{
  "id": "AIBD-0266",
  "title": "Johns Hopkins LSTM click detector lets a man with ALS spell 10.2 characters a minute for 90 days without retraining",
  "summary": "A chronically implanted high-density ECoG BCI with an LSTM click detector trained on under 44 minutes of data supported switch-scan spelling for 626 minutes over 90 days, all in the laboratory.",
  "date_observed": "2024-10-22",
  "date_basis": "unassessed",
  "date_precision": "unassessed",
  "benefit_status": null,
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  "account": "Candrea et al. (Communications Medicine, 22 October 2024) report a clinical-trial participant with ALS (NCT03567213) at Johns Hopkins. He had a chronically implanted high-density electrocorticographic BCI over sensorimotor cortex. High-gamma power vectors from 128 channels fed a long short-term memory layer with 25 hidden units and fully connected layers. These classified rest versus grasp every 100 ms. The click detector was trained on almost 44 minutes of data (480 trials) collected up to 21 days before use. It then ran for 90 days without retraining. The participant controlled a switch-scanning speller for a total of 626 minutes with a median spelling rate of 10.2 characters per minute. The paper states all data collection and testing were performed in the laboratory. No home use is reported.",
  "category": "benefit created",
  "unexpected": false,
  "purpose": "Restore text communication for a person with ALS through a single neural click command driving a switch-scanning speller",
  "system": "Click-based electrocorticographic brain-computer interface with an LSTM click detector (NCT03567213)",
  "model_version": "LSTM (25 hidden units) with two fully connected layers, Keras/TensorFlow 2.8.0",
  "developer": "Johns Hopkins University (Crone lab and co-authors)",
  "deployer": "Johns Hopkins University (laboratory sessions)",
  "location": "Baltimore, Maryland, USA",
  "domain": "Health; assistive communication",
  "segment": "People with ALS and impaired speech or movement",
  "benefit_type": "Improved Accessibility",
  "taxonomy_note": null,
  "registry_ids": {},
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  "evidence": [
    {
      "kind": "peer-reviewed study",
      "citation": "Candrea DN, Shah S, Luo S, et al. Commun Med 4:207 (2024)",
      "title": "A click-based electrocorticographic brain-computer interface enables long-term high-performance switch scan spelling",
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC11494178/",
      "date": "2024-10-22",
      "written_by": "makers",
      "quote": "the study participant can maintain a median spelling rate of 10.2 characters per min"
    },
    {
      "kind": "peer-reviewed study",
      "citation": "Candrea DN, et al. Commun Med 4:207 (2024), Methods",
      "title": "A click-based electrocorticographic brain-computer interface enables long-term high-performance switch scan spelling",
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC11494178/",
      "date": "2024-10-22",
      "written_by": "makers",
      "quote": "All data collection and testing were performed in the laboratory."
    },
    {
      "kind": "preprint",
      "citation": "Candrea DN, et al. Research Square, 25 Sep 2023",
      "title": "A click-based electrocorticographic brain-computer interface enables long-term high-performance switch-scan spelling",
      "url": "https://doi.org/10.21203/rs.3.rs-3158792/v1",
      "date": "2023-09-25",
      "written_by": "makers",
      "quote": "a new click decoder achieved comparable performance despite being trained with even less data (< 15 min, within one day)."
    }
  ],
  "replication": {
    "produced_by": [
      "High-density ECoG over sensorimotor cortex",
      "LSTM click detector trained on under 44 minutes of data",
      "Switch-scanning speller interface"
    ],
    "must_hold": [
      "Signal power modulation remains stable (a transient reduction interrupted use of the fixed model)",
      "Laboratory setting with research staff"
    ],
    "echoes": [
      {
        "date": "2016-11-12",
        "setting": "Utrecht fully implanted click-based BCI, home use over seven years",
        "model_version": null,
        "outcome": "recurred",
        "source": "https://pmc.ncbi.nlm.nih.gov/articles/PMC5326682/"
      }
    ]
  },
  "paired_incident": null,
  "headline": "Johns Hopkins LSTM BCI lets a man with ALS spell for 90 days",
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  "comparator": {
    "against": "the Utrecht fully implanted switch-scan BCI reported by Vansteensel et al. (four contacts over hand motor cortex)",
    "before": "a spelling rate of 1.8 letters per minute with a latency of at least 1 s per click",
    "after": "a spelling rate of 10.2 CCPM and 0.68 s latency",
    "basis": "measured",
    "quote": "In that study a participant with ALS was implanted with four contacts over hand motor cortex and achieved a spelling rate of 1.8 letters per minute with a latency of at least 1 s per click (compared to a spelling rate of 10.2 CCPM and 0.68 s latency reported in the present work).",
    "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC11494178/"
  },
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    "note": "An October 2025 medRxiv preprint concerns longitudinal gesture decoding in the same CortiCom trial. Its findings remain unverified.",
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  "confidence": "claimed",
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        "review_state": "record_mapped",
        "coverage": "partial"
      }
    },
    "summary": {
      "total": 91,
      "addressed": 91,
      "known": 33,
      "reviewed": 0,
      "record_mapped": 33,
      "not_assessed": 58,
      "complete": false,
      "by_state": {
        "value_present": 33,
        "not_reported": 0,
        "unresolved": 0,
        "not_assessed": 58,
        "not_applicable": 0,
        "withheld": 0,
        "source_unavailable": 0
      }
    }
  }
}