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Hearing Research Sep 2021Wideband tympanometry performs a more thorough analysis of middle-ear mechanics than the conventional single-frequency method with a 226-Hz probe tone. The present work...
Wideband tympanometry performs a more thorough analysis of middle-ear mechanics than the conventional single-frequency method with a 226-Hz probe tone. The present work examines the sensitivity of wideband tympanometry to the stiffness of the stapes-annular ligament system in relation to intracranial pressure (ICP) and labyrinthine fluid pressure. Here, body tilt allowed ICP to be set at different values. Sixty-eight ears of volunteers were tested sequentially in upright, supine, head-down (-30°) and upright postures. Energy absorbance of the ear was measured in these postures with a commercially available wideband-tympanometry device between 0.25 and 3 kHz, at ear-canal pressures between -600 and 300 daPa. In each posture, it was possible to find a single (posture-dependent) pressure in the ear canal at which a tympanometric peak occurred at all frequencies below about 1.1 kHz. The average across ears of tympanometric-peak pressure (TPP), close to 0 in upright posture, got increasingly positive, +19 daPa in supine and +27 daPa in head-down positions. The three-dimensional plot of energy absorbance against frequency and pressure displayed an invariant shape, merely shifting with TPP along the pressure axis. Thus, a properly adjusted ear-canal pressure neutralized the effects of ICP on the ear's energy absorbance. Comparisons to published invasive assessments of ICP in the different tested body positions led to the proposed relationship ICP ≈ 15 TPP, likely describing the transformer effect between tympanic membrane and stapes-annular ligament system at quasi-static pressures. With wideband tympanometry, the middle ear may serve as a precision scales for noninvasive ICP measurements.
Topics: Acoustic Impedance Tests; Ear, Inner; Ear, Middle; Humans; Intracranial Pressure; Tympanic Membrane
PubMed: 34298416
DOI: 10.1016/j.heares.2021.108312 -
Ear and Hearing Jul 2013Several alternative ear-canal measures are similar to absorbance in their requirement for prior determination of a Thévenin-equivalent sound source. Examples are (1)... (Review)
Review
Several alternative ear-canal measures are similar to absorbance in their requirement for prior determination of a Thévenin-equivalent sound source. Examples are (1) sound intensity level, (2) forward pressure level, (3) time-domain ear-canal reflectance, and (4) cochlear reflectance. These four related measures are similar to absorbance in their utilization of wideband stimuli and their focus on recording ear-canal sound pressure. The related measures differ from absorbance in how the ear-canal pressure is analyzed and in the type of information that is extracted from the recorded response. Sound intensity level and forward pressure level have both been shown to be better as measures of sound level in the ear canal compared with sound pressure level because they reduced calibration errors due to standing waves in studies of behavioral thresholds and otoacoustic emissions. Time-domain ear-canal reflectance may be used to estimate ear-canal geometry and may have the potential to assess middle ear pathology. Cochlear reflectance reveals information about the inner ear that is similar to what is provided by other types of otoacoustic emissions, and may have theoretical advantages that strengthen its interpretation.
Topics: Acoustic Impedance Tests; Acoustic Stimulation; Audiology; Ear Canal; Humans; Terminology as Topic
PubMed: 23900185
DOI: 10.1097/AUD.0b013e31829c7229 -
The Journal of International Advanced... Jul 2021Fibromyalgia syndrome is a disorder of widespread pain with unknown etiology. These patients frequently suffer from otologic complaints. This study aims to analyze the...
OBJECTIVES
Fibromyalgia syndrome is a disorder of widespread pain with unknown etiology. These patients frequently suffer from otologic complaints. This study aims to analyze the audiovestibular functions in patients with fibromyalgia syndrome.
METHODS
The study included 33 fibromyalgia patients and 33 healthy volunteers. All the study subjects underwent audiological assessment, multifrequency tympanometry, transient otoacoustic emission, and ocular and cervical vestibular-evoked myogenic potentials tests.
