Implanted brain-computer interface functionality during nighttime in late-stage amyotrophic lateral sclerosis

The 60-second view

What problem?

A communication BCI for someone who is locked in has to work around the clock, not least to call for help at night. Nobody had tested one during sleep.

What did they do?

Analysed the night-time signals of one long-term user of an implanted ECoG BCI, ran the daytime decoder on them, then built a night mode and followed it in use.

What changed?

The signal itself is different at night: power in the low and high frequency bands was higher and more variable than by day, enough to set off a daytime decoder hundreds of times an hour.

Why does it matter?

A caregiver call that goes off 13 times an hour by mistake is one a household learns to ignore. For an implant meant for use at home, how it behaves during sleep belongs in the evidence.

Method

Participants

One person with late-stage ALS, a long-term user of an implanted ECoG BCI

Interface

Fully implanted electrocorticography system

Signal

Power in low and high frequency bands

Task

Click-based control and a call to the caregiver, by day and at night

Decoder

The daytime click decoder, and a separate night mode

Results

100%

Nights with unintended activations

Daytime decoder applied to night data

245 per hour

Unintended clicks at night

Daytime decoder

13 per hour

Unintended caregiver calls at night

Daytime decoder

79%

Nights the night mode ran without error

Over about 1.5 years

Strength of evidencePeer reviewed, one participant with late-stage ALS, with the night mode followed for about a year and a half.

Figures are quoted from the published abstract and were checked on 11 Oct 2026.

Limitations

• A single participant, with one implant and one decoder design.
• The night mode was free of errors on about four nights in five, not on all of them.

What this could enable

Treating round-the-clock reliability as a requirement with tests of its own, separate from daytime accuracy.