Implantable Hearing Aids Research Articles

2B03 超磁歪素子を利用した埋め込み型骨導補聴器の開発 : 実使用に近い状態における補聴性能評価(OS4-1:臨床バイオメカニクスと医療デバイス(1))

2B03 超磁歪素子を利用した埋め込み型骨導補聴器の開発 : 実使用に近い状態における補聴性能評価(OS4-1:臨床バイオメカニクスと医療デバイス(1))

Influence of the middle ear anatomy on the performance of a membrane sensor in the incudostapedial joint gap

There is a great demand for implantable microphones for future generations of implantable hearing aids, especially Cochlea Implants.An implantable middle ear microphone based on a piezoelectric membrane sensor for insertion into the incudostapedial gap is investigated. The sensor is designed to measure the sound-induced forces acting on the center of the membrane. The sensor mechanically couples to the adjacent ossicles via two contact areas, the sensor membrane and the sensor housing. The sensing element is a piezoelectric single crystal bonded on a titanium membrane. The sensor allows a minimally invasive and reversible implantation without removal of ossicles and without additional sensor fixation in the tympanic cavity.This study investigates the implantable microphone sensor and its implantation concept. It intends to quantify the influence of the sensor's insertion position on the achievable microphone sensitivity. The investigation considers anatomical and pathological variations of the middle ear geometry and its space limitations.Temporal bone experiments on a laboratory model show that anatomical and pathological variations of the middle ear geometry can prevent the sensor from being placed optimally within the incudostapedial joint. Beyond scattering of transfer functions due to anatomic variations of individual middle ears there is the impact of variations in the sensor position within the ossicular chain that has a considerable effect on the transfer characteristics of the middle ear microphone. The centering of the sensor between incus and stapes, the direction of insertion (membrane to stapes or to incus) and the effect of additional contact points with surrounding anatomic structures affect the signal yield of the implanted sensor. The presence of additional contact points has a considerably impact on the sensitivity, yet the microphone sensitivity is quite robust against small changes in the positioning of the incus on the sensor. Signal losses can be avoided by adjusting the position of the sensor within the joint.The findings allow the development of an improved surgical insertion technique to ensure maximally achievable signal yield of the membrane sensor in the ISJ and provides valuable knowledge for a future design considerations including sensor miniaturization and geometry.Measurements of the implanted sensor in temporal bone specimens showed a microphone sensitivity in the order of 1 mV/Pa.This article is part of a Special Issue entitled “MEMRO 2012”.

A Music Appreciation Training Program Developed for Clinical Application with Cochlear Implant Recipients and Hearing Aid Users

A clinically focused music training program was developed, aimed at enhancing a listener's music appreciation levels. The program was pilot tested on 18 adult cochlear implant (CI) recipients and 13 adult hearing aid (HA) users, with each device group divided into a control and training group. The training groups were asked to use the program four times a week for 10 weeks. Both the training and control groups were assessed on their quality ratings of the musical stimuli as well as tests of instrument and style identification and pitch ranking, before and after the “training” period. In addition to examining the potential benefit of training on appreciation, we examined the relationship between appreciation and perceptual accuracy. The results showed that the training program improved CI recipients' quality ratings for ensemble stimuli, as well as both CI and HA users' subjective ratings of their music perception skills; however, there were no significant improvements for CI or HA users on the timbre identification or pitch ranking tasks. This suggests that CI recipients' music enjoyment can be improved with training, independent of perceptual accuracy. The pretraining baseline scores highlight that music appreciation and perception are two different issues, that everyday experience with the device does not improve music listening, and that music appreciation is still a significant issue for both CI and HA users.

Concept and evaluation of an endaurally insertable middle-ear implant

A concept for a partially implantable hearing device, for which the power supply and signal transmission are provided by an optical transmission path, is evaluated. The actuator is designed to fit into the round-window niche and to couple directly to the round-window membrane. Implantable hearing aids can be a suitable solution in the case of severe hearing loss, where conventional hearing aids often fail. However, the surgical effort for an implantation is comparatively high. Therefore, the objective of our work was to provide a hearing system which combines reliable coupling to the auditory system with an easy implantation technique. The actuator was designed as a piezoelectric thin-film cantilever. The optical transmission path was realised using an infrared light-emitting diode combined with an active receiver circuit. For a voltage of 1V, the unloaded actuator presents displacement amplitudes of 1μm up to a stimulus frequency of 25kHz and forces up to 0.2mN. Proportionally larger forces can be achieved by stacking single actuators. The overall transmission loss from the electrical input of the light-emitting diode driver to the mechanical output of the unloaded actuator was less than 25dB at 1kHz and maximum output.