RESULTS
Pure-tone hearing thresholds of right and left ears were found to be decreased in fibromyalgia patients compared to controls (P < 0.05). Middle ear resonance frequency values were significantly decreased in patients with fibromyalgia syndrome compared to controls (P < .05). The values for signal-to-noise ratios were higher in controls than in the FMS patients. The difference was significant for 1000, 2000, and 4000 Hz (P > .005). Cervical vestibular-evoked myogenic potential waves were obtained in all controls, but could not be obtained in 5 right ears and 4 left ears of the fibromyalgia patients (P < .05). Also, ocular vestibular-evoked myogenic potentials were obtained in all controls, but could not be obtained in 7 right ears and 10 left ears of the patients with fibromyalgia syndrome (P < .05).
CONCLUSION
Our findings support the presence of audiovestibular dysfunction in patients with fibromyalgia. Further research that focuses on the pathogenesis of these dysfunctions is required.
Topics: Acoustic Impedance Tests; Audiometry; Fibromyalgia; Humans; Otoacoustic Emissions, Spontaneous; Vestibular Evoked Myogenic Potentials
PubMed: 34309557
DOI: 10.5152/JIAO.2021.8709 -
European Annals of Otorhinolaryngology,... Oct 2018French Society of ENT (SFORL) good practice guidelines for audiometric examination in adults and children.
INTRODUCTION
French Society of ENT (SFORL) good practice guidelines for audiometric examination in adults and children.
METHODS
A multidisciplinary working group performed a review of the scientific literature. Guidelines were drawn up, reviewed by an independent reading group, and finalized in a consensus meeting.
RESULTS
Audiometry should be performed in an acoustically controlled environment (<30dBA); audiometer calibration should be regularly checked; and patient-specific masking rules should be systematically applied. It should be ensured that masking is not overmasking. Adult pure-tone audiometry data should be interpreted taking account of clinical data, speech audiometry and impedancemetry. In case of discrepancies between clinical and pure-tone and speech audiometry data, objective auditory tests should be perform. In children aged 2 years or younger, subjective audiometry should be associated to behavioral audiometry adapted to the child's age. In suspected hearing impairment, behavioral audiometry should be systematically supplemented by objective hearing tests to determine and confirm the level and type of hearing impairment.
Topics: Acoustic Impedance Tests; Audiometry, Evoked Response; Audiometry, Pure-Tone; Audiometry, Speech; Auditory Threshold; Evoked Potentials, Auditory, Brain Stem; Hearing Loss, Central; Hearing Loss, Sensorineural; Humans; Reflex, Acoustic
PubMed: 29929777
DOI: 10.1016/j.anorl.2018.05.009 -
Archives of Osteoporosis Feb 2019The estimation of cortical thickness (Ct.Th) and porosity (Ct.Po) at the tibia using axial transmission ultrasound was successfully validated ex vivo against...
UNLABELLED
The estimation of cortical thickness (Ct.Th) and porosity (Ct.Po) at the tibia using axial transmission ultrasound was successfully validated ex vivo against site-matched micro-computed tomography. The assessment of cortical parameters based on full-spectrum guided-wave analysis might improve the prediction of bone fractures in a cost-effective and radiation-free manner.
PURPOSE
Cortical thickness (Ct.Th) and porosity (Ct.Po) are key parameters for the identification of patients with fragile bones. The main objective of this ex vivo study was to validate the measurement of Ct.Po and Ct.Th at the tibia using a non-ionizing, low-cost, and portable 500-kHz ultrasound axial transmission system. Additional ultrasonic velocities and site-matched reference parameters were included in the study to broaden the analysis.
METHODS
Guided waves were successfully measured ex vivo in 17 human tibiae using a novel 500-kHz bi-directional axial transmission probe. Theoretical dispersion curves of a transverse isotropic free plate model with invariant matrix stiffness were fitted to the experimental dispersion curves in order to estimate Ct.Th and Ct.Po. In addition, the velocities of the first arriving signal (υ) and A mode (υ) were measured. Reference Ct.Po, Ct.Th, and vBMD were obtained from site-matched micro-computed tomography. Scanning acoustic microscopy (SAM) provided the acoustic impedance of the axial cortical bone matrix.
RESULTS
The best predictions of Ct.Po (R = 0.83, RMSE = 2.2%) and Ct.Th (R = 0.92, RMSE = 0.2 mm, one outlier excluded) were obtained from the plate model. The second best predictors of Ct.Po and Ct.Th were vBMD (R = 0.77, RMSE = 2.6%) and υ (R = 0.28, RMSE = 0.67 mm), respectively.
