置换部分听骨赝复物后对人耳听力恢复的影响

目的探讨听骨部分置换术中不同的置换方式对患者术后听力的影响。方法根据人体正常右耳CT扫描结果,用自编程序将CT扫描数值化并导入PATRAN重建人耳三维有限元模型,对其进行声音传导动力分析,并与试验数据对比。结果通过正常人耳结构动力响应分析结果与实验数据吻合,验证了模型的正确性;在0.1～10 kHz频率下保留部分锤骨柄置换人工听骨比不保留锤骨柄术后听力恢复更好,听力恢复值在11.56～28.91 dB之间;保留部分锤骨柄时鼓膜处的最大应力值比不保留锤骨柄时更小;厚2.0 mm软骨片在0.1～0.6 kHz,2～10 kHz频率上听力恢复较好;厚0.1 mm软骨片在0.6～2 kHz频率上听力恢复较好。结论在听骨部分置换术中,保留部分锤骨柄比不保留锤骨柄听力恢复效果更好;鼓膜与人工听骨的接触面上垫置的软骨片厚度在0.1～2.0 mm之间对人耳听力恢复效果较好。     

人工听骨不同接入方式对耳结构动力响应的影响

目的 研究人工听骨接入方式对听力恢复的影响。方法 通过CT扫描技术,结合自编C＋＋程序读取CT数据中体单元建立人耳结构几何模型,将几何模型导入PATRAN中建立有限元数值模型。采用频率响应方法对耳结构模型进行流固耦合计算,同时分析人工听骨不同接入方式及接入位置对耳结构声音传导的影响。结果 通过对正常人耳的动力响应分析,得到数值模型中计算出的鼓膜凸与镫骨底板振幅与试验数据吻合,验证本文模型的正确性。结论接在鼓膜凸的位置其动力响应最好,镫骨振幅高于其他连接方式。即人工听骨接在鼓膜凸的位置比较吻合人耳的生理功能,其重建听力效果更好。     

同种异体软骨听骨赝复物与羟基磷灰石听骨赝复物修复听骨链损伤的比较

背景:以往多采用同种异体软骨听骨赝复物作为听骨链重建的材料,近年来羟基磷灰石听骨赝复物已广泛地应用于鼓室成形术的临床工作中。而目前有关两种听骨赝复物在鼓室成形术、听骨链重建中的临床疗效比较尚无相关报道。目的:比较两种听骨赝复物的临床疗效,旨在探求更适宜临床推广应用的听骨赝复物。方法:将进行鼓室成形、听骨链重建术的慢性中耳炎患者60例分为同种异体软骨听骨赝复物组和羟基磷灰石听骨赝复物组,两组在术前、术后进行纯音听力测试,以语言频率区(0.5,1.0,2.0kHz)听阈气导平均值及气骨导差平均值统计,取最后一次(至少6个月以后)复查听力结果作为组间对比指标之一。同时记录两组病例移植鼓膜愈合情况,即移植鼓膜良好上皮化的时间,两组听骨赝复物的脱出率。结果与结论:在相同病变类型、相同术式患者中,同种异体软骨听骨赝复物与羟基磷灰石听骨赝复物植入后听力恢复水平方面差异不显著(P0.05),术后移植鼓膜愈合情况方面差异不显著(P0.05)。在相同病变类型、相同术式的术后赝复物脱出率均为0。提示同种异体软骨听骨赝复物与羟基磷灰石听骨赝复物在慢性中耳炎患者行鼓室成形、听骨链重建术中的临床疗效相似。     

细菌生物膜厚度和面积对人耳听力的影响

依据临床健康志愿者右耳的CT扫描结果,将CT扫描数据数值化导入PATRAN软件进行人耳三维有限元模型的重建,并用NASTRAN软件对该模型进行频率响应分析。通过对正常人耳结构进行频率响应分析得出数据与实验数据吻合,验证了模型的正确性。结合临床中耳炎病症实际情况,研究细菌生物膜的成长阶段对人耳听力的影响。结果表明：在不同声压相同的频率段,细菌生物膜的厚度变化对人耳听力的影响是相同的。在相同声压不同频率段,细菌生物膜的厚度增加会引起镫骨振幅和速度降低,在较低频率段镫骨振幅和速度下降幅度较大,下降的最大值为1.64 dB;在较高频率段镫骨振幅和速度下降幅度较小,下降的最大值为1.04 dB。在不同声压作用下,在相同的频率段细菌生物膜的面积增加会引起镫骨振幅和速度降低。在100～1 000 Hz频率段镫骨振幅和速度的下降幅度较小,下降的最大值为0.18 dB。在1000～10 000 Hz频率段镫骨振幅和速度的下降幅度较大,下降的最大值为2.26 dB。细菌生物膜厚度或面积增加都会使人耳听力下降,厚度增加在低频时比高频时下降更多,而面积增加则刚好相反。     