Ethnic Disparity in Skin Complications following Bone-Anchored Hearing Aid Implantation

Sound processor loading after implantation of a bone-anchored hearing aid is often delayed by skin-site complications. This study examined the frequency of skin-site complications in various ethnic groups and determined factors that may lead to higher rates of skin-site complications resulting in delayed processor loading. Adult, English-speaking patients who underwent implantation of a bone-anchored hearing aid between 2007 and 2010 were reviewed. Demographic data including ethnicity, tobacco use, diabetes mellitus, immunosuppression, and long-term steroid use were determined. Major and minor skin-site complications and the time to processor loading were recorded. The mean time to processor loading was 9.5 weeks, and the mean follow-up time was 23 months. There were no cases of osseointegration failure. African American patients had a significantly higher rate of major skin-site complications (p < 0.005) and a longer time to processor loading (mean, 17.6 weeks; p < 0.05) than the other ethnic groups. There was no significant difference in minor skin complication rates. There was no correlation between diabetes mellitus, long-term immunosuppression, or tobacco use and skin-site complications. Skin complications can delay processor loading following implantation of a bone-anchored hearing aid. There is a higher rate of major skin-site complications in African American patients, and these often delay processor loading. The risk of skin-site complications is not correlated with smoking, diabetes mellitus, or immunosuppression. An increased risk of skin-site complications is an important consideration for preoperative counseling.

Bone-anchored hearing aids and chronic pain: a long-term complication and a cause for elective implant removal

To report a case series of elective removal of bone-anchored hearing aid implants, and reasons for removal. Retrospective review of a prospectively collected database. Two tertiary referral centres in the Manchester area: Manchester Royal Infirmary and Salford Royal University Hospital. A series of 499 adults and children who had undergone a total of 602 implant insertions (1984-2008). Implant removal rates, and reasons. Twenty-seven of the 602 implants (4.5 per cent) required removal. Of these, 12 were due to pain (2.0 per cent), seven to persistent infection (1.2 per cent), three to failure of osseointegration (0.5 per cent), three to trauma (0.5 per cent) and two to other reasons (0.4 per cent). Chronic implant site pain represents the main reason why implants are removed electively, and affects 2 per cent of all implants. This complication has important medico-legal implications and should be discussed when obtaining informed consent for implantation.

A modified weighted overlap and add-based spectral subtraction method

The Weighted Overlap and Add (WOLA) method is an optimization of frequency modulated DFT filter banks. However, the decrement in frequency resolution of speech signal caused by WOLA leads to noise estimation error. In this study, a speech power compression and gain compensation method was proposed to solve the low-resolution problem from the WOLA process. Finally, a multi-band spectral subtraction method was developed by combining the WOLA and the spectral subtraction algorithm in frequency domain. The noise reduction degrees were determined by the individual Signal-to-Noise Ratios (SNRs) in each frequency bands. Objective evaluation of the proposed noise reduction method was performed based on Itakura-Saito Distortion Measure under different types of noise. Statistical results showed that this proposed method could improve noisy speech by 5 dB SNR with little distortion. This noise reduction method has an advantage on low computation load, real-time processing and good performance on noise reduction. So this method can be implemented in embedded devices, e.g. hearing aid and cochlear implants. # This work is supported by National Natural Science Foundation of China (11104316). and Shanghai Natural Science Foundation (11ZR1446000).

Re-implantation of the Rion E-type semi-implantable hearing aid: Status of long-term use and hearing outcomes in eight patients

The Rion Ehime (E)-type implantable hearing aid (IHA) is the first middle ear implant. We implanted 39 IHAs into 39 patients, and found that the IHA functioned well for >15 years. So far, 28 IHAs have been removed because they stopped functioning. An IHA was re-implanted in 8 of the 28 cases. This study assessed the status of long-term use and hearing outcomes in the eight patients to confirm the safety and advantages of repeated implant operation. Current status and operational findings of the eight re-implantees and hearing outcomes were investigated by reviewing the patients' records. Four of the eight cases still use their devices; all four originally suffered from cholesteatoma. In the remaining four cases, the devices stopped functioning 2.4-9.4 years after re-implantation; they suffered from chronic otitis media. Preoperative air and bone conduction hearing and IHA hearing 3 months after the first implantation were 61.1±13.1dB, 40.6±11.3dB, and 26.9±10.5dB, respectively (n=8). At the time of removal, they were 59.4±12.4dB, 40.2±14.2dB, and 42.9±14.9dB, respectively. Three months after re-implantation, they were 60.4±14.6dB, 37.3±14.7dB, and 29.4±13.4dB, respectively. Re-implantation of an IHA is beneficial and safe for patients. As the absence of active inflammation has a crucial effect on the period of use, re-implantation should be judged carefully after deterioration of the initial implant.

