Likely this one, from 1998. https://iopscience.iop.org/article/10.1088/0960-1317/8/2/028/pdf https://iopscience.iop.org/article/10.1088/0960-1317/8/2/028... U

Likely this one, from 1998. https://iopscience.iop.org/article/10.1088/0960-1317/8/2/028/pdf https://iopscience.iop.org/article/10.1088/0960-1317/8/2/028... Unfortunately, Steven Hawking's muscular dystrophy affected his tongue as well so he was unable to use it, but it was in that context that I heard about it.