Identification of the most significant electrode positions in electromyographic evaluation of swallowing-related movements in humans.

Surface electromyography (sEMG) is a well-established procedure for recording swallowing-related muscle activities. Because the use of a large number of sEMG channels is time consuming and technically sophisticated, the aim of this study was to identify the most significant electrode positions associated with oropharyngeal swallowing activities. Healthy subjects (N = 16) were tested with a total of 42 channels placed in M. masseter, M. orbicularis oris, submental and paralaryngeal regions. Each test subject swallowed 10 ml of water five times. After having identified 16 optimal electrode positions, that is, positions with the strongest signals quantified by the highest integral values, differences to 26 other ones were determined by a Mann-Whitney U test. Kruskal-Wallis H test was utilized for the analysis of differences between single subjects, subject subgroups, and single electrode positions. Factors associated with sEMG signals were examined in a linear regression. Sixteen electrode positions were chosen by a simple ranking of integral values. These positions delivered significantly higher signals than the other 26 positions. Differences between single electrode positions and between test subjects were also significant. Sixteen most significant positions were identified which represent swallowing-related muscle potentials in healthy subjects.

Vibrant Soundbridge® in preschool children with unilateral aural atresia: acceptance and benefit.

The aim of this pilot study was to determine the acceptance and benefit from the middle ear implant system Vibrant Soundbridge® (VSB, MED-EL Corporation, Austria) by means of a questionnaire, compared to a previously used conventional bone conducting hearing device, in preschool children with unilateral congenital aural atresia. Prospective cohort study. All nine children with unilateral congenital aural atresia used the VSB and had previous experience with a bone conducting hearing device. The benefit from the VSB was evaluated by questionnaires concerning acceptance of hearing aids, handling, listening effort, behavior, quality of life, and the duration of daily use and compared to the experience with the bone conducting hearing device. In addition, to quantify the benefit from the VSB use, audiological assessment (pure-tone audiometry via free field testing, speech audiometry, and localization test) was performed with and without VSB. The questionnaires and audiological test results were compared pairwise. According to all questionnaire areas, children benefited significantly more from the VSB compared to bone conducting hearing device (ps <.05). The most important finding was a significant increase in daily use from 2 h for the bone conducting hearing device to 10 h for the VSB. Children performed significantly better with the VSB than without it in the audiological assessment. Children with unilateral aural atresia benefited significantly more from the VSB compared to a conventional bone conducting hearing device according to the parents' questionnaires and yielded better results in the audiometry and localization test with the VSB than without it.