Previous animal study revealed that post-implantation electrical detection levels significantly declined within days. The impact of cochlear implant (CI) insertion on human auditory pathway in terms of impedance and electrically evoked compound action potential (ECAP) variation within hours after surgery remains unclear, since at this time frequency mapping can only commence weeks after implant...

The influence of functional hair cells on electrical stimulation of the auditory nerve is an important issue as individuals with significant residual hearing are now cochlear implant candidates. Previous work has shown that chemical deafening during the course of acute experiments changes the auditory nerve's responses to electrical stimulation [Third Quarterly Progress Report, NIH contract N01...

HYPOTHESIS Limiting spatial overlap between electrical stimulation (ES) and acoustical stimulation (AS) in the cochlea reduces the effects of AS on electrically evoked auditory nerve activity. BACKGROUND Some hybrid cochlear implant systems have a regular array, whereas others have short arrays that spatially segregate ES from AS. AS settings in hybrid implants may also affect electroacoustic...

The effects of ultrasonic impact treatment (UIT) and UIT with equal channel angular pressing (ECAP), on the microstructure Cu37Zn alloy are studied at ambient cryogenic temperatures. With decreasing process temperature, highly twinned areas submicro/nano-scale thickness/spacing, together dislocation tangles/cells, introduced in alloy. Direct microscopy observation stored energy release analysis...

After Severe Plastic Deformation (SPD), the strength of Armco iron sharply increases with number Equal-Channel Angular Pressing (ECAP) passes. So, ultimate tensile stress (UTS) reached up to 800 MPa after eight passes, reflecting an increment around four times than as-received material strength. The original grain size annealed about 70 ?m also experimented drastic changes ECAP, reaching sizes ...

Abstract. The increasing share and expansion of miniature devices requires the mastery parts production, including metal parts. In microforming, due to conditions mechanical similarity, aim is use materials with smallest grain. Ultra-fine-grained metals (UFG) fulfill this requirement. These can be obtained, inter alia, in SPD processes such as ECAP. work uses extension based on ECAP additional ...

Ternary Mg–Y–Zn alloys have attracted considerable attention due to their excellent mechanical properties and unique microstructures. Microstructural variation and the resulting mechanical properties can be affected by various processing routes, particularly those involving severe plastic deformation of a cast billet. The following approach was used in this work to perform a comparative study: ...