EAS-Combined electric and acoustic stimulation

Abstract

Electric-acoustic stimulation (EAS) is a special treatment modality for those patients who are profoundly deaf in the high-frequency (HF) region and retain usable hearing in the low-frequency (LF) region. Combining the electric stimulation with cochlear implant (CI) in the HF and acoustic amplification of residual hearing using a conventional hearing aid (HA) in the LF region defines EAS. The EAS concept was first proposed by C. von Ilberg from Frankfurt, Germany in the year 1997. In association with MED-EL, all the necessary safety studies were performed in non-human subjects before the first patient received it in 1997. In association with MED-EL, all the necessary safety studies were performed in non-human subjects before the first patient received it in 1999. For the patient to successfully use the EAS concept, the residual hearing needs to be preserved to a high extent and for several years. This requires a highly flexible electrode array in safeguarding the intra-cochlear structures during and after the CI electrode array insertion. Combining the HA unit with the audio processor unit of the CI was necessary for the convenient wearing of the unified audio processor. Fitting of the unified audio processor is another important factor that contributes to the overall success of the EAS treatment. The key translational research efforts at MED-EL were on the development of flexible electrodes, a unified audio processor, innovations in the fitting process, intra-operative monitoring of cochlear health during electrode insertion, pre-operative soft-ware tool to evaluate the cochlear size and electrode selection and some new innovations tried within EAS topic. This article covers the milestones of translational research from the first concept to the widespread clinical use of EAS.

Graphical Abstract

Chinese abstract

对于那些在高频（HF）区域严重失聪并在低频（LF）区域保持可用听力的患者, 电声刺激（EAS）是一种特殊的治疗方式。对于HF, 采用电刺激；对于LF区域, 采用常规助听器（HA）进行残余听力的声学放大。两者结合即可形成EAS。 EAS概念最早是由德国法兰克福的冯·伊尔伯格（von Ilberg）教授于1997年提出的。与MED-EL联合, 所有必要的安全性研究都是在非人类受试对象中进行的。后来, 于1999年安全性研究被用于人类。为使患者成功使用EAS概念, 应始终保留LF残余听力。这需要高度灵活的电极阵列, 以便在CI电极阵列插入期间和之后保护耳蜗内结构。为了方便使用统一音频处理器, 必须将HA单元与CI的音频处理器单元组合在一起。统一音频处理器的安装是有助于EAS治疗总体成功的另一个重要因素。本章介绍了MED-EL在柔性电极、统一音频处理器的开发和装配过程中的创新, 电极插入时术中对耳蜗健康的监测, 术前评估耳蜗大小电极选择的工具, 以及EAS主题中尝试的一些创新。

Keywords:

• Electric-acoustic stimulation
• flexible electrode
• unified audio processor
• hearing preservation
• Electro-cochleography

Acknowledgments

The authors would gratefully like to acknowledge the key contributors to the development of the subject matter. Their contributions are outlined in this article. The authors further acknowledge Marek Polak from MED-EL for his valuable input and comments during several rounds of review meetings that contributed to the final version of this article.

Disclosure statement

This article is sponsored by MED-EL and has not undergone the regular peer-review process of Acta Oto-Laryngologica. Both the authors are affiliated with MED-EL.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.