| 1. |
- den Besten, C. A., et al.
(författare)
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Stability, Survival, and Tolerability of an Auditory Osseointegrated Implant for Bone Conduction Hearing: Long-Term Follow-Up of a Randomized Controlled Trial
- 2016
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Ingår i: Otology & Neurotology. - : Ovid Technologies (Wolters Kluwer Health). - 1531-7129. ; 37:8, s. 1077-1083
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To compare implant stability, survival, and soft tissue reactions for a novel (test) and previous generation (control) percutaneous auditory osseointegrated implant for bone conduction hearing at long-term follow-up of 5 years. Study Design: Single follow-up visit of a previously completed multicenter, randomized, controlled trial. Patients: Fifty-seven of the 77 participants of a completed randomized controlled trial on a new auditory osseointegrated implant underwent a single follow-up visit 5 years after implantation, which comprised implant stability measurements and collection of Holgers scores. Additionally, implant survival was recorded for all 77 patients from the original trial. Results: The test implant showed significantly higher implant stability quotient (ISQ) values compared with the control implant throughout the 5-year follow-up. Mean area under the curve of ISQ high from baseline to 5 years was 71.6 (standard deviation [SD] +/-2.0) and 66.7 (SD +/-3.4) for the test and control implant, respectively (p < 0.0001). For both implants, the mean ISQ value recorded at 5 years was higher compared with implantation (test group +2.03 [SD +/-2.55, within group p < 0.0001] and control group +2.25 [SD +/-4.95, within group p = 0.12]). No difference was noticed in increase from baseline between groups (p = 0.64). Furthermore, evaluation of soft tissue reactions continued to show superiority of the test implant. At the 5-year follow-up visit, one patient (2.5%) presented with a Holgers grade 2 in the test group, compared with four patients (23.5%) in the control group (p = 0.048); no patient presented with more severe soft tissue reactions. Excluding explantations, the survival rate was 95.8% for the test group and 95.0% for the control group. The corresponding rates including explantations were 93.9 and 90.0%. Conclusion: The test implant showed superiority in terms of higher mean ISQ values and less adverse soft tissue reactions, both at the single 5-year follow-up visit and during the complete follow-up. In addition, both implants showed an equally high implant survival.
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| 2. |
- Fredén Jansson, Karl-Johan, 1988, et al.
(författare)
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Magnetic resonance imaging investigation of the bone conduction implant - a pilot study at 1.5 Tesla.
- 2015
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Ingår i: Medical devices (Auckland, N.Z.). - 1179-1470. ; 8, s. 413-23
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this pilot study was to investigate if an active bone conduction implant (BCI) used in an ongoing clinical study withstands magnetic resonance imaging (MRI) of 1.5 Tesla. In particular, the MRI effects on maximum power output (MPO), total harmonic distortion (THD), and demagnetization were investigated. Implant activation and image artifacts were also evaluated.
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| 3. |
- Fredén Jansson, Karl-Johan, 1988, et al.
(författare)
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Robustness and lifetime of the bone conduction implant - a pilot study
- 2019
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Ingår i: Medical Devices: Evidence and Research. - 1179-1470. ; 12, s. 89-100
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The objective of this study was to develop methods for evaluating the mechanical robustness and estimating the lifetime of the novel bone conduction implant (BCI) that is used in a clinical study. The methods are intended to be applicable to any similar device. Materials and methods: The robustness was evaluated using tests originally developed for cochlear implants comprising a random vibration test, a shock test, a pendulum test, and an impact test. Furthermore, magnetically induced torque and demagnetization during magnetic resonance imaging at 1.5 T were investigated using a dipole electromagnet. To estimate the lifetime of the implant, a long-term age-accelerated test was performed. Results: Out of all the tests, the pendulum and the impact tests had the largest effect on the electro-acoustic performance of the BCI implant, even if the change in performance was within acceptable limits (< 20%). In comparison with baseline data, the lower and higher resonance peaks shifted down in frequency by 13% and 18%, respectively, and with a loss in magnitude of 1.1 and 2.0 dB, respectively, in these tests. Conclusion: A complete series of tests were developed, and the BCI passed all the tests; its lifetime was estimated to be at least 26 years for patients who are using the implant for 12 hours on a daily basis.