CONCLUSIONS
Ct.Th and Ct.Po were accurately predicted at the human tibia ex vivo using a transverse isotropic free plate model with invariant matrix stiffness. The model-based predictions were not further enhanced when we accounted for variations in axial tissue stiffness as reflected by the acoustic impedance from SAM.
Topics: Acoustic Impedance Tests; Bone Density; Bone Diseases; Cortical Bone; Humans; Image Processing, Computer-Assisted; Porosity; Predictive Value of Tests; Radius; Tibia; Ultrasonography; X-Ray Microtomography
PubMed: 30783777
DOI: 10.1007/s11657-019-0578-1 -
Scientific Reports Oct 2018Microbial electrochemical systems provide an environmentally-friendly means of energy conversion between chemical and electrical forms, with applications in wastewater...
Microbial electrochemical systems provide an environmentally-friendly means of energy conversion between chemical and electrical forms, with applications in wastewater treatment, bioelectronics, and biosensing. However, a major challenge to further development, miniaturization, and deployment of bioelectronics and biosensors is the limited thickness of biofilms, necessitating large anodes to achieve sufficient signal-to-noise ratios. Here we demonstrate a method for embedding an electroactive bacterium, Shewanella oneidensis MR-1, inside a conductive three-dimensional poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) matrix electropolymerized on a carbon felt substrate, which we call a multilayer conductive bacterial-composite film (MCBF). By mixing the bacteria with the PEDOT:PSS precursor in a flow-through method, we maintain over 90% viability of S. oneidensis during encapsulation. Microscopic analysis of the MCBFs reveal a tightly interleaved structure of bacteria and conductive PEDOT:PSS up to 80 µm thick. Electrochemical experiments indicate S. oneidensis in MCBFs can perform both direct and riboflavin-mediated electron transfer to PEDOT:PSS. When used in bioelectrochemical reactors, the MCBFs produce 20 times more steady-state current than native biofilms grown on unmodified carbon felt. This versatile approach to control the thickness of bacterial composite films and increase their current output has immediate applications in microbial electrochemical systems, including field-deployable environmental sensing and direct integration of microorganisms into miniaturized organic electronics.
Topics: Acoustic Impedance Tests; Bacteria; Biosensing Techniques; Bridged Bicyclo Compounds, Heterocyclic; Electric Conductivity; Electronics; Membranes, Artificial; Microscopy, Electron, Scanning; Polymerization; Polymers; Polystyrenes
PubMed: 30327574
DOI: 10.1038/s41598-018-33521-9 -
The South African Journal of... Jul 2018Literature suggests that there is a correlation between video otoscopy and standard tympanometry findings. However, there is limited evidence on whether these two... (Comparative Study)
Comparative Study
Literature suggests that there is a correlation between video otoscopy and standard tympanometry findings. However, there is limited evidence on whether these two measures are comparable in the identification of middle ear pathologies in adults living with human immunodeficiency virus (HIV). Objective: This study aimed to determine the correlation between video otoscopy and standard tympanometry with 226 Hz probe tone in the identification of middle ear pathologies in adults living with HIV in Limpopo, South Africa. Method: A prospective, non-experimental, comparative design was employed on HIV-positive adults aged 18 years and older. All participants underwent basic audiological assessment including case history interviews, video otoscopy, tympanometry with a 226 Hz probe tone and pure tone audiometry. Two ear, nose and throat (ENT) specialists independently analysed video otoscopic images and provided their reports to the researcher, and these were compared to the tympanometry results. The IBM SPSS v.24 was used for data analysis, including the use of Cohen's kappa to determine the agreement between the two procedures. Pearson's correlation coefficient was used to determine the strength of the correlation between tympanometry and video otoscopy. Results: A total of 87 adults (N = 161 ears) took part in the study. Middle ear pathology was observed in 8% (n = 13) of the sample when tympanometry was used, and this increased to 10.6% (n = 17) when video otoscopy was utilised. Kappa statistics found a good agreement (k = 0.7) between the diagnoses made by two ENTs. However, there was poor agreement (k = 0.2) between the diagnoses by video otoscopy and tympanometry. Pearson's correlation coefficient indicated weak correlation between video otoscopy and tympanometry (r = 0.195). Conclusion: Findings from this study suggest that video otoscopy may be more accurate in the identification of middle ear pathologies in adults living with HIV when compared to tympanometry. These findings have training implications in the use of video otoscopy to ensure accuracy and reliability. Clinical implications of current findings include the use of both video otoscopy and tympanometry in a complementary manner for more sensitive identification of middle ear pathologies in this population. Lastly, tele-audiologic implications of the use of video otoscopy to increase access in resource-constrained contexts are raised.