Einsatz implantierbarer Hörgeräte am Beispiel der Vibrant Soundbridge

Over the last decade, bone conducting hearing aids, cochlear implants and implantable hearing aids have come to represent additional treatment options in clinical routine-alongside conventional hearing aids-for hearing impaired patients. Thanks to experience gained in recent years with implantable hearing aids and the consistent evaluation of functional results, the original spectrum of indications has been progressively extended. Today, implantable hearing aids are available for the hearing (re)habilitation of various forms of middle ear pathology as well as sensorineural hearing loss within the audiological criteria. With CE certification for children, the treatment of younger patients with implantable hearing aids has also become possible. Using the Vibrant Soundbridge as an example, the function, indications and contraindications of implantable hearing aids are described and the surgical procedure and post-operative care discussed.

Implants cochléaires chez l’adulte

Cochlear implant in adults is a procedure, dedicated to rehabilitate severe to profound hearing loss. Because of technological progresses and their applications for signal strategies, new devices can improve hearing, even in noise conditions. Binaural stimulation, cochlear implant and hearing aid or bilateral cochlear implants are the best opportunities to access to better level of comprehension in all conditions and space localisation. By now minimally invasive surgery is possible to preserve residual hearing and use a double stimulation modality for the same ear: electrical for high frequencies and acoustic for low frequencies. In several conditions, cochlear implant is not possible due to cochlear nerve tumour or major malformations of the inner ear. In these cases, a brainstem implantation can be considered. Clinical data demonstrate that improvement in daily communication, for both cochlear and brainstem implants, is correlated with cerebral activation of auditory cortex.

8H11 埋め込み型骨導補聴器の開発 : 補聴システムの高効率化(OS10 生体の音響・振動に関する諸問題1)

8H11 埋め込み型骨導補聴器の開発 : 補聴システムの高効率化(OS10 生体の音響・振動に関する諸問題1)

Influence of implantable hearing aids and neuroprosthesison music perception.

The identification and discrimination of timbre are essential features of music perception. One dominating parameter within the multidimensional timbre space is the spectral shape of complex sounds. As hearing loss interferes with the perception and enjoyment of music, we approach the individual timbre discrimination skills in individuals with severe to profound hearing loss using a cochlear implant (CI) and normal hearing individuals using a bone-anchored hearing aid (Baha). With a recent developed behavioral test relying on synthetically sounds forming a spectral continuum, the timbre difference was changed adaptively to measure the individual just noticeable difference (JND) in a forced-choice paradigm. To explore the differences in timbre perception abilities caused by the hearing mode, the sound stimuli were varied in their fundamental frequency, thus generating different spectra which are not completely covered by a CI or Baha system. The resulting JNDs demonstrate differences in timbre perception between normal hearing individuals, Baha users, and CI users. Beside the physiological reasons, also technical limitations appear as the main contributing factors.

B115 超磁歪素子を用いた埋め込み型骨導補聴器の開発 : モルモットのABR計測による補聴性能評価(B1-3 聴覚器官のバイオメカニクス)

B115 超磁歪素子を用いた埋め込み型骨導補聴器の開発 : モルモットのABR計測による補聴性能評価(B1-3 聴覚器官のバイオメカニクス)

Konsensus na temat leczenia niedosłuchów przy zastosowaniu implantów zakotwiczonych w kości

In this review authors presented up to date indications for implantable hearing aids. This consensus was elaborated by a team of outstanding polish surgeons and audiologists and was accepted by the board of the Polish Otolaryngologist Society. In this article the indications audiology diagnostic, surgical issues and postoperative management are presented.

Implantierbare Hörgeräte

Strictly speaking, implantable hearing aids are technical systems that process audiological signals and convey these by direct mechanical stimulation of the ossicular chain or cochlea. They have certain benefits over conventional hearing aids in terms of wearing comfort and general acceptance. As current studies lack convincing audiological results, the indications for implantable hearing aids are primarily of medical or cosmetic nature. To date, three systems are available in Germany: Vibrant Soundbridge®, Carina®, and Esteem®. Because the performance of the different implantable and nonimplantable hearing systems together with various surgical procedures are currently undergoing major changes, audiological indications may also develop in the future.

Outcome of the Bone-Anchored Hearing Aid Procedure Without Skin Thinning

To evaluate the outcome of Bone-Anchored Hearing Aid surgery without skin thinning, a test group with direct implantation without such thinning was compared with a control group that underwent the traditional procedure. This was a single-center, prospective clinical trial designed to evaluate a novel approach to Bone-Anchored Hearing Aid implantation. Eligible patients were enrolled consecutively in the test group or selected to be age-matched controls. University Hospital. Eighteen adult patients, suffering from hearing loss, suitable for implantable hearing aid. Single-step surgery was performed on 18 patients under local anesthesia. In 9 of these, a linear incision was made, a hole was punched through the skin above the bone-anchored implant, and a longer abutment (8.5-12 mm) was introduced, whereas the other 9 were subjected to the standard protocol, using a dermatome and skin thinning. All of the patients were followed for 12 months. The test group exhibited good preservation of the tissue, no increasing skin reactions and no adverse events. The time required for this surgery was reduced, as was their healing time. These patients also experienced less numbness and pain in the surrounding area and had an improved cosmetic outcome. MAIN OUTCOME AND CONCLUSION: This clinical trial indicates that introduction of the abutment to the osseointegrated screw directly through the skin, without skin thinning, could be beneficial. This approach had fewer negative effects than the conventional procedure during the 12- month follow-up period.