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| 4. |
- Hakansson, B., et al.
(författare)
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VEMP using a new low-frequency bone conduction transducer
- 2018
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Ingår i: Medical Devices-Evidence and Research. - : Informa UK Limited. - 1179-1470. ; 11, s. 301-312
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Tidskriftsartikel (refereegranskat)abstract
- Objective: A new prototype bone conduction (BC) transducer B250, with an emphasized low-frequency response, is evaluated in vestibular evoked myogenic potential (VEMP) investigations. The aim was to compare cervical (cVEMP) and ocular (oVEMP) responses using tone bursts at 250 and 500 Hz with BC stimulation using the B250 and the conventional B81 transducer and by using air conduction (AC) stimulation. Methods: Three normal subjects were investigated in a pilot study. BC stimulation was applied to the mastoids in cVEMP, and both mastoid and forehead in oVEMP investigations. Results: BC stimulation was found to reach VEMP thresholds at considerably lower hearing levels than in AC stimulation (30-40 dB lower oVEMP threshold at 250 Hz). Three or more cVEMP and oVEMP responses at consecutive 5 dB increasing mastoid stimulation levels were only obtained in all subjects using the B250 transducer at 250 Hz. Similar BC thresholds were obtained for both ipsilateral and contralateral mastoid stimulation. Forehead stimulation, if needed, may require a more powerful vibration output. Conclusion: Viable VEMP responses can be obtained at a considerably lower hearing level with BC stimulation than by AC stimulation. The cVEMP and oVEMP responses were similar when measured on one side and with the B250 attached to both ipsilateral and contralateral mastoids.
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| 5. |
- Håkansson, Bo, 1953, et al.
(författare)
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The bone conduction implant - a review and 1-year follow-up
- 2019
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Ingår i: International Journal of Audiology. - : Informa UK Limited. - 1499-2027 .- 1708-8186. ; 58:12, s. 945-955
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The objective of this study is to evaluate its safety and effectiveness of the bone conduction implant (BCI) having an implanted transducer and to review similar bone conduction devices. Design: This is a consecutive prospective case series study where the patients were evaluated after 1, 3, 6 and 12 months. Outcome measures were focussed on intraoperative and postoperative safety, the effectiveness of the device in terms of audiological performance and patient's experience. Study sample: Sixteen patients with average age of 40.2 (range 18-74) years have been included. Thirteen patients were operated in Gothenburg and three in Stockholm. Results: It was found that the procedure for installing the BCI is safe and the transmission condition was stable over the follow-up time. No serious adverse events or severe adverse device effects occurred. The hearing sensitivity, speech in noise and the self-assessment as compared with the unaided condition improved significantly with the BCI. These patients also performed similar or better than with a conventional bone conduction reference device on a softband. Conclusions: In summary, it was found that the BCI can provide a safe and effective hearing rehabilitation alternative for patients with mild-to-moderate conductive or mixed hearing impairments.
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| 6. |
- Reinfeldt, Sabine, 1978, et al.
(författare)
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Nasal sound pressure as objective verification of implant in active transcutaneous bone conduction devices
- 2019
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Ingår i: Medical Devices: Evidence and Research. - 1179-1470. ; 12, s. 193-202
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Active transcutaneous bone conduction devices consist of an external audio processor and an internal implant under intact skin. During the surgical procedure, it is important to verify the functionality of the implant before the surgical wound is closed. In a clinical study with the new bone conduction implant (BCI), the functionality of the implant was tested with an electric transmission test, where the output was the nasal sound pressure (NSP) recorded in the ipsilateral nostril. The same measurement was performed in all follow-up visits to monitor the implant's functionality and transmission to bone over time. The objective of this study was to investigate the validity of the NSP method as a tool to objectively verify the implant's performance intraoperatively, as well as to follow-up the implant's performance over time. Design: Thirteen patients with the BCI were included, and the NSP measurement was part of the clinical study protocol. The implant was electrically stimulated with an amplitude-modulated signal generator using a swept sine 0.1-10 kHz. The NSP was measured with a probe tube microphone in the ipsilateral nostril. Results: The NSP during surgery was above the noise floor for most patients within the frequency interval 0.4-5 kHz, showing NSP values for expected normal transmission of a functioning implant. Inter-subject comparison showed large variability, but follow-up results showed only minor variability within each subject. Further investigation showed that the NSP was stable over time. Conclusion: The NSP method is considered applicable to verify the implant's functionality during and after surgery. Such a method is important for implantable devices, but should be simplified and clinically adapted. Large variations between subjects were found, as well as smaller variability in intra-subject comparisons. As the NSP was found to not change significantly over time, stable transmission to bone, and implant functionality, were indicated.
