Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “EAR CANAL”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources
PubMed2003

[Combined reconstruction of tympanic membrane and posterior wall of external ear canal with cartilage].

OBJECTIVE: To study the reconstruction technique of tympanic membrane and posterior wall of external ear canal with auricular cartilage at same time. METHOD: The tympanic membrane and posterior wall of external ear canal of 43 cases of chronic suppurative otitis media were reconstructed with auricular cartilage after mastoidectomy between 1995-2000. The results were compared with that of without reconstruction of the posterior wall of external canal group of 60 ears in same period. RESULT: The average follow-up period was 32 months, 3 cases were faced in all of 43 cases, the others were healed in one stage. Postoperative period to be a dry ear was significantly shorter in the reconstruction group than in the canal-wall-down and open group (t-test, t = 3.98, < 0.01). The rezidive results is statistic not significant between this two groups. The patients of both groups have had good hearing results. CONCLUSION: The auricular cartilage is a good material for the reconstruction of tympanic membrane and posterior wall of the external auditory canal. It can not only reduce the time of drying ear, improve the hearing results, but also avoid the second operation. The quality of the patients life can be improved.

Adolescent↗
PubMed1995

External ear canal cholesteatoma. Case report.

External ear canal cholesteatoma is a rare condition in otologic practice. A case in a 43-year-old woman is presented in which despite the extensive nature of the lesion, minimal symptoms and absence of signs delayed diagnosis. The cause of the lesion and its treatment are discussed.

Adult↗
PubMed2006

A nonlinear finite-element model of the newborn ear canal.

A three-dimensional nonlinear finite-element model of a 22-day-old newborn ear canal is presented. The geometry is based on a clinical x-ray CT scan. A nonlinear hyperelastic constitutive law is applied to model large deformations. The Young's modulus of the soft tissue is found to have a significant effect on the ear-canal volume change, which ranges from approximately 27% to 75% over the static-pressure range of +/-3kPa. The effects of Poisson's ratio and of the ratio C10: C01 in the hyperelastic model are found to be small. The volume changes do not reach a plateau at high pressures, which implies that the newborn ear-canal wall would not be rigid in tympanometric measurements. The displacements and volume changes calculated from the model are compared with available experimental data.

Cartilage↗
PubMedDate not supplied

Correcting for ear canal collapse during audiometry.

The hearing thresholds of 20 subjects with normal hearing and normal ear canals and two subjects with collapsible ear canals were measured at octave frequencies from 250 to 8000 Hz under standard transducers (TDH-39) fitted with standard cushions (MX-41/AR) and experimental cushions (Telephonics 266CIII). When correction factors based on normal threshold differences were applied, thresholds obtained under the experimental cushion reasonably approximated the actual hearing of individuals with collapsible canals.

Adolescent↗
PubMed1987

Malignancies of the external ear canal and temporal bone: surgical techniques and results.

A combined therapy approach to malignancies of the external auditory canal and middle ear has been developed. A technique of external canal resection and gross tumor removal from the middle ear, parotid gland, and superior cervical lymph nodes is followed by postoperative full-therapy irradiation. This combined approach has been used in 30 patients with malignancies involving the external auditory canal and temporal bone. The preoperative evaluation and surgical technique, including the intraoperative decision-making process, is described. Twenty-four patients had squamous cell carcinoma of the external auditory canal, and two patients had basal cell carcinoma. There was one patient each with adenocystic carcinoma, acinic cell carcinoma, high grade mucoepidermoid carcinoma, and a giant cell tumor of bone. This group of patients was broken down into three groups based on the extent of disease as determined at surgery. Overall control of disease, both locally and distant, for the 30 patients was 66%. There were 12 patients with disease limited to the ear canal. These patients had a 91% survival of this disease process. Seven patients were determined to have limited extension beyond the ear canal. These were treated with combined therapy with an overall control of disease of 72%. Eleven patients had extensive disease outside of middle ear into the carotid jugular spine, stylomastoid foramen, and skull base, with a survival rate of 45%. It is concluded that a step-wise removal of all gross tumor, as opposed to an en bloc dissection of the temporal bone and skull base, followed by full-therapy irradiation gives equally as good, or even better, long-term survival for this malignancy of the external auditory canal and middle ear.

Adult↗
PubMed1987

Clinical ear canal probe tube measurements.

