8/17/2016 Today’s Topics • Intro to TLIS • Intro to BCI (brain-computer interface) • OHSU studies – BCI for yes/no communication – Interviews with spouses – User-centered design of AAC Augmentative and Alternative • Partner training Communication for Adults • Ethical issues with Total Locked-In Syndrome Betts Peters, Brandon Eddy, Kendra McInturf, & Melanie Fried-Oken What is LIS? • Severe or total paralysis with preserved consciousness Locked-in Syndrome • Also known as “minimal movement” – See work by Susan Fager, David Beukelman, and colleagues More on LIS More on LIS • Underlying diagnoses include: • Highly recommended: – Brainstem stroke – The Diving Bell and the Butterfly by – Advanced ALS Jean-Dominique Bauby – TBI – Film adaptation from 2007 – Tumor • Average age range: 17 – 52 years • Younger patients have better potential of survival • More than 85% of individuals are still alive after 10 years 1
8/17/2016 Classifications of LIS AAC for people with LIS • Low-tech: blinking or eye movement, partner- • Incomplete LIS: Recovery of some assisted scanning voluntary movements in addition to eye • High-tech: SGD with eye control, switch movements scanning, or other alternative access • Classic LIS: Preserved vertical eye movement and blinking • Complete or Total LIS: Quadriplegia and anarthria; no voluntary movement (Bauer et al, 1979) AAC for people with LIS AAC for people with LIS • People with total LIS have no voluntary motor function • Others with LIS may not have consistently reliable motor function (fatigue, illness) AAC for people with LIS AAC for people with LIS 2
8/17/2016 How can we break the ice? Introduction to BCI Brain-Computer Interface (BCI) • Technology whereby a computer detects a ‘selection’ made by a person without using muscle activity • Uses the person’s changes in brain activity as the control signal • Allows people can interact with their environments through brain signals rather than through muscle movement Current human BCI research Electroencephalography (EEG) for communication & control • Electrodes placed on scalp Invasive BCI: Braingate Noninvasive BCI (EEG) • Records voltage fluctuations from ionic current flows in neurons • Often used for diagnostic tests: epilepsy, disorders of consciousness, sleep studies • Shows reactions to stimulation 3
8/17/2016 EEG for control ERPs: effect of single strobe flashes presented at 1 Hz during routine EEG • Signal types – Steady state visually evoked potential (SSVEP) – Event-related potential (ERP) • P300 – Motor imagery • ERP = Brain response to a specific stimulus – Visual – Auditory – Tactile ERPs: P300 ERPs: P300 • Positive deflection in voltage occurring ~300ms (actually 250-500ms) after stimulus presentation • Elicited by low-probability stimuli ERPs in BCI RSVP Keyboard™ • ERP responses to known stimuli allow us • P300-based spelling system to infer the user’s intent • Letters appear rapidly on screen • Examples: • User looks for target letter in a stream of – Binary-choice tactile BCI: Attend to vibrations other letters on left hand for ‘yes’ or right hand for ‘no’ – Spelling systems: Appearance or highlighting of desired letter elicits P300 Are you ready? 4
8/17/2016 GO_TO_THE_MOVIES GO_TO_THE_MOVIES GO_TO_ GO_TO_ + S GO_TO_THE_MOVIES GO_TO_THE_MOVIES GO_TO_ GO_TO_ _ N GO_TO_THE_MOVIES GO_TO_THE_MOVIES GO_TO_ GO_TO_ A B 5
8/17/2016 GO_TO_THE_MOVIES GO_TO_THE_MOVIES GO_TO_ GO_TO_ T Y GO_TO_THE_MOVIES GO_TO_THE_MOVIES GO_TO_ GO_TO_ R GO_TO_THE_MOVIES GO_TO_THE_MOVIES GO_TO_ GO_TO_T H T DECISION: 6
