In situ Probe Microphone Measurement for Testing the Direct Acoustical Cochlear Stimulator

Hypothesis: Acoustical measurements can be used for functional control of a direct acoustic cochlear stimulator (DACS).Background: The DACS is a recently released active hearing implant that works on the principle of a conventional piston prosthesis driven by the rod of an electromagnetic actuator. An inherent part of the DACS actuator is a thin titanium diaphragm that allows for movement of the stimulation rod while hermetically sealing the housing. In addition to mechanical stimulation, the actuator emits sound into the mastoid cavity because of the motion of the diaphragm.Methods: We investigated the use of the sound emission of a DACS for intra-operative testing. We measured sound emission in the external auditory canal (PEAC) and velocity of the actuators stimulation rod (Vact) in five implanted ears of whole-head specimens. We tested the influence various positions of the loudspeaker and a probe microphone on PEAC and simulated implant malfunction in one example.Results: Sound emission of the DACS with a signal-to-noise ratio >10 dB was observed between 0.5 and 5 kHz. Simulated implant misplacement or malfunction could be detected by the absence or shift in the characteristic resonance frequency of the actuator. PEAC changed by <6 dB for variations of the microphone and loudspeaker position.Conclusion: Our data support the feasibility of acoustical measurements for in situ testing of the DACS implant in the mastoid cavity as well as for post-operative monitoring of actuator function

Needs and supporting tools for primary care physicians to improve care of patients with vertigo and dizziness: a national survey.

BACKGROUND The diagnostic workup and treatment decisions for vertigo or dizziness in primary care can be challenging due to the broad range of possible causes and limited time and expertise of physicians. This can lead to delays in treatment and unnecessary tests. We aimed to identify the unmet needs of primary care physicians (PCPs) and strategies to improve care for dizzy patients. MATERIALS AND METHODS An online survey was conducted among board-certified PCPs in Switzerland to explore needs in caring for dizzy patients and potential educational approaches. RESULTS Based on responses from 152 participating PCPs, satisfaction and confidence were higher in diagnosing (82%) and treating (76%) acute dizziness compared to episodic/chronic cases (63 and 59%, respectively). Younger PCPs had lower diagnostic yield and confidence. Areas for improvement in specialist interactions included communication between physicians (23%/36%; always/often true), shorter waiting times for consultations (19%/40%), more detailed feedback (36%/35%), and consistent patient back referrals (31%/30%). PCPs expressed interest in hands-on courses, workshops, practical guidelines, web-based algorithms, and digital tools such as printed dizzy diaries and apps for follow-up. CONCLUSION Enhanced dialog between PCPs and specialists is crucial to address the most common unmet needs. Reducing waiting times for referrals and providing clear instructions to specialists for triage are essential. The findings from this survey will guide the development of tools to improve the diagnosis and treatment of dizzy patients. Younger PCPs, who face higher diagnostic uncertainty, should be prioritized for educational approaches such as hands-on courses, workshops, and practical recommendations

What is the current status of primary care in the diagnosis and treatment of patients with vertigo and dizziness in Switzerland? A national survey

BackgroundVertigo and dizziness are among the most frequent presenting symptoms in the primary care physicians' (PCPs) office. With patients facing difficulties in describing their complaints and clinical findings often being subtle and transient, the diagnostic workup of the dizzy patient remains challenging. We aimed to gain more insights into the current state of practice in order to identify the limitations and needs of the PCPs and define strategies to continuously improve their knowledge in the care of the dizzy patient.Materials and methodsBoard-certified PCPs working in Switzerland were invited to participate in an online survey. A descriptive statistical analysis was performed, and prospectively defined hypotheses were assessed using regression analyses.ResultsA vast majority of participating PCPs (n = 152) were familiar with the key questions when taking the dizzy patient's history and with performing provocation/repositioning maneuvers when posterior-canal benign paroxysmal positional vertigo (BPPV) was suspected (91%). In contrast, strong agreement that performing the alternating cover test (21%), looking for a spontaneous nystagmus with fixation removed (42%), and performing the head-impulse test (47%) were important was considerably lower, and only 19% of PCPs were familiar with lateral-canal BPPV treatment. No specific diagnosis could be reached in substantial fractions of patients with acute (35% [25; 50%], median [inter-quartile range]) and episodic/chronic (50% [40; 65.8%]) dizziness/vertigo. Referral to specialists was higher in patients with episodic/chronic dizziness than in acutely dizzy patients (50% [20.3; 75] vs. 30% [20; 50]), with younger PCPs (aged 30–40 years) demonstrating significantly increased odds of referral to specialists (odds ratio = 2.20 [1.01–4.81], p = 0.048).ConclusionThe assessment of dizzy patients takes longer than that of average patients in most primary care practices. Many dizzy patients remain undiagnosed even after a thorough examination, highlighting the challenges faced by PCPs and potentially leading to frequent referrals to specialists. To address this, it is crucial to promote state-of-the-art neuro-otological examination and treatment techniques that are currently neglected by most PCPs, such as “HINTS” and lateral-canal BPPV treatment. This can help reduce referral rates allowing more targeted treatment and referrals