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| 7. |
- Reinfeldt, Sabine, 1978, et al.
(författare)
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New developments in bone-conduction hearing implants: a review
- 2015
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Ingår i: Medical Devices: Evidence and Research. - 1179-1470. ; 8, s. 79-93
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Tidskriftsartikel (refereegranskat)abstract
- The different kinds of bone-conduction devices (BCDs) available for hearing rehabilitation are growing. In this paper, all BCDs currently available or in clinical trials will be described in categories according to their principles. BCDs that vibrate the bone via the skin are referred to as skin-drive devices, and are divided into conventional devices, which are attached with softbands, for example, and passive transcutaneous devices, which have implanted magnets. BCDs that directly stimulate the bone are referred to as direct-drive devices, and are further divided into percutaneous and active transcutaneous devices; the latter have implanted transducers directly stimulating the bone under intact skin. The percutaneous direct-drive device is known as a bone-anchored hearing aid, which is the BCD that has the largest part of the market today. Because of some issues associated with the percutaneous implant, and to some extent because of esthetics, more transcutaneous solutions with intact skin are being developed today, both in the skin-drive and in the direct-drive category. Challenges in developing transcutaneous BCDs are mostly to do with power, attachment, invasiveness, and magnetic resonance imaging compatibility. In the future, the authors assume that the existing percutaneous direct-drive BCD will be retained as an important rehabilitation alternative, while the transcutaneous solutions will increase their part of the market, especially for patients with bone-conduction thresholds better than 35 dB HL (hearing level). Furthermore, the active transcutaneous direct-drive BCDs appear to be the most promising systems, but to establish more detailed inclusion criteria, and potential benefits and drawbacks, more extensive clinical studies are needed.
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| 8. |
- Reinfeldt, Sabine, 1978, et al.
(författare)
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Study of the Feasible Size of a Bone Conduction Implant Transducer in the Temporal Bone
- 2015
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Ingår i: Otology and Neurotology. - 1531-7129 .- 1537-4505. ; 36:4, s. 631-637
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Tidskriftsartikel (refereegranskat)abstract
- Hypothesis: The aim was to assess the temporal bone volume to determine the suitable size and position of a bone conduction implant (BCI) transducer. Background: A BCI transducer needs to be sufficiently small to fit in the mastoid portion of the temporal bone for a majority of patients. The anatomical geometry limits both the dimension of an implanted transducer and its positions in the temporal bone to provide a safe and simple surgery. Methods: Computed tomography (CT) scans of temporal bones from 22 subjects were virtually reconstructed. With an algorithm in MATLAB, the maximum transducer diameter as function of the maximum transducer depth in the temporal bone, and the most suitable position were calculated in all subjects. Results: An implanted transducer diameter of 16 mm inserted at a depth of 4 mm statistically fitted 95% of the subjects. If changing the transducer diameter to 12 mm, a depth of 6 mm would fit in 95% of the subjects. The most suitable position was found to be around 20 mm behind the ear canal. Conclusion: The present BCI transducer casing, used in ongoing clinical trials, was designed from the results in this study, demonstrating that the present BCI transducer casing (largest diameter [diagonal]: 15.5 mm, height: 6.4 mm) will statistically fit more than 95% of the subjects. Hence, the present BCI transducer is concluded to be sufficiently small to fit most normal-sized temporal bones and should be placed approximately 20 mm behind the ear canal.
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| 9. |
- Reinfeldt, Sabine, 1978, et al.
(författare)
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The bone conduction implant: Clinical results of the first six patients.
