measured neural activation and more accurate therapy delivery.
Quality-of-life analysis
A secondary analysis of the EVOKE trial examined the durability of quality-of-life outcomes alongside pain scores, rather than pain reduction in isolation.
These are the studies specific to Saluda. For the trials that shaped the whole field — and for how to read an industry-sponsored study fairly — see the clinical evidence library.
The Trade-offs
What to weigh before choosing this platform
No system is the right answer for every patient. These are considerations to discuss with the clinician who knows your history.
Objective measurement is a genuine advance, but it measures neural activation — not pain itself, which remains a subjective experience.
Closed-loop control depends on a usable ECAP signal, which is not equally clean at every spinal level or in every patient.
The system is rechargeable.
Regulatory status
The Evoke SCS System holds FDA premarket approval (PMA) for the management of chronic intractable pain of the trunk and/or limbs.
Indications, contraindications, warnings and MRI conditions are defined by the current labeling. Review the manufacturer's Instructions for Use at saludamedical.com and discuss them with your physician.
Wondering whether this therapy fits your situation?
Explore how candidacy is assessed, then discuss your pain pattern, imaging and prior treatments with a clinician. Device selection comes later.