Topics: Acoustic Impedance Tests; Adult; Aged; Ear Diseases; Ear, Middle; Female; HIV Infections; Humans; Male; Middle Aged; Otoscopy; Prospective Studies; Reproducibility of Results; South Africa; Video Recording
PubMed: 30035605
DOI: 10.4102/sajcd.v65i1.591 -
Journal of Clinical Sleep Medicine :... Oct 2011Guidance is needed to help clinicians decide which out-of-center (OOC) testing devices are appropriate for diagnosing obstructive sleep apnea (OSA). A new classification... (Review)
Review
Guidance is needed to help clinicians decide which out-of-center (OOC) testing devices are appropriate for diagnosing obstructive sleep apnea (OSA). A new classification system that details the type of signals measured by these devices is presented. This proposed system categorizes OOC devices based on measurements of Sleep, Cardiovascular, Oximetry, Position, Effort, and Respiratory (SCOPER) parameters.Criteria for evaluating the devices are also presented, which were generated from chosen pre-test and post-test probabilities. These criteria state that in patients with a high pretest probability of having OSA, the OOC testing device has a positive likelihood ratio (LR+) of 5 or greater coinciding with an in-lab-polysomnography (PSG)-generated apnea hypopnea index (AHI) ≥ 5, and an adequate sensitivity (at least 0.825).Since oximetry is a mandatory signal for scoring AHI using PSG, devices that do not incorporate oximetry were excluded. English peer-reviewed literature on FDA-approved devices utilizing more than 1 signal was reviewed according to the above criteria for 6 questions. These questions specifically addressed the adequacy of different respiratory and effort sensors and combinations thereof to diagnose OSA. In summary, the literature is currently inadequate to state with confidence that a thermistor alone without any effort sensor is adequate to diagnose OSA; if a thermal sensing device is used as the only measure of respiration, 2 effort belts are required as part of the montage and piezoelectric belts are acceptable in this context; nasal pressure can be an adequate measurement of respiration with no effort measure with the caveat that this may be device specific; nasal pressure may be used in combination with either 2 piezoelectric or respiratory inductance plethysmographic (RIP) belts (but not 1 piezoelectric belt); and there is insufficient evidence to state that both nasal pressure and thermistor are required to adequately diagnose OSA. With respect to alternative devices for diagnosing OSA, the data indicate that peripheral arterial tonometry (PAT) devices are adequate for the proposed use; the device based on cardiac signals shows promise, but more study is required as it has not been tested in the home setting; for the device based on end-tidal CO(2) (ETCO(2)), it appears to be adequate for a hospital population; and for devices utilizing acoustic signals, the data are insufficient to determine whether the use of acoustic signals with other signals as a substitute for airflow is adequate to diagnose OSA.Standardized research is needed on OOC devices that report LR+ at the appropriate AHI (≥ 5) and scored according to the recommended definitions, while using appropriate research reporting and methodology to minimize bias.
Topics: Equipment Design; Humans; Monitoring, Ambulatory; Oximetry; Plethysmography, Impedance; Predictive Value of Tests; Respiratory Function Tests; Sleep Apnea, Obstructive; Transducers, Pressure
PubMed: 22003351
DOI: 10.5664/JCSM.1328 -
Ear and Hearing 2012This study compares measurements of ear-canal reflectance (ECR) to other objective measurements of middle ear function including audiometry, umbo velocity (VU), and... (Clinical Trial)
Clinical Trial Comparative Study
OBJECTIVE
This study compares measurements of ear-canal reflectance (ECR) to other objective measurements of middle ear function including audiometry, umbo velocity (VU), and tympanometry in a population of strictly defined normal-hearing ears.