8/17/2016 Range and Average of AUC ‐ People with LIS Here’s the catch… 1.00 0.90 AUC 0.80 0.70 0.60 0.50 Participant (# of calibration attempts) Current BCIs don’t work for everyone, especially people with disabilities! Range and Average of AUC ‐ Controls 1.00 0.90 AUC 0.80 0.70 0.60 0.50 Control Participant (# of calibration attempts) What we know so far… • EEG-based systems: generally poor results for people with TLIS • Invasive systems: limited human trials mindBEAGLE: • fMRI-based systems: some promising trials with people with DOC and TLIS (but A COMMERCIAL BCI SYSTEM expensive and difficult to access) • Commercial EEG-based system (mindBEAGLE): mixed results for people with DOC or TLIS mindBEAGLE mindBEAGLE • Made by g.tec (Linz, Austria) • mindBEAGLE paradigms: – Auditory P300 (response detection only) – 2-tactor P300 (response detection only) • Designed for consciousness assessment – 3-tactor P300 (response detection and yes/no and communication for people with DOC communication) – Motor imagery (response detection and yes/no communication) 7
8/17/2016 mindBEAGLE MI • Goal: trial mindBEAGLE motor imagery paradigm with people with LIS • Questions: mindBEAGLE FOR YES/NO – Can people with LIS learn to control an MI COMMUNICATION BCI with repeated practice? – Does a custom MI prompt improve performance compared to a generic prompt? • Outcome variables: – Assessment score – Yes/no questions (#/10) mindBEAGLE MI mindBEAGLE MI • 2 participants • AB design – Joe: incomplete LIS after brainstem stroke – A: 6-7 sessions with generic MI prompt • Previously successful with P300-based RSVP – B: 5-6 sessions with custom prompt Keyboard™ – Bob: total LIS or DOC due to advanced ALS • Generic prompt: imagine touching thumb • Spouse reports inconsistent yes/no response to fingers – “Good days and bad days” – Not observed during study visits • Previous experience with mindBEAGLE P300 • Custom prompts: imagine wrestling moves paradigms: inconsistent performance or guitar playing mindBEAGLE MI: Results mindBEAGLE MI: Results Question Accuracy: Joe (Incomplete LIS) Calibration Accuracy: Joe (incomplete LIS) 100 100 Baseline Intervention Baseline Intervention 90 90 Average Accuracy (%) 80 80 Average Accuracy (%) 70 70 60 60 50 50 40 40 30 30 20 20 10 0 10 1/26/2016 2/2/2016 2/9/2016 2/16/2016 2/23/2016 3/1/2016 3/5/2016 3/15/2016 3/22/2016 3/29/2016 4/5/2016 4/12/2016 4/19/2016 4/19/2016 0 1/26/2016 2/2/2016 2/9/2016 2/16/2016 2/23/2016 3/1/2016 3/5/2016 3/15/2016 3/22/2016 3/29/2016 4/5/2016 4/12/2016 4/19/2016 4/19/2016 Date Date Question Accuracy: Bob (TLIS) Calibration Accuracy: Bob (TLIS) Intervention Baseline 100 100 Baseline 90 90 Intervention Average Accuracy (%) 80 Average Accuracy (%) 80 70 70 60 60 50 50 40 40 30 30 20 20 10 10 0 0 1/13/2016 1/20/2016 1/27/2016 2/3/2016 2/10/2016 2/17/2016 2/24/2016 3/2/2016 3/9/2016 3/16/2016 3/23/2016 3/30/2016 1/13/2016 1/20/2016 1/27/2016 2/3/2016 2/10/2016 2/17/2016 2/24/2016 3/2/2016 3/9/2016 3/16/2016 3/23/2016 3/30/2016 Date Date 8
8/17/2016 mindBEAGLE MI: Discussion mindBEAGLE MI: Discussion • mindBEAGLE MI was not effective for • Bob’s status unknown: LIS vs. DOC? these participants • Joe had poor performance despite – (Very small sample!) preserved consciousness & cognition • Custom MI prompt had no effect – Poor BCI assessment performance = inconclusive result • Further exploration needed Purpose of this study To gain insight into the current communication needs of families living with What do spouses of people with TLIS, as well as how future BCI research and design might work toward meeting LIS think about BCI? those needs Methods Protocol Design: Study design: Qualitative interview, • 3 Interviews: 2 prior to BCI trials, 1 exit interview case studies • 3 mindBEAGLE trial sessions with spouses Participants: Francine Sandra Age 69 45 Education Graduate degree Some graduate school Spouse’s Diagnosed with ALS 1996; Brainstem stroke secondary to condition mechanically ventilated since 1999 AVM 2009 Other Francine and Bob have been Sandra and her spouse have been married for 36 years and live married for 18 years. She lives at together in a private residence. home with their 2 children; spouse lives at an AFH. 9
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