What would brain-computer interface users want? Opinions and priorities of potential users with amyotrophic lateral sclerosis

Abstract

Universal design principles advocate inclusion of end users in every design stage, including research and development. Brain-computer interfaces (BCIs) have long been described as potential tools to enable people with amyotrophic lateral sclerosis (ALS) to operate technology without moving. Therefore the objective of the current study is to determine the opinions and priorities of people with ALS regarding BCI design. This information will guide BCIs in development to meet end-user needs. A telephone survey was undertaken of 61 people with ALS from the University of Michigan's Motor Neuron Disease Clinic. With regard to BCI design, participants prioritized accuracy of command identification of at least 90% (satisfying 84% of respondents), speed of operation comparable to at least 15-19 letters per minute (satisfying 72%), and accidental exits from a standby mode not more than once every 2-4 h (satisfying 84%). While 84% of respondents would accept using an electrode cap, 72% were willing to undergo outpatient surgery and 41% to undergo surgery with a short hospital stay in order to obtain a BCI. In conclusion, people with ALS expressed a strong interest in obtaining BCIs, but current BCIs do not yet provide desired BCI performance.

Figure 1

Maximum time investments acceptable to respondents. First column shows numbers of responses with * indicating median response. Second column shows percentage of respondents who would be satisfied with each answer.

Figure 2

BCI performance answers.

Figure 3

Interest rating for BCI-operated tasks. Graphs were generated using the SAS boxplot procedure. The box extends from Q₁ to Q₃ with the vertical line indicating median. The narrowing around the median measures the significance of differences between medians. The diamond indicates the mean and the whiskers indicate the range of answers. Outliers, when present, are indicated by circles.

Figure 4

A) Importance of different BCI design features (n=56). B) Importance ratings from verbal response group (n=31); C) from verbal-relay group (n=19); and D) from non-verbal relay group (n=6). * indicates one less response.