VEMP using a new low-frequency bone conduction transducer

Hȧkansson, Bo; Jansson, Karl-Johan Fredén; Tengstrand, Tomas; Johannsen, L.; Eeg-Olofsson, Måns; Rigato, Cristina; Dahlström, Elisabeth; Reinfeldt, Sabine

doi:10.2147/mder.s171369

Cited by 15 publications

(23 citation statements)

References 32 publications

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“…Other types of bone conduction devices are available; these are named as "active transcutaneous" devices (or "direct bone drive devices with implanted transducer") and "passive transcutaneous" devices (or "over skin drive devices with implanted retention magnet"), both of which leave the skin intact; for a review, see Reinfeldt et al 2015 1 and Håkansson et al 2019. 2 Furthermore, bone conduction transducers are also used in consumer products, with the intention of being applied over intact skin, such as in headsets, speech training systems, and for diagnoses of hearing and vertigo (Fredén Jansson et al 2015, 3 Håkansson et al 2018 4 ).…”

Section: Bone Conduction Hearing Devicesmentioning

confidence: 99%

“…diagnostics. Diagnostic transducers for bone conduction hearing testing (such as the B81) and for vestibular testing (such as B250 as proposed by Håkansson et al 2018 4 ) are calibrated using an artificial mastoid B&K4930 from Bruel & Kjaer, having an intact skin pad as load. For direct bone drive devices, a skull simulator is needed that in some way simulates the skull impedance.…”

Section: Skinpenetrating Abutmentmentioning

confidence: 99%

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<p>The Mechanical Impedance of the Human Skull via Direct Bone Conduction Implants</p>

Hȧkansson¹,

Woelflin²,

Tjellström³

et al. 2020

MDER

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Point your SmartPhone at the code above. If you have a QR code reader, the video abstract will appear. Or use: https://youtu.be/zbv0NO6djwo Purpose: The mechanical skull impedance is used in the design of direct bone drive hearing systems. This impedance is also important for the design of skull simulators used in manufacturing, service, and fitting procedures of such devices. Patients and Methods: The skull impedance was measured in 45 patients (25 female and 20 male) who were using percutaneous bone conduction implants (Ponto system or Baha system). Patients were recruited as a consecutive prospective case series and having an average age of 55.4 years (range 18-80 years). Seven patients were treated in Gothenburg, Sweden, and 38 patients in Edmonton, Canada. An impedance head (B&K 8001), driven by an excitation transducer with emphasized low-frequency response, was used to measure the mechanical point impedance with a swept sine from 100 to 10k Hz. Results and Discussion: The skull impedance was found to have an anti-resonance of approximately 150 Hz, with a median maximum magnitude of 4500 mechanical ohms. Below this anti-resonance, the mechanical impedance was mainly mass-controlled corresponding to an effective skull mass of 2.5 kg at 100 Hz with substantial damping from neck and shoulder. Above the anti-resonance and up to 4 kHz, the impedance was stiffness-controlled, with a total compliance of approximately 450n m/N with a small amount of damping. At frequencies above 4 kHz, the skull impedance becomes gradually mass-controlled originating from the mass of the osseointegrated implant and adjacent bone. No significant differences related to gender or skull abnormalities were seen, just a slight dependence on age and major ear surgeries. The variability of the mechanical impedance among patients was not found to have any clinical importance. Conclusion: The mechanical skull impedance of percutaneous implants was found to confirm previous studies and can be used for optimizing the design and test procedures of direct bone drive hearing implants.