中耳病变及人工镫骨形体研究

目的 研究听骨韧带、肌腱硬化和切除以及人工镫骨置换对声音传导的影响。方法 基于CT扫描数据,通过自编C＋＋程序读取CT数据中体单元建立人耳结构几何模型,将几何模型导入PATRAN中赋予材料参数、设置关节接触面以及相应其他边界条件生成数值模型。结果 利用本文人耳数值模型进行正常耳和病变耳的谐响应分析,得到正常耳和病变耳镫骨底板和鼓膜凸的振幅变化规律。并由此构建了套型人工镫骨。结论 正常耳的模拟结果与实验测试结果吻合,证明了本模型准确性,可以模拟人传声功能。本模型模拟病变耳的计算结果可以从力学角度解释病变对声音传导的影响,为病变耳治疗提供参考。本文的套型人工镫骨较我国临床用的环型人工镫骨更吻合人耳的生理功能,其重建听力效果更好。     

听骨检测实验装置

目的：探讨对人工听骨赝复物传音功能进行评价的客观方法。方法：用两块圆形的弹性膜来分别代替鼓膜和卵圆窗，两膜之间放置人工听骨，在人工外耳道侧给予纯音刺激，同时记录其声强，在卵圆窗膜处用激光测振仪测量卵圆窗膜的振动速度，通过比较振动速度的大小来比较人工听骨的传音特性。结果：模型“感觉阈曲线”和正常人听阈曲线对比，两者走势基本相同。结论：中耳机械模型是检验人工听骨传音特性并进行人工听骨赝复物客观评价理想的工具之一。     

中耳炎病变对圆窗激振听力补偿影响的数值分析

为了研究中耳炎引起的鼓膜病变和听小骨腐蚀对圆窗激振式人工中耳听力补偿的影响,利用计算机断层扫描(CT)技术和逆向成型技术建立了包含耳蜗不对称结构的人耳有限元模型,并与相关实验数据对比,验证模型的可靠性。基于该模型,通过改变相应的组织结构,分别模拟中耳炎引起的鼓膜病变和听小骨腐蚀,并对比相应的基底膜特征频率处的位移响应,来研究中耳炎病变对圆窗激振听力补偿效果的影响。结果表明:鼓膜增厚和鼓膜硬化主要恶化圆窗激振低频段的听力补偿效果;鼓膜穿孔和未导致听骨链脱离的听小骨腐蚀,对圆窗激振的影响较小;不同于前述病变类型的影响,听小骨腐蚀导致听骨链脱离时,将提高圆窗激振低频段的听力补偿性能。因此,设计圆窗激振作动器时,应综合考虑中耳炎病变对其听力补偿性能的影响,特别是鼓膜增厚及硬化对其低频段性能的恶化,适当增大其低频段的输出增益,确保其术后的实际听力补偿性能。     

自体软骨和Tos改良联合进路鼓室成形术在中耳手术中的应用

目的 探讨自体软骨和Tos改良联合进路鼓室成形术在中耳手术中的临床应用.方法 对23例胆脂瘤型中耳炎用Tos改良的联合进路行鼓室成形术进行治疗,去除的上鼓室外侧壁和后鼓室外侧壁,用耳屏软骨重建,再视镫骨状况,同时用部分听小骨赝复体(PORP)或全听小骨赝复体(TORP)行Ⅲ型听骨链重建.所有病例随访3至5年.结果 所有23例患者在术后4至6周获得干耳,鼓膜愈合好,形态正常.软骨重建的上鼓室和后鼓室外侧壁无1例内陷.术后1年纯音听力,言语频率(500、1000、2000、3000、4000Hz)气导较术前提高≥30dB者8例(34.78%),20～29dB者9例(39.13%),10～19dB者4例(17.39%),听力无改善者2例(8.69%).随访3年,听力稳定,5年内无胆脂瘤复发.结论 Tos改良的联合进路鼓室成形术是胆脂瘤型中耳炎手术治疗的好方法,既彻底清除病灶,又保留外耳道后壁完整,术后能获得良好的听力.Tos改良术因去除了上鼓室和后鼓室外侧壁,用软骨重建可有效的防止新生鼓膜的内陷和继发胆脂瘤形成.     