- 2015
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Ingår i: International journal of audiology. - : Informa UK Limited. - 1708-8186 .- 1499-2027. ; 54:6, s. 408-416
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate audiological and quality of life outcomes for a new active transcutaneous device, called the bone conduction implant (BCI), where the transducer is implanted under intact skin. Design: A clinical study with sound field audiometry and questionnaires at six-month follow-up was conducted with a bone-anchored hearing aid on a softband as reference device. Study sample: Six patients (age 18-67 years) with mild-to-moderate conductive or mixed hearing loss. Results: The surgical procedure was found uneventful with no adverse events. The first hypothesis that BCI had a statistically significant improvement over the unaided condition was proven by a pure-tone-average improvement of 31.0 dB, a speech recognition threshold improvement in quiet (27.0 dB), and a speech recognition score improvement in noise (51.2 %). At speech levels, the signal-to-noise ratio threshold for BCI was - 5.5 dB. All BCI results were better than, or similar to the reference device results, and the APHAB and GBI questionnaires scores showed statistically significant improvements versus the unaided situation, supporting the second and third hypotheses. Conclusions: The BCI provides significant hearing rehabilitation for patients with mild-to-moderate conductive or mixed hearing impairments, and can be easily and safely implanted under intact skin.
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| 10. |
- Rigato, Cristina, 1989, et al.
(författare)
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Audiometric comparison between Bone Anchored Hearing Aid and Bone Conduction Implant
- 2016
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Ingår i: AudiologyNOW!2016.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Patients suffering from conductive or mixed hearing losses can often be successfully rehabilitated using bone conduction devices (BCDs). Percutaneous BCDs are widely used today, but the trend is to develop transcutaneous solutions able to providing equally good rehabilitation and less complications. Here, the transcutaneous Bone Conduction Implant was compared with percutaneous BCDs under the hypothesis that they are equally effective. Tone and speech audiometry and questionnaires were utilized to assess the overall performance. The outcome confirmed the initial hypothesis.
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| 11. |
- Rigato, Cristina, 1989, et al.
(författare)
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Audiometric Comparison Between the First Patients With the Transcutaneous Bone Conduction Implant and Matched Percutaneous Bone Anchored Hearing Device Users
- 2016
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Ingår i: Otology & Neurotology. - : Ovid Technologies (Wolters Kluwer Health). - 1531-7129 .- 1537-4505. ; 37:9, s. 1381-1387
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Tidskriftsartikel (refereegranskat)abstract
- Hypothesis:The transcutaneous bone conduction implant (BCI) is compared with bone-anchored hearing aids (BAHAs) under the hypothesis that the BCI can give similar rehabilitation from an audiological as well as patient-related point of view.Background:Patients suffering from conductive and mixed hearing losses can often benefit more from rehabilitation using bone conduction devices (BCDs) rather than conventional air conduction devices. The most widely used BCD is the percutaneous BAHA, with a permanent skin-penetrating abutment. To overcome issues related to percutaneous BCDs, the trend today is to develop transcutaneous devices, with intact skin. The BCI is an active transcutaneous device currently in a clinical trial phase. A potential limitation of active transcutaneous devices is the loss of power in the induction link over the skin. To address this issue, countermeasures are taken in the design of the BCI, which is therefore expected to be as effective as percutaneous BCDs.Methods:An early observational study with a matched-pair design was performed to compare BCI and BAHA groups of patients over several audiometric measurements, including speech audiometry and warble tones thresholds with and without the device. Additionally, questionnaires were used to assess the general health condition, benefit, and satisfaction level of patients.Results:No statistically significant difference was detected in any of the audiological measurements. The outcome of patient-related measurements was slightly superior for BCI in all subscales.Conclusion:Results confirm the initial hypothesis of the study: the BCI seems to be capable of providing as good rehabilitation as percutaneous devices for indicated patients.
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| 12. |
- Rigato, Cristina, 1989, et al.
