Diagnosing Middle Ear Malformation by Pure-Tone Audiometry Using a Three-Dimensional Finite Element Model: A Case-Control Study.

BACKGROUND: Hearing loss caused by middle ear malformations is treated by tympanoplasty to reconstruct the acoustic conduction system. The mobility of the ossicles plays a crucial role in postoperative success. However, identifying the location of ossicular malformation based solely on preoperative audiograms is challenging due to the complex relationship between fixation location, deformity levels, and ossicular mobility. METHODS: Middle ear finite element models for simulating ossicular malformations were created, and the results were compared with the actual preoperative audiograms. RESULTS: This approach objectively diagnosed ossicular fixation and disarticulation, bypassing traditional criteria reliant on physician examination or imaging. CONCLUSION: This study suggests that future research should focus on developing a diagnostic framework utilizing large-scale data.

A Systematic Review of the Audiological Efficacy of Cartilage Conduction Hearing Aids and the Factors Influencing Their Clinical Application.

This systematic review evaluates the efficacy and benefit of cartilage conduction hearing aids (CC-HAs) and that factors that influence purchasing decisions. The hearing thresholds and functional gain following CC-HA wear were synthesised. A one-way analysis of variance compared the differences in the hearing thresholds and functional gain at individual frequencies and in patients with a variety of pathological changes. The synchronised aided hearing threshold and functional gain at 2.0 kHz were significantly better than at 0.5, 1.0, and 4.0 kHz. There was no significant difference in the synchronised unaided hearing thresholds across individual frequencies between 0.5 and 4.0 kHz. The synchronised functional gain in patients with atresia was significantly greater than in patients with aural atresia or stenosis and middle ear pathologies with normal ear canals. The acceptability of CC-HAs in terms of purchase decision is influenced by the condition of the external auditory meatus and severity of hearing loss, with the highest purchase rate seen in patients with aural atresia or stenosis. CC-HAs' fitting procedure advantages and cosmetic considerations make these devices a viable and preferred choice for individuals with microtia and aural atresia. Additional research to evaluate the benefits towards emotional well-being is crucial to gain insights into the psychological impact of CC-HA use.

Exploring Mechanisms Underlying Unexplained Air-Bone Gaps Post-Myringoplasty: Temporal Bone Model and Finite Element Analysis.

PURPOSE: Air-bone gap (ABG) is an essential indicator of middle ear transfer function after myringoplasty. However, there is still uncertainty about the mechanisms behind unexplained ABGs in patients post-myringoplasty. The present study investigated these mechanisms using cadaveric temporal bone (TB) measurement and finite element (FE) modeling. METHODS: Three conditions of tympanic membrane (TM) perforation were modeled with a perforated area of 6%, 24%, and 50% of the total TM area to simulate a small, medium, or large TM perforation of TB model. A piece of paper was used to patch the TM perforation to simulate the situation post-myringoplasty. In the FE model for post-operation, the material properties at the perforation area were changed. Measurement of TM vibration at the umbo was undertaken with a laser Doppler vibrometer (LDV). RESULTS: As the perforated area increased vibration of the TM at the umbo decreased in both the TB and FE models. But the reduction of TM vibration is more minor in the FE model than in the TB model. After the perforation was repaired, the displacement of TM at the umbo could not be recovered totally in the TB and FE models. In the FE model, the displacement of TM at the umbo decreased markedly when the cone shape of TM flattened, and the reduction was almost the same as that in the TB model in the condition of large perforation. CONCLUSION: The material properties and the anatomical shape of the repaired TM could influence the TM's modal motion and wave motion. Except for appearance and shape current clinical instruments are unable to resolve factors that affect TM motion. Consequently the ABG seen post-myringoplasty remains unexplained.

An Air Recirculation System Based on Bioinspired Soft Re-Air Valve for Highly Efficient Pneumatic Actuation.

Owing to their compliance, lightweight, and high force density characteristics, pneumatic actuation systems have been widely implemented in various soft robots. However, pneumatic actuation systems exhibit low efficiency, poor control performance, and high noise; these make it extremely challenging to widely employ a pneumatic actuation system in mobile robots. To overcome these limitations, many researches were conducted on recycling the compressed air within such systems. However, the proposed approaches do not consider the system efficiency and exhaust performance of pneumatic systems. Therefore, this article proposes a recirculation system using a novel soft re-air valve based on the cardiac structure of fish. In particular, the proposed recirculation system recycles the compressed air to improve the system efficiency and pressurizing performance, and the soft re-air valve simultaneously prevents a decrease in the depressurizing performance. For the validation of the proposed scheme, experiments were conducted to evaluate the system efficiency, control performance, and exhaust noise. In contrast to conventional pneumatic systems, the experimental results revealed that the proposed system increased the overall system efficiency by 47.58%, reduced the position root mean square error by 8.16%, and reduced the exhaust noise by 47.52%.

Piezoelectric vibrator-stimulated potential and heart rate accelerations detected from the fetus.

OBJECTIVES: The fetus is well known to have a substantial capacity for sound recognition in the uterine environment. The aim of this study was to develop a sound stimulus system equipped with a piezoelectric vibrator (PV), record the PV-stimulated potential (PVSP) of the fetus and monitor changes of the fetal heart rate (FHR) under PV stimulation. METHODS: The relationship between the input voltage applied to a piezoelectric vibrator and the sound pressure generated in the uterus was calibrated based on a model of the maternal abdomen. Fourteen fetuses for the measurement of the PVSP and 22 fetuses for the measurement of the heart rate changes from low-risk pregnant women were recruited. RESULTS: The PVSP responses were obtained in 9 out of 14 fetuses. All the tested fetuses accelerated the FHR after the 2 kHz tone stimulation at 70 dB intensity generated by PV from 32 to 37 weeks gestational age. CONCLUSIONS: Using a newly developed sound stimulus system equipped with PV, the electric responses of a fetus recorded from electrodes placed on the mother's abdomen may be closely related to the auditory evoked response. Significant accelerations of FHR were objectively, accurately and readily obtained after the sound stimulation.