A New Communication Device Using the Anal Sphincter

Objective: The purpose of this study was to invent a new communication device by utilizing the function of anal sphincter muscles that was another residual motor function to the last in amyotrophic lateral sclerosis (ALS) patients. Method: We designed a sensor which worked by changing intensity of the contraction and was enable severely paralyzed patients to communicate by means of self-regulation of the anal sphincter contraction. This device made sentences through combination of selected Korean letters deprived from sphincter contractions. Results: This device was composed of three parts. Anal sensor: the head part of the sensor regulated by sphincters was located in the rectum, signal processing module: the raw signal from the sensor was boosted up and set up on the baseline voltage equal to threshold by threshold detector, and device program: the icon mode which was composed of routine questions and requested to their care-givers. And in user-writing mode, patients could choose syllable elements using the sensor operating by sphincter. Conclusion: This system was designed for advanced ALS patients with only the available function of sphincter muscles and could give them another new option in selecting communication devices. (J Korean Acad Rehab Med 2006; 30: 513-521)