中耳畸形对圆窗激振听力补偿性能影响的数值分析

目的研究中耳畸形对圆窗激振性能的影响,为圆窗激振式人工中耳的优化提供理论支持。方法构建包含两腔不对称的非螺旋耳蜗的人耳有限元模型,并与实验数据进行对比,验证模型的可靠性。基于该模型,通过改变相应组织的材料属性,分别模拟听骨链固定、听骨链融合、听小骨缺损3种中耳畸形对圆窗激振性能的影响。结果中耳畸形主要影响圆窗激振式人工中耳的低频性能,听骨链固定和听骨链融合对圆窗激振起恶化效果。镫骨固定对圆窗激振补偿性能的影响最大,恶化量高达47.93 dB;听小骨缺损可提高圆窗激振的性能,最大改善量为6.24 dB。结论中耳畸形对圆窗激振的低频性能有影响,临床植入圆窗激振式人工中耳时需要针对性地提高其作动器的输出量。     

初始压力与支撑刚度对圆窗激振听力补偿影响的数值研究

为了研究初始压力与支撑刚度对圆窗激振式人工中耳听力补偿性能的影响,建立了包括作动器和支撑体在内的人耳力学有限元模型。该模型基于一位无任何听力损伤病史的成年人的右耳,采用微计算机断层扫描技术(Micro-CT)和逆向成型技术建立而成,并通过与相关实验数据进行对比,验证了模型的可靠性。基于该模型,通过在圆窗上施加不同幅值的初始压力和改变支撑体的支撑刚度,对比分析相应的基底膜动态响应变化,研究其对圆窗激振听力补偿性能的影响。结果表明:初始压力的施加将恶化低频段的听力补偿效果,但提高了圆窗激振中高频段的听力补偿性能;相对于现有临床上所用的筋膜支撑作动器的方法,采用刚度较大的钛合金作为支撑结构,将在全频段提升圆窗激振的听力补偿性能。     

Unilateral auditory cortex ablation in macaques results in a contralateral hearing loss

1. The behavioral audiograms of four Japanese macaques (Macaca fuscata) were assessed before and after unilateral ablation of auditory cortex. The tones were presented via insertion earphones so that each ear could be tested separately. 2. Each animal had a hearing loss in the ear contralateral to the lesion, whereas the ipsilateral ear showed no change in sensitivity. The hearing loss initially appeared as a large shift in thresholds followed by rapid but incomplete recovery during the first 3-5 wk after surgery. The initial hearing loss ranged as high as 68 dB at some frequencies, although thresholds at other frequencies were occasionally unchanged. A threshold shift could be demonstrated with broadband noise as well as with tones. Although thresholds for some tones returned to normal within a few weeks, most were still elevated 16 wk after surgery when testing was discontinued. The largest long-term hearing losses occurred at frequencies from 4 to 25 kHz. 3. Analysis of the animals' psychophysical functions suggested that the hearing loss resembled a sensory deficit, as opposed to a nonsensory deficit in attention or vigilance. 4. Testing with binaural stimuli indicated that the hearing loss could best be described as a contralateral "ear" deficit, as opposed to a contralateral "auditory field" deficit. 5. It is suggested that a similar hearing loss occurs in humans after unilateral damage to auditory cortex.     

Effect of bilateral auditory cortex lesions on absolute thresholds in Japanese macaques

1. The behavioral audiograms of four Japanese macaques (Macaca fuscata) were assessed before and after receiving two-stage bilateral lesions of auditory cortex. Thresholds were assessed for each ear with the use of insertion earphones. 2. The bilateral lesions resulted in a large initial hearing loss followed by partial recovery that left the animals with a permanent hearing loss in both ears. 3. The initial hearing loss consisted of a total insensitivity to sound in the ear contralateral to the second lesion with limited hearing in the other ear. However, the animal with the most complete lesion was initially unable to hear sound in either ear. Broadband noise was often more effective in eliciting a behavioral response than tones. 4. Partial recovery occurred in all animals and was observed as early as the first week after surgery. Most of this recovery occurred during the first 3-7 wk after surgery. This rapid phase of recovery was sometimes followed by a more gradual phase although thresholds were still elevated after 94 wk. 5. The permanent hearing loss, which averaged from 30 to 44 dB, was not constant across frequency. Threshold shifts were smallest at 63 Hz and progressively increased with frequency to a maximum loss from 8 to 25 kHz with slightly less loss at 32 kHz. 6. Analysis of the psychophysical functions and threshold stability gave no indication of any nonsensory deficits in attention or vigilance. 7. These results, taken with those of previous experiments, indicate that each hemisphere is primarily involved in the detection of sound in the contralateral ear and secondarily involved in detection in the ipsilateral ear. This arrangement differs from that seen in sound localization where each hemisphere is involved with the contralateral hemifield as opposed to the contralateral ear. Thus it appears that the functional organization of auditory cortex for sound localization is different from that for the detection and identification of sound itself.     

