A novel spelling system for locked-in syndrome patients using only eye contact

Abstract

Purpose: We developed and evaluated a novel spelling system for patients with locked-in syndrome: patients with tetraplegia, not able to talk, and only able to blink their eyes. Method: A new communication grid was compared with existing non-technical communication methods for practical daily use. The means of the number of decision steps to reach a full sentence were compared testing 10 sentences relevant in daily care. These 10 sentences together encompass all letters of the alphabet. Results: The new communication grid is organised alphabetically in 4 columns and 2 main rows, with each row subdivided in three rows. The first column contains vowels while the other columns contain consonants. Letters in each column are alphabetically ordered. When spelling a sentence the conversation partner counts the columns, until the patient indicates by an upward eye movement that the column contains the intended letter. Hereafter, the patient indicates by looking straight ahead or by looking down, whether the intended letter is in the upper or in the lower main row, respectively. The conversation partner will then read out the letters until the patient indicates the intended letter. Compared to other spelling systems, this system requires only vertical eye movement, is easier to memorise, and faster in use. The comparison of means of decision steps to reach the 10 full sentences for different communication grids shows that using the new communication grid is approximately one-third to three times faster than the existing spelling systems (p = 0.005). Conclusion: This new grid is a valuable communication tool, especially in situations, such as bathing, getting dressed or out of house activities where no devices are available.

Implications for Rehabilitation

• Communication with patients with locked-in syndrome is a complicated and strenuous task.

• Communication methods, such as the alphabet board and brain-computer interfaces, are time consuming or too sophisticated to use in daily life tasks.

• This communication grid is fast, easy to use and memorise and requires only vertical eye movement.

• Aid
• alphabet
• communication
• locked-in
• nonverbal
• spelling
• system
• table

Acknowledgements

The authors would like to express their gratitude to Prof. Dr G. Rozenberg for his constructive remarks on the manuscript.