Molecular analysis of aquaporin genes 1 to 4 in patients with Menière's disease

Menière's Disease (MD) is an episodic cochleovestibular dysfunction of unknown etiology, still lacking a specific test and therapy. The proposed theories on the pathophysiology include genetic factors and factors relating to inner ear homeostasis. Various aquaporins (AQP), water channels, expressed in the inner ear and the vestibular organ, are involved in homeostasis. Mutations in AQP genes could result in disturbed inner ear homeostasis and endolymphatic hydrops, and therefore be involved in the pathogenesis of MD. Aim: To search for mutations in AQP1 to 4 in patients suffering from MD

Factors improving the vibration transfer of the floating mass transducer at the round window

With the placement of a floating mass transducer (FMT) at the round window, a new approach of coupling an implantable hearing system to the cochlea has been introduced. The aim of the present experimental study is to examine the influence of different ways of FMT placement at the round window on the vibration energy transfer to the cochlea

The floating mass transducer at the round window: direct transmission or bone conduction?

The round window placement of a floating mass transducer (FMT) is a new approach for coupling an implantable hearing system to the cochlea. We evaluated the vibration transfer to the cochlear fluids of an FMT placed at the round window (rwFMT) with special attention to the role of bone conduction. A posterior tympanotomy was performed on eleven ears of seven human whole head specimens. Several rwFMT setups were examined using laser Doppler vibrometry measurements at the stapes and the promontory. In three ears, the vibrations of a bone anchored hearing aid (BAHA) and an FMT fixed to the promontory (pFMT) were compared to explore the role of bone conduction. Vibration transmission to the measuring point at the stapes was best when the rwFMT was perpendicularly placed in the round window and underlayed with connective tissue. Fixation of the rwFMT to the round window exhibited significantly lower vibration transmission. Although measurable, bone conduction from the pFMT was much lower than that of the BAHA. Our results suggest that the rwFMT does not act as a small bone anchored hearing aid, but instead, acts as a direct vibratory stimulator of the round window membrane

Single-Center Study Investigating Foreign Language Acquisition at School in Children, Adolescents, and Young Adults With Uni- or Bilateral Cochlear Implants in the Swiss German Population

Otology & Neurotology, Vol 38, No 6 (2017), pp. 833-83

What neuro-otology specialists need for better care of dizzy patients: a national survey.

BACKGROUND A substantial fraction of dizzy patients are assessed by neurologists and ear-nose-throat (ENT) physicians. With the differential diagnosis being broad and often different specialties involved, we aimed to assess the interaction with generalists from the specialists' perspective to identify limitations and needs and to define strategies for improvement in patient care and education by the specialist. METHODS One hundred eleven board-certified neurologists (n = 62) and ENT physicians (n = 49) working in Switzerland participated in an online survey. Here, we focused on limitations faced in the diagnostic workup and treatment of the dizzy patient and potential strategies to improve the standard of care and the interaction between generalists and specialists. Descriptive statistical analyses were performed. We hypothesized that those specialists applying modern concepts in history-taking and bedside examination techniques reach a specific diagnosis more often and request fewer referrals. RESULTS Specialists indicated higher confidence in reaching a specific diagnosis for patients presenting with acute dizziness than episodic/chronic dizziness (80% vs. 60%) at the first consultation. Knowledge of the timing-and-trigger concept [odds ratio (OR) = 0.81 (0.67-0.98), p = 0.034], as well as of subtle oculomotor/vestibular signs [OR = 0.80 (0.68-0.94), p = 0.007] was predictive of the self-reported probability of reaching a specific diagnosis in patients with episodic/chronic dizziness, while no such differences were observed in the care of acutely dizzy patients. Further referrals of acutely dizzy patients were significantly higher in neurologists than in ENT physicians (17% vs. 10%, p < 0.001) and in specialists located in the Latin part of Switzerland [OR = 2.84 (1.63-4.93), p < 0.001], while this was not the case for patients with episodic/chronic dizziness. Identified unmet needs included regular communication between physicians (27%/53%; always/often true) and sufficiently detailed information on the previous workup from the referrals (27%/53%). Specialists expressed most interest in hands-on courses/workshops, webinars, and practical guidelines for education. CONCLUSION In our survey, bedside state-of-the-art assessments were key in reducing the fraction of unclear dizzy cases. Several gaps were identified that should be addressed. Specifically, referring physicians should provide more comprehensive details regarding urgency, prior diagnostics, and treatment. Specifically, when promoting the knowledge of neurologists and ENT physicians, this should be preferentially done by offering a combination of hands-on courses and webinars