(författare)
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Audiometric comparison in BCI and BAHA matched patients
- 2015
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Purpose: Patients that are suffering from outer or middle ear hearing impairment can often benefit more from rehabilitation using bone conduction devices (BCDs) rather than conventional air conduction devices. The most widely used BCD is the percutaneous Bone Anchored Hearing Aid (BAHA), which gives excellent sound, but can cause side effects from the skin penetration abutment. There is a growing interest in the development of transcutaneous BCDs such as the Bone Conduction Implant (BCI), comprising an externally worn audio processor wirelessly driving a transducer implanted in the temporal bone. In an ongoing clinical study, the device is used in six patients and the objective with this study is to compare their audiometric results with patients using the BAHA.Methods & Materials: Audiometric measurements are currently carried out on patients using a BAHA (Ponto Pro Power, Oticon Medical) that are matched one by one according to age- and hearing loss-based criteria with the six first patients treated with the BCI. In particular, warble tone thresholds, speech recognition score (SRS) in noise, speech recognition threshold (SRT) and signal-to-noise ratio (SNR) threshold are compared in a sound field. The patients’ general health status and personal satisfaction is also evaluated using Glasgow Benefit Inventory and Abbreviated Profile of Hearing Aid Benefit questionnaires. Furthermore, maximum power output and total harmonic distortion are measured for each device on a skullsimulator.Results: The study is on-going and detailed results will be presented. Preliminary results from two patients tested with the BAHA indicate that they generally perform the same or slightly worse than matched patients with BCI regarding warble tone thresholds, SRS, SRT and SNR threshold. The self-reported questionnaires show in general similar outcome for both devices, but slightly better results for BCI compared with the BAHA concerning physical benefit and avoidance of negative reactions to unpleasant sounds.Conclusion: Preliminary results from audiometric measurements show a clear improvement over the unaided condition for both devices, and indicate that the BCI is equal or slightly better
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| 13. |
- Rigato, Cristina, 1989, et al.
(författare)
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Audiometric results of the Bone Conduction Implant: a comparative study with the Bone Anchored Hearing Aid
- 2015
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background:Patients suffering from conductive-, sensorineural- or mixed hearing loss that are unable to use conventional air conduction hearing aids, can often be rehabilitated with bone conduction devices (BCDs) . The most widely used BCD is the percutaneous Bone Anchored Hearing Aid (BAHA), which gives excellent sound but has some known complications related to the side effects from the skin penetration. In order to overcome such issues, the development of transcutaneous BCDs has increased. Among them, the Bone Conduction Implant (BCI) is an active BCD developed in Gothenburg, Sweden. It comprises an externally worn audio processor unit which is magnetically attached to an implanted unit to wirelessly drive a transducer in the temporal bone. The device is currently implanted in six patients in the clinical trial phase and the objective with this study is to compare the BCI and BAHA devices.Methods:Audiometric measurements are currently carried out on BCI and BAHA patients matched one by one according to age- and hearing loss-based criteria. In particular, pure tones hearing thresholds, speech recognition threshold (SRT) in quiet and speech recognition score (SRS) in noise are compared as well as signal to noise ratio (SNR). In addition, maximum power output (MPO) and total harmonic distortion (THD) are measured for each device on a skullsimulator in an anechoic chamber. The patients’ satisfaction and general health condition are also evaluated by means of questionnaires. Results:Results from three patients tested with the BAHA indicate that they generally perform as or slightly worse than matched patients with BCI in all tested audiometric measurements. The self-reported questionnaires show in general similar outcome for both devices, with slightly better results for BCI compared with the BAHA concerning physical benefit and avoidance of negative reactions to unpleasant sounds.Conclusions:Results from audiometric measurements show a clear improvement over the unaided condition for both devices, and indicate that the BCI is equal or slightly better than the BAHA. As this is a pilot study currently ongoing, the results may change when all six BCI patients have been matched with a BAHA patient.
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| 14. |
- Rigato, Cristina, 1989, et al.