DESIGN
Data were prospectively gathered from 58 ears of 29 normal-hearing subjects, 16 females and 13 males, aged 22 to 64 yr. Subjects met all of the following criteria to be considered as having normal hearing: (1) no history of significant middle ear disease; (2) no history of otologic surgery; (3) normal tympanic membrane on otoscopy; (4) pure-tone audiometric thresholds of 20 dB HL or better for 0.25 to 8 kHz; (5) air-bone gaps no greater than 15 dB at 0.25 kHz and 10 dB for 0.5 to 4 kHz; (6) normal, type-A peaked tympanograms; and (7) all subjects had two "normal" ears (as defined by these criteria). Measurements included pure-tone audiometry for 0.25 to 8 kHz, standard 226 Hz tympanometry, ECR for 0.2 to 6 kHz at 60 dB SPL using the Mimosa Acoustics HearID system, and umbo velocity (VU) for 0.3 to 6 kHz at 70 to 90 dB SPL using the HLV-1000 laser Doppler vibrometer (Polytec Inc).
RESULTS
Mean power reflectance (|ECR|) was near 1.0 at 0.2 to 0.3 kHz, decreased to a broad minimum of 0.3 to 0.4 between 1 and 4 kHz, and then sharply increased to almost 0.8 by 6 kHz. The mean pressure reflectance phase angle (∠ECR) plotted on a linear frequency scale showed a group delay of approximately 0.1 msec for 0.2 to 6 kHz. Small significant differences were observed in |ECR| at the lowest frequencies between right and left ears and between males and females at 4 kHz. |ECR| decreased with age but reached significance only at 1 kHz. Our ECR measurements were generally similar to previous published reports. Highly significant negative correlations were found between |ECR| and VU for frequencies below 1 kHz. Significant correlations were also found between the tympanometrically determined peak total compliance and |ECR| and VU at frequencies below 1 kHz. The results suggest that middle ear compliance contributes significantly to the measured power reflectance and umbo velocity at frequencies below 1 kHz but not at higher frequencies.
CONCLUSIONS
This study has established a database of objective measurements of middle ear function (ECR, umbo velocity, tympanometry) in a population of strictly defined normal-hearing ears. These data will promote our understanding of normal middle ear function and will serve as a control for comparison to similar measurements made in pathological ears.
Topics: Acoustic Impedance Tests; Adult; Audiometry, Pure-Tone; Calibration; Ear Canal; Ear, Middle; Female; Hearing; Humans; Male; Middle Aged; Reference Values; Sex Characteristics; Young Adult
PubMed: 21857517
DOI: 10.1097/AUD.0b013e31822ccb76 -
European Annals of Otorhinolaryngology,... Sep 2017Temporal bone fractures are frequently associated with ossicular dislocations or fractures, most commonly involving the incus. To our knowledge, isolated fracture of the...
INTRODUCTION
Temporal bone fractures are frequently associated with ossicular dislocations or fractures, most commonly involving the incus. To our knowledge, isolated fracture of the posterior crus of the stapes has not been previously reported.
CASE REPORT
A 20-year-old man consulted for persistent left hypoacusis several months after a head injury. Initial computed tomography of the temporal bone showed a simple temporal bone fracture with no other associated abnormalities. The diagnosis of stapes fracture was suggested by increased compliance on tympanometry, leading to a second thin-section temporal bone computed tomography, which suggested a fracture of the posterior crus of the stapes. Endaural surgical exploration confirmed the diagnosis and allowed placement of ionomer cement in the posterior crus.
DISCUSSION
The possibility of ossicular dislocation or fracture must be considered in patients with persistent conductive hearing loss associated with increased compliance on tympanometry, even when computed tomography of the temporal bone does not show dislocation of the ossicular chain or ossicular fracture. Hearing rehabilitation can be performed by hearing aid or surgical reconstruction of the ossicles.
Topics: Acoustic Impedance Tests; Adult; Hearing Loss, Conductive; Humans; Male; Otologic Surgical Procedures; Skull Fractures; Stapes; Stapes Surgery; Temporal Bone; Tomography, X-Ray Computed; Treatment Outcome
PubMed: 28320600
DOI: 10.1016/j.anorl.2017.02.008