典型中耳病变对圆窗激振听力补偿性能影响的数值分析

目的研究典型中耳病变对圆窗激振听力补偿效果的影响,为圆窗激振式人工中耳的优化设计提供参考。方法利用CT扫描和逆向成型技术建立包括中耳和耳蜗的有限元模型,并验证模型的可靠性。再基于该模型,通过改变相应组织的材料属性,分别模拟镫骨环韧带硬化、镫骨不正常发育和锤骨前韧带硬化3种典型中耳病变。通过对比相应的基底膜响应,分析这3种病变对圆窗激振听力补偿效果的影响。结果镫骨不正常发育主要在高频处降低圆窗激振的效果,镫骨环韧带硬化和锤骨前韧带硬化主要恶化圆窗激振低频段的响应。3种病变中,镫骨环韧带硬化对圆窗激振听力补偿效果影响较大,等效声压的减小量可高达17 d B。结论中耳病变恶化圆窗激振的听力补偿效果,且恶化量较大,故在设计圆窗激振式人工中耳时需要针对性地提高其作动器的输出量。     

Investigation of hearing loss in patients with acute brucellosis by standard and high-frequency audiometry

This study aimed to determine the effect of acute brucellosis on the auditory system. Forty-two patients with acute brucellosis were evaluated clinically, and with serological and audiological tests, before and after treatment. Hearing threshold averages were calculated at 11 different frequencies (250-8000 Hz) of the auditory airway, and statistical analysis was performed. The average hearing thresholds were > 20 dB, with standard audiometry at 6000-8000 Hz, and < 20 dB at all other frequencies. After treatment, the average auditory threshold decreased to < 20 dB at 6000-8000 Hz (p < 0.0001). Pure-tone hearing thresholds were improved at all frequencies after treatment, with statistically significant differences at all frequencies except 12,000, 14,000 and 16 000 Hz (p < 0.05). There was no permanent hearing loss caused by acute brucellosis, and hearing thresholds were restored after treatment. It was concluded that acute brucellosis affects the auditory system, especially at high frequencies, and that patients with all forms of brucellosis should be evaluated for hearing loss.     

Unilateral hearing losses alter loud sound-induced temporary threshold shifts and efferent effects in the normal-hearing ear

In animals with bilaterally normal hearing, olivocochlear pathways can protect the cochlea from the temporary shifts in hearing sensitivity (temporary threshold shifts; TTSs) caused by short-duration intense loud sounds. The crossed olivocochlear pathway provides protection during binaural loud sound, and uncrossed pathways protect when monaural or binaural loud sounds occur in noise backgrounds. Here I demonstrate that when there is a chronic unilateral hearing loss, effects of loud sounds, and efferent effects on loud sound, in the normal-hearing ear differ markedly from normal. Three categories of test animals with unilateral hearing loss were tested for effects at the normal-hearing ear. In all categories a monaural loud tone to the normal-hearing ear produced lower-than-normal TTSs, apparently because of a tonic re-setting of that ear's susceptibility to loud sound. Second, in the two test categories in which the hearing-loss ear was only partly damaged, binaural loud sound exacerbated TTSs in the normal-hearing ear because it caused threshold shifts that were a combination of "pure" TTSs and uncrossed efferent suppression of cochlear sensitivity. (In normal cats, this binaural tone results in crossed olivocochlear protection that reduces TTS.) Binaural loud sound did not produce such uncrossed efferent effects in the test category in which the nontest ear had suffered total hearing loss, suggesting that this uncrossed efferent effect required binaural input to the CNS. It is noteworthy that, in the absence of this uncrossed efferent suppression, the pure loud sound-alone induced TTSs after binaural exposure were low. Thus in the absence of any efferent effect, the normal-hearing cochlea had a reduced susceptibility to loud tone-induced damage. Finally, the results suggest that, with respect to cochlear actions at high sound levels, uncrossed and crossed efferent pathways may exert different effects at the one type of receptor cell.     

Computer assisted optimization of an electromagnetic transducer design for implantable hearing aids

A simple, contactless electromagnetic transducer design for implantable hearing aids is investigated. It consists of a coil and a permanent magnet, both of which are intended for implantation in the middle ear. The transducer is modeled and optimized using computer simulations, followed by experimental verification. It is shown that the proposed transducer design can, because of its size and geometry, allow implantation through the external auditory canal, and provide a sufficiently high acoustic output corresponding to approximately 120 dB sound pressure level. It can be optimized to be tolerant of radial displacements between coil and magnet of up to 1 mm.