(författare)
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Direct bone conduction stimulation: effect of different transducer attachments
- 2017
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Ingår i: Osseo 2017, Nijmegen, The Netherlands.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Objective(s): When choosing a method to implant a transducer for direct bone conduction stimulation, several options are available with the trade-off being, among other aspects, between achieving a robust contact to the bone and keeping an open possibility for potential future explantation. The aim of this study is to compare how different attachment methods for direct bone conduction stimulation can affect the vibrations transmission to the cochleae. The ultimate goal is to gain more insights on the dynamical properties of the skull to apply them to the design and optimization of bone conduction devices for hearing rehabilitation.Study design:Experimental.Patients:Measurements were performed on four human heads. The tympanic membrane, the malleus and the incus were removed to expose the cochlear promontory on both sides of each subject. The subjects have not undergone any previous surgery as verified by visual inspection.Methods:Three different attachments are tested on eight sides: (A) flat small-sized surface, (B) flat wide surface and (C) two separated screws. The different typologies of contact to bone are established by three dummy implants and an adapter to attach the transducer giving a swept sine stimulus from 0.1 to 10 kHz. The response is evaluated in terms of cochlear promontory acceleration and ear canal sound pressure level (ECSP). The measurement setup consists of the following parts: human head, transducer with adaptor (to apply the stimulus), signal generator and analyzer (to drive the transducer and receive the recorded data), Laser Doppler Vibrometer (LDV, measuring the cochlear promontory acceleration), video to USB converter (to couple the built-in camera of LDV with the computer), microphones (to measure ECSP) and laptop (to save data).Results:Average results show slightly higher ECSP level and cochlear promontory acceleration for attachment A compared to attachment B especially at frequencies above 1 kHz. An improvement in transmission is achieved with attachment C compared to B in the frequency range 5–7 kHz, where the levels differ by nearly 10 dB both ipsi- and contralaterally. In the same frequency range, the transmission from attachment C appears to be slightly higher relative to attachment A as well, however no statistical significance is found. The comparison between attachment A and C is not straightforward due to high variability over frequencies and sometimes contradictory results between LDV and ECSP measurements.Conclusion:On an average level, the screw stimulation technique seems to improve the transmission at frequencies above 5 kHz. However,, when considering the whole frequency range, average results from the different attachment techniques are comparable. Still, conclusions for single subjects should be drawn with care as measurements show a very high inter-subject variability.
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| 15. |
- Rigato, Cristina, 1989, et al.
(författare)
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Direct bone conduction stimulation: Ipsilateral effect of different transducer attachments in active transcutaneous devices
- 2018
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Ingår i: Hearing Research. - : Elsevier BV. - 0378-5955 .- 1878-5891. ; 361, s. 103-112
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Tidskriftsartikel (refereegranskat)abstract
- Active transcutaneous bone conduction devices, where the transducer is implanted, are used for rehabilitation of hearing impaired patients by directly stimulating the skull bone. The transducer and the way it is attached to the bone play a central role in the design of such devices. The actual effect of varying the contact to bone has not been addressed yet. The aim of this study is therefore to compare how different attachment methods of the transducer to the bone for direct stimulation affect the ear canal sound pressure and vibration transmission to the ipsilateral cochlea. Three different attachments to the bone were tested: (A) via a flat small-sized surface, (B) via a flat wide surface and (C) via two separated screws. Measurements were done on four human heads on both sides. The attachments were compared in terms of induced cochlear promontory velocity, measured by a laser Doppler vibrometer, and ear canal sound pressure, measured by a low noise microphone. A swept sine stimulus was used in the frequency range 0.1-10 kHz. On an average level, the attachment method seems to affect the transmission mainly at frequencies above 5 kHz. Furthermore, the results suggest that a smaller contact surface might perform better in terms of transmission of vibrations at mid and high frequencies. However, when considering the whole frequency range, average results from the different attachment techniques are comparable. (C) 2018 The Authors. Published by Elsevier B.V.
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| 16. |
- Rigato, Cristina, 1989, et al.
(författare)
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Effect of transducer attachment on vibration transmission and transcranial attenuation for direct drive bone conduction stimulation
- 2019
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Ingår i: Hearing Research. - : Elsevier BV. - 0378-5955 .- 1878-5891. ; 381
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Tidskriftsartikel (refereegranskat)abstract
- Direct drive bone conduction devices (BCDs) are used to rehabilitate patients with conductive or mixed hearing loss by stimulating the skull bone directly, either with an implanted transducer (active trans cutaneous BCDs), or through a skin penetrating abutment rigidly coupled to an external vibrating transducer (percutaneous BCDs). Active transcutaneous BCDs have been under development to overcome limitations of the percutaneous bone anchored hearing aid (BAHA), mainly related to the skin penetration. The attachment of a direct drive BCD to the skull bone can differ significantly between devices, and possibly influence the vibrations' transmission to the cochleae. In this study, four different attachments are considered: (A) small-sized flat surface, (B) extended flat surface, (C) bar with a screw at both ends, and (D) standard bone anchored hearing aid screw. A, B, and C represent three active transcutaneous options, while D is for percutaneous applications. The primary aim of this study was to investigate how the different transcutaneous attachments (A, B, and C) affect the transmission of vibrations to the cochleae to the ipsilateral and the contralateral side. A secondary aim was to evaluate and compare transcranial attenuation (TA, ipsilateral minus contralateral signal level) between transcutaneous (A, B, and C) and percutaneous attachments (D). Measurements were performed on four human heads, measuring cochlear promontory velocity with a LDV (laser Doppler vibrometer) and sound pressure in the ear canal (ECSP) with an inserted microphone. The stimulation signal was a swept sine between 0.1 and 10 kHz. The comparison of ipsilateral transmission between transcutaneous adaptors A, B, and C was in agreement with previous findings, confirming that: (1) Adaptor C seems to give the most effective transmission for frequencies around 6 kHz but somewhat lower in the mid frequency range, and (2) keeping a smaller contact area seems to provide advantages compared to a more extended one. The same trends were seen ipsilaterally and contralaterally. The observed TA was similar for adaptors A, B, and C at the mastoid position, ranging-10-0 dB below 500 Hz, and 10-20 dB above. A lower TA was seen above 500 Hz when using adaptor D at the parietal position. (C) 2019 The Authors. Published by Elsevier B.V.