This paper describes a variety of areas in which ear canal probe tube microphone measurements can be useful to the audiologist. Areas such as measurement of hearing aid insertion gain to match some predetermined target levels, output sound pressure level in the ear canal (real ear SSPL90), and assessment of FM systems and FM system-hearing aid combinations are discussed. In addition, some variables affecting the accuracy of these measurements and the reliability will be discussed.

Acoustics↗
PubMed1996

Evaluation of dogs and cats with tumors of the ear canal: 145 cases (1978-1992).

OBJECTIVE: To characterize the frequency, clinical signs, biologic behavior, and response to treatment of tumors of the ear canal in dogs and cats. DESIGN: Retrospective analysis of medical records. ANIMALS: Medical records of 81 dogs (48 malignant tumors, 33 benign tumors) and 64 cats (56 malignant tumors, 8 benign tumors). PROCEDURE: Data were analyzed for cats and dogs with malignant tumors, and risk factors were analyzed for their potential impact on survival time. RESULTS: Malignant tumor types most commonly reported included ceruminous gland adenocarcinoma, squamous cell carcinoma, and carcinoma of undetermined origin. Median survival time of dogs with malignant aural tumors was > 58 months, whereas that of cats was 11.7 months. A poor prognosis was indicated by extensive tumor involvement (dogs) and by neurologic signs at time of diagnosis, diagnosis of squamous cell carcinoma or carcinoma of undetermined origin, and invasion into lymphatics or blood vessels (cats). CLINICAL IMPLICATIONS: Malignant tumors of the ear canal in dogs and cats have a propensity for local invasion, but tend not to metastasize. Squamous cell carcinoma and carcinoma of undetermined origin were the most locally aggressive tumors. Malignant tumors of the ear canal are best managed by aggressive surgical excision. Radiotherapy may be useful when tumors cannot be completely removed.

Adenocarcinoma↗
PubMed1995

Incidence of bony outgrowths of the external ear canal in U.S. Navy divers.

Bony outgrowths of the temporal bone into the external ear canal are common in populations that participate in cold water activities. The incidence in professional divers is unknown. Eighty-seven U.S. Navy divers were interviewed and examined to determine the history of aquatic activity and degree of ear canal compromise. An age-matched control population of 42 non-divers without significant history of aquatic activities was also examined. The outgrowths, or exostoses, were found in 23 (26%) divers, and in no controls. Sixteen (70%) of the exostoses were minor, causing 10-20% narrowing of the auditory canal. The largest exostoses were found in divers with an extensive history of aquatic activities. The difference in total hours of aquatic activity was significant between divers and controls. The difference in total hours diving, as well as total time of all aquatic activities, was statistically significant between divers with exostoses and those divers without exostoses. The data confirm the relatively common incidence of this condition in a professional diving community.

Adult↗
PubMed2005

Use of a continuous, local infusion of bupivacaine for postoperative analgesia in dogs undergoing total ear canal ablation.

OBJECTIVE: To determine whether addition of a continuous, local infusion of bupivacaine would improve postoperative analgesia in dogs undergoing total ear canal ablation. DESIGN: Randomized controlled trial. ANIMALS: 16 dogs undergoing total ear canal ablation (12 unilaterally and 4 bilaterally with > 1 month between procedures). PROCEDURE: Dogs were randomly allocated to receive morphine (0.25 mg/kg [0.11 mg/lb]) at the end of the procedure (10 procedures) or morphine and a continuous, local infusion of bupivacaine (0.13 to 0.21 mg/kg/h [0.06 to 0.1 mg/lb/h]; 10 procedures). Dogs were observed for 48 hours after surgery. Additional doses of morphine were administered up to every 4 hours in dogs with signs of severe pain. RESULTS: Temperament, sedation, analgesia, and cumulative pain scores were not significantly different between groups any time after surgery. Recovery score was significantly higher for dogs that received bupivacaine than for control dogs 2 hours after extubation but not at any other time. Serum cortisol concentration was not significantly different between groups at any time but, in both groups, was significantly increased at the time of extubation, compared with all other observation times. Total number of additional doses of morphine administered was not significantly different between groups. Bupivacaine was not detected in the plasma of any of the dogs that received the local bupivacaine infusion. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that addition of a continuous, local infusion of bupivacaine did not significantly increase the degree of postoperative analgesia in dogs that underwent total ear canal ablation and were given morphine at the end of surgery.

Anesthetics, Local↗
PubMed1988

High-frequency plane waves in the ear canal: application of a simple asymptotic theory.

