Department of Otolaryngology and Institute of Audioneurotechnology (VIANNA), Hannover Medical School, Hannover, Germany.
Linköping University, Department of Biomedical and Clinical Sciences, Linköping, Sweden.
Hear Res. 2022 Aug;421:108369. doi: 10.1016/j.heares.2021.108369. Epub 2021 Oct 19.
The output performance of a novel semi-implantable transcutaneous bone conduction device was compared to an established percutaneous bone-anchored hearing system device using cadaver heads. The influence of actuator position, tissue growth below the actuator and mounting it on the surface or in a flattened bone bed on the performance of the implanted actuator was investigated.
The percutaneous and the new transcutaneous device were sequentially implanted at two sites in five human cadaver heads: 55 mm superior-posterior to the ear canal opening (position A) and, closer to the cochlea, about 20 mm inferior-posterior to the ear canal opening behind the pinna on the mastoid (position B). The ipsi- and contralateral cochlear promontory (CP) velocity magnitude responses to percutaneous and transcutaneous stimulation were measured using laser Doppler vibrometry. In addition, the CP vibration of the transcutaneous device placed directly on the skull bone surface was compared with the placement in a flattened bone bed at a depth of about 3 mm. Finally, the influence of placing a thin silicone interposition layer under the implanted transducer was also explored.
The percutaneous device provided about an 11 dB higher average CP vibration level than the transcutaneous device at frequencies between 0.5 and 10 kHz. The ipsilateral CP vibration responses with stimulations at position B were on average 13 dB higher compared to stimulation at position A. The placement of the transcutaneous transducer at position B provided similar or higher average vibration magnitudes than the percutaneous transducer at position A. The 3 mm deep flattened bone bed had no significant effects on the output performance. Placing a thin silicone layer under the transcutaneous transducer had no significant influence on the output of the transcutaneous device.
Our results using the CP vibration responses show that at frequencies above 500 Hz the new transcutaneous device at position B provides similar output levels as the percutaneous device at position A. The results also indicated that neither a bone bed for the placement of the transcutaneous transducer nor a simulated tissue growth between the actuator and the bone affect the output performance of the device.
使用尸体头颅比较新型半植入式经皮骨导装置和已建立的经皮骨锚式听力系统装置的输出性能。研究了在植入式激励器下方的激励器位置、组织生长以及将其安装在表面或扁平骨床上对激励器性能的影响。
将经皮骨和新型经皮骨导装置顺序植入五具人尸头颅的两个位置：耳道口后上方 55mm（位置 A），以及更靠近耳蜗，耳道口后下方约 20mm 处，在耳屏后乳突上（位置 B）。使用激光多普勒测振仪测量经皮和经皮刺激时同侧耳蜗鼓岬（CP）速度幅度响应。此外，还比较了直接放置在颅骨表面的经皮骨导装置的 CP 振动与放置在深度约 3mm 的扁平骨床中的 CP 振动。最后，还探讨了在植入换能器下方放置薄硅胶间隔层的影响。
在 0.5 至 10kHz 之间，经皮装置提供的 CP 振动平均水平比经皮装置高约 11dB。与刺激位置 A 相比，刺激位置 B 时的同侧 CP 振动响应平均高 13dB。经皮骨导装置在位置 B 的放置提供了类似于或高于位置 A 时经皮骨导装置的平均振动幅度。3mm 深的扁平骨床对输出性能没有显著影响。在经皮骨导装置下方放置薄硅胶层对其输出没有显著影响。
我们使用 CP 振动响应的结果表明，在高于 500Hz 的频率下，位置 B 的新型经皮骨导装置提供的输出水平与位置 A 的经皮骨导装置相似。结果还表明，无论是为放置经皮骨导换能器而放置的骨床还是在激励器和骨骼之间模拟的组织生长都不会影响装置的输出性能。
