[Aerodynamic study of the low-resistance Groningen button in voice prosthesis]

To study the aerodynamic characteristics of low-resistance Groningen voice prosthesis for total laryngectomees and the related clinical significance.

Three aerodynamic parameters were measured in 24 laryngectomees implanted with low-resistance Groningen voice prosthesis: the sound pressure level (SPL), intratracheal pressure (pressure) and airflow rate (flowrate). Among them, 6 cases were initially implanted with other prosthesis which was replaced by the Groningen buttons later. The parameters were measured for both old and new prosthesis. The relationship between the variables were computed with means of Pearson' s product-moment correlations.

The parameters were measured repeatedly among all cases, 180 group data were collected. Screening test showed that the median of sound pressure level, intratracheal pressure and airflow rate are respectively 88.0 dB, 73.6 cm H2O (1 cm H2O = 0.098 kPa) and 123.2 ml/s. Thirty times measurement of patients phonation showed that the correlation between SPL and pressure was not significant (r = -0.058, P > 0.05). The relationship between flow rate and SPL was not significant(r = -0.119, P > 0.05). The correlation between pressure and flow rate was significant(r = 0.699, P < 0.05). CONCLUSIONS When pseudoglottis vibration is produced by sub pseudoglottis air flow, pseudoglottis vibration and voice loudness can not be increased by continuous air flow.