An asymptotic theory describing the propagation of plane waves in a variable cross-section ear canal is combined with pressure measurements in order to determine the energy reflection coefficient at the eardrum and the standing wave patterns along the length of the canal. The relative phase of the reflected wave, and the cross-sectional area function of the ear canal, are also determined from the noninvasive pressure measurements. The theory is based on a high-frequency multiscale solution of the one-dimensional horn equation and is shown to agree well with the phase and amplitude of experimental measurements in human replica ear canals.

Acoustics↗
PubMed1996

Dosimetry measurements using a probe tube microphone in the ear canal.

Federal and international standards recommended use of microphone placement either on or in the vicinity of the shoulder for dosimetry to minimize deviations from the undisturbed sound field. Probe microphone measurements from the ear canal were compared to shoulder and chest measures in order to investigate the validity of current dosimetry methodologies. Six subjects were monitored in an industrial setting. As expected, ear-canal levels exceeded other measures for all subjects. Shoulder and chest measures showed very low intersubject variability whereas ear-canal measures resulted in large intersubject variability. The ear-canal methodology has the potential to identify individuals whose external ear gain exceed the mean, putting them at increased risk of noise-induced permanent threshold shift (NIPTS). It is proposed that overall external ear pressure gain be used as an index to adjust exposure levels when predicting NIPTS using ISO 1999. A normative database of external ear pressure gain was constructed from 30 ears for this purpose.

Adult↗
PubMed1990

Outer ear canal shape and its relation to the effectiveness of sound attenuating earplugs.

This investigation was undertaken to explore the relationship between the level of sound attenuation achieved by the wearing of hearing protectors, and the shape of the external ear canal. Bilateral molds of the outer portion of the external ear canal were made in 93 males and females with normal hearing, who had participated in a previous study on the effect of gender on sound attenuation, measured for a variety of insert type devices. The ear canal molds were analyzed in terms of tortuosity, caliber, and degree of funneling. The results showed that individuals with straight canals achieved significantly higher attenuation scores than those with twisted canals. With regard to caliber, the more important of the two parameters reviewed was the cross-sectional area of the canal measured at the cartilaginous-bony junction (IA). The relationship between IA and attenuation depended on both gender and the type of earplug tested. Funneling, measured by the ratio of concheomeatal and cartilaginous-bony cross-sectional areas, had the opposite effect of that for IA. These findings underscore the need for more controlled prescription and fitting procedures for the insert type of hearing protectors commonly used in the industrial setting.

Ear Canal↗
PubMed1987

Basic acoustic considerations of ear canal probe measurements.

This publication contains a review of several acoustic investigations in which the effects of probe location on real-ear gain were examined through theoretical models based on acoustic properties of the average human ear and ear simulator studies. The results of these investigations are used to demonstrate the effect of standing waves and eardrum impedance on probe measurements made in the ear canal. Investigations were also conducted in the sound field with a KEMAR manikin. A commercial probe microphone system was used to measure the SPL and real-ear gain at various locations with the KEMAR ear canal. The results emphasize the critical effect of probe location on absolute or relative ear canal measurements and indicate the necessity to establish clinical procedures for probe measurements based on relevant acoustic principles.

Acoustic Impedance Tests↗
PubMed1999

[Effect of ear-canal air pressure variation on tempanometry using a sweep-frequency probe tone].

OBJECTIVE: By observing the effect of ear-canal pressure variation (ECPV) on tempanometry using a sweep-frequency probe tone, the roles of sweep-frequency tempanograms changes were studied. METHOD: Tympanograms using a sweep-frequence probe tone were measured for 60 ears of 30 subjects at ECPV by admittance (Y), susceptance (B), conductance (G) with GSI33 middle ear analyzer. RESULT: There was not obviously difference about phase angle and resonance frequency among 3 measured conditions (P > 0.05); Resonance frequency became higher with higher positive pressure and lower with lower negative pressure in ear-canal; delta Y, delta G got lower with higher positive and lower negative pressure at resonance frequency; delta B is about 0 mmhos and almost didn't change with ECPV; phase angle decreased with higher positive or lower negative pressure. delta Y, delta G and delta phi were the highest at the peak pressure. CONCLUSION: The higher the ear-canal positive pressure or the lower the negative pressure is, the higher the compliance and the lower the mass of middle ear is comparatively. The rub of middle ear is the lowest at normal peak pressure.

Acoustic Impedance Tests↗