The Use of Implants in the Management of Tinnitus

Program Description: Tinnitus is one of the most common health problems in the United States and recent figures show that tinnitus is increasing in frequency. As otolaryngologists we are the primary specialty responsible for the diagnosis and management of tinnitus. Despite a great deal of work in this area definitive treatment options for tinnitus are lacking in many cases. Recognizing the importance of this issue the AAO-HNSF and the Martha Entenmann Tinnitus Foundation have endowed a series of miniseminars to address tinnitus. This year’s panel will once again be comprised of national and international experts who will discuss advances in tinnitus treatment using implantable devices. The panel will discuss the use of cochlear implants, implantable hearing aids, and other, more novel, implantable devices. In particular the presenters will focus on the physiologic basis for tinnitus response to electrical or mechanical stimulation, cases series and outcomes, and patient selection for various treatments. The panel will finish by discussing several cases and will provide time for audience questions. Educational Objectives: 1) Better understand treatment options for tinnitus. 2) Better understand the principals that support the use of electrical stimulation in tinnitus. 3) Provide a more clear understanding of the impact of cochlear implants on tinnitus.

Implant survival rate in bone-anchored hearing aid users: long-term results

To investigate the long-term survival rate of bone-anchored hearing aid implants, and to assess the number of patients who stop using their bone-anchored hearing aid. Patients who underwent bone-anchored hearing aid surgery between September 1977 and December 1986 were identified from a prospective database. Data were collected from patient records. During the study period, 143 patients were fitted with a bone-anchored hearing aid. Records from 132 patients were found, with a mean follow up of nine years. A total of 150 implants were installed in these patients. A total of 41 implants (27 per cent) were lost during follow up: 17 lost osseointegration, 16 were removed and eight were lost due to direct trauma. At the end of follow up, 119/132 (90 per cent) patients were still using their bone-anchored hearing aid. Despite a high incidence of implant loss over time, a large number of patients still continued to use their bone-anchored hearing aid.

Complications of bone-anchored hearing aids in pediatric patients

Objective To describe the range and rate of complications related to bone-anchored hearing aids in pediatric patients. Method We conducted a retrospective review all children 16 years of age or less who were implanted with a bone-anchored hearing aid from 2002 to 2009. The main outcome measures were post Baha ® implantation complications including infection, soft tissue hypertrophy, loss of osseointegration, and need for further surgery. Results Thirty-one patients were identified and 27 had sufficient follow up for complete analysis. Soft tissue reactions were seen in 24 patients (89%), half of which were considered minor. Ten patients (37%) had major complications defined as requiring revision surgery or removal of the implant. Soft tissue overgrowth and infection at the abutment required removal in 5 children (19%) and three implants (11%) failed to osseointegrate. Recurrent antibiotic treatment was required in eight patients (30%). Seven patients (26%) had a history of trauma and one of them lost the implant. To date, three of the children (11%) have been unable to use the device because of chronic infection and overgrowth of the abutment. There was a statistically significant increased risk for major complications in patients from socioeconomically deprived backgrounds and obesity appears to incur additional risk. Conclusions Complications of bone-anchored hearing aid implants are common in our experience and obesity and socioeconomic factors appear to contribute to a higher risk for complications. Frequent follow up and meticulous care of the implant site may minimize complications but can be challenging in this population.

Passive and active middle ear implants.

Besides eradication of chronic middle ear disease, the reconstruction of the sound conduction apparatus is a major goal of modern ear microsurgery. The material of choice in cases of partial ossicular replacement prosthesis is the autogenous ossicle. In the event of more extensive destruction of the ossicular chain diverse alloplastic materials, e.g. metals, ceramics, plastics or composits are used for total reconstruction. Their specialised role in conducting sound energy within a half-open implant bed sets high demands on the biocompatibility as well as the acoustic-mechanic properties of the prosthesis. Recently, sophisticated titanium middle ear implants allowing individual adaptation to anatomical variations are widely used for this procedure. However, despite modern developments, hearing restoration with passive implants often faces its limitations due to tubal-middle-ear dysfunction. Here, implantable hearing aids, successfully used in cases of sensorineural hearing loss, offer a promising alternative. This article reviews the actual state of affairs of passive and active middle ear implants.