The Rez-1 Adult Language Clinical Application Of Cochlear Implant Recipients And Related Basic Research,

Effects of stimulation mode,level and location on forward-masked excitation patterns in REZ-1 cochlear implant patientsObjective To evaluate electrode interaction in REZ-1 cochlear implantees with respect of stimulation mode,level,location, and to compare the spatial spread width of neural excitation between patients with Nucleus-22 cochlear implant. Methods With standard assessment table and standard testing program,20 postlingual hearing-impaired adults with REZ-1 cochlear implants and 10 postlingual hearing-impaired adults with Nucleus-22 cochlear implants were tested. In the present study, forward-masked excitation patterns were measured in the 30 cochlear implant patients as functions of stimulation mode, level and location within the cochlea. All stimuli were 500 pulses-per-second biphasic pulse trains. Masker stimuli were 200ms in duration; the bi-polar configuration was varied from narrow (BP+1) to wide (BP+17), depending on the test condition. Probe stimuli were 20 ms in duration and masker-probe delay was 5 ms; the probe configuration was fixed at BP+1. Results As the distance between the active and return electrodes in a bi-polar pair was increased, the excitation pattern broadened within the cochlea. When the distance between active and return electrodes was sufficiently wide, two peaks were often observed in the excitation pattern, comparable to non-overlapping electric fields produced by widely separated dipoles. Analyses of the normalized data showed little effect of stimulation level on the shape of the excitation pattern. Analyses of the area under the normalized curve showed that there was no significant difference between the two cochlear implants. Conclusions Forward-masked excitation patterns would be effected by stimulation mode in cochlear implantees with REZ-1 cochlear implants; Forward masking patterns are a reliable measure of channel interaction.Part Two Clinical effectiveness of REZ-1 multi-channel unilateral cochlear implants for profoundly postlingual deaf adultsObjective To investigate the development of hearing and speech rehabilitation of severe-to-profound hearing-impaired adults, each of them received a REZ-1 cochlear implant that was made in China. And the security and stability of the new cochlear implant was also studied. Methods With standard assessment table and standard testing program,48 postlingual hearing-impaired adults aged from 18 to 62 years (mean age at implantation,35.0 years) who were operated in 5 clinical centers from June 2009 to November 2009 were tested and scored at different periods for their hearing and speech perception rehabilitation. Sound field audio-metry were performed at the same time. Quality of life at the twelfth month after cochlear implantation was conducted for each implantees Complications of the procedure and audiological outcome with this new implant were also analyzed. Results All the patients'average audiometry thresholds decreased gradually during the postoperative following-up. Preoperative average threshold was 107. 1dB, after 12 months training, the average threshold was decreased to (39.0±5.4) dB. Preoperative hearing and speaking ability scores were almost 0 with the exception of the environmental sounds (0.97±1.70), after 12 months training the average scores were increased significantly (59.55～82.06). There was a statistic significant difference between pre-and post-implantation whether in subjective audiometry thresholds or hearing ability and speech perception (P<0.01). REZ-1 cochlear implantation is a effective intervention in the postlingually deaf adults. All the adverse events did not statistically correlate with the cochlear implant. Conclusions REZ-1 cochlear implantation could improve hearing and speech perception ability of adults with postlingual severe-to-profound hearing loss via appropriate postoperative rehabilitation and it can be taken as an effective and safe treatment for postlingual deaf adults.