Analysis of wideband acoustic immittance measurements in patients with unilateral Ménière's disease / 临床耳鼻咽喉头颈外科杂志

Objective:To investigate the characteristics of wideband acoustic immittance（WAI） measurements in patients with unilateral Ménière's disease（MD） and evaluate the clinical value of WAI in diagnosis of MD. Methods:WAI was performed in 30 patients with unilateral MD（30 ears for symptomatic and 30 ears for asymptomatic） and in 26 healthy individuals（52 ears）（control group）. The WAI measurements, including the frequency first appearing two peaks in energy absorbance（EA） tympanogram, resonance frequency（RF）, the peak value of absorbance（PVA）, the integral area of absorbance（IAA）, EA curve at peak pressure, were analyzed. Results:①The occurrence of two peaks in EA tympanogram in both the MD symptomatic and asymptomatic ear was observed in 27 ears（84.4%）, and 38 ears（70.4%） in the control group, with no significant difference in the frequency of first appearing in two peaks onset between the groups（all P>0.05）. ②The RF of the MD symptomatic ears was significantly lower than that of the asymptomatic ears（t=-3.544, P=0.001） and that of the control subjects（t=2.084, P=0.041）; there was no difference of RF between the MD asymptomatic ears and the control group（P>0.05）. ③The PVA were significantly lower in both MD symptomatic（t=4.240, P<0.01） and asymptomatic ears（t=4.202, P=0.001） than in controls. ④The IAA in MD symptomatic（t=3.295, P=0.001） and asymptomatic ears（t=3.193, P=0.003） was significantly lower than in the control group. ⑤Comparison of the EA curve at peak pressure of the three groups: the EAs of MD symptomatic ears were lower than those of the control group at the range of 1 059-2 911 Hz（all P<0.05）; the EAs of MD symptomatic ears were lower than those of MD asymptomatic ears within 1 000 Hz and 1 834-2 119 Hz（all P<0.05）; the EAs of MD asymptomatic ears were lower than those of the control group at the range of 515-2 748 Hz（all P<0.05）. Conclusion:Symptomatic ears in unilateral MD patients show alterations in some WAI measurements compared to asymptomatic ears and/or controls, suggesting that middle ear mechanical fuction of the affected side may be modified due to the endolymphatic hydrops. The clinical significance of WAI needs to be further explored in the context of evaluating MD.

The Effect of Ethnicity on Wideband Absorbance of Neonates with Healthy Middle Ear Functions in Malaysia: A Preliminary Study

BACKGROUND AND OBJECTIVES: Although ethnicity effect on wideband absorbance (WBA) findings was evident for adults, its effect on neonates has not been established yet. This study aimed to investigate the influence of ethnicity on WBA measured at 0 daPa from neonates with healthy middle ear functions. SUBJECTS AND METHODS: Participants were 99 normal, healthy, full-term newborn babies with chronological age between 11 and 128 hours of age (mean=46.73, standard deviation=26.36). A cross-sectional study design was used to measure WBA at 16 one-third octave frequency points from 99 neonates comprising of three ethnic groups: Malays (n=58), Chinese (n=13) and Indians (n=28). A total of 165 ears (83.3%) that passed a battery of tests involving distortion product otoacoustic emissions, 1 kHz tympanometry and acoustic stapedial reflex were further tested using WBA. Moreover, body size measurements were recorded from each participant. RESULTS: The Malays and Indians neonates showed almost identical WBA response across the frequency range while the Chinese babies showed lower absorbance values between 1.25 kHz and 5 kHz. However, the differences observed in WBA between the three ethnic groups were not statistically significant (p=0.23). Additionally, there were no statistically significant difference in birth weight, height and head circumference among the three ethnic groups. CONCLUSIONS: This study showed that Malays, Chinese and Indians neonates were not significantly different in their WBA responses. In conclusion, to apply for the ethnic-specific norms is not warranted when testing neonates from population constitute of these three ethnicities.