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Section: Bone Conduction Hearing Devicesmentioning

confidence: 99%

Section: Skinpenetrating Abutmentmentioning

confidence: 99%

<p>The Mechanical Impedance of the Human Skull via Direct Bone Conduction Implants</p>

Hȧkansson¹,

Woelflin²,

Tjellström³

et al. 2020

MDER

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“…A new transducer, the B250, was recently described by Håkansson et al 21 . It is based on the B81 design but slightly larger and optimized for output at 250 Hz.…”

Section: Introductionmentioning

confidence: 99%

Influence of bone conduction transducer type and placement on ocular and cervical vestibular evoked myogenic potentials

Fröhlich

Wilke

Plontke

et al. 2021

Sci Rep

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Evaluating the effectiveness of different bone conduction (BC) transducers with controlled coupling force to elicit cervical and ocular vestibular evoked myogenic potentials (cVEMPs, oVEMPs) in healthy subjects by comparing response rates, amplitudes, latencies, thresholds and asymmetry ratios. Prospective experimental study including healthy participants. VEMPs were measured to different stimulation modes; the BC transducer coupling force was controlled to 5.4 (± 0.5) Newton. cVEMPs: to bone conducted vibration (BCV) with the B81 transducer on the mastoid; oVEMPs: to BCV with the B81 on the mastoid, BCV with the B81 on the forehead, and BCV with the Mini-Shaker 4810 on the forehead. Air conducted sound (ACS) with insert earphones was used as reference. Data of 24 normal subjects (mean age 25.3 (± 3.0) years) were analyzed. ACS and BCV with the B81on the mastoid evoked cVEMPs in 100% of ears. The highest oVEMP response rates were obtained with the B81 on the mastoid (83–92%), the lowest with the B81 on the forehead (17–22%). The Mini-Shaker elicited lower response rates (65%) compared to results from the literature without coupling force control and compared to ACS (78–87%). Amplitudes were higher for BCV than ACS. ACS and BCV on the mastoid caused higher asymmetry compared to BCV forehead stimulation. The B81 was feasible to elicit VEMPs with mastoid placement and can be used as an approved medical device to measure BCV VEMPs in a clinical set-up. Normative asymmetry values have to be established due to higher variability for mastoid stimulation.

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“…The B71 conventional bone conduction transducer (RadioEar) was tried as an alternative. However, the output of the B71 is not always sufficient to for measuring oVEMP responses (5). A new bone conduction transducer, the B81 (RadioEar), has recently become available.…”

Section: Introductionmentioning

confidence: 99%

Effects of External Auditory Meatus Occlusion on Ocular Vestibular Evoked Myogenic Potentials Induced by Bone Conducted Sound

2021

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To facilitate more reliable recordings of the ocular vestibular evoked myogenic potentials (oVEMP) induced by bone-conducted sound using the B81 bone conduction transducer, we preliminarily studied the effects of external auditory meatus occlusion using an earplug on such oVEMP. Eight healthy volunteers (four males and four females, 26–48 years of age, mean age: 34. 5 years) and 14 patients with vestibular disease (2 males and 12 females, 18–59 years of age, mean age: 41.5 years) were enrolled. oVEMP testing was performed using a B81 placed on the temple. Tone bursts (500 Hz, rise/fall time: 2 ms, plateau time: 2 ms, and 70 dB nHL) were presented at a rate of 5.1 Hz. N1-P1 amplitudes were measured and analyzed. Occlusion resulted in significantly larger N1-P1 amplitudes [mean ± SE (SD): 12.3 ± 1.67 (6.71) μV vs. 9.55 ± 1.55 (6.21) μV; p = 0.020, paired t-test]. While four patients did not exhibit any response on either side in the absence of occlusion, all of them showed unilateral or bilateral responses when occlusion was employed. In any patient occlusion did not result in loss of oVEMP responses. External auditory meatus occlusion using an earplug could allow more reliable recordings of bone conduction transducer-induced oVEMP.

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VEMP using a new low-frequency bone conduction transducer

Cited by 15 publications

References 32 publications

<p>The Mechanical Impedance of the Human Skull via Direct Bone Conduction Implants</p>

<p>The Mechanical Impedance of the Human Skull via Direct Bone Conduction Implants</p>

Influence of bone conduction transducer type and placement on ocular and cervical vestibular evoked myogenic potentials

Effects of External Auditory Meatus Occlusion on Ocular Vestibular Evoked Myogenic Potentials Induced by Bone Conducted Sound

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