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| 17. |
- Rigato, Cristina, 1989, et al.
(författare)
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Rehabilitating Patients with Bone Conduction Hearing Devices: Two Effective Alternatives
- 2017
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Ingår i: Engineering Health.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Background: Bone conduction devices (BCDs) are today widely used to rehabilitate patients suffering from specific types of hearing impairment, when the main hearing loss originates in the middle or outer ear. BCDs act by stimulating the skull bone with vibrations that are directly transmitted to the cochlea in the inner ear and result in a hearing sensation, referred to as bone conduction hearing.BCDs are on the market since several decades in various alternative designs, externally worn or partially implanted. In 1977 the first bone anchored hearing aid (BAHA) was implanted in a patient in Gothenburg, and now this technology is one of the most used all over the world. A novel device, the BCI (Bone Conduction Implant), was developed in collaboration between Chalmers and Sahlgrenska in the past few years. The BCI is an alternative to the well-established BAHA that aims at overcoming some of its limitations mainly related to the skin-penetrating abutment. Objectives: In this study, the well-established BAHA and the novel BCI are compared in terms of rehabilitation effect on hearing impaired patients. The purpose of comparing the BCI with an established device available on the market is to find out if the BCI can be a valuable rehabilitation alternative for indicated patients.Methods: Audiometric measurements and user self-reported questionnaires were performed on two groups of patients, one fitted with the BCI and one fitted with BAHAs.Six BCI users were included in the study as part of the clinical trial for the device, and six BAHA users were selected in order to match them one by one in terms of hearing ability, gender and age.Results: The overall results from the performed measurements show a clear improvement over the unaided condition for both devices. Outcomes from the audiometric tests as well as from the patient-related measurements were comparable in the two groups. Conclusions: The two devices seem to give an equally satisfactory rehabilitation for indicated patients. The novel BCI is shown to be a successful example of translational science, where the collaboration between Chalmers and Sahlgrenska provided solid bases to integrate technical and medical requirements.
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| 18. |
- Taghavi, Hamidreza, 1981, et al.
(författare)
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Technical design of a new bone conduction implant (BCI) system
- 2015
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Ingår i: International Journal of Audiology. - : Informa UK Limited. - 1499-2027 .- 1708-8186. ; 54:10, s. 736-744
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The objective of this study is to describe the technical design and verify the technical performance of a new bone conduction implant (BCI) system. Design: The BCI consists of an external audio processor and an implanted unit called the bridging bone conductor. These two units use an inductive link to communicate with each other through the intact skin in order to drive an implanted transducer. Study sample: In this study, the design of the full BCI system has been described and verified on a skull simulator and on real patients. Results: It was found that the maximum output force (peak 107 dB re 1 N) of the BCI is robust for skin thickness range of 2-8 mm and that the total harmonic distortion is below 8% in the speech frequency range for 70 dB input sound pressure level. The current consumption is 7.5 mA, which corresponds to 5-7 days use with a single battery. Conclusions: This study shows that the BCI is a robust design that gives a sufficiently high output and an excellent sound quality for the hearing rehabilitation of indicated patients.
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