Wideband Absorbance Measurements: Norms and Middle Ear Disorders / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: To evaluate the usefulness of wideband tympanometry in predicting middle ear disorders by comparing the absorbance measurements of the disorder and the norm. SUBJECTS AND METHOD: Wideband tympanometry, pure tone audiometry, and endoscopic examination were performed on 284 ears of 190 subjects. Wideband absorbance (WBA) was measured from normal ears (adults: 128 ears, children: 32 ears), disorders of middle ear included effusion (adults: 24 ears, children: 21 ears), tympanic membrane (TM) retraction (adults: 26 ears, children: 6 ears) and perforation (47 adult ears). RESULTS: The normative data of WBA were similar to previous reports from other countries. WBA of the 17-29 age group showed higher values than other age groups at 1600-3150 Hz. Men had higher absorbance at low frequencies whereas women had higher absorbance at high frequencies. There was a significant gender difference at 4000 Hz. Adults showed higher absorbance at 1000, 1250, and 1600 Hz and lower absorbance at 2500, 3150, and 4000 Hz than children did at those respective frequencies. Compared to the normal group, WBA was decreased at all frequencies by more than 500 Hz in ears with middle ear effusion and at most frequencies by less than 2000 Hz in ear with TM retraction. TM perforation showed higher absorbance in low frequencies; the absorbance decreased as the size of perforation increased. CONCLUSION: The present study established normative WBA data and the results showed comparable statistics to former studies in age and gender difference. WBA provided a high reliability in discrimination of middle ear effusion and TM retraction. WBA is a simple, non-invasive and useful diagnostic tool for middle ear disease.

Clinical Applications of Wideband Tympanometry / 대한이비인후과학회지

Conventional impedance audiometry uses only specific tympanometric frequencies (e.g., 226 Hz) and cannot test above 1500 Hz. As many hearing frequencies must be evaluated when diagnosing middle ear pathologies, wideband clicks stimulating tympanometric receptors from 226 to 8000 Hz are commonly delivered. Since wideband tympanometry (WBT) was introduced in 1993, several studies have explored its clinical utility. WBT yields information on absorbances at various frequencies and pressures. Recently, WBT has become increasingly used to diagnose and monitor the hearing of newborns and patients with otosclerosis, ossicular chain disruptions, tympanic perforations, superior semicanal dehiscence syndrome, and middle ear effusions. WBT is also employed for pre/postoperative monitoring using non-pressurized wideband absorbance. Here, we review the concept of WBT, the basic mechanism, and the clinical applications.

Development of ultrasonic imaging transducer / 国际生物医学工程杂志

Transducer,which acts as both ultrasound emitter and echo receiver,is the most important acoustics part in medical ultrasonic imaging system.The development of ultrasonic imaging technology makes ultrasound image clearer and more intuitionistic.This paper mainly introduces the technical development and the prospects of piezocomposite transducer,piezoelectric single crystal transducer,wide-band transducer,3D imaging transducer and capacitive micromachined ultrasonic transducer(cMUT).

A UWB Probe for Early Breast Tumor Detection / 医疗卫生装备

Objective Ultra-wideband (UWB) microwave imaging is one of the promising alternatives for breast tumor detection, which can provide the desired high resolution and high sensitivity. Methods For UWB microwave early breast tumor detection, a UWB antenna with small size and compact structure is generally desired. To meet the demands of UWB microwave imaging and detection, a novel compact UWB probe is developed and tested. The probe is a combination of an exponentially-flared TEM horn and a pyramidal back-cavity, where the pyramidal back-cavity is employed to block back and side radiation. To increase the operation bandwidth, a low-frequency compensation loop loaded with resistors and a dielectric material block at the throat of TEM horn are added to the probe. Results The compact probe is fabricated and tested by vector network analyzer E8362B, and the results demonstrate an operation frequency band ranging from 1.36GHz to 20GHz for return loss under -10dB. Conclusion The probe can meet the needs of UWB microwave imaging for the early breast tumor detection.