In situ Probe Microphone Measurement for Testing the Direct Acoustical Cochlear Stimulator

Hypothesis: Acoustical measurements can be used for functional control of a direct acoustic cochlear stimulator (DACS). Background: The DACS is a recently released active hearing implant that works on the principle of a conventional piston prosthesis driven by the rod of an electromagnetic actuator. An inherent part of the DACS actuator is a thin titanium diaphragm that allows for movement of the stimulation rod while hermetically sealing the housing. In addition to mechanical stimulation, the actuator emits sound into the mastoid cavity because of the motion of the diaphragm. Methods: We investigated the use of the sound emission of a DACS for intra-operative testing. We measured sound emission in the external auditory canal (PEAC) and velocity of the actuators stimulation rod (Vact) in five implanted ears of whole-head specimens. We tested the influence various positions of the loudspeaker and a probe microphone on PEAC and simulated implant malfunction in one example. Results: Sound emission of the DACS with a signal-to-noise ratio >10 dB was observed between 0.5 and 5 kHz. Simulated implant misplacement or malfunction could be detected by the absence or shift in the characteristic resonance frequency of the actuator. PEAC changed by <6 dB for variations of the microphone and loudspeaker position. Conclusion: Our data support the feasibility of acoustical measurements for in situ testing of the DACS implant in the mastoid cavity as well as for post-operative monitoring of actuator function

What is the current status of care by neuro-otology specialists in Switzerland-A national survey.

BACKGROUND Vertigo and dizziness are frequent presenting symptoms in the emergency department and in outpatient centers. While the majority of dizzy patients are evaluated by primary care physicians, specialists are often involved in the diagnostic workup. We aimed to gain more insights into the role of specialists in the care of dizzy patients. MATERIALS AND METHODS Board-certified neurologists and ear-nose-throat (ENT) physicians working in Switzerland were invited to participate in an online survey. Descriptive statistical analyses were performed, and prospectively defined hypotheses were assessed using correlation analyses. RESULTS All 111 participating specialists (neurologists = 62; ENT specialists = 49) were familiar with testing for posterior canal benign paroxysmal positional vertigo (BPPV), and 66% regularly applied provocation maneuvers for suspected lateral canal BPPV. Reposition maneuvers for posterior (99%) and lateral (68%) canals were frequently performed. ENT physicians were familiar with lateral canal BPPV repositioning maneuvers significantly more often than neurologists (84 vs. 56%, p ≤ 0.012). Specialists strongly agreed that performing the head impulse test (86%) and looking for deficient eccentric gaze holding (82%) are important. Compared to neurologists, significantly fewer ENT physicians indicated ordering brain MRI in acutely dizzy patients (OR = 0.33 [0.16-0.067], p = 0.002) and physical therapy in patients with acute (50 vs. 20%, p = 0.005) or episodic/chronic dizziness (78 vs. 50%, p = 0.003). CONCLUSION We found substantial differences in the care of dizzy patients by neurologists and ENT physicians. This underlines the need for a standardized, guideline-oriented diagnostic workup and treatment across specialties. Dedicated training for performing lateral canal BPPV repositioning maneuvers should be prioritized for neurologists. Similarly, physical therapy should be considered more often by ENT physicians