Independent security researchSystem assurance / 2026

Assurance for closed-loopneuromodulation

Defocus studies the integrity of sensing, decision, and stimulation across closed-loop neuromodulation systems, including behavior under unintended or adversarial inputs. The research is prospective and does not state or imply findings in any deployed device.

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Research domainClosed-loop neuromodulation

Assurance modelSense / decide / stimulate

Research framework / 01–04

Security properties under study

Four points of assurance across the therapy as delivered.

01Sensed input

Sensing

Signal authenticity

The control law acts on a biomarker extracted from neural recordings, for example spectral power in a narrow band of a local field potential. Everything the device decides is downstream of that measurement, which places the sensed signal inside the trust boundary rather than outside it.

Establishing that a measurement originated from the patient is harder than it appears. The recording is contaminated by the device's own stimulation output, so the input and the output of the loop are not independent. Artifact rejection is therefore not a preprocessing step but a security relevant function, and the question of what a corrupted measurement would look like is open.

02Control law

Decision

Control integrity

A closed loop device adjusts stimulation continuously, without a clinician present between adjustments. Its safety limits are principally electrochemical, bounding charge per phase and charge density at the electrode tissue interface, and these are well characterised in the clinical literature.

Those limits bound the magnitude of a single stimulus. They do not bound the behaviour of the loop. A device can remain inside every per channel limit while the loop as a whole enters a regime its designers did not intend, and the properties that hold under noise, drift and physiological variation are not necessarily the properties that hold when an input is chosen rather than drawn from nature.

03Device link

Telemetry

Telemetry confidentiality

Short range device links carry two distinct things: physiological recordings, and the configuration state of the device itself. The first is sensitive personal data and is increasingly regulated as such.

The second matters for a different reason. Configuration state is not only information about the device, it is the surface through which the device is changed. Treating the telemetry link purely as a privacy concern understates what passes across it.

04Command origin

Programming

Programming chain provenance

Stimulation parameters reach the implant through a chain that includes clinician facing programming software, a patient side monitor, a telemetry link, and in current systems a manufacturer operated data service. Each element is a place where a command can originate or be altered.

Provenance is the question of establishing where a given parameter change came from, and it is a supply chain problem as much as an access control one. It is complicated by adaptive behaviour: a device that adjusts itself over months is not the device that was verified at deployment, so the record of how it arrived at its current state is itself something that needs to be trustworthy.

Published work is citable and paired with a disclosure process designed for predictable coordination.

Closed-loop devices act on neural tissue without a clinician in the loop. The security properties of that loop are underexamined relative to their consequence.

Research limits

Scope boundary

The research covers closed loop systems in clinical use, specifically responsive neurostimulation and adaptive deep brain stimulation. These systems are studied as the therapy as delivered, including the implant, sensing path, programming environment, telemetry links, and operational context, rather than the implant alone.

No work is performed on devices implanted in human subjects. No interaction takes place with any therapeutic device in clinical use. Bench work is limited to explanted or manufacturer supplied hardware, development kits, and simulation, under a documented ethics and disclosure protocol.

Research record

Current status

The research is in its foundational phase. The coordinated disclosure protocol is published in advance of any finding. Published work will appear in the research section with a DOI as it is completed.

Last